Brief Summary of Minutes of Annual Meeting

Accomplishments: Objective 1: To advance basic and applied biological research on existing and emerging rice invertebrate pests, including mosquitoes California Larry D. Godfrey Research was conducted in 2007 on the biology and management of key invertebrate pests of California rice. Concentrated efforts continued on rice water weevil (RWW) and limited studies were continued on armyworm (AW), two important rice arthropod pests of rice in CA. In addition, research was done on two early-season pests of seedling rice, seed midge and tadpole shrimp. The goal was to refine IPM schemes for these pests and to maximize the management in light of the environmentally sensitive nature of the rice agroecosystem. The cost effectiveness of any management efforts in rice must also be carefully considered. Four overall themes provided direction for the 2007 research program. 1.) CA-DPR is currently placing pyrethroid insecticides into reevaluation based on their propensity to accumulate and move off-site on organic sediment. Therefore, studies continued to develop alternative active ingredients and classes of chemistry for arthropod pest control. (This is reported under objective 2). 2.) Best Management Practices have been developed and put forth for the industry to aid in mitigation of mosquito populations. This area has taken on added importance with the emphasis on West Nile Virus in California. A study was continued to evaluate the effects of registered and experimental rice insecticides on non-target invertebrates, which could play an important role in mosquito management in rice fields. As part of this, possible changes in rice seeding methods were studied and the role of these changes in mosquito populations monitored. 3.) Early-season invertebrate pests were more common in 2007 than in recent years. To respond to grower questions about control of these pests, studies were done on seed midge and tadpole shrimp control. 4.) Exotic pests moving into California are unfortunately being a more common occurrence. The rice panicle mite was found in the southern U.S. rice belt in 2007. Samples from California were processed for this pest and so far there has been no occurrence of the panicle mite in California. Communication and education on this pest was hastened in 2007. Significant progress was made on all objectives. AW populations were overall low and this hindered research on this pest but this was not a key objective in 2007. RWW biology was studied in terms of adult flight, relative susceptibility of commonly grown rice varieties to RWW infestation and to yield losses, and the influence of rice seedling establishment methods of RWW population severity. For instance in the spring of 2007, we recorded RWW flight only on 13 of the 76 nights we evaluated. The RWW flight was concentrated from 26 April to 8 May. Two periods were noteworthy with 2/3 of the seasonal catch occurring on 7 May and another 30% on 26-27 April A total of ~2700 RWW adults were captured which was ~15% higher than in 2006. Twelve rice varieties were compared for susceptibility to and yield loss from RWW in field plots with a moderate natural infestation. M-104, M-206, M-202, and S-102 had the highest levels of RWW leaf scarring and these same varieties, along with Calamylow-201, had the highest larval populations. S-102 was most responsive with a severe negative yield loss to RWW infestation, Calhikari-202 and Calamylow-201 were moderately responsive, and the PI line, M-206, and M-202 showed slight yield losses. The other six varieties showed no yield losses across the levels of RWW present in these plots. in ring plots infested with RWW, ~1/3 as many larvae survived on Calmati-202 compared with the other three varieties but grain yield losses were highest in Calmati-202 on a loss per larva basis. Refined rice seedling establishment techniques are being investigated at the RES primarily as a means to improve weed management through stale seedbed and dry seeding techniques. However, these techniques will also likely affect insect pest populations and mosquitoes. Leaf scarring from RWW adults was higher in all the other treatments compared with the standard water-seeded method and larval populations were much higher in the drill-seeded conventional than the water-seeded conventional treatments. Both stale seedbed treatments (drill- and water-seeded) had slightly fewer larvae than the water-seeded standard. Compared to the standard water-seeded treatment, there were about 20% more mosquito larvae in the drill-seeded, stale seedbed, no-till treatment and only ½ as many larvae in the water-seeded, stale seedbed, spring till treatment. Armyworm Biology and Infestations in Rice: Armyworm larval populations and damage were monitored in two studies at the RES and were too low to draw meaningful conclusions. Moth flights were monitored using pheromone traps and the true armyworm exhibited a high flight peak in early Aug. and the western yellow-striped armyworm flight was overall low with no real peaks. Early-Season Invertebrate Pests: Tadpole shrimp populations occur in many rice fields and damage can range from minimal to severe. In recent years, there have been reports that copper sulfate is not reducing shrimp numbers as well as previously. Recent results from Board funding showed the interaction of rice straw residue and reduced algal control with copper sulfate; this may also explain the lack of shrimp control in some cases. Seven registered and experimental insecticide treatments were evaluated in ring plots infested with tadpole shrimp. Stand counts showed that numerically the lowest stand count was in the copper sulfate treatment and the highest value was in the Dimilin treatment. Seed midge populations were unexpectedly high in the spring of 2007. This pest is generally worse during cool springs when the rice struggles to germinate and to establish; conditions which generally were not present in 2007. The unpredictable nature of this pest makes it difficult on which to conduct research, but we flooded a field and delayed seeding to try to facilitate populations. There were no significant differences in stand counts or yield among treatments in this study and no clear sign that the pest was present. Exotic Pests of Rice: We maintained a vigilant watch for exotic pests through our visits to numerous rice fields throughout the Sacramento Valley. The rice panicle mite is a potentially extremely serious pest that is present in Asia and Central/South America and was found in TX in July and later in the season in LA, AR, Puerto Rico, and NY. Some 20-30 suspect samples from CA rice fields were examined for the panicle mite from Aug. to Oct. and no mites were found. Sharon Lawler The purpose of this project is to determine what constitute effective, environmentally sound control methods for pests in rice fields and nearby habitat, including mosquitoes emerging from rice fields that that can pose disease risks to rural residents and livestock. In 2007, the laboratory completed work on two studies that assessed the efficacy and non-target effects of a commonly-used formulation for controlling adult mosquitoes in riceland and other habitats. This formulation is pyrethrin synergized with piperonyl butoxide. It is applied as an ultra-low volume droplet fog over the landscape, by either truck or air. The first study (Boyce et al) exposed replicated caged adult mosquitoes and caged non-target invertebrates (dragonflies and spiders) to aerial application of synergized pyrethrin. Non-target insects were collected on replicated tarps placed adjacent to vegetation. These 'sentinel' organisms were also caged in several unsprayed areas. At rates used in mosquito control, synergized pyrethrin did not cause significant mortality of the common dragonflies nor garden spiders exposed to the spray in cages. Tarps collected more dead non-target insects in sprayed areas than control sites, however virtually all of these were very small-bodied insects. Sentinel mosquito data showed that the efficacy of the spray was often good in open areas but sometimes all mosquitoes survived under vegetation. The second study (Lawler et al) tested whether repeated applications of synergized pyrethrin over wetlands caused mortality of two aquatic invertebrates: the zooplankter Daphnia magna and a mayfly, Callibaetis californicus. Mayflies and daphnia are often used in biomonitoring studies because they are known to be sensitive to contaminants. 15 miniature wetlands constructed in cattle tank mesocosms were either exposed to repeated pyrethrin sprays by truck, or were protected by lids. Invertebrates in screened cages were placed in mesocosms before the 5th and 11th spray, and directly into wetlands before spray 11. Six mesocosms were exposed to spray deposition. Caged adult mosquitoes were used to verify that sprays drifted over mesocosms. Sediments were analyzed for insecticide residues. There were no detectable effects of synergized pyrethrin on 36 h survival of Daphnia or mayflies, but most exposed adult mosquitoes died. Some exposed sediments yielded pyrethrin ( up to 34.5 ppb); most showed piperonyl butoxide (up to 14.9 ppb). For three sprays, efficacies against mosquitoes were 71, 30 and 82 percent respectively. Walton A native larvivorous fish, the arroyo chub (GILA ORCUTTI), is being evaluated as a replacement for the non-native mosquitofish (GAMBUSIA AFFINIS) for mosquito control in environmentally sensitive wetlands and watersheds of southern California. The effects of vegetation patch size on the effectiveness of the arroyo chub as a biological control agent for mosquitoes that utilize wetlands as developmental sites were examined in experimental wetlands. Three patch sizes (0.1, 0.4 and 0.9 square meter) of emergent bulrush (SCHOENOPLECTUS CALIFORNICUS) were established in twelve 28 square meter wetlands by planting bulrush in nursery pots. Two bulrush culms consisting of 3 to 5 stems of bulrush were planted in each nursery pot. Twelve individual pots, four groups of four pots and two groups of nine pots were then placed into each wetland. 32 g (22-30 fish/wetland) of arroyo chubs were stocked into one half (6) of the wetlands. Mosquitoes and aquatic invertebrates were sampled biweekly using hand dippers and activity traps. During the late autumn 2006 and early spring 2007, mosquito abundance in wetlands containing the arroyo chub was significantly lower than in wetlands without fish. Mosquito abundance in the smallest vegetation patches was significantly lower than in the largest patches during the same time period; however, larval mosquito populations in bulrush patches of intermediate size did not differ significantly from the two other treatments. Samples from the late spring and summer 2007 are currently being processed. During this time period, mosquito production and fish reproduction typically reach their highest levels annually. Louisiana Stem-borer studies Several greenhouse experiments were conducted to test the hypothesis that rice plants infested with sugarcane borer larvae (Diatraea saccharalis) are less preferred for oviposition by sugarcane borer adults than uninfested rice plants. The results of three experiments were consistent with this hypothesis. Research on rice varietal preference of sugarcane borer females continues. A new graduate student has been recruited to help develop a management program for stem borers in Louisiana. Induced resistance in rice A series of greenhouse experiments were conducted in 2007 to detect induced resistance to chewing insects in rice seedlings. Rice seedlings at the three leaf stage were damaged by placing fourth/fifth instar fall armyworms on plants (1 larva per plant) for several hours. Foliage from damaged and undamaged plants was then used for feeding assays at two time points: 3-4 days after damage and 11-14 days after damage. At the earlier time point, growth rates of fall armyworm larvae on damaged leaves and undamaged leaves were compared; at the second time point, larval growth rates were compared on newly-emerged leaves from damaged plants (i.e., leaves not present at time of damage) and on newly-emerged leaves from undamaged plants. In bioassays at both time points, armyworm growth rates were lower when fed leaves from damaged plants. The systemic response was stronger than the response in damaged leaves. This induced resistance could be mimicked by applying jasmonic acid to rice seedlings. Jasmonic acid also induced resistance to the rice water weevil in rice seedlings. Moreover, the induced response to armyworm feeding was stronger in transgenic plants in which salicylic acid levels were suppressed. Applications of jasmonic acid were made to rice in small field plots in an effort to induce resistance to the rice water weevil in the field. Applications of jasmonic acid failed to induce resistance to the rice water weevil in field-grown rice plants. Rice stink bug research The chemical ecology of rice stink bug defensive secretions is being investigated. A number of volatile compounds emitted by stink bugs have been identified using SPME and GC/MS. In addition, the possibility that plant volatiles emitted by heading rice attract stink bugs to fields will be explored. Rice panicle mite (Hummel, lead investigator) In the summer of 2007, infestations of the panicle rice mite (PRM), Steneotarsonemus spinki Smiley (Acari: Tarsonemidae), were detected in several greenhouses and research fields at the Louisiana State University AgCenter Rice Research Station and in several commercial fields in Louisiana. The PRM is a severe pest of rice in a number of tropical rice growing areas. However, questions remain about the ability of this arthropod to establish and to become a perennial pest of rice in the southeastern United States; in particular, differences in climate (colder winters) and agronomic practices (4 to 6 month interval between harvest and planting) may prevent the mite from becoming a serious pest in sub-tropical and temperate climates. A series of experiments were carried out in the fall of 2007 to investigate several aspects of the biology and management of the PRM relevant to its pest status in Louisiana. Exposure of infested leaves and stems of rice to phosphine (Phostoxin® tablets, Degesch America, Inc.) resulted in >90% mortality of mites. In another experiment, 60 g samples of grain from a mite-infested, recently harvested field were subjected to one of five treatments: 1) freezing samples at -20ºC for three days; 2) heating samples in an oven at 35ºC for three days; storing samples in a 3) refrigerator or 4) incubator; and 5) keeping samples on a laboratory bench. Approximately four days after initiating treatments (eight days after harvest), grains were sampled for mites. Living mites were found in all samples except samples from treatments placed in the freezer and the oven. Approximately one week later, no live mites were found associated with grain from any of the treatments. In addition to these experiments, a series of observations were made using plant material from infested fields located in Vermillion Parish, Louisiana. In a sampling made in mid-October, live mites were found associated with vegetative material and grains of rice plants in both the milk and hard-dough stages of development. In a sampling made in late November, live mites were found associated with rice stubble and regrowth rice and with plant material from several weed species. The results of these experiments and observations suggest that practices commonly used during the processing and storage of rice grain-- in particular, drying under low heat and the use of phostoxin fumigant-- will result in heavy mortality of mites. However, the presence of live mites in plant material through late November also suggests that the mite may be able to survive winter conditions in southwest Louisiana. Mississippi Gravid traps were employed in and around rice fields to determine population trends of mosquitoes that are known to carry the west nile virus. No differences were noted in populations of these mosquitoes in rice fields than outside rice fields. Texas Rice water weevil (RWW), Lissorhoptrus oryzophilus was studied in a variety of experiments. Experiments conducted by Jiang detected parthenogenesis (<7% of females) in summer populations in TX. He also found RWW oviposited in and larvae fed on ratoon rice. RWW summer/fall biology is very plastic in Texas. Experiment by Groth and Way was conducted to determine effects of RWW damage on sheath blight (SB) severity. Main plot effects: Rice stands were significantly higher in Cocodrie than Jefferson. SB severity and RWW populations also were significantly higher in Cocodrie than Jefferson. However, yield of Cocodrie was significantly higher than Jefferson (1028 lb/A more than Jefferson). Sub plot effects: As expected, control of RWW in fipronil-treated plots was excellent on both RWW sample dates. Treated plots significantly outyielded untreated plots by 360 lb/A. Sub-sub plot effects: SB severity was high in SB-inoculated plots. In spite of Quadris applications, SB was observed in uninoculated plots. Yields were significantly higher in uninoculated than SB-inoculated plots (1344 lb/A higher). Interactions: No interactions between RWW damage and SB damage were detected. Thus, data suggest RWW damage does not predispose rice to greater SB damage. Rice stink bug (RSB), Oebalus pugnax was studied in a number of experiments. Treatment thresholds revised based on Espinos dissertation work. RSB did not cause significant yield loss or reduction in head rice. Adults and older instar nymphs cause peck. Hypothesis: as yield increases, peck decreases; peck is diluted in higher yielding fields. Most susceptible grain maturation stages are milk and soft dough. No significant difference in sampled populations between a.m. and p.m. Aquatic beetles  Tropisternus lateralis were also studied. Experiments conducted by Pearson for MS degree in Biology at Lamar University revealed Tropisternus lateralis (Hydrophilidae) can be a significant stand reducer. Objective 2: To determine the most effective control methods for rice pests while maintaining environmental quality compatible with the needs of society Arkansas Chemicals for Rice Water Weevil Control. The chemical Dermacor X-100 (rynaxypyr, Dupont) was tested as a seed treatment for control of rice water weevils. Experimental design was a randomized complete block with 4 replications. Each plot was surrounded by levees. The density of larvae and pupae was estimated in 12 cores per treatment at 3 and 4 weeks postflood. Dermacor at all rates and KarateZ gave excellent control. No significant differences were found between grain yields for any treatment. The chemicals dinotefuran 70SG and 1G and etofenprox 3G (Mitsui) were tested for control of rice water weevil. Experimental design was a randomized complete block with 4 replications. Each plot was surrounded by levees. The density of larvae and pupae was estimated in 12 cores per treatment at 3 and 4 weeks postflood. KarateZ gave better control than etofenprox (Trebon) when both were applied at 6 days after permanent flood. At the rate used of the two formulations and the three application times, dinotefuran did not give adequate control of rice water weevils. A combination of soil amendments from 3-Tier Technologies was tested for control of rice water weevils. The treatments were a soil fertilizer, Establish 5-16-12, plus a soil nutrient solution with mycorrhizal stimulants, Soil Restore, and either Huma Boost, humic acid and soil microbes, or Huma Cal Plus XL, humic acid with soil microbes and 5 new strains of Bt. Experimental design was a randomized complete block with 4 replications and each plot was surrounded by levees. The density of larvae and pupae was estimated in 12 cores per treatment at 3 weeks postflood. No significant control of rice water weevils was found with Huma Cal Plus XL. Chemical for Control of Billbug on Rice Levees and in Furrow-Irrigated Rice. Seed treatment with thiamethoxam (Cruiser) at 140 g ai/100 kg of seed for control of billbug larvae was tested in furrow-irrigated rice and in drill-seeded rice on the levees. A test plot of five acres was planted within a 91 acre grower field. The variety was XL 723. On July 27 the field had headed and the lower half of the panicle was in flower. Two sites inside the treated area and two sites in the adjacent untreated area were chosen at random for samples. Five rows on either side of my walkway were examined for the presence of whiteheads and dead plants (or tillers). The area sampled in each site was 0.1 acre. An average of 108 damaged plants were observed in the untreated and 86.5 damaged plants were found in the treated area. Cruiser did not give adequate control of billbug. Seed treatment with thiamethoxam (Cruiser) at 140 g ai/100 kg of seed for control of billbug larvae was tested in drill-seeded rice on the levees. The test consisted of seven pairs of levees with one treated and one untreated. The area of each levee averaged 0.3 acre. The sampling procedure consisted of examining a 10 ft. section along the top of the levee. Within this section of levee the number of plants (stem clusters) was recorded as well as whether the stem clusters were undamaged or damaged by feeding from billbug larvae. Both north and south side of each levee was examined. The sampled areas were 50 to 75 feet from the field edge. The number of stem clusters did not differ in the treated and untreated levees. Cruiser did not give adequate control of billbug. Chemicals for grape colaspis control Seed treatments of the chemicals Avicta (abamectin), Cruiser (thiamethoxan), 4 rate combinations of Avicta+Crusier, Dermacor X-100 (rynaxypyr, 4 rates), dinotefuran (4 rates, Mitsui) were planted in plots in a farmers field near the RREC. Arkansas where a grape colaspis test was last year. The test area was near the field edge and must have received a double rate of Command herbicide. At the two leaf stage, plants in all plots and border rows were completely white. A week later 75% of the plants were dead. The test was abandoned. Cultural Practice for Rice Water Weevil Management. Rice water weevil larval damage to root systems occurs only after rice is flooded. Thus, water management has always seemed a logical means to influence the level of infestation. Previous studies using a short extension (7 to 10 days) to drill-seeded rice with delayed flood had reduced larval infestation by about 50%. Another approach was suggested by observations of differences in flood depth between levees on the high end and low end of a paddy. The influence of flood depth on rice water weevil infestation and damage were tested in an experimental design was a randomized complete block with 4 replications. Each plot was surrounded by levees. Treatments were: 4" depth maintained all season (check); 2" depth maintained all season; initial flood of 2" depth maintained for 1, 2, 3 or 4 weeks then a 4" depth maintained for the remainder of the season. The density of larvae and pupae was estimated in 12 cores per treatment at 3 and 4 weeks postflood. Overall weevil infestation was low and no significant differences were found between treatments. However, there was a trend of progressively lower densities where the shallower flood was maintained for more weeks. No significant differences were found between grain yields for any treatment. Cultural Practice for Rice Insect Management, Rice Cultivars. In 2003 nine indica x indica rice lines were evaluated for susceptibility to three insect pests - rice water weevil, rice stalk borer, and rice stink bug (RTWG presentation in 2004). The lines were released by the USDA, ARS and the U of A (Rutger et al. 2005. Registration of nine indica germplasm lines. Crop Science 45:1170-1171). Compared to japonica checks the indicas were competitive in yield, similar in amylose, lodged more, not susceptible to kernel smut, had tolerance to rice water weevil, were resistance to rice stalk borer, but had moderate to high susceptibility to rice stink bug. In 2007, the nine indica lines were again evaluated for susceptibility to the same three rice pests. Experimental design was a split plot with 4 replications. The main plots were untreated and treated bays (Icon 0.05 lb ai/acre seed treatment) and the subplots were rice lines. Each bay had 12 rice plots 8 ft long by 5 ft wide (9 rows) and was surrounded by levees. As in 2003, plots were planted late in the season (June 12) to take advantage of normally high insect pressure. In 2003, rice water weevil densities were high and all japonica check lines but only indica lines 3 and 9 benefited from insecticide protection. All other 2003 and notable indica lines tolerated moderate to high densities of larvae. In 2007, larval densities were higher than differences in larval densities were found between the indica lines. Tolerances to weevils were found in nearly all the same lines, but unlike 2003 three additional lines had yield losses. If the data is examined closely, it will be noted that those three lines (indica 5, 6, and 7) had higher larval densities than those in 2003. In 2007 the incidence of rice stalk borer was very low. Only an occasional whitehead was found in test area. In 2003 high densities were present and none of the indica lines were found to highly or moderately susceptible, such as Cocodrie. Indica lines 3, 5 and 9 were rated as slightly susceptible as LaGrue and the remainder were rated as resistant as Wells (see next table). Rice stink bugs feed on rice kernels at every stage of development between fertilization through soft dough. Feeding probes either introduce fungi and bacteria or the pathogens enter through the breach in hulls. Pathogens cause the infected area to become discolored. This quality reduction is not desired by rice millers and heavily discolored rice is of less value. Unlike the japonica lines, the indica lines were all highly susceptible to damage from rice stink bugs. Diseases like kernel smut and false smut can also discolor the rice kernel. The kernel smut pathogen infests and consumes the kernel from inside the hulls, while the false smut pathogen consumes the kernel and swells causing a much larger ball of gold spores. Unlike the japonica cultivars, the indica lines were resistant to kernel smut. The japonica checks Wells and Jupiter and indica 1, 7, and 8 were moderately susceptible to false smut. California Rice Water Weevil: Studies were continued in 2007 in ring plots to evaluate experimental materials versus registered standards for RWW control and to modify the use patterns of the existing products to facilitate management. Twenty treatments (a total of eight different active ingredients) were established in ring plots to accomplish this research. Research continued on four experimental insecticide active ingredients; etofenprox (Trebon®), indoxacarb (Steward®), rynaxypyr, and clothianidan. In summary, etofenprox, indoxacarb, and clothianidan all appear to have significant potential for RWW management. All these products are a few years from any possible registration with their progress in this regard being approximately in the order listed above (from nearest to farthest from registration). Indoxacarb is active via a post-flood application whereas clothianidan has the most flexibility in terms of application timing. Given the re-evaluation of pyrethroid registrations due to possible off-site movement, it is important to continue to develop alternative active ingredients and classes of chemistry. These active ingredients have some very favorable properties in terms of toxicity to non-targets, persistence, etc. In these studies, Dimilin, Warrior (preflood and 3-leaf), Trebon (3-leaf), V10170 (preflood+3-leaf, preflood only, and 3-leaf only), Mustang Max, and Steward (0.11 rate) significantly reduced the RWW populations compared with the untreated plots. The best control was a 95% reduction in larval populations. The Trebon 3G preflood applications were not effective; it had shown some promise in testing in 2005 and 2006, but it appears that the 3-leaf stage application is going to be the preferred application method for this product. The Clorox seed soak (used for Bakanae control) greatly affected the activity of V10170 seed treatment; the soaked treatment was largely ineffective whereas without the Clorox soak the activity was good. This was not observed in studies in 2006. The E2Y45 (rynaxypyr) seed treatment was largely ineffective, although these seeds were similarly soaked in Clorox. This likely affected the activity. Only Warrior was evaluated, among the pyrethroids, as a preflood application in 2007. In summary, the early preflood application of Warrior (1 week before flooding) provided only about 50% control, whereas the preflood application immediately before flooding was equally effective as the 3-leaf stage application. We have generally had excellent results with an application made up to 7 days before flooding, but there have been some inconsistencies in control with this application at the longer intervals before flooding. Environmental conditions between application and flooding undoubtedly influence the residual control results. It appears that those undefined conditions reduced efficacy in 2007. Warrior was registered for use with this application method in 2007. Aza-Direct, a neem-based product containing azadirachtin, was evaluated and provided RWW control in the 50% range. The effects of insecticide treatments in rice on populations of non-target invertebrates and mosquitoes were studied. From 2006, a preflood Warrior application reduced populations of aquatic insects compared with the untreated for the first week after application but not thereafter. Seven treatments applied at the 3-leaf stage were compared and V10170 and Mustang reduced aquatic insect populations at 2 and 3 weeks after application; averaged over the 5-week period following application, all the treated plots had levels of aquatic insects equal to or greater than in the untreated. Warrior was evaluated as a representative material that could be applied against armyworms in July and this treatment was very damaging to populations of aquatic insects at 1 and 2 weeks after treatment. Mississippi Seed treatments that target RWW showed excellent efficacy compared to standard foliar treatments. Rice yields from plots treated with Trebon (etofenprox) to control RWW were higher than those plots untreated but not as high as those treated with Karate Z at standard rates. Texas RWW - Dermacor X-100 seed treatment gave excellent control. V10170 and Cruiser 5FS also gave excellent control (Table 2). RSB - Dinotefuran provided excellent knock-down and fair residual activity. This insecticide may have some repellant activity. TX will submit a Section 18 for this product in 2008. Stalk borers  Mexican rice borer (MRB), Eoreuma loftini and sugarcane borer (SCB), Diatrea saccharralis - Dermacor X-100 seed treatment at 0.1 mg ai/seed gave excellent control of MRB and SCB. Objective 3 : To conduct research direct toward maintaining the effectiveness of current pest-control techniques. California (Walton) The genetics of insecticide resistance in the mosquito CULEX QUINQUEFASCIATUS to toxins produced by BACILLUS THURINGIENSIS ISRAELENSIS was studied using Mendelian crosses. Resistance was generally polyfactorial, however Cry11Ba cross-resistance was monofactorial in the Cry11Aa resistant line, whereas Cry11Aa cross-resistance was monofactorial in the Cry4A+ Cry4B selected line. Dominance was generally intermediate to the susceptible and resistant parents and no sex-linkage or maternal effect was observed. Both colonies showed highly stable resistance in the absence of selection pressure, suggesting that the resistant alleles had reached fixation. Crosses between the two resistant colonies revealed strong allelism for resistance to the various Cry toxins and indicate that the colonies independently evolve resistance at the same loci. These studies are yielding important clues to the mechanism(s) of insecticide resistance and to the mode of action of B. THURINGIENSIS ISRAELENSIS toxins. Impacts: Arkansas Results from 2007 could be used by rice farmers to significantly improve rice water weevil management. A seed treatment with Dermacor X-100, should it become registered, would give an excellent chemical control option for rice water weevil and perhaps the grape colaspis. In addition, the cultural practice of keeping the permanent flood shallow for the first four weeks could also be of benefit and reduce rice water weevil infestation. An infusion of indica rice genes with tolerance to damage from weevils and resistance to the rice stalk borer could also benefit rice farmers. California Wildlife managers, the public and mosquito abatement agencies are all concerned with the efficacy and environmental impacts of chemicals used in mosquito control. Results showed no significant mortality of aquatic invertebrates and large-bodied terrestrial invertebrates exposed to sprays by truck or air. Some concerns remain for small-bodied insects but this is unsurprising because pyrethrin is known to be a general insecticide. This work has led to greater acceptance of synergized pyrethrin as an environmentally rational material that can be used for the control of mosquitoes when necessary to protect public health. Further work is needed to understand the relative efficacy of applying synergized pyrethrin by truck or air. The results of this study will also help to provide criteria for the management of pest and pathogen-transmitting mosquitoes that utilize rice fields and constructed treatment wetlands as developmental sites. Mosquito abatement and resistance management of mosquitoes to control agents must be included as part of any comprehensive plan for the design and operation of multipurpose constructed treatment wetlands, particularly where human residences are situated near wetlands. The work summarized here will assist a multiagency effort to develop criteria for the construction of large-scale wetlands systems that will be designed to conserve precious water resources, promote the biodiversity of endemic wetlands organisms, and protect the public from mosquitoes and the diseases that they cause. Mississippi Rice farmers and consultants used the data gathered to help increase yields and determine the best timing for RWW control. Seed treatments provided the rice consultant and grower with a possible new product if registered. Rice stink bug control with new foliar insecticides provided the grower with alternatives to help increase rice yields. Texas Seed treatment data will help expedite rice registration of Dermacor X-100. The new RSB treatment thresholds will reduce pesticide usage.

Publications: Arkansas Liu, G. J.L. Bernhardt, M.H. Jia, Y.A. Wamishe and Y. Jia. 2007. Molecular characterization of the recombinant inbred line population derived from a japonica-indica rice cross. Euphytica. 159:73-82. Singh, N., D.T. Johnson, R.J. Byrant, and J.L. Bernhardt. 2007. Volatiles induction in rice stink bug host-grasses and rice plants, pp. 178-183. In R.J. Norman, J.-F. Meullenet and K.A.K. Moldenhauer [eds.], B.R. Wells Rice Research Studies, 2006. Ark. Agric. Exp. Stn. Res. Series 550. University of Arkansas, Fayetteville. Moldenhauer, K.A.K., J.W. Gibbons, F.N. Lee, B. Scott, J.L. Bernhardt, C.E. Wilson, R.D. Cartwright, R.J. Norman, M.M. Blocker, S.E. Prislovsky, D.K. Ahrent, V.A. Boyett, and J.M. Bullock. 2007. CL171-AR, the first Arkansas Clearfield variety. B.R. Wells Rice Research Studies 2006:104-107. Abstracts. Bernhardt, J.L. 2007. Pecky rice - through the past darkly. Proceed. 31st Rice Tech. Working Group. p. 100. Bernhardt, J.L. 2007. Influence of age of rice when flooded on rice water weevil infestation and damage. Proc. 31st Rice Tech. Working Group. p. 111. Liu, G., Bernhardt, J.L., Jia, M.H., Wamishe ,Y.A., and Jia, Y. 2007. Molecular characterization of the recombinant inbred line population derived from a japonica-indica rice cross. Proc. 31st Rice Tech. Working Group. p. 59. Singh, N., Johnson, D.T., Byrant, R.J., and Bernhardt, J.L. 2007. Chemical ecology and population dynamics of the rice stink bug, Oebalus pugnax F., and natural enemies around rice plantings. Proc. 31st Rice Tech. Working Group. p. 110. Rutger, J.N., Bryant, R.J., Lee, F.N., Bernhardt, J.L., Gibbons, J.W., and W. Wan. 2007. The indica revolution I. Improving tropical germplasm for the United States. Proc. 31st Rice Tech. Working Group. p. 42. Wan, W., Bryant, R.J., Gibbons, J.W., Lee, F.N., Bernhardt, J.L., Rutger, J.N. 2007. The indica revolution II. Improving Chinese germplasm for the United States. Proc. 31st Rice Tech. Working Group. p. 42. Extension Publications. Wilson, C.E., K. Moldenhauer, J. Gibbons, R. Cartwright, F. Lee, R. Norman, J. Bernhardt, M. Blocker, J. Bulloch, D. Frizzell, R. Mazzanti, C. Parsons, S. Runsick, J. Yingling. 2007. Arkansas Rice Performance Trials, 2005-2007. Rice Information No. 166. University of Arkansas, Cooperative Extension Service. Little Rock. California Boyce, W. M., S. P. Lawler, J. M. Schultz, S. J. McCauley, L. S. Kimsey, M. K. Niemala, C.F. Nielson and W. K. Reisen. 2007. Non-target effects of the mosquito adulticide pyrethrin applied aerially during a West Nile Virus outbreak in an urban California environment. Journal of the American Mosquito Control Association 23: 335-339. Lawler, S. P., D. A. Dritz, C. S. Johnson and M. Wolder. In press. Does synergized pyrethrin applied over wetlands for mosquito control affect Daphnia magna zooplankton or Callibaetis californicus mayflies? Pest Management Science. Walton, W. E., M. C. Wirth and P. W. Workman. 2007. Environmental Factors Influencing Survival of Threespine Stickleback GASTEROSTEUS ACULEATUS in a Multipurpose Constructed Treatment Wetland in Southern California. Journal of Vector Ecology 32: 90-105. Walton, W. E. 2007. Larvivorous Fish Including GAMBUSIA. In: Biorational Control of Mosquitoes. (T. Floore, ed.) American Mosquito Control Association, Bull. No. 7, Mount Laurel, NJ. Journal of the American Mosquito Control Association 23 (2) Suppl.: 184-220. Van Dam, A. R. and W. E. Walton. 2007. Comparison of Mosquito Control Provided by the Arroyo Chub GILA ORCUTTI and the Mosquitofish GAMBUSIA AFFINIS. Journal of the American Mosquito Control Association 23: 430-441. Wirth, M. C., A. Zaritsky, E. Ben-Dov, R. Manasherob, V. Khasdan, S. Boussiba, and W. E. Walton. 2007. Cross-resistance Spectra of CULEX QUINQUEFASCIATUS Resistant to Mosquitocidal Toxins of BACILLUS THURINGIENSIS toward Recombinant ESCHERICHIA COLI Expressing Genes from B. THURINGIENSIS subsp. ISRAELENSIS. Environmental Microbiology 9: 1393-1401. Wirth, M. C., Y. Yang, W. E. Walton, B. A. Federici, and C. Berry. 2007. Mtx Toxins Synergize BACILLUS SPHAERICUS and Cry11Aa Against Susceptible and Insecticide-Resistant CULEX QUINQUEFASCIATUS. Applied and Environmental Microbiology: 73 (19): 6066-6071. Louisiana Stout, M.J. 2007 Types and mechanisms of rapidly-induced resistance to herbivorous arthropods. In Waters, D, A. Newton, and G. Lyon (eds.), Induced Resistance for Plant Defense: A Sustainable Approach to Crop Protection, pgs. 89-104. Thipyapong, P., M.J. Stout, and J. Attajarusit. 2007. Functional analysis of polyphenol oxidases by antisense/sense technology. Molecules 12: 1569-1595. Stout, M.J. and M. J. Frey. 2006. Rice insecticide trial: comparison of foliar and granular insecticides against the rice water weevil in a drill-seeded trial. Ann. Res. Rpt., Rice Res. Stn., LSU Agricultural Center 98: 348-349. Stout, M.J. and M. J. Frey. 2006. Rice insecticide trial: comparison of pyrethroids against the rice water weevil in a late-season, drill-seeded trial. Ann. Res. Rpt., Rice Res. Stn., LSU Agricultural Center 98: 350-351. Stout, M.J. and M. J. Frey. 2006. Rice insecticide trial 1: comparison of insecticidal seed treatments in a drill-seeded trial. Ann. Res. Rpt., Rice Res. Stn., LSU Agricultural Center 98: 352-353. Stout, M.J. and M. J. Frey. 2006. Rice insecticide trial 2: comparison of insecticidal seed treatments in a drill-seeded trial Ann. Res. Rpt., Rice Res. Stn., LSU Agricultural Center 98: 354-355. Smith, T.P., A.M. Hammond, M.J. Stout, and B.R. Leonard. 2007. Sugarcane beetle: a potential threat to Louisiana crops. Louisiana Agriculture 50: 27-28. Stout, M.J. 2007. Efforts to improve stink bug management continue. Louisiana Agriculture 50: 28 Texas Peer-reviewed: Espino, L. and M.O. Way. 2007. Relative susceptibility of stages of rice panicle development to male and female Oebalus pugnax. Southwestern Entomologist. 32(4):203-211. Espino, L., M.O. Way and L.T. Wilson. Determination of Oebalus pugnax (Hemiptera: Pentatomidae) spatial pattern in rice and development of visual sampling methods and population sampling plans. J. Econ. Entomol. (in press). Espino, Luis, M.O. Way and J.K. Olson. 2007. Most susceptible stage of rice panicle development to Oebalus pugnax (Hemiptera: Pentatomidae). J. Econ. Entomol. 100(4):1282-1290. Espino, L., M.O. Way and L.T. Wilson. Sequential sampling plans for sweep net and visual sampling of Oebalus pugnax in rice. Southwestern Entomologist. (in press). Jiang, Mingxing, M.O. Way, Wenjun Zhang and Jiam Cheng. 2007. Rice water weevil females of different elytral color morphs: comparison of locomotor activity, mating success and reproductive capacity. Environ. Entomol. 36(5):1040-1047. Reay-Jones, F.P.F., M.O. Way and L. Tarpley. 2007. Nitrogen fertilization at the rice panicle differentiation stage to compensate for rice water weevil (Coleoptera: Curculionidae) injury. Crop Protection 27:84-89. Reay-Jones, F.P.F., L.T. Wilson, A.T. Showler, T.E. Reagan and M.O.Way. 2007. Role of oviposition preference in an invasive crambid impacting two gramin aceous host crops. Environ. Entomol. (accepted). Reay-Jones, F.P.F., L.T. Wilson, M.O. Way, T.E. Reagan and C.E. Carlton. 2007. Movement of Mexican rice borer (Lepidoptera: Crambidae) through the Texas Rice Belt. J. Econ. Entomol. 100(1): 54-60. Reay-Jones, F.P.F., M.O. Way and T.E. Reagan. 2007. Economic assessment of controlling stem borers (Lepidoptera: Crambidae) with insecticides in Texas rice. Crop Protection. 26:963-970. Editor reviewed: Way, M.O. 2007. Weeds Are No. 1 Public Enemy. Specialist Speaking. Rice Farming. March. 40(4):18-19 (check on Jan., Feb. issues). Way, M.O. 2007. Scout for Insect Pests Early and Often. Specialists Speaking. Rice Farming. April. 41(5):18-19. Way, M.O. 2007. Progress Managing Stem Borers in Rice. Texas Rice. Vol. VII. No. 1 pp 3-5. Way, M.O. 2007. Cool, Wet Soils and Other Stand Reducers. Specialist Speaking. Rice Farming. May. 41(6):20-21. Jiang, M.X. and M.O. Way. 2007. Biology and Ecology of Rice Water Weevil in Southeastern Texas. Texas Rice. Vol. VII. No. 7. pp 3-4. Way, M.O. 2007. Scout Carefully for Insects and Disease. Specialist Speaking. Rice Farming. June. 41(7):18-19. Way, M.O. and Luis Espino. 2007. Entomology/Weed Management. Texas Rice. Vol. VII. No. 5 pp V-VII. Way, M.O. 2007. Seed Shortage and Weather Thwart Texas. Specialist Speaking. Rice Farming. December. 42(1):26-27.