Brief Summary of Minutes of Annual Meeting

Chair J. Bernhardt called the meeting to order at 8:00 a.m. Following a few comments from M. O. Way, local arrangement chair, and the collection of the registration fees, the participants introduced themselves including a guest at the meeting (Natalie Hummel, USDA-ARS, KBUSLIRL). This meeting coincided with the conclusion of the S-300 Cooperative Multi-State Project (Mosquito and Agricultural Pest Management in Riceland Ecosystems) which ended on 30 Sept. 2006 and the initiation of the new S-1029 Cooperative Multi-State Project (Improved Methods to Combat Mosquitoes and Crop Pests in Rice Fields) which started on 1 Oct. 2006. The project members acknowledged and thanked Sharon Lawler and M.O. Way for their dedication and excellent writing efforts in drafting the new project proposal and Dr. Crickenberger for his assistance in shepherding the proposal through the system. Cynthia Tribble was thanked for coordinating the outstanding local arrangements at this meeting. Selection of Officers: The second item of business was the selection of chairman for the next meeting. Larry Godfrey will assume the chair. 2008 Meeting Site: The group discussed a site for the 2008 meeting. The Rice Technical Working Group meeting, held biennially, will be in 18-21 Feb. 2008 in San Diego. It was decided to hold the S-1029 meeting in conjunction with and preceding that meeting. The exact date (Feb. 17 or 18) will be selected once the RTWG schedule is finalized. Roger Crickenberger commented on the review process for the new multi-state project; there are two independent reviews that may, as in our case, have differing suggestions and responses to the project proposal. This caused some additional consternation in finalizing our proposal but is the standard operating procedure and, overall, strengthens the project. The federal budget was discussed and, in particular, possible changes in Hatch funding. Earmark monies may flow through the Hatch funding, with corresponding requirements for multi-state and integrated uses of the additional funds through Hatch. Two new initiatives 1.) Biofuels and 2.) Specialty Crops are being proposed as high priority for the new Farm Bill. These comments prompted a spirited discussion on funding opportunities for rice pest/riceland mosquito research and the impact of biofuels on rice. Jeff Tomberlin introduced some new funding opportunities to the group and his innovative ideas contributed greatly to the discussion. Acreage reports were given from each state with the estimates for 2007 being declines in Texas and Arkansas (and possibly Louisiana depending on how quickly some lands can be brought back into production following the severe 2005 hurricane season), steady acreage in California and Mississippi and increasing rice acreage in Missouri. With the initiation of the 5-year S-1029 project, the history of this rice/mosquito project was discussed. The consensus was that the efforts had been continuing for 30 years, which may be the longest running regional project. J. K. Olson agreed to research and to write the history of the project. Following our advisors comments and the discussion, participants presented state reports. Arkansas, Max Meisch: (a) The efficacy of ground ULV applications of Duet (5% sumithrin, 1% prallethrin plus 5% PBO) were compared with Anvil (10% sumithrin plus 10% PBO) against adult Anopheles quadrimaculatus. Duet is supposed to stimulate excitation in mosquitoes, and the excitation may improve efficacy. Observations did not provide conclusive evidence that excitation occurred. Further study under controlled conditions is required to document not only excitation but also susceptibility levels to the two insecticides. (b) Four larvicides were assessed against Psorophora columbiae larvae in small rice plots. Two experimental compounds were tested at two rates each and compared to two standard larvicides. All formulations were very effective. (c) Two similar field studies were conducted in which bifenthrin was used as a barrier spray. Twenty-eight potted wax myrtle plants were arranged in a square and sprayed. A mosquito trap was placed in the center of each plot. Captured mosquitoes along with foliage samples were used as tarsal contact bioassay and residue determinants were utilized to assess efficacy. Arkansas, John Bernhardt: (a) Avicta+Crusier (abamectin+thiamethoxam) seed treatments and two formulations of lambda cyhalothrin were tested for control of rice water weevils. The higher rates of Avicta and Cruiser gave good control, the CS formulation of lambda cyhalothrin performed well. No significant differences were found between grain yields for any treatment. (b) The seed treatments, Avicta, Cruiser, Avicta+Crusier, KarateZ, V-10170, and V-10194, foliar treatment Mustang Max were compared in 80 plots at an experiment station in Lonoke, Arkansas where grape colaspis had been a pest previously. At the two leaf stage, plots were examined for the presence and damage by grape colaspis; no damage was found in any plot. California, Sharon Lawler: (a) A 3rd year of fieldwork was completed on the effects of ultra-low volume applications of synergized pyrethrin for mosquito control on invertebrates of wetlands adjacent to rice fields. The Colusa Mosquito Abatement District applied pyrethrin with piperonyl butoxide over wetlands 2X per week in Sept. - Oct. 2006. On the 5th and 10th spray nights, two cages of 10 Baetidae mayflies and two cages of 20-25 Daphnia magna were placed in mesocosms and adult mosquitoes were caged over the mesocosms. Despite effective control of mosquitoes, survival of non-targets was excellent. This indicates low deposition of the insecticide into the wetland. (b) The effects of vegetation control on mosquito populations in seasonal wetlands were studied; the wetlands produce the same mosquito species as nearby ricelands. Large-scale vegetation control was found to be effective in reducing mosquito populations. (c) A project assessing non-target effects of pyrethrin on terrestrial invertebrates was conducted. California, Larry Godfrey: (a) Indoxacarb applied post-flood, V-17170 with application flexibility of seed treatment, pre-flood application, and 3-leaf stage application, and etofenprox applied post-flood all showed potential for rice water weevil control. Results with preflood application of etofenprox were excellent in 2006, which was in contrast with previous results. (b) Two additional active ingredients, DPX-E2Y45 and V10194, showed good performance but somewhat less than the previously mentioned products. (c) Work on a biological insecticide, azadirachtin, was de-emphasized in 2006 with only one greenhouse tested conducted. This greenhouse study was intended to provide some explanation of the poor field results obtained in 2005. The foliar application was more effective against rice water weevil than the preflood application, a liquid formulation was more effective than a granular product, and the 0.01 lb. AI rate of the liquid was highly effective with about 4 times more of the granular formulation needed to reach comparable levels of control. (d) California Dept. of Pesticide Regulation is currently placing pyrethroid insecticides into re-evaluation based on their propensity to accumulate and move off-site on organic sediment. (e) Studies were conducted to evaluate the effects of insecticide treatments in rice on populations of invertebrate non-targets. Preflood applications of Warrior had minimal effects on the number of aquatic insects and the number of invertebrates. For the post-flood applications, the first two weeks after application, there were some slight to moderate effects of the treatments on populations of aquatic insects. Reductions were most severe with dinotefuron and Mustang Max; intermediate with indoxacarb, etofenprox, and Warrior on aquatic insects; Dimilin and azadirachtin had no effects in aquatic insect populations. Levels of other aquatic invertebrates were even less severely affected by the treatments. Warrior was evaluated as a mid-July application against armyworms. Numbers of aquatic insects were reduced by ~70% by the Warrior application at 1 week after treatment but no effects were seen thereafter. (f) There were significantly more rice water weevil larvae in L-206 than in M-205, M-206, M-104, a PI line under development, and S-102. (g) Refined rice seedling establishment techniques are being investigated primarily as a means to improve weed management through stale seedbed and dry seeding techniques. The stale seedbed water-seeded treatments had 1.4 to 2 times more scarring than the conventional water-seeded treatment. Conversely, the larval populations were higher in the drill-seeded than the water-seeded treatments. (h) True armyworm moth flights peaked in early-July. Western yellow-striped armyworm flight was overall low in 2006. The early-July moth peak corresponded to a mid-July peak of larvae found in the rice field searches. Louisiana, Wayne Kramer: (a) Work was initiated on aspects of West Nile virus ecology specifically mosquito host preference studies. The goal is to determine if Culex quinquefasciatus females demonstrate a shift in host feeding preference from birds early in the season to mammals later in the season. (b) Information on mosquito populations and viral activity in mosquitoes and birds is being collected as well as host availability (bird abundance) data at local study sites. (c) Studies addressing the issue of WNV overwintering and viral maintenance from year to year are underway; vertical transmission of West Nile virus does occur in Louisiana. (d) A BTI formulation was evaluated at three rates against Culex mosquitoes. Inadequate levels of control (< 80%) were observed but may be explained by the high organic matter in the test tubs. (e) Diflubenzuron was evaluated at 250 ppb and 1 ppm as a mosquito larvicide. Both rates yielded 100% control at 10 days against Cx. quinquefasciatus and Cx. coronator larvae naturally colonizing these tubs. By 28 days post treatment water from the high rate tubs still killed 60% of larvae in the lab while the low rate showed no activity. Louisiana, Mike Stout: (a) Rice was found to be susceptible to infestation by sugarcane borer females from the mid-tillering stage to the heading stage in a no-choice test. When females were given a choice of crop stage, the preference was for egg laying at the boot and heading stages compared with the panicle initiation and mid-tillering stages of rice. (b) Preliminary data indicate that sugarcane borer larvae enter rice stems within five to nine days of eclosion. (c) Female Culex quinquefasciatus were found to lay more egg rafts in water that had been previously exposed to various species of aquatic insects (species in the families Notonectidae, Dytiscidae, Belostomatidae, and Hydrophilidae) than in water that had not been previously exposed. These results suggest that some aquatic insects release substances into water that encourage oviposition by mosquitoes. (d) Louisiana submitted a Section 18 to the EPA for use of granular formulations of carbofuran and etofenprox for control of rice water weevil. (e) Rice water weevil control studies indicated that several seed treatments gave good to excellent control in drill-seeded rice tests and a numbered compound as a seed treatment also performed well in a water-seeded test. Split applications of dinotefuran provided excellent control as well as a single application of dinotefuran at 21 days post-flooding. Lambda cyhalothrin and zeta cypermethrin impregnated on fertilizer applied preflood gave only adequate control and a late season application of the same insecticides failed to control weevils. In three 3 large plot sites, etofenprox gave 31 to 43% larval control. (f) The relationship between densities of adult rice water weevil and densities of larvae was evaluated in the greenhouse. (g) Control of Culex quinquefasciatus larvae was better with lambda cyhalothrin than with WS-BTI or BTI (Aquabac7) and adult C. quinquefasciatus placed on leaves from lambda cyhalothrin treated plots had higher mortality than adults on leaves from untreated plants. (g) Several breeding lines of rice were found to have greater resistance/tolerance to rice water weevil than others in laboratory and field tests. Mississippi, Jim Robbins: (a) Seed treatments of thiamethoxam and applications of granular etofenprox insecticide resulted in rice yield increases and control of rice water weevil from research plots. (b) Foliar pyrethroid insecticides provided good control of rice stinkbug but with shorter residual control than in past years. (c) Mosquito populations and species were surveyed in several areas. Texas, J. Olson: (a) Studies on insecticide susceptibility were continued on Culex quinquefasciatus female adults in the rice-producing region of southeastern Texas. Insecticide resistance management strategies were recommended for implementation against the malathion-tolerant mosquito populations. Populations of Cx. quinquefasciatus in Orange Co., TX, continued to be susceptible to all commonly used mosquito adulticides throughout the reporting period. Several populations of this species in Harris Co. demonstrated elevated tolerances to the pyrethroids, resmethrin and sumethrin, especially in the central Houston area. A greater susceptibility of these same populations to malathion than was anticipated was detected. Insecticide resistance assessments were conducted on Cx. quinquefasciatus adult populations representing seven different areas in Brazos County, TX. All populations tested demonstrated high levels of susceptibility to all adulticidal chemicals tested against them (4 pyrethroids, 2 organophosphates). (b) A public survey was conducted in select neighborhoods of Bryan and Houston, TX, to assess what citizens are doing to protect themselves from mosquitoes and West Nile virus (WNv) infections and to assess the effectiveness of public information programs designed to inform people as to how to protect themselves from such public health problems. (c) The distribution patterns of the Anopheles quadrimaculatus species complex was studied. An. quadrimaculatus was the most widely distributed species, while An. smaragdinus was confined primarily to wooded wetland areas of east and southeast Texas. (d) Populations of Aedes aegypti and Ae. albopictus eggs continue to be analyzed for inferences as to why Ae. albopictus is able to replace Ae. aegypti in certain regions of the state. Texas, M. Way: (a) A regional Section 18 for acephate in rice for rice stinkbug control was submitted to the EPA but this was not approved. (b) Rice water weevil populations were lower in a stale seedbed than conventional tillage seedbed; Karate Z and Icon 6.2FS gave good control regardless of type of seedbed. (c) A new sampling method for rice stinkbug was developed for and delivered to clientele. Two sweeps of a sweep stick can suffice for 10 sweeps of a sweep net. Sequential sampling plans were developed for both sweep net and sweep stick-sampling methods. (d) Preliminary economic injury levels for stalk borers were developed. (e) The Mexican rice borer has been detected in all counties of the Texas Rice Belt except for Orange Co., which borders Louisiana. (f) Three different seed treatments targeting rice water weevil performed well compared to previous Icon 6.2FS data. (g) V-10170 and Venom 70SG were evaluated for residual activity against rice stink bug and gave similar results relative to Orthene 97SG at 6 days after treatment. (h) Two applications of either Mustang Max or Karate Z at 1-2 inch panicle and late boot/early heading gave excellent control of stalk borers. One application of rynaxypyr at late boot/early heading gave good control of stalk borers. The meeting was adjourned near 4:30 pm on February 18, 2007. Respectfully submitted by S-300 2007 Secretary, Larry Godfrey.