Brief Summary of Minutes of Annual Meeting

ACCOMPLISHMENTS   These are only a selection of 2019 results.  This large, collaborative group works on OVER 140 different species of arthropod and weed pests. 

Goal A:  Import and Establish Effective Natural Enemies

Objective 1.  Survey indigenous natural enemies.

Surveys were conducted in 2019 for natural enemies of the following species:

Drosophila suzukii (spotted-winged drosophila):  A number of teams surveyed northern California sites for the larval and pupal parasitoids attacking the spotted wing drosophila.

Cytisus scoparius (Scotch broom): The dispersal of the adventive Scotch broom mite in California was examined. The mite is dispersing rapidly in northern California and climate modeling suggests it will continue to disperse on Scotch broom in this state, and is climatically suitable for parts of Scotch broom’s invasive range in Argentina, Australia and New Zealand.

Brown marmorated stink bug (BMSB):  A team surveyed northern California sites for the egg parasitoids attacking the brown marmorated stinkbug.  A UC-Riverside laboratory conducted extensive field surveys for native and introduced egg parasitoids of BMSB and has completed a survey for southern California (Los Angeles Basin). Survey methods included the deployment of frozen sentinel BMSB egg masses and subsequent collection of these eggs after a 3-4 day exposure period. Field exposed eggs are sent to CDFA for parasitoid rearing. The goal is to collect the self-introduced BMSB egg parasitoid, Trissolcus japonicus, which has been previously collected in the LA Basin by the Hoddle lab.

Coconut rhinoceros beetle:  University of Guam personnel traveled to Taiwan in May 2019 to receive 80 adult coconut rhinoceros beetles collected Taiwan Normal University. The Taiwan population is of special interest because specimens in a previous collection were all determined to be CRB-G and 80% of these tested positive for OrNV (virus).

Coffee berry borer:  Surveys for potential parasitoids of coffee berry borer, Hypothenemis hampei, present in Hawaii were conducted, revealing a diversity of species emerging from Scolytinae. A number of species including Phymastichus xylebori, and a number of potentially new species were found.

Light brown apple moth (LBAM):  Investigations continued on the distribution, abundance and parasitism of LBAM in California. Larval populations were found in landscape plantings from Santa Rosa to Rancho Santa Fe, but frequency of occurrence and abundance varied considerably between region and location. No larvae were found in landscape plantings that had been recently pruned. Larval and pupal parasitism were slightly lower in 2019 than previous years, but continued to be dominated by Meteorus ictericus, Nemorilla pyste and Pediobius ni.

Lepdium draba (hoary cress): Surveys were continued at 30 sites (15 in Montana; 15 in Colorado) for insect herbivores (both native and previously established introduced species) in preparation for evaluating effects of releasing the approved mite, Aceria drabae. 

A research group coordinated a regional monitoring effort of Virginia creeper leafhopper (Erythroneura ziczac) in the North Coast region of California. This is an invasive insect that was introduced to California in the 1980s. It is primarily found in the Sacramento Valley and Sierra Foothills, but was recently introduced into the North Coast, where it has reached outbreak proportions due to a lack of biological control. The key parasitoid that controls E. ziczac is Anagrus daanei (Hymenoptera: Mymaridae). They surveyed the state in 2014 and identified a population of A. daanei in the Sacramento Valley that attacks VCLH. Releases were made in the North Coast between 2015-2017, with mixed results. They are continuing to monitor parasitism rates of VCLH today to see if the introduced parasitoids established, or if local populations of A. erythroneurae (endemic to the North Coast) may be adapting to the new leafhopper host.

Objective 2.  Conduct foreign exploration and ecological studies in native range of pest.

Several institutions in the western US conducted foreign exploration and importation of natural enemies for both new and established arthropod and weed pests this past year.  Many of these exploratory trips are only partially successful.  Species sent to quarantine facilities must survive the trip and reproduce.  Subsequent cultures will then be used for non-target host testing and evaluation for potential release.  Select studies follow.

With colleagues in Colombia and Brazil, an investigation assessing feasibility of classical biocontrol of R. palmarum (South American palm weevil) with a tachinid fly, Billaea rhynchophorae, was initiated. The goal is to determine whether or not it is possible to mass rear the fly and see if live flies can be exported out of Brazil to California for safety evaluations in quarantine.

Surveyed for natural enemies of insect pests (Bagrada hilaris, Pyrrhalta viburni, Phytomyza gymnostoma, Bactrocera oleae), and of weeds (Genista monspessulana, Vincetoxicum sp., Ailanthus altissima, Taeniatherum caput-medusae, and Ventenata dubia) in Europe and Asia.

Collecting occurred for:  Gryon sp, Trissolcus sp for biological control of Bagrada hilaris; Pteromalus sp. for Phytomyza gymnostoma; Aprostocetus sp. for Pyrrhalta viburni; Lepidapion argentatum for Genista monspessulana; Aculops mosoniensis for Ailanthus altissima; Tetramesa sp. for Taeniatherum caput-medusae; and Chrysochus asclepiadeus for Vincetoxicum sp.

Collecting continued for spotted wing drosophila to So. Korea and China to find and import larval parasitoids.  California Dept. of Food and Agriculture and the USDA Biological Control Laboratory (EBCL) continued importation of Psyllaphaegus spp. attacking the olive psyllid.  They also continued importation of Psyttalia ponerophaga and Psyttalia lounsburyi attacking the olive fruit fly.

Exploration is underway in South Africa for biocontrol agents of Guineagrass, Megathyrsus maximus.   A Diptacus sp. has been imported, tested and rejected.  Exploration is underway in Vietnam for agents of cattle fever tick, Rhipicephalus microplus and in Bulgaria for Rhipicephalus annalatus.

Objective 3.  Determine systematics and biogeography of pests and natural enemies.

Results were published on the relationships of a group of parasitoids (Oraseminae) that are parasitic on ants in the Solenopsis, Pheidole, Wasmannia and other myrmicine ants. Results show Pheidole was the ancestral Old World host, and a single invasion of the New World occurred about 20 million years ago resulting in a massive diversification onto New World genera of myrmicine ants.  The lab also looked at a group of eulophids that attack leafminers including Citrus Leafminer and Citrus Peelminer. A new genus was recognized, Burkseus, that includes four species previously recognized as the single widespread species, Cirrospilus vitattus.

Eichhornia crassipes (water hyacinth): microsatellite loci were used to determine the genetic consequences of repeated introduction of the water hyacinth weevils Neochetina eichhorniae and Neochetina bruchi, including transfers from Florida to Texas and Texas to California during the biological control program in the U.S. Results demonstrated that the species hybridized in the U.S. as well as in Uganda and in the native range in Uruguay. Genetic drift and inbreeding have occurred in California, but number of beetles released did not significantly affect genetic diversity level. 

One lab conducted phylogenetic analysis, species delineation and a taxonomic revision of the egg parasitoids (mainly Gryon gonikopalense) of Bagrada hilaris; a genetic comparison of the Pyrrhalta viburni parasitoids, such as Aprostocetus celtidis and A. suevius; they resolved the taxonomic status of parasitoids of Halyomorpha halys in Italy, leading to the species complex of Trissolcus japonicus and T. mitsukurii; conducted a taxonomic inventory of the European Chrloropidae on Arundo donax; conducted genetic fingerprinting of Trissolcus japonicus on Halyomorpha halys from Canada and USA; analyzed populations of Euphyllura olivina from Spain, France and California; and analyzed 26 invasive populations of Ventenata dubia using enzyme electrophoresis (allozymes).

A study with USDA and Italian taxonomists is working on the description of Drosophila suzukii parasitoids Asobara spp. (Braconidae), Leptopilina japonica and Ganaspis brasiliensis (Figitidae). They are also working closely with a UC Riverside taxonomist on the description of Anagrus spp. collected in vineyards.

Invasive Texas Guineagrass has been found to match with populations near Durban, South Africa.  Systematic research has also shown that Cattle Fever Ticks populations in Texas match with Vietnam (R. microplus) and Bulgaria (R. annalatus).

With collaborators in Argentina, a research group continued to research parasites of the imported fire ant (Solenopsis) in South America and of the Little Red Fire Ant (Wasmannia) in the Caribbean and Central America. In a larger phylogenetic analysis of the subfamily Oraseminae, results support an ancestral association with the ant genus Pheidole, followed by an ancient shift to the New World and diversification onto a wider variety of ant hosts, including Solenopsis, Wasmannia and other myrmicine ant hosts. They are currently working with an Argentinian researcher on the molecular and morphological recognition of ants attacking the Solenopsis saevissima complex, which includes the fire ant.

This researcher is also working on leafminer parasitoids. A graduate student is studying the taxonomy and relationships of the tribe Cirrospilini (Eulophidae), which include important parasitoids of the Citrus leafminer and the Citrus Peelminer. They published results on a group that provide a new genus name, Burskeus, that includes 4 new species. They recently completed a study of the genus Zagrammosoma, a group of 24 species that all attack leafmining Lepidoptera. Studies are trying to address the evolution of host breadth in the genus. In a final paper, they addressed the relationships of specie across the entire tribe and will be revising the genera to provide a better taxonomic framework for understanding the underlying pattern of host association and distribution. 

More from this particular researcher who concentrates on systematics include the following projects. They continued a new research program on the genus Encarsia. The initial objectives are a revision of the Encarsia strenua species group and a molecular phylogeny of the entire genus. This research is being conducted by a graduate student.  Research is underway on developing a molecular phylogeny for the egg-parasitic Mymaridae.  This research is utilizing three different molecular approaches to look at congruence of results, and ultimately the proposal of a new classification for the group.  They continue work on a National Science Foundation grant to revise the classification of the entire superfamily Chalcidoidea. This is a massive undertaking that involves molecular, morphological and bioinformatic approaches to resolve the relationships of the superfamily, and to disseminate information on the group through electronic resources and a new book that outlines the classification and biology of the group. Members of this superfamily are among the most important natural and introduced control agents of other pest insects, and this will form a foundation for all future studies on the group. To date they obtained nexgen sequencing data for over 600 taxa that cover the breadth of the entire superfamily. The final results are in progress and they are working on an edited book to cover the entire superfamily. They are also taking a bioinformatic approach by developing a new database to house all of the taxonomic and biological information on the superfamily in TaxonWorks, which is based on a migration of data from the Universal Chalcidoidea database. This will manage data for more than 30,000 taxonomic names and over 50,000 literature references.   In addition to these projects, they regularly provide identifications of parasitoids that are directly related to biological projects worldwide. As well, more than 1000 specimens of Aphelinidae and other Chalcidoidea were curated and added to the Entomology Research Museum (UC-Riverside) collection of parasitic Hymenoptera.

Objective 4.  Determine environmental safety of exotic candidates prior to release.

Proactive screening of an egg parasitoid, Anastatus orientalis, a natural enemy of the invasive spotted lantern fly, is underway in quarantine at UC Riverside. The goal of this project is to have host range and host specificity tests completed for A. orientalis in advance of the anticipated invasion by L. delicatula into California.

In a study of a group of Aphelinus wasps that attack aphids, including the Russian Wheat aphid, researchers were able to demonstrate much localized host specificity that affect how we choose and establish effective parasitoids.

Summarized details follow on host specificity and environmental studies on various natural enemies under evaluation:

Bagrada hilaris (bagrada bug): The biology of the parasitic wasp, Gryon gonikopalense, was examined as the first candidate non-native biocontrol agent targeting bagrada bug. This parasite attacks bagrada bug eggs 1-4 days after ovipositiion and can complete its life cycle in about 25 days. Adults live about 66 days when fed honey.

Drosophila suzukii (spotted-wing drosphila): Thermal tolerance studies suggested that South Korean populations of two endoparasitoids, Ganaspis brasiliensis and Leptopilina japonica (Hymenoptera: Figitidae) were slightly more cold-tolerant that Chinese populations, and that low temperatures induced facultative diapause in both species from both countries. 

Eichhornia crassipes (water hyacinth): Thermal tolerance studies in the USDA-ARS quarantine lab in Albany, CA of four accessions of the leaf and stem-feeding weevil Neochetina eichhorniae indicated that an Australian population was better-suited than a weakly-established California accession for freezing conditions typical of the Sacramento-San Joaquin Delta of northern California.

Genista monspessulana (French broom): Quarantine lab host range studies found that the leaf-feeding psyllid Arytinnis hakani can develop and reproduce on three species of California native lupins under no-choice conditions.

Egeria densa (Brazilian waterweed): Host range studies of the candidate agent Hydrellia egeriae (Diptera: Ephydridae) found that larvae can develop on native Elodea canadensis (American pondweed), precluding further consideration for biocontrol.

Host specificity tests were conducted in open door experiments for Chrysochus asclepiadeus on Vincetoxicum

In collaboration with researchers at USDA, Italy, Oregon State University,  and colleagues in China and South Korea, a researcher imported 8 parasitoid species that attack the spotted wing drosophila (Drosophila suzukii). These parasitoids included at least three larval parasitoids Asobara spp. (Braconidae), Leptopilina japonica and Ganaspis brasiliensis (Figitidae), and two pupal parasitoids, Pachycrepoideus vindimiae (Pteromalidae), Trichopria drosophilae (Diapriidae). This material is currently being studied in Quarantine.  In collaboration with the California Dept. of Food and Agriculture (CDFA) and the USDA Biological Control Laboratory (EBCL) in France and their colleagues, they continued release efforts with Psyttalia lounsburyi (Braconidae) against the olive fruit fly in different regions of California and the evaluation of Psyttalia ponerophaga.  They also continued quarantine studies of Psyllaphaegus spp. attacking the olive psyllid.

Host range screening for Phymastichus coffea, an African parasitoid of Hypothenemus hampei is underway. Results to date show that P. coffea does not parasitize any native Scolytinae species, not any other Coleoptera other than H. obscurus, an introduced pest species. The host screening is almost completed.

Many natural enemies are being screened for potential release against weeds.  A few examples follow.

Rush skeletonweed: Chondrilla juncea.  A shipment of approximately 200 roots infested with the rush skeletonweed crown moth, Oporopsamma wertheimsteini was received from the BBCA in October 2019. However the shipment was delayed for one month and all moths had emerged. A few adults were still alive and laid eggs. These will be used for an impact study to determine the impact non-target plants that the moth larvae fed upon in no-choice tests.

Hawkweed: Pilosella spp.  Availability of an Environmental Assessment for the Release of Cheilosia urbana for Biological Control of Invasive Hawkweeds was published in the Federal Register May 28, 2019 for public comment. The Finding of No Significant Impact (FONSI) was signed by APHIS in July 2019 and published in the Federal Register September 24, 2019.  This lab plans to receive Cheilosia eggs from CABI in early spring 2020 for eventual field release.

Objective 5.  Release, establish and redistribute natural enemies.

Many releases and redistributions of natural enemies (millions) were carried out against pests in 2019. Examples follow.

One research group sent shipments to US cooperators of Gryon gonikopalense (647) for biological control of Bagrada hilaris.  They also sent shipments to US cooperators of Psyttalia lounsburyi (17,300) and P. ponerophaga (1,900) for biological control of Bactrocera oleae. In collaboration with the CDFA and the USDA EBCL and their colleagues, they continued release of P. lounsburyi against the olive fruit fly.

Releases were made by a Montana lab for the following two weeds. Russian knapweed:  this lab held two collection days at the end of September 2018 in which five agencies collect Aulacidea acroptilonica galls. An estimated 1 million galls were collected for redistribution. Emergence of adults from galls held outdoors in Bozeman was very low. Approximately 39,750 adult wasps were provided for field releases. These went to Ft Belknap and Flathead Indian Reservations (via APHIS) and to Gallatin and Broadwater Counties. Consignments were also made to New Mexico State University and the Nez Perce Biocontrol Center.  Hoarycress:  In May 2019 they collected galls of Aceria drabae in Greece (plus a collection by the BBCA) and hand carried them back to Montana to reinitiate a laboratory colony. Approximately 365 galls (from a previous colony) were used to inoculate plants at two field sites in Montana. Infested plants were observed at both sites. They will determine in spring of 2020 if the mite survived.

The coconut rhinoceros beetles invading Guam (2007), Hawaii (2013), Papua New Guinea (2015), and Solomon Islands (2015) are genetically different from other populations of this pest, are resistant to Oryctes nudivirus, the biocontrol agent of choice for this species, and behave differently. For these reasons, they are being referred to as the "the Guam Biotype" CRB-G.   Results of ongoing releases of OrNV have revealed no virulence of any of the cultured strains of O. nudivurus to CRB on Guam.

Parasitoids were reared from Asian cycan scale (ACS) at collection sites throughout the island. All specimens appear to be Arhenophagus sp.

Anagrus daanei was introduced into the North Coast of California from 2015-2017, with mixed results. A lab is currently conducting molecular evaluations of the A. daanei in the North Coast and Sacramento Valley to determine if they are different strains or species. Previous work revealed that Anagrus epos was a complex of three species. Something similar may be happening with A. daanei.

Adventive populations of Trissolcus japonicus were discovered in Michigan in 2018, which is an exotic natural enemy of the invasive brown marmorated stink bug (Halyomorpha halys). A laboratory rearing was initiated using field captured T. japonicus and in 2019 field releases were conducted to augment existing populations in Michigan. A total 4000 adult T. japonicus were released at 8 field sites in southwestern Michigan and 92 brown marmorated stink bug egg masses infested with T. japonicus were placed at additional 4 field sites.

Releases were conducted (including redistributions) of natural enemies for Russian knapweed.   Jaapiella ivannikovi (20 sites) and Aulacidea acroptilonica (8 sites) in the Arkansas Valley, San Luis Valley, and Gunnison Basin. 

Objective 6.  Evaluate natural enemy efficacy and study ecological/physiological basis for interactions.

Arundo donax (Arundo): The shoot tip-galling wasp Tetramesa romana is widely established in the Lower Rio Grande Basin of Texas and Mexico, where it attains larger populations than in the native range in Mediterranean Europe. This difference is due primarily to higher degree-days in Texas. Lower degree-days in California may limit wasp population size. In a separate study, the root- and shoot-feeding arundo armored scale was found to be established at several release sites in Texas along the Rio Grande, and the combined presence of the wasp and scale reduced live arundo biomass by up to 55 percent compared to plots with only the wasp.

Tamarix spp. (Saltcedar): The distribution and dispersal of four species of leaf-seeding Diorhabda spp. beetles was evaluated in Texas, New Mexico, Oklahoma and Kansas. Three beetle species (D. carinata, D. elongata and D. sublineata) were released in this region, and while initial D. carinulata releases failed, this species later dispersed into the region from other areas. The three former species have hybridized extensively, defoliated saltcedar over large areas of these states between 2005 and 2013, and dispersed hundreds of km from the original release sites. However, defoliation of saltcedar trees is now sporadic, and beetle populations are low or absent at many sites. A separate study in northern California found similar outcomes of release of D. elongata.

One research group did the following work.  They conducted an experiment to measure the interaction between a root-galling weevil, Ceutorhynchus assimilis, and a soil pathogen, Rhizoctonia sp., attacking the invasive weed, Lepidium draba; they improved knowledge on the seasonal life cycle of Lepidapion argentatum with 1 generation for the seedpod ecotype and 2 for the gall ecotype; exposed Chrysochus asclepiadeus in open field tests to non-target plants, milkweeds, with no herbivory impact observed; conducted a taxonomic revision of Chloropid flies on Arundo donax establishing 13 valid species from 500 specimens examined; tested populations of Psyttalia lonsburyi for Wolbacchia infection; and evaluated the virulence of Metarhizium anisopliae on Bactrocera oleae.

Extensive studies continue of Drosophila suzukii resident and imported natural enemies.

Studies in Utah were completed to evaluate the phenology and survivorship of immature stages of the stem-mining weevil Mecinus janthiniformis Toševski and Caldara (Coleoptera: Curculionidae) within stems of Dalmatian Toadflax (Linaria dalmatica [L.], Lamiales: Plantaginaceae).  Survivorship of immatures within stems was high, and most individuals had completed pupal development by early August.  Parasitism accounted for most mortality, with at least three parasitoid species (Chalcidoidea: Pteromalidae and Eupelmidae) attacking weevil larvae within stems. 

A research group at UC-Riverside is assessing the feasibility of using snail- and slug-parasitic nematodes in the genus Phasmarhabditis to control pest gastropods. Last year they conducted a survey of the natural enemies of pest gastropods in California and this year they have been assessing their potential in biological control against several pest grastropods, including an invasive white snail that is gaining ground in Southern California. They have also been investigating the potential use of entomopathogenic nematodes (EPNs) to control the darkling beetle Alphitobius diapernus; they completed a trial assessing the virulence of Phasmarhabditis californica, P. hermaphrodita, P. papillosa, and Sluggo Plus, against Deroceras reticulatum (Slug pest) in a lath house experiment replicating nursery like conditions; they completed a trial assessing the amount of damage that D. reticulatum is able to cause to Canna cannova when treated with P. californica, P. hermaphrodita, P. papillosa, and Sluggo Plus in nursery like conditions which were simulated in a lath house; the assessed the virulence of P. californica, P. hermaphrodita, P. papillosa, and Sluggo Plus against Theba pisana (an invasive white snail expanding in Southern California) in a controlled environment setup in an incubator (submitted for publication; in revision at PLoS One); and completed two trials assessing the virulence of various EPN species to adult A. diapernus in lab conditions to identify promising biological control agents.

A classical biological control program against invasive black and pale swallow-worts (Vincetoxicum nigrum and Vincetoxicum rossicum) was initiated in Michigan using the biological control agent, Hypena opulenta. In 2019, this defoliating moth was reared in the laboratory at Michigan State University (MSU) to build up populations for field release, which are planned for 2020 summer. During 2019 common garden field experiments were used to evaluate the synchrony of H. opulenta phenology with the climate in Michigan and the impact of various release sizes on establishment success and efficacy.

Work continued on greenhouse and field cage studies of the interactions (facilitation and competition) between the two biocontrol agents, Jaapiella ivannikovi and Aulacidea acroptilonica, for control of Russian knapweed.

Studies continued on reciprocal, common garden experiments involving 15 Montana and 15 Colorado populations of hoary cress.  They are comparing growth architecture, flowering phenology, and susceptibility to herbivory in these 30 populations. They also continue to examine (with field and cage experiments) foraging behavior differences among C. glomerata populations that differ in their association with C. rubecula, the superior competitor (CO: no association for over 140 years; MD: co-exist in the same host populations), and these are agents for Pieris rapae. 

Goal B: Conserve Natural Enemies to Increase Biological Control of Target Pests.

Objective 7.  Characterize and identify pest and natural enemy communities and their interactions.

One lab assessed the occurrence and abundance of indigenous early egg parasitoids, Trissolcus japonicus and T. mitsukurii on Halyomorpha halys in Italy and they assessed the presence of Aculops moisonensis as a foliage herbivore on Ailanthus altissima in Italy. 

In collaboration with UC Riverside, they are investigating the use of a unique irrigation system in pistachio to help trap and monitor stink bugs as well as increase the activity of their natural enemies.

Native ground dwelling predators of invasive cattle fever ticks are being investigated to determine which species have the greatest impact and how these predators are distributed in native vs. exotic grass dominated pastures.

Work on Asian citrus psyllid, Diaphorina citri, biological control has clearly demonstrated the negative impacts the invasive Argentine ant (AA) has on the parasitoid Tamarixia radiata and some generalist predators. Controlling AA with liquid baits significantly increases parasitism rates and predator densities in citrus. Consequently, pest infestations of citrus flush, branches, and fruit drop significantly in comparison to untreated control blocks. Further, this group has demonstrated that it is possible to use biodegradable hydrogel beads for AA control. They are now moving into larger scale field trials with ant baits and combining infra-red sensors to monitor ant activity in orchards and to assess whether flowering cover crops enhance the impacts of generalist natural enemies in citrus orchards. Of particular interest are predatory syrphid flies which have been shown to have a significant impact on ACP and other citrus pests.

Research on the citrus peelminer (Marmara gulosa) and citrus leafminer (Phyllocnistis citrella) has involved assistance with the identification of parasitoids from field studies in California and central Mexico. A researcher is currently looking at the eulophid parasitoids associated with Citrus Leafminers through projects conducted by a graduate student. This lab will also be addressing relationships in the Gonatocerus species group, which include important egg parasitoids of sharpshooters in California. This will be the first molecular analysis of the group and will try to address some recent controversial taxonomic changes that have been made at the genus level.

Objective 8.  Identify and assess factors potentially disruptive to biological control.

Current efforts against Asian citrus psyllid are focused on automated in-field monitoring of foraging Argentine ants. The goal is to use the internet of things to monitor ant activity in near real time to identify hot spots within orchards that require ant control. Argentine ant is highly disruptive to biocontrol because ants protect honeydew producing pests from natural enemies and in return they are rewarded with sugar, a highly coveted resource in citrus orchards. Additionally, this study is investigating the efficacy of cover crops for increasing natural enemy activity against sap sucking citrus pests, and whether or not conservation biocontrol is synergized when ants are controlled.

The overwintering survival of Chrysochus asclepiadeus larvae was measured. It is a candidate for biological control of Vincetoxicum spp.

A large study is looking at pesticides used in vineyards, and the focus has been on the application of materials that do not disrupt natural enemies.

Guam researchers have continued to survey invasive ants on the islands of Guam, Saipan, Tinian, and Rota in the Mariana Islands during 2019.  This activity is part of an ongoing USDA-APHIS-CAPS funded project on the surveillance of Wasmannia auropunctata and Solenopsis invicta on Guam and the CNMI.  A related study seeks to describe attendance behavior of Guam’s invasive ants towards aphids, scales and mealybugs commonly encountered in the Marianas, and the effects this might have on biological control agents against hemipteran plant pests. 

The USDA-ARS laboratory in Arizona worked on several areas of potential disruption to biocontrol.  Field studies examined non-target effects of Bt cotton targeting plant bugs and thrips using natural enemy community sampling and life tables to assess impacts on biological control of whiteflies.  Field studies showed that 4 new insecticides for whitefly are highly selective; they do not harm arthropod natural enemies in cotton and provide for favorable predator to pest rations favoring biological control. Plot sizes of 18 x 18m appear to be sufficient to optimally measure non-target effects. A database was completed cataloging all non-target field studies conducted on Bt-maize and meta-analysis of this data to examine impacts on natural enemies and biological control function is underway. 

Researchers are studying the generalist predator Geocoris pallens and trying to understand key influences on its population dynamics.  They have found that a pathogen is present in Geocoris pallens populations that is virulent, causing increased developmental mortality, slowed development, and reduced fecundity.  The pathogen also elicits elevated expression of cannibalism.  Geocoris populations in California have shown pathogen-induced collapses, some transient and some more persistent.  The identity of the pathogen remains elusive; studies are underway that are currently characterizing a group of RNA viruses present in G. pallens and attempting to determine if they are associated with the cannibalism disease.

University of Wyoming researchers focused efforts on understanding factors that limit biological control of alfalfa weevil Hypera postica. The most common parasitoid of alfalfa weevil in Wyoming is the wasp Bathyplectes curculionis, at levels as high as 50% of alfalfa weevils assays. However, alfalfa weevil remains quite problematic, so in 2019 they shifted their focus to evaluate which hyperparasitoids are infecting this wasp, to learn if this is disruptive to biological control in this system. Thus far, they have found 4 different species of hyperparasitoids, and are still working on identifying these species.

Objective 9.  Implement and evaluate habitat modification, horticultural practices, and pest suppression tactics to conserve natural enemy activity.

Ongoing work has demonstrated that conservation biological control of Asian citrus psyllid (ACP) natural enemies significantly increases predator activity towards colonies of immature ACP. Provisionment of flowering plants, especially alyssum, recruits and retains adult hover flies (i.e., syrphids). These highly vagile adults lay eggs on ACP patches and larvae are voracious predators of ACP nymphs and other sap sucking pests. In citrus orchards, ACP mortality from larval hover fly predation is significantly greater in the vicinity of alyssum when compared to control plots lacking this cover crop. It is speculated that conservation biocontrol can be synergized when ants are suppressed.

For the past year, research was conducted to evaluate the attractiveness of various annual and perennial flowering plants to pollinators and natural enemies. Results will be used to select suitable plants for habitat plantings associated with saffron to combat bulb mites and thrips. Field beds of saffron were established at the Univ. of Vermont Horticultural Research Ctr., where habitat bands of annual and perennial flowering plants will be established in 2020. These will serve as attractive environments for beneficials that may contribute to reducing bulb mite populations.

Leaffooted bug (Coreidae: Leptoglossus zonatus). Work was recently initiated to evaluate the use of trap crops to control L. zonatus populations in pistachio orchards. The experimental ground covers both act as a trap crop for L. zonatus but also provision resources for Gryon pennsylvanicum, the key egg parasitoid of L. zonatus. They have also initiated studies on the ecology of G. pennsylvanicum in Central California to better understand bottlenecks and limits on conservation biological control.

Navel orangeworm (Pyralidae: Amyelois transitella). Reseachers recently initiated a study to evaluate the effects of winter ground covers on mortality of A. transitella larvae overwintering in mummy nuts. The idea is that mortality of A. transitella is higher when mummy nuts are placed within stands of ground cover, possibly due to changes in abiotic conditions along with increased microbial activity.

Work was completed on macadamia nut canopy management to increase diversity of natural enemies of macadamia felted coccid (Acanthococcus [Eriococcus] ironsidei) in orchards. Researchers demonstrated that producing open canopies (compared with dense closed canopies) increased understory flowering plant diversity and biomass, which in turn increased natural enemy (primarily Coccinellidae) abundance and impact on the pest populations.

Goal C:  Augment Natural Enemies to Increase Biological Control Efficacy.

Objective 10.  Assess biological characteristics of natural enemies.

Results have been reported under other objectives, but a few specific examples from 2019 follow. 

The thermal tolerance of two native endoparastoids, Pachycrepoideus vindemiae (Hymenoptera: Pteromalidae) and Trichopria drosophilae (Hymenoptera: Diapriidae) was studied in the lab. An Oregon population of T. drosophilae was more cold-tolerant and less heat-tolerant than a California population. California populations of both insects were tolerant of 1 month or more of cold storage as part of a simulated mass-rearing program.

Studies determined survival rate, longevity, and fecundity under various development temperatures for Gryon gonikopalense in host eggs of Bagrada hilaris in controlled conditions

Work on the temperature requirements for the development of two Asian citrus psyllid parasitoids, Tamarixia radiata (Hymenoptera: Eulophidae) and Diaphorencyrtus aligarhensis (Hymenoptera: Encyrtidae), one of their hyperparasitoids, Psyllaphycus diaphorinae (Hymenoptera: Encyrtidae), and the target pest, ACP, were completed. These data have significant value for modeling parasitoid establishment and impacts in varying geographic locations with significantly different climatic conditions. This work has either been accepted for publication (ACP and P. diaphorinae) or published (T. radiata and D. aligarhensis).

Identification of plant volatile semiochemicals that may influence Trichogramma searching is being investigated as potential means to improve augmentative release impact of Trichogramma spp. We are currently examining T. papilionis responses to semiochemicals released by sun hemp plants following Lepidoptera oviposition. At least four potential semiochemicals have been identified using head-space analysis and y-tube olfactometer studies of the wasps’ responses to the compounds.

Objective 11.  Develop procedures for rearing, storing, quality control and release of natural enemies, and conduct experimental releases to assess feasibility.

Results have been reported under other objectives, but a few specific examples from 2019 follow. 

Experiments were conducted to optimize cold storage conditions on survival and parasitism rate of Gryon gonikopalense in host eggs of Bagrada hilaris in controlled conditions.

Experiments were also conducted to increase efficiency of mass-rearing the parasitoid Psyttalia lounsburyi and P. ponerophaga for biological control of Bactrocera oleae.

Cold storage and mass production techniques were evaluated for the Drosophila suzukii parasitoids Pachycrepoideus vindimiae (Pteromalidae), Trichopria drosophilae (Diapriidae) in order to improve mass production.

Objective 12.  Implement augmentation programs and evaluate efficacy of natural enemies.

Many results have been reported under other objectives.  A few examples follow:

In collaboration with researchers at USDA, a University of California group has released two pupal parasitoids, Pachycrepoideus vindimiae (Pteromalidae) and Trichopria drosophilae (Diapriidae) near blue berry and strawberry fields to ‘inoculate’ these resident parasitoids before and after the harvest cycle.

Continued studies observing bulb mites associated with diseased saffron corms in Vermont trials, confirmed their pest status in New England saffron. Researchers continued to refine rearing of the Rhizoglyphus robini (bulb mite) colony established in 2018. Further trials were conducted showed that drying the Petri dishes filled with potato dextrose agar (PDA) under a laminar flow hood for 1 mo reduced the moisture content to 67%, which increased mite survival. It was also found that adding antibiotics or a fungicide to the medium had a negative effect on mite populations. Mite populations peaked between 10-20 days after introduction into the Petri dish.

Lab trials in Petri dishes were also conducted to assess predation of R. robini by Stratiolaelaps scimitus, and it was determined that the predatory mite consumed greater than 30 thrips per day. Three predator/prey ratios were used (1:5, 1:10 and 1:15) with 5 S. scimitus to 25, 50 and 75 R. robini. Predation was assessed after 48 hours. Results showed the 1:5 predator:prey ratio yielded mortality of 72.47 percent, which was statistically greater than the other treatments and control. This ratio will be used for the next stage, which is trials with saffron corms in pots, to which predatory and bulb mites are added.  

Goal D:  Evaluate Environmental and Economic Impacts and Raise Public Awareness of Biological Control.

Objective 13.  Evaluate the environmental and economic impacts of biological control agents.

Many results have been reported under other objectives.  One example follows:

From the USDA-ARS Laboratory in Arizona:  a comprehensive synthesis of the global literature showed the economic value of classical biological control averages $37.4M per successful project with a benefit to cost ratio of 61:1, and the value of conservation biological control averages $74/Ha. These estimates are considered conservative as they do not include external costs of alternative insecticide use and other sociological factors.

Objective 14.  Develop and implement outreach activities for biological control programs.

A UC-Berkeley group presented at many research or grower-oriented programs to reach an estimated audience of about 2000 persons (estimated at 100 persons per presentation).

The annual PPQ workshop was held in Guam in March 2019, again without SPC participation.  It is hoped SPC's financial situation will ameliorate and allow their future participation and financial support for the PPQ workshops in the future.

Over this review period a total of 9 semitechnical/scholarly articles (e.g., Citrograph, CAPCA Adviser) on ACP, BMSB, Argentine ant, SAPW, and SLF were published. Updates were posted to www.biocontrol.ucr.edu  and www.cisr.ucr.edu.  A total of 30 extension talks covering ACP biocontrol, conservation biocontrol and IPM, management of Argentine ant, BMSB invasion ecology and biocontrol, and SAPW invasion ecology and management were given. Approximately 20 media interviews to newspapers (e.g., New York Times, Press Enterprise, San Bernardino Sun), radio (e.g., NPR 4 times which included “The Salt”, “Deep Look”, “Radio Lab”, and the “California Report”), T.V. (e.g., CBS-8 News San Diego), and various trade (e.g., Ag. Alert, Western Farm Press) and popular magazines (e.g., Sunset) were given on aspects of the work reported on here.

As part of a funded NSF project a UC-Riverside group is developing modules that explain parasitoids to high school students, Master Gardeners and other venues (http://outreach.chalcid.org/). The approach is to teach more upper-division students or adults about the importance of parasitoids in biological control. They are developing outreach materials to teach about chalcidoids and other parasitic Hymenoptera in the classroom. The idea is to develop independent modules for classrooms centered on yellow pan trap ‘observatories’ as a means to discuss ‘true’ biodiversity. Their ideas for outreach are being vetted through a broad group of local teachers, and extension researchers at UC Riverside and Texas A&M University. The display box on right is populated with mounted specimens and the QR codes lead to web-links that have more information on each group.  They have also developed an online powerpoint presentation, with audio, on biodiversity of parasitic Hymenoptera that we have been able to get introduced into high school curriculums on ecology. They are currently in the process of developing a web page that can deliver all of the products, and are also working with Master Gardeners to develop modules and information appropriate for their clientele

Impacts 2019

Water and soil resources for agriculture, and habitat for native plant species, in rangelands, forests, wetland and aquatic systems, have been protected through biological and integrated control of alligatorweed, arundo, Cape-ivy, Dalmatian toadflax, French broom, Russian thistle, Scotch broom, water hyacinth, and yellow starthistle

Control for bagrada bug, olive fruit fly and spotted-wing drosophila have been improved with reduced insecticide use and improved protection of crops.

Gryon gonikopalense, a host specific egg parasitoid of the cole crop pest Bagrada hilaris.  It is an ideal biological control agent as its impact prevents any major damage to the host plants. The development cycle of the egg parasitoid is perfectly synchronized with its host and is able to attack a high percentage of host eggs on various species.  It is effective at low host density, and targets eggs that are dominantly buried into the ground by the Bagrada hilaris females making this parasitoid an invaluable tool for pest containment.

The phylogeography study conducted on Pyrrhalta viburni parasitoids strongly suggests that there is only one egg parasitoid of P. viburni present in Europe, which provided important clues regarding the assemblage of natural enemies attacking it in its native range.

The genetic barcoding of olive psyllid, Euphyllura olivine, individuals collected in Spain, France and California revealed that the Californian population is closely related to one population in Southern Spain and one population in Southern France, indicating the potential origin of the Californian invasive populations and suggesting where to look for promising natural enemies.

In 2019, a UC-Berkeley laboratory conducted research and compiled results on invasive pests (spotted wing drosophila, olive psylla, brown marmorated stink bug, vine mealybug) and native pests (stink bugs and leaffooted bugs). The work resulted in numerous presentations to growers and researchers, 13 peer-reviewed publications, and two USDA APHIS petitions to release natural enemies of invasive species (spotted wing drosophila and olive psylla).

A large team of researchers are collaborating to build a global database that is being used to evaluate the influence of the agricultural and natural landscape on the success of biological pest control.

Growers were presented a greater number of control tools for invasive and native pests of vineyards, nut crops and various row crops, including hemp. This information has aided growers in more sustainable farming techniques, resulting in a reduction of the pesticide load in the environment, a reduction in pest damage and an increase in farm profitability.

Over 155,000 Aulacidea acroptilonica galls and adults were consigned or released in ID, MT, and NM. The gall wasp is now established and increasing in population at least 25 sites in Montana and dispersing over 8 km at some establishments. The gall mite, Aceria drabae, was also released in Montana. This is the first biological control agent to be released in North America against hoarycress.

Orcytes nudivirus is currently being disseminated throughout Guam and its impact monitored.  New strains of O. nudivirus are being sought from coconut rhinoceros  infested countries in the Western Pacific Region.

Low summer mortality rates within Dalmatian Toadflax stems should promote weevil establishment under the hot, dry conditions typical of locations in Utah where the weed is problematical.  Increased understanding of weevil phenology within host stems will facilitate development of standardized, summer monitoring for this biocontrol agent by stem dissection. 

The importance of controlling the invasive Argentine ant in citrus orchards was demonstrated.  The positive flow on effects for natural enemies and subsequent biocontrol of sap sucking citrus pests was significant. These results suggest that insecticide sprays for citrus pests could be reduced if ants are controlled and natural enemy activity increases. These beneficial effects could be amplified if flowering cover crops are planted around the margins of citrus orchards. Work demonstrated that natural enemies, especially hover flies, respond strongly to this resource and impacts on key citrus pests such as Asian citrus psyllid increase substantially. The results of this work were extended to hundreds of end users via talks, the web, field days/workshops, and media interviews.

Information on rearing bulb mites was shared with other scientists who are working on this pest, and intend to adopt these methods, for their biological control research. Multiple presentations and factsheets were prepared and given on the value of habitat plantings, reaching at least 1,000 growers, many of whom have adopted this practice which benefits the environment by supporting beneficial arthropods.

New pest control technologies (new insecticides, new Bt crops) need to be proactively assessed to determine compatibility with existing biological control services. The economic value of biological control is immense and additional efforts should balance the cost of more complete assessments with the need to implement biological control more widely and inform policy makers of its value. 

Regional monitoring of Virginia creeper leafhopper allows us to follow the impacts of the A. daanei rear-release program that ran between 2015-2018. In 2018, the first year without releases, a rather drastic reduction in parasitism rates was noted.  We are now considering the possibility of resuming A. daanei introductions, but first clarifying a few questions about the biogeography and behavior of this natural enemy. Multiple presentations were given on this leafhopper/parasitoid in 2019, including grower (EcoFarm, Santa Cruz Mountains Winegrowers Association, Wild Farm Alliance, CAPCA Fresno/Madera, CAPCA North Coast), professional talks (ESA Pacific Branch) and public talks (Cal. Academy of Sciences “NightLife!” event)

The effectiveness of canopy thinning of macadamia nut orchards was demonstrated to facilitate diversification of understory plant assemblages, and the impact on natural enemies of macadamia felted coccid (Ericoccus ironsidei).

Chalcidoidea are economically and biologically one of the most important groups of insects, and yet very little is known of their taxonomy (identification) or relationships. Research is identifying new potential biological control agents for use against pestiferous leafminers on citrus, whitefly on citrus, aphids on wheat and other crops, and for wasps attacking pestiferous ants. New research on cryptic species complexes (morphologically identical but reproductively and biologically distinct species) using molecular markers has tremendous potential for the identification of new biological control agents. This research is providing a better understanding of the wasp parasitoids attacking several pest groups in California including the Citrus Peelminer, Citrus Leafminer, sharpshooter parasitoids and the Asian Citrus psyllid. Identification keys and other products will help other researchers to better understand the impact of these groups, and identify gaps that aid in targeting new biological control agents.

PUBLICATIONS ISSUED - 2019

Arnold, J. E., Egerer, M., and Daane, K. M. 2019. Local and landscape effects to biological controls in urban agriculture – a Review. Insects 10 (7), 215. doi:10.3390/insects10070215.

Baker, A.J., Heraty, J.M., Mottern, J., Zhang, J., Hines, H.M., Lemmon, A.R., Lemmon, E.M. 2019. Inverse dispersal patterns in a group of ant parasitoids (Hymenoptera: Eucharitidae: Oraseminae) and their ant hosts. Systematic Entomology DOI: 10.1111/syen.1237.

Banks, H.T., J.E. Banks, N.G. Cody, M.S. Hoddle, and A.E. Meade. 2019. Population model for the decline of Homalodisca vitripennis (Hemiptera: Cicadellidae) over a ten-year period. J. Biol. Dynamics. 13: 422-446.

Ben Ghabrit, S., Bouhache, M., Birouk, A., Bon, M. 2019. Macromorphological variation of the invasive Silverleaf nightshade (Solanum laeagnifolium Cav.) and its relation to climate and altitude in Morocco. Revue Marocaine des Sciences Agronomiques et Vétérinaires. 7(2), 234-251.

Bitume, EV, Moran PJ, Sforza RFH. 2019. Impact in quarantine of the galling weevil Lepidapion argentatum on shoot growth of French broom (Genista monspessulana), an invasive weed in the western U.S. Biocontrol Science and Technology, 1-11.

Bodwitch, H., Getz, C., Hickey, G., Daane, K. M., Carah, J., Grantham T. E., and Wilson, H. 2019. Growers say cannabis legalization excludes small growers, supports illicit markets, and undermines local economies. California Agriculture 73(3-4): 177-184.

Chaplin-Kramer, R., M. O’Rourke, N. Schellhorn, W. Zhang, B. Robinson, C. Gratton, J. A. Rosenheim, T. Tscharntke, and D. S. Karp.  2019.  Measuring what matters: actionable information for conservation biocontrol in multifunctional landscapes.  Frontiers in Sustainable Food Systems 3:60.  doi: 10.3389/fsufs.2019.00060.

Chardonnet, F., Blanchet, A, Hurtrel, B, Marini, F, Smith, L. 2019. Mass rearing optimization of the parasitoid Psyttalia lounsburyi for biological control of the olive fruit fly. Journal of Applied Entomology.  143: 277– 288. doi: 10.1111/jen.12573.

 Clarke CW, Calatayud P-A, Sforza RFH, Ndemah RN, Nyamukondiwa C 2019. Editorial: Parasitoids' Ecology and Evolution. Frontiers in Ecology and Evolution (7): 485  DOI=10.3389/fevo.2019.00485.   

Daane, K. M., Yokota, G. Y., and Wilson, H. 2019. Seasonal dynamics of the leaffooted bug Leptoglossus zonatus and its implications for control in almonds and pistachios. Insects 10, 255. doi:10.3390/insects10080255.

Dainese, M., et al.  2019.  A global synthesis reveals biodiversity-mediated benefits for crop production.  Science Advances 5: eaax0121.

Dalton, D. T., Hilton, R. J., Kaiser, C., Daane, K. M., Sudarshana, M. R., Vo, J., Zalom, F. G., Buser, J. Z., and Walton, V. M. 2019. Spatial associations of vines infected with grapevine red blotch virus in Oregon vineyards. Plant Disease 103(7): 1507-1514. DOI: 10.1094/PDIS-08-18-1306-RE.

Desurmont, G.A., Kerdellant, E., Pfingstl, T., Auger, P., Tixier, M.S. and Kreiter, S., 2019. Mites associated with egg masses of the viburnum leaf beetle Pyrrhalta viburni (Paykull) on Viburnum tinus L. Acarologia. 59(1): 57-72. doi: 10.24349/acarologia/20194311.

Emery, S. E. and Mills, N. J.  2019.  Effects of temperature and other environmental factors on the post-diapause development of walnut husk fly Rhagoletis completa (Diptera: Tephritidae).  Physiological Entomology 44: 33-42.

Gariepy, TD, Bruin, A, Konopka, J, Scott Dupree, C., Fraser, H., Bon, M.C., Talamas, E. 2019. A modified DNA barcode approach to define trophic interactions between native and exotic pentatomids and their parasitoids. Molecular Ecology 28: 456– 470. doi: 10.1111/mec.14868.

Garzón-Orduña, I. J., Winterton, S. L., Jiang, Yunlan, Breitkreuz, L. C., Duelli, P., Engel, M. S., Penny, N. D., Tauber, C. A., Mochizuki, A., Liu, Xingyue. 2019. Evolution of green lacewings (Neuroptera: Chrysopidae): a molecular supermatrix approach. Systematic Entomology 44: 499-513. https://onlinelibrary.wiley.com/doi/epdf/10.1111/syen.12339.

Giorgini, M., Wang, X.-G., Wang, Y., Chen, F.-U., Hougardy, E., Hong-Mei, Zhang, H.-M., Chen, Z.-Q., Chen, H.-Y., Liu, C.-X., Casconea, P., Formisano, G. Carvalho, G. A., Biondi, A., Buffington, M., Daane, K. M., Hoelmer, K. A., and Guerrieri, E. 2019. Exploration for native parasitoids of Drosophila suzukii in China reveals a diversity of parasitoid species and narrow host range of the dominant parasitoid.  Journal of Pest Science. https://doi.org/10.1007/s10340-018-01068-3.

Gols R, Ros VID, Ode PJ, Vyas D, Harvey JA.  2019.  Varying degree of physiological integration among host instars and its endoparasitoid affect stress-induced mortality.  Entomologia Experimentalis et Applicata 167: 424-432.  https://doi.org/10.1111/eea.12765

Goolsby, J.A., Moran, P.J.  2019. Field impact of the arundo scale, Rhizaspidiotus donacis (Homoptera: Diaspididae) on Arundo donax on the Rio Grande. Subtrop. Agric. Environ. 70, 11-16. http://www.subplantsci.org/wp-content/uploads/2019/09/SAES-Goolsby-et-al.-2019-3.pdf.

Harvey JA, Gols R, Smith B, Ode PJ.  2019.  Invasive moth facilitates use of a native food plant by other native and invasive arthropods.  Ecological Research 34:659-666.  https://doi.org/10.1111/1440-1730.12035

Heraty, J.M., Derafshan, H.A., Ghafouri, M. 2019. Review of the Philomidinae ruschka (Hymenoptera: Chalcidoidea: Perilampidae), with description of three new species. Arthropod Systematics and Phylogeny 77: 39–56.

Hogg, B.N., Moran, P.J., Smith, L. 2019. Relative performance and impacts of the psyllid Arytinnis hakani (Hemiptera: Psyllidae) on nontarget plants and the target weed Genista monspessulana (Fabales: Fabaceae). Environ. Entomol. 48, 524-532. doi: 10.1093/ee/nvz041.

Hopper, J.V., McCue, K.F., Pratt, P.D., Duchesne, P., Grosholz, E.D., Hufbauer, R. 2019. Into the weeds: matching importation history to genetic consequences and pathways in two widely used biological control agents. Evol. Appl. 12, 773-790. doi:10.1111/eva.12755.

Hougardy, E., Hogg, B. N., Wang, X.-G., and Daane, K. M. 2019. Comparison of thermal performances of two Asian larval parasitoids of Drosophila suzukii. Biological Control 136: https://doi.org/10.1016/j.biocontrol.2019.104000.

Jalali, M. A., Sakaki, S., Ziaaddini, M., and Daane, K. M. 2019. Temperature-dependent development of Oenopia conglobata (Col.: Coccinellidae) fed on Aphis gossypii (Hem.: Aphididae). International Journal of Tropical Insect Science 38(4): 410-417.

Jarrett B. J. M., J. Pote, E. Talamas, L. Gut and M. Szűcs. 2019. The discovery of Trissolcus japonicus (Hymenoptera: Scelionidae) in Michigan. The Great Lakes Entomologist. 52:6-11.

Jourdan, M., Thomann, T.,Kriticos, D., Bon, M.C., Sheppard, A., Baker, G.H. 2019. Sourcing effective biological control agents of conical snails, Cochlicella acuta, in Europe and North Africa for release in southern Australia. Biological Control. 134: 1-14. doi: 10.1016/j.biocontrol.2019.03.020.

Kaufman, L.V., Yalemar, J., & Wright, M.G. 2019. Classical biological control of the erythrina gall wasp, Quadrastichus erythrinae, in Hawaii: conserving an endangered habitat. Biological Control (In press). https://doi.org/10.1016/j.biocontrol.2019.104161.

Lara, J.R., C. Pickett, and M.S. Hoddle. 2019. Physiological host range of Trissolcus japonicus in relation to Halyomorpha halys and other pentatomids in California. BioControl 64: 514-528. doi.org/10.1007/s10526-019-09950-4.

Lee, J. C., Wang., X.-G., Daane, K. M., Hoelmer, K. A., Isaacs, R., Sial, A. A., Walton, V. M. 2019. Biological control of spotted-wing drosophila – current and pending tactics. Journal of Integrated Pest Management 10(1): 13; 1–9. doi.org/10.1093/jipm/pmz012.

Luna E, van Eck L, Campillo T, Weinroth M, Metcalf J, Perez-Quintero AL, Botha A-M, Thannhauser TW, Pappin D, Tisserat NA, Lapitan NLV, Argueso CT, Ode PJ, Heck ML, Leach LE.  2018.  Bacteria associated with Russian wheat aphid (Diuraphis noxia) enhance aphid virulence to wheat.  Phytobiomes 2: 151-164.  https://doi.org/10.1094/PBIOMES-06-18-0027-R

Martel, G, Augé, M, Talamas, E, Roche, M, Smith, L, Sforza, R.F.H. 2019. First laboratory evaluation of Gryon gonikopalense (Hymenoptera: Scelionidae), as potential biological control agent of Bagrada hilaris (Hemiptera: Pentatomidae). Biological Control. 135: 48-56 doi: 10.1016/j.biocontrol.2019.04.014.

McCalla, K.A., M. Keçeci, D.A. Ratkowsky, and M.S. Hoddle. 2019. The influence of temperature variation on life history parameters and thermal population curves of Tamarixia radiata (Hymenoptera: Eulophidae), a parasitoid of the Asian citrus psyllid (Hemiptera: Liviidae). J. Econ. Entomol. https://doi.org/10.1093/jee/toz067.

Miller, R.H., R.G. Foottit, E. Maw, and K.S. Pike.  2019.  Genetic and morphological diversity in Aphis gossypii Glover (Hemiptera: Aphididae) in the Pacific Basin.  Pacific Science 70(3): 367-387.

Milosavljevic, I. and M.S. Hoddle. 2019. Chapter 13: Advances in classical biological control that support IPM in perennial agricultural crops. In: Integrated Management of Insect Pests: Current and Future Developments. Eds: M. Kogan and L. Higley. Burleigh Dodds Science Publishing. 

Milosavljevic, I., K.A. McCalla, D.A. Ratkowsky, and M.S. Hoddle. 2019. Effects of constant and fluctuating temperatures on the development rates and longevity of Diaphorencyrtus aligarhensis (Hymenoptera: Encyrtidae). J. Econ. Entomol. doi: 10.1093jee/toy429.

Naranjo, S.E. 2019. Assessing insect flight behavior in the laboratory: A primer on flight mill methodology and what can be learned. Annals of the Entomological Society of America 112: 182-199.

Naranjo, S.E., Frisvold, G.B., Ellsworth, P.C. 2019. Economic value of arthropod biological control. 49-85, in The Economics of Integrated Pest Management for Insects, D. Onstad, P. Crain (eds.). Springer, Dordrecht-Heidelberg-London-New York.

Naranjo, S.E., Hellmich, R.L., Romeis, J., Shelton, A.M., Velez, A.M. 2019. The role and use of genetically engineered insect-resistant crops in IPM systems. P. 1-58, In Integrated management of insect pests: Current and future developments, M. Kogan, E. Heinrichs (eds.). Burleigh Dodds Science Publishing, Cambridge, UK.

Ode PJ.  2019.  Plant toxins and parasitoid trophic ecology.  Current Opinion in Insect Science 32: 118-123.  https://doi.org/10.1016/j.cois.2019.01.007

Perry, R.K., Heraty J.M. 2019. A tale of two setae: how morphology and ITS2 help delimit a cryptic species complex in Eulophidae (Hymenoptera: Chalcidoidea). Insect Systematics and Biodiversity 3: 1–23.

Pratt, P.D., Herr, J.C., Carruthers, R.I., Pitcairn, M.J., Villegas, B., Kelley, M.B., 2019. Release, establishment and realized geographic distribution of Diorhabda carinulata and D. elongata (Coleoptera: Chrysomelidae) in California, U.S.A. Biocon. Sci. Technol. 29, 686-705. doi: 10.1080/09583157.2019.1587739.

Pratt, P.D., Pitcairn, M.J., Oneto, S., Kelley, M.B., Sodergren, C.J., Herr, J., Beaulieu F., Andreas, J., 2019. Invasion of the gall forming mite Aceria genistae, a natural enemy of the invasive weed Cytisus scoparius, into California, U.S.A. and predictions of its potential for establishment in other regions using ecological niche modeling. Environ. Entomol. 29, 494–513. doi:10.1080/09583157.2019.1566440.

Reddy, A.M., Pratt, P.D., Hopper, J.V., Cibils-Stewart, J., Walsh, G.C., McKey, F. 2019. Variation in cool temperature performance between populations of Neochetina eichhorniae (Coleoptera: Curculionidae) and implications for the biological control of water hyacinth, Eichhornia crassipes, in a temperate climate. Biol. Control 128, 85-93. doi: 10.1016/j.biocontrol.2018.09.016.

Romeis, J., Naranjo, S.E., Meissle, M., Shelton, A.M. 2019. Genetically engineered crops help support conservation biological control. Biological Control 130: 136-154.

Rosenheim, J. A., N. Booster, M. Culshaw-Maurer, T. Mueller, R. Kuffel, Y.-H. Law, P. B. Goodell, T. Pierce, L. D. Godfrey, W. B. Hunter, and A. Sadeh.  2019.  Disease, elevated cannibalism expression, and associated population crash in an omnivorous bug, Geocoris pallens.  Oecologia 190:69-83.

Sforza RFH 2019. La lutte biologique contre les adventices est-elle possible? (in French) Réussir Fruits & Légumes, Hors Série Prospectives (399): 66-70.

Stahl, J., Tortorici, F., Pontini, M., Bon, M.C., Hoelmer, K.H.,  Mazari, C., Tavella, L, Haye, T. 2019. First discovery of adventive populations of Trissolcus japonicus in Europe. Journal of Pest Science 92: 371-379. doi: 10.1007/s10340-018-1061-2.

Szűcs M, E. Vercken, E. Bitume and R.A. Hufbauer. 2019. The implications of rapid eco-evolutionary dynamics for biological control – a review. Entomologia Experimentalis et Applicata. 167:598-615.

Szűcs M, P. Salerno, B. Teller, U. Schaffner, J. Littlefield and R.A. Hufbauer. 2019. The effects of agent hybridization on the efficacy of biological control of tansy ragwort at high elevations. Evolutionary Applications 12 (3): 470-481 doi.org/10.1111/eva.12726.

Szucs, M., P. Salerno, U. Schaffner, B. Teller, J. Littlefield, and R. Hufbauer. 2019. Could hybridization between agent biotypes increase biological control efficacy? In: H.L. Hinz et al. (Eds), Proceedings of the XV International Symposium on Biological Control of Weeds, Engelberg, Switzerland, pp. 255. https://www.ibiocontrol.org/proceedings/.

Tauber, C. A., Simmons, Z., and Tauber, A. J. 2019. Type specimens of Neuropterida in the Hope Entomological Collection, Oxford University Museum of Natural History. ZooKeys 823: 1-126. https://zookeys.pensoft.net/article/30231/download/pdf/.

Tauber, C. A. 2019. South American Nothochrysinae: I. Description of Nothochrysa ehrenbergi n. sp. (Neuroptera: Chrysopidae). ZooKeys 866: 1-18. https://zookeys.pensoft.net/article/35394/.

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Vankosky, M.A. and M.S. Hoddle. 2019. Two parasitoids of Diaphorina citri (Hemiptera: Liviidae) have shared, stage specific preference for host nymphs that does not impact mortality rates. Fla. Entomol. 102: 49-58. https://doi.org/10.1653/024.102.0108.

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