Brief Summary of Minutes of Annual Meeting

Goal A: Import and Establish Effective Natural Enemies Objective 1. Survey indigenous natural enemies. Surveys for natural enemies of arthropod and weed pests were conducted either in the native home of the pest or within the country of invasion. Several of these surveys are highlighted. Surveys of natural enemies of Icerya seychellarum and Aspidiotus destructor in the Manu'a Islands were completed. Visits to the islands this year confirmed that populations of I. seychellarum continue to be maintained at very low levels by the introduced lady beetles Rodolia limbata and R. pumila. Surveys were conducted on papaya mealybug (Paracoccus marginatus) and Erythrina gall wasp (Quadrastichus erythrinae) for indigenous natural enemies in Hawaii. None were detected. To facilitate surveys of natural enemies in the USA, taxonomic materials were developed (keys, descriptions, illustrations, images) for identifying chrysopids. Adult and larval specimens were collected, especially in California's central valley and coastal region. Specimens from several populations were reared and preserved for morphological study. Surveys of more than 50 sites indicated that olive psyllid is well established in parts of Orange and San Diego Counties, however it is now found in 3 additional CA counties. Natural enemies were rarely observed within psyllid clusters. An Orius-like predator was found feeding on the psyllids collected for lab. purposes. Assassin bugs, were surveyed in Southern California with an emphasis on the genera Zelus and Apiomerus. Other Zelus of interest as natural enemies include native species of Pselliopus, Sinea and, most importantly, Apiomerus. Species of Zelus are native to California and feed on prey such as lygus, caterpillar larvae, and boll weevils. 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. Field research on the arundo scale, R. donacis was completed in Spain. Field experiments using both mechanical and chemical exclusion have shown that A. donax without arundo scale grows significantly larger and faster. Several cooperative projects with colleagues in Argentina and Brazil were continued on the diversity, seasonal occurrence, comparative biology, and abundance of chrysopids in orchards. A large number of species were collected; their taxonomy and developmental requirements being determined. An endemic complex of 20 parasitoid speices provides a year round supply of natural enemies that suppress a complex of citrus leaf and peelminers more effectively that the exotic A. citricola in CA. Work in 2011 also included looking for biocontrol agents for the following species: olive psylla in Spain and France; European lettuce aphid in Spain; Russian olive and Russian knapweed in Turkey, Central Asia and Iran; Brazilian waterweed in South America; yellow starthistle in Turkey; Russian and scotch thistle, perennial pepperweed, and rush skeletonweed in Italy, Spain, Bulgaria and Turkey; French broom in France and Italy; and white peach scale in Samoa. In most cases, arthropods were sought as natural enemies, however plants diseases are also identified as potential biocontrol agents (caused visible blisters and deformations on scotch thistle leaves). 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. Objective 3. Determine systematics and biogeography of pests and natural enemies. Systematics studies generate both molecular and morphological data that are essential to distinguishing between biotypes of both pests and natural enemies. These data also provide information about species biogeography, which ultimately helps select the best biological control species. Studies on the phylogenetic relationships of Apiomerus using molecular and morphological information are in progress. Efforts focus placements of these genera within the tribes Apiomerini and Harpactorini and on species-level phylogenies within these genera. Systematics of the Asian Citrus Psyllid, the vector of Citrus Greening Disease, and its relatives within the genus Diaphorina have been on-going. Systematics of Diaphorina is largely unknown and investigations focus on a molecular study based on broad sampling of Diaphorina species in South East Asia, the Near East, and South Africa. Molecular phylogeny indicates that the genus Diaphorina is monophyletic and that an association with Rutaceae (citrus and allies) has occurred more than once within the genus. Scientists in Argentina are helping W2185 researchers on with studies on parasites of the imported fire ant (Solenopsis) in South America and of the Little Red Fire Ant (Wasmannia) in the Caribbean and Central America. Studies include the molecular characterization of the different species using ribosomal markers. Studies funded through foreign exploration funds have focused on the ecology and characterization of Orasema minutissima, which is attacking Wasmannia in Dominica and Costa Rica. This latter species is a promising control agent for invasive populations of the LRF in the Pacific. A project is underway to study the species of Coccophaginae, a diverse group of parasitoids attacking whiteflies and armored scales. Objective 4. Determine environmental safety of exotic candidates prior to release. Many non-target studies are underway. Examples follow: Laboratory host range assessment of a predatory pentatomid, Podisus maculiventris is being studied for field release on Guam. Predation by Podisus maculiventris was evaluated with Erionota thrax (Lepidoptera; Hesperidae), Pericyma cruegeri, Pareuchaetes pseudoinsulata (Lepidoptera: Arctiidae), Papilio polytes, and Eudocima phalonia. Both free-choice and no-choice experiments indicated that the P. maculiventris attacked and consumed all the larvae of the 5 species included in the tests. Although larvae died at different intervals, most of them were dead within 24-120 h of the introduction of the predatory species. Since the P. maculiventris is polyphagous in nature and the present findings indicate that these predators will feed on the introduced biocontrol moth, P. pseudoinsulata, it is recommended not to take the predators out of the quarantine laboratory for the field release on Guam. Additionally, P. maculiventris will feed on some native species as they become available. Two agents, the arundo wasp, Tetramesa romana and the arundo scale, Rhizaspidiotus donacis have been permitted for release. Host specificity testing of the crown moth Oporopsamma wertheimsteini was conducted at the MSU quarantine facility in 2011. No-choice tests were performed on 32 plant species, plus 4 cultivars and 3 biotypes of rush skeletonweed. A shipment of rush skeletonweed roots infested with the moth was received from Armenia in 2011; collected by local cooperators in association with the Russian Biocontrol Group. Over 160 adults emerged and laid eggs; which are being held in cold storage. Sphenoptera foveola was also collected by the Russian Biocontrol Group from sites located in Kazakhstan and then transported to field plots in Armenia to determine the utilization of North American Chondrilla juncea. Objective 5. Release, establish and redistribute natural enemies. Many releases and redistributions of natural enemies were carried out against pests in 2011. Well over 100,000 individual natural enemies were released or redistributed. Pest species include (but were not limited to): giant reed, rush skeletonweed, Mediterranean sage, purple loosestrife, olive fly, Diaprepes root weevil, Lygus hesperus, vine mealybug, Asian citrus psyllid, tansy ragwort, Russian knapweed, field bindweed, St. Johnswort, Bemisa spp., melon aphid, saltcedar, leafy spurge, yellow starthistle, musk thistle, spotted and diffuse knapweed, Dalmation toadflax, common mullein, poison hemlock, Canada thistle, tansy ragwort, scotchbroom, and giant sensitive weed. Most of these projects required collecting or rearing the natural enemies and releasing them at many sites, followed by evaluating their establishment. Specific examples follow: A permit from USDA-APHIS was obtained during to import the predatory mite Neoseiulus californicus for the control of plant feeding mites on vegetable crops from the continental United States. 5000 predatory mites were released at various locations on Guam in January 2011. Post release monitoring will be conducted to determine the establishment of the predatory mites. Eurytoma erythrinae and Anagrus loekii, parasitoids of Erythrina gall wasp (Quadrastictus erythrinae) have been distributed and established state-wide in Hawaii. A relatively new biological control agent for Russian knapweed, Acroptilon repens, was permitted for release in the U.S. in 2009. This insect, Jaapiella ivannikovi, is a cecidomyiid gall midge from central Asia. Releases were made at three new sites in the project area (Wyoming). No galls were observed later in the summer at these sites, suggesting a failure of the agent to establish. Objective 6. Evaluate natural enemy efficacy and study ecological/physiological basis for interactions. The impact of Cecidochares connexa on Chromolaena odorata in Guam was evaluated. To assess the impact of this gall fly on this weed, eight field sites in northern, central and southern Guam, each with well-established stands of C. odorata, were assessed in 2011. Measurements of various growth parameters of C. odorata indicated steady decline in the number of stems and leaves, and height of plants at the sites from October 2009 to September 2010. This gives a snapshot picture of the decline of C. odorata on Guam, likely due to the introduced natural enemies. A study is identifying parasitoids for a survey of Citrus leafminer (Phyllocnistis citrella) in southern California and developing a pictorial identification key to species. The impact and effectiveness of seed-feeding insects on squarrose knapweed was evaluated by sampling throughout the west desert of Utah where the weed is widely established. The weevil was found to infest 55-80% of knapweed seedheads across areas of heavy weed infestation, while the formerly abundant fly continues to infest small percentages (up to 10%) at many sites as well. Shared use by the two biocontrol agents of individual knapweed sites, and of individual seedheads within sites, was investigated. Rates of parasitism of the cereal leaf beetle (Oulema melanopus) by the parasitoid Tetrastichus julius were determined by sampling weekly throughout the growing season in fields of small grains (barley, wheat, and oats) in northern Utah. Sampling emphasis was placed on comparing rates of parasitism of the beetle between grain fields that had been planted with small grains also during the previous growing season and fields that were newly planted with grains. 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. Research focused on understanding predatory natural enemies associated with Lygus species in California cotton. The dispersal abilities of several generalist predators (Geocoris spp., Nabis spp., Hippodamia convergens, and Chrysoperla spp.) and Lygus were quantified using a large-scale mark-capture study. Lygus does not appear to escape from its predators by out-dispersing them. New statistical methods were developed to be used with protein mark-capture data to study long-distance movement by arthropods in an agricultural landscape. The diets of ladybird beetles in alfalfa fields were determined by using the contents of frass as diagnostic indicators. Laboratory experiments demonstrated that ladybird beetle consumption of the two major insect pests in Utah alfalfa fields, alfalfa weevil larvae and pea aphids, as well as consumption of other ladybird beetles, could be detected readily from prey fragments in frass. Field studies revealed that consumption by ladybird beetles of alfalfa weevil larvae as well as aphids occurred frequently in spring alfalfa. To understand the effects of seasonal aphid availability on alternative prey use, an order-specific monoclonal antibody was used to examine the frequency of dipteran predation by these important natural enemies. Over 400 larvae were hand-collected from alfalfa and, in parallel, arthropod abundance was recorded. Harmonia axyridis and Coccinella septempunctata larvae were abundant early in the season when aphid populations were at their peak and Coleomegilla maculata larvae were collected later in the season when potato leafhoppers were abundant in the alfalfa. A new Hawaii record for an unintentionally introduced egg parasitoid, Trichogramma achaeae, was reported. Objective 8. Identify and assess factors potentially disruptive to biological control. Studies were conducted on the extent to which biological control of spider mites (Tetranychus urticae) and aphids (Aphis gossypii) in California cotton is disrupted by cannibalism or intraguild predation. Field experiments demonstrated that cannibalism in Geocoris pallens populations appear to be the key constraint limiting the ability of this predator to respond numerically to localized outbreaks of spider mite or aphid prey. A series of controlled laboratory studies have been initiated to measure potential impacts of transgenic Bt crops on a range of natural enemy species. Protocols involve tri-trophic exposure scenarios in which the prey or host are fed on Bt crops and then exposed to predators or parasitoids. To control for prey or host quality mediated effects, Bt resistance and susceptible prey and hosts are being employed. Researchers continued to survey invasive ants on the islands of Guam, Saipan, Tinian, and Rota in the Mariana Islands during 2011. This activity is part of an ongoing USDA-APHIS funded project on the surveillance of Wasmannia auropunctata and Solenopsis invicta on Guam and other Mariana Islands. A study related to this project describes the 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 released in the islands. The effects of pesticides on the parasitoid (Anagrus loekii) of papaya mealybug (Paracoccus marginatus) were investigated. Objective 9. Implement and evaluate habitat modification, horticultural practices, and pest suppression tactics to conserve natural enemy activity. Large plot field studies were initiated in 2011 to develop baseline data for incorporating the density and activity of natural enemies into action thresholds for managing Bemisia tabaci in cotton. Different rates of a known broad-spectrum insecticide were used to manipulate predator/prey ratios and attempt to determine levels of these ratios needed to suppress pest populations or require the need for remedial insecticidal control. Protein mark-capture studies are being conducted to assess the movement of lygus bugs and associated natural enemies between alfalfa strips planted within an organic strawberry field. Studies indicated that Lygus and several species of predators remain in the alfalfa trap crop and do not disperse far into the adjacent strawberries. Protein mark-capture studies were initiated to examine the movement of spotted winged Drosophila (SWD) and associated natural enemies between wild Himalayan blackberry (HB) and soft fruit crops (berries, grapes, and stone fruits) in wild land areas of the Pacific Northwest. A laboratory study showed that protein markers are very effective SWD markers. These markers are currently being used to study SWD movement between native vegetation and small fruit crops. The effects of cover cropping and intercropping corn with sun hemp, buckwheat, and cowpea on parasitism of Helicoverpa zea by Trichogrammatidae is being investigated. Goal C: Augment Natural Enemies to Increase Biological Control Efficacy. Objective 10. Assess biological characteristics of natural enemies. To investigate predation strategies and natural history of species of the genus Zelus, researchers have established lab cultures of several species of Zelus. They have observed and videotaped reproductive and predation behaviors of Z. renardii and Z. tetracanthus. Researchers (in collaboration with colleagues in Mexico and Brazil) continue to evaluate the potential of chrysopids for mass-rearing and release in the U.S.A. and Latin America. Emphasis in Mexico is on Ceraeochrysa species against homopteran pests of citrus; Brazil focuses on Ceraeochrysa, Chrysopodes and Leucochrysa species against homopteran pests of fruit and vegetable crops. A critical review was completed covering the nutrition and feeding behavior of chrysopids, especially as they relate to pest management. Egg parasitism by Trissolcus basalis in architecturally varied habitats and observations on parasitism in macadamia nut orchards and other habitats following augmentative release is also being studied. Genetic effects of augmentative introductions of Tephritid parasitoids using Diachasmimorpha tryoni as the study organism have been analyzed. Molecular tools and fitness measurements have predicted the potential effects of captive colony outbreeding during augmentative release using the parasitoid, Diachasmimorpha tryoni. Research continued towards the long-term goal of finding more efficient and effective ways to use the predatory mite, Phytoseiulus persimilis, as an augmentative biological control agent of the twospotted mite, Tetranychus urticae, on greenhouse vegetable and floricultural crops. Because this predator is tiny, flightless, and must forage in diverse complex crop landscapes in which prey are patchily-distributed, testing has focused on lines artificially selected to enhance various foraging traits, including consumption rate and tendency for dispersal. Objective 11. Develop procedures for rearing, storing, quality control and release of natural enemies, and conduct experimental releases to assess feasibility. Work has continued with Trichogramma papilionis for augmentative release into corn fields, with and without cover crops, specifically sunn hemp, to increase parasitism of Helicoverpa zea eggs. In addition, rearing procedures continue to be developed and refined for Light Brown Apple Moth, Epiphyas postvittana. Extant species of Trichogramma egg parasitoids are under evaluation to determine their effectiveness in augmentation biological control of the light brown apple moth. Interest focuses on the combined effects of egg parasitoids and sterile insect technology (SIT) using sterile light brown apple moths. Research in large field cages (12' x 24') was initiated. Results were favorable for both parasitism (using T. platneri) and SIT. Objective 12. Implement augmentation programs and evaluate efficacy of natural enemies. Results have been reported under other objectives. 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. Research was undertaken to examine the role of detrital subsidies in strawberry crops to promote biological control of exotic and native mollusks. Detrital inputs were compared to traditional bare ground plantings to test the hypothesis that (1) native mollusks would be consumed in greater frequency than non-native species, and (2) levels of predation would be greater in crops that were not treated with detrital subsidies since their application can increase habitat complexity and biodiversity of the prey community, potentially disrupting pest predation. Diagnostic molecular gut-content analysis was used to examine the strength of trophic pathways between a community of carabid beetles and two slug species, the exotic Deroceras reticulatum and native Deroceras laeve, in strawberry agroecosystems. Although slug populations were too low to allow between-treatment comparison, the interaction pathways determined were of significant value in mitigating the effect of slug damage in strawberry agroecosystems and conservation management tactics should therefore focus on those approaches that will promote the diversity of carabids early in the season and prior to fruiting of the crop. The population dynamics of web-building spiders were examined to compare phenological patterns in relation to crop cycles among species in an alfalfa agroecosystem using quadrat-based sampling and time-series analysis. Three common species of web-building spiders had generation times similar to the duration of a crop cycle (31 to 44 days), with peak abundances of adult spiders occurring at 15 to 18 days after harvest. The timing of these peaks corresponds with the critical early phase of the pest population cycle, during which natural enemies can have the maximum impact on pest populations, suggesting that these spiders are capable of contributing to pest suppression as part of an assemblage of natural enemies. Objective 14. Develop and implement outreach activities for biological control programs. A series of brief one-page Extension Circulars have been developed to highlight the identification, biology and biological control potential of some of the more common arthropod predators in the cotton system (spiders, big-eyed bugs, assassin bugs, Collops beetles). A circular was developed to stress the importance of proper sampling and choice of insecticides that allow these key natural enemies to function in the cotton system. Circulars were distributed widely to growers, pest control advisor, county extension personnel and other industry representatives. Approximately 35 quarantine personnel on Guam, the CNMI, the Republic of Palau, the Republic of the Marshall Islands, and the Federated States of Micronesia were trained in the importance of natural enemies regulating populations of invasive pests in Micronesia, with special recognition of the potential impact of Hemiptera and ants if not intercepted or detected. Regulations for importing natural enemies and prohibiting the entry of potential pests were discussed, along with methods for inspection and enforcement of regulations. This activity was the 9th of its kind hosted by the University of Guam and sponsored jointly by the Secretariat of the Pacific Commission, the Guam Department of Agriculture and USDA-APHIS. A presentation was given to state weed managers on the ongoing biological program for Russian knapweed using J. ivannikovi in Wyoming.