Source: UNIVERSITY OF ARKANSAS submitted to
BIOLOGY AND MANAGEMENT OF INSECT PESTS OF RICE
Sponsoring Institution
National Institute of Food and Agriculture
Project Status
TERMINATED
Funding Source
Reporting Frequency
Annual
Accession No.
0172433
Grant No.
(N/A)
Project No.
ARK01672
Proposal No.
(N/A)
Multistate No.
(N/A)
Program Code
(N/A)
Project Start Date
Oct 1, 2002
Project End Date
Sep 30, 2008
Grant Year
(N/A)
Project Director
Bernhardt, J. L.
Recipient Organization
UNIVERSITY OF ARKANSAS
(N/A)
FAYETTEVILLE,AR 72703
Performing Department
ENTOMOLOGY
Non Technical Summary
Rice production in the U.S. can be affected by factors that reduce productivity. One factor is insect pests such as the rice water weevil, rice stink bug, grape colaspis, and rice stalk borer. Insect pests contribute to revenue losses directly by grain loss and/or quality, or indirectly by reducing stand density and/or by delayed maturity. Knowledge of pest ecology, sampling, damage, and control by cultural practices and chemicals are essential to rice production.
Animal Health Component
70%
Research Effort Categories
Basic
20%
Applied
70%
Developmental
10%
Classification

Knowledge Area (KA)Subject of Investigation (SOI)Field of Science (FOS)Percent
21115301130100%
Goals / Objectives
1) Evaluate the efficacy of new and registered insecticides. 2) Evaluate rice breeding lines for susceptibility to insect pests. 3) Evaluate the impact of cultural practices on pest levels. 4) Identify key insect-plant and insect-insect relationships. 5) Evaluate sampling techniques and treatment thresholds.
Project Methods
Efficacy, best rate, and timing of application for new and registered insecticides will be established. Advanced rice lines from the Arkansas breeding program and Uniform Regional Rice Nursery will be screened for susceptibility to rice stink bug, rice water weevil, and rice stalk borer. The effects of cultural practices such as delayed flood, nitrogen management, planting date, seeding depth, and conservation tillage on rice water weevil infestation and damage will be assessed. The influence of grass weed hosts on timing of infestations and amount of damage by rice stink bug will be studied. The impact of insecticides on Telenomus podisi (rice stink bug egg parasite) survival and levels of parasitism will be monitored. Treatment thresholds for the rice weevil adults based on sampling with the aquatic barrier trap will be established. Volatiles from heading rice and weed hosts will be collected and assessed for attractiveness to rice stink bugs. Damage by rice stink bug and rice water weevil will be more clearly defined.

Progress 10/01/02 to 09/30/08

Outputs
OUTPUTS: The goal of this project was to provide rice growers with management options for control of rice insect pests. Results from numerous efficacy testing studies have provided data for the registration of three insecticides for rice water weevil control and the possible registration of three more for weevils and two for rice stink bug control. In addition, a new trap was designed, tested, and verified as a means to monitor rice water weevil adults and can be used to time postflood insecticides application more efficiently. Cultural management options were added to recommendations for weevil management. The options are delaying flood by one week and using shallow flood water for 3 or 4 weeks after permanent flood. Both cultural options would use less water for rice production. All of these options were communicated to extension personnel and were communicated to stakeholders by way of meetings, freely disseminated publications, and web sites. A third option was presented to rice breeders that may aid in the production of resistant cultivars. Host plant resistance for multiple pests was identified when indica germplasm lines were found to have valuable attributes that would add sources of tolerance to rice water weevil, and resistance to rice stalk borer and kernel smut. In addition, results from studies provided identification of volatiles release from rice and other grasses when fed upon by rice stink bugs. Many volatiles are known as attractants for insects to select host plants but by the release of amounts in excess of normal amounts could be a plant defense mechanism to reduce herbivory. This information does not impact growers directly until plant breeders successfully use the information for the production of resistant varieties. PARTICIPANTS: J.L. Bernhardt, University of Arkansas TARGET AUDIENCES: Nothing significant to report during this reporting period. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

Impacts
Insecticide applied as a seed treatment provides an alternative to foliar applications and reduces concerns about effects on non target organisms and drift issues. The insecticide rynaxypyr and thiamethoxam were tested as seed treatments for control of rice water weevil and gave excellent control similar to that of lambda cyhalothrin. Cultural practices can be an economic alternative to reduce pests without use of insecticides. In a second year of testing, the cultural practice of keeping the permanent flood at a shallow for 3 to 4 weeks after onset of flood reduced rice water weevil infestation by 29 percent. Holding a shallow flood for the short specified length did not exacerbate rice blast disease as would susceptible cultivars with season long shallow flood. The insecticides dinotefuran and clothiandin gave excellent knock-down control of rice stink bugs and 7 to 10 days of residual control. What is lacking in currently registered insecticides for rice stink bug is the lack of residual control. The two insecticides, if registered, would be welcomed by rice growers.

Publications

  • Bernhardt, J.L. 2008. Influence of Flood Depth on Rice Water Weevil Infestation and Damage, Pages 99-102. In B.R.Wells Rice Research Studies 2007. Ark. Agric. Exp. Stn. Res. Series 560.
  • Gibbons, J.W. K.A.K. Moldenhauer, F.N. Lee, J.L. Bernhardt, M.M. Anders, N.A. Slaton, R.J. Norman, J.M. Bullock, E. Castaneda, and A.M. Stivers. 2008. Development of Semidwarf Long- and Medium-Grain Cultivars, Pages 44-49. In B.R.Wells Rice Research Studies 2007 Ark. Agric. Exp. Stn. Res. Series 560.
  • Moldenhauer, K.A.K., J.W. Gibbons, F.N. Lee, J.L. Bernhardt, M.M. Anders, C.E. Wilson, Jr., R.D. Cartwright, R.J. Norman, R. Byrant, M.M. Blocker, D.K. Ahrent, V.A. Boyett, S.E. Prislovsky, J.M. Bullock, and E. Castaneda. 2008. Breeding and Evaluation for Improved Rice Varieties. The Arkansas Rice Breeding and Development Program, Pages 50-56. In B.R.Wells Rice Research Studies 2007 Ark. Agric. Exp. Stn. Res. Series 560.


Progress 01/01/07 to 12/31/07

Outputs
Given demonstrated control of rice water weevil and possibly other pests, a section 18 request was submitted to the EPA for use of rynaxypyr as an economically and environmentally better choice for rice water weevil control than aerial, foliar application. The results of a field test using a cultural practice to reduce damage from rice water weevils by using a shallow permanent flood for only 3 to 4 weeks after onset was described in a university rice publication that is freely disseminated to farmers. Rice breeders were encouraged to include indica germplasm lines in conventional breeding programs because of valuable attributes that would add sources of tolerance to rice water weevil, and resistance to rice stalk borer and kernel smut to new rice cultivars.

Impacts
An insecticide applied as a seed treatment provides an alternative to foliar applications and reduces concerns about effects on non target organisms and drift issues. The insecticide rynaxypyr was tested as a seed treatment for control of rice water weevil and at all rates gave excellent control similar to that of lambda cyhalothrin. Cultural practices can be an economic alternative to reduce pests without use of insecticides. A cultural practice of keeping the permanent flood at a shallow 2 inch depth for 3 to 4 weeks after onset of flood reduced rice water weevil infestation by 33 percent. Holding a shallow flood for the short specified length did not influence grain yield and did not exacerbate rice blast disease as would a season long shallow flood. In a third approach to rice water weevil management, indica germplasm lines were tested for desirable attributes. Compared to japonica checks the indicas were competitive in yield, possessed a desired grain amylose content, and lodged more; but were not as susceptible to kernel smut, had tolerance to moderate rice water weevil infestation, were resistance to rice stalk borer, had moderate to high susceptibility to rice stink bug, and were only slightly susceptible to false smut.

Publications

  • 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. [abstract]
  • 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. [abstract]
  • 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. [abstract]
  • 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 to183. 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.
  • Rutger, J.N., R.J. Bryant, J.L. Bernhardt, and J.W. Gibbons. 2005. Registration of nine indica germplasms of rice. Crop Science. 45:1170-1171.


Progress 01/01/06 to 12/31/06

Outputs
Two new formulations of lambda cyhalothrin that were applied at 0.33 kg AI/ha gave control of rice water weevils comparable to that of KarateZ at the same rate. Seed treatment with thiamethoxam at 80 g AI/kg of seed plus abamectin at 50 g AI/kg of seed gave 95% control of rice water weevils and the two insecticides at 40 and 25 g AI/kg, respectively, gave 90% control; both seed treatments were not significantly different than lambda cyhalothrin at 0.33 kg AI/ha. Compounds released into the air from different rice stink bug host grasses and rice varieties were captured and identified. Limonene and methyl salicylate were found to be emitted from panicles of all host grasses sampled. Limonene was induced to be released at a higher level when hosts were fed upon by rice stink bugs. Limonene was produced in higher amounts in Kaybonnet rice variety than in the Bengal and Cocodrie rice varieties. Kaybonnet is known to be less susceptible to rice stink bug damage than Bengal and Cocodrie. These findings suggest that limonene may be involved in the chemical defense of rice from rice stink bug.

Impacts
Results from this project will continue to provide viable chemical, biological, or cultural options for growers to manage rice insect pests. Rice stink bug feeding was found to increase release of volatiles from rice and other grasses. Volatiles are known as attractants for insects to select host plants but by the release of amounts in excess of normal amounts the volatiles could be a plant defense mechanism to reduce herbivory. This knowledge may be used to aid plant breeders in the production of resistant varieties.

Publications

  • Bernhardt, J.L. 2006. Influence of age of rice when flooded on rice water weevil infestation and damage, pp. 168-172. In B.R.Wells Rice Research Studies, 2005. Ark. Agric. Exp. Stn. Res. Series 540.
  • Singh, N., D.T. Johnson, R.J. Bryant, and J.L. Bernhardt. 2006. Chemical ecology and population dynamics of rice stink bug, Oebalus puganx F., and natural enemies around rice plantings, pp. 173-180. In B.R.Wells Rice Research Studies, 2005. Ark. Agric. Exp. Stn. Res. Series 540.


Progress 01/01/05 to 12/31/05

Outputs
Acephate at 0.56 kg AI/ha gave better and longer control of rice stink bug adults than did methyl parathion at the same rate. Residual activity of above 90% control was found for 5 days after application of acephate whereas no residual activity was measured for methyl parathion. Clothianidin at 29.6 ml of formulated product per 112 kg of seed/ha gave excellent control of grape colaspis larvae. A 2-fold rate of clothianidin was needed for acceptable rice water weevil control. A cultural practice of a 10 day extended delay beyond the normal 30 day delay of permanent flood in dry seeded rice reduced the infestation of rice water weevil larvae by an average of 36% compared to the number of larvae in the normal delay treatment. Flooding rice 10 days earlier than the normal delay had an average of a 250% increase in the number of larvae compared to the normal delay treatment. Tests to screen advanced rice lines for susceptibility to kernels discolored by rice stink bugs were continued. Rice stink bug feeding for 3 days on rice and vassey grass panicles induced a 4-fold more release of limonene, methyl salicylate and caryophyllene, than did panicles of other host grasses, rice and vasey grass panicles fed on for 5 days or not fed on controls. Significantly more limonene was induced than methyl salicylate or caryophyllene. No difference was found in rice stink bug counts from traps unbaited or baited with limonene, methyl salicylate or both. Some dates had higher counts of meloid beetles in methyl salicylate baited traps. Rice fields adjacent to more diverse habitat and ground cover vegetation had higher counts of coccinellids, chrysomelids, meloids and pompilids than those with less diversity. Rice fields surrounded by host grasses had higher rice stink bug counts in traps and grass sweeps than did rice sites bordered by broadleaf plants and/or non host grasses.

Impacts
Results from this project will continue to provide viable chemical, biological, or cultural options for growers to manage rice insect pests. Knowledge of movements of rice stink bugs in and out of rice fields might help in improve management options. Rice stink bug feeding was found to increase release of volatiles from rice and other host grasses. The volatiles might provide a method to monitor adults and could provide chemical cues to assist rice stink bug natural enemies in locating rice stink bugs. Growers may suppress rice stink bugs by having less rice stink bug host grasses in rice field margins.

Publications

  • Rashid, T., D.T. Johnson and J.L. Bernhardt. 2005. Rice stink bug development relative to temperature. Southwestern Entomol. 30:215-221.
  • Rashid, T., D.T. Johnson and J.L. Bernhardt. 2005. Feeding preference, fecundity and egg hatch of rice stink bug on artificial diet, rice and alternate host grasses. Southwestern Entomol. 30:257-226.
  • Rutger, J.N., R.J. Byrant, J.L. Bernhardt and J.W. Gibbons. 2005. Registration of nine indica germplasms of rice. Crop Sci. 45:1170-1171.
  • Bernhardt, J.L., K.A. Moldenhauer and J.W. Gibbons. 2005. Screening lines for susceptibility to rice stink bug: Results from the Arkansas Rice Performance Tests, pp. 159-166. In B.R.Wells Rice Research Studies, 2004. Ark. Agric. Exp. Stn. Res. Series 529.


Progress 01/01/04 to 12/30/04

Outputs
Gamma cyhalothrin at 0.017 kg AI/ha gave control of rice water weevil adults statistically comparable to lamba cyhalothrin at 0.034 kg AI/ha and zeta cypermethrin at 0.02 kg AI/ha. Again in 2004, a rice water weevil management system based on monitoring adults with aquatic barrier traps was tested with Cooperative Extension Service agents in ten counties. A problem was encountered with fields treated with phosphorus fertilizer just prior to flood when algae (scum) interfered with rice water weevil movement and trap performance. Otherwise, the predicted levels of larvae when compared to the actual levels were such that no estimate was obviously incorrect. In fields without the scum problem, no field that should have been treated was missed. The testing program with aquatic barrier traps will be given to extension personnel and continued. Field studies to establish treatment thresholds for rice water weevils on new rice cultivars Francis, Cybonnet, MedArk and Banks were continued. Tests to screen advanced rice lines for susceptibility to discolored kernels caused by rice stink bug and fungal diseases were continued. Sweep net sampling captured more rice stink bug at 9am and 7pm than at 2 pm. Yellow pyramid traps and sweep net sampling in grass captured more rice stink bugs in field margins before and after rice heading than during rice heading. Trap catches increased to 20 bugs per trap in late September and then dropped to less than 1 bug per trap after 3 October. Headspace volatiles from the hosts barnyardgrass, bearded sprangletop and R5 stage rice panicles fed upon by 16 rice stink bugs for 2 days emitted elevated amounts of limonene and a small amount of methyl salicylate. Amazon sprangletop grass, a non-host for rice stink bug, emitted more limonene than rice and the above grass hosts plus caryophyllene.

Impacts
Results from this project will continue to provide viable chemical, biological, or cultural options for growers to manage rice insect pests. The development, testing, and release of a management system based on monitoring adults will provide better timed and more efficacious application of adulticides to prevent excessive losses to rice yield from rice water weevils and rice stink bugs.

Publications

  • Bernhardt, J. L. 2004. Aspects of the Ecology of the Rice Stalk Borer in Arkansas. Pages 165-174. In B.R. Wells Rice Research Studies, 2003. Ark. Agric. Exp. Stn. Res. Series 517.
  • Bernhardt, J. L. and T.L. Richards. 2004. Verification of a Monitoring Program for Rice Water Weevil. Pages 175-181. In B.R. Wells Rice Research Studies, 2003, Ark. Agric. Exp. Stn. Res. Series 517.
  • Gibbons, J.W., et al. 2004. Development of Semi-Dwarf Long- and Medium-Grain Cultivars. Pages 43-48. In B.R. Wells Rice Research Studies 2002, Ark. Agric. Exp. Stn. Res. Series 517.
  • K.A.K. Moldenhauer, et al. 2004. Banks, A High-Yielding Blast-Resistant Long-Grain Rice Variety. Pages 73-77. In B.R. Wells Rice Research Studies 2002, Ark. Agric. Exp. Stn. Res. Series 517.


Progress 01/01/03 to 12/31/03

Outputs
Gamma cyhalothrin at 0.017 kg AI/ha gave control of rice water weevil adults statistically comparable to lamba cyhalothrin at 0.034 kg AI/ha, zeta cypermethrin at 0.02 kg AI/ha, and a seed treatment of fipronil at 0.042 kg AI/ha. A rice water weevil management system based on monitoring adults with aquatic barrier traps was tested with Cooperative Extension Service agents in nine counties. The peak trap catch ranged from 2 to 4 days after traps were placed in a field. This gave data on densities that was well within the 10-day window needed for a decision to treat with adulticides. Also, soil-core samples were used to estimate the density of rice water weevil immatures and to verify predictions based on numbers of adults captured in the aquatic barrier traps. The predicted levels when compared to the actual levels were such that no estimate was obviously incorrect. No field that should have been treated was missed. The education/ testing program with aquatic barrier traps will be continued next year. Field studies to establish treatment thresholds for rice water weevils on new rice cultivars Francis and Ahrent were continued.

Impacts
Results from this project will continue to provide viable chemical, biological, or cultural options for growers to manage rice insect pests. The development, testing, and release of a management system based on monitoring adults will provide better timed and more efficacious application of adulticides to prevent excessive losses to rice yield from rice water weevils.

Publications

  • Hix, R., Johnson, D. T., and Bernhardt, J. L. 2003. Antennal sensory structures of Lissorhoptrus oryzophilus (Coleoptera:Curculionidae) with notes on aquatic adaptations. Coleopterists Bull. 57(1): 85-94.
  • Dennett, James A., Bernhardt, J. L., and Meisch, M. V. 2003. Effects of fipronil and lambda - cyhalothrim against Anopheles quadrimaculatus (Diptera: Culicidae) larvae and non-target aquatic mosquito predators in Arkansas small riceplots. Journal of American Mosquito Control ASSN. 19 (1) 23:25.
  • Bernhardt, J. L. and Richards, T. L. 2003. Screening rice lines for susceptibility to rice water weevil. Pages 185-190. In B.R. Wells Rice Research Studies, 2002. Ark. Agric. Exp. Stn. Res. Series 504.
  • Bernhardt, J. L., Moldenhauer, K. A. K. and Gibbons J. W. 2003. Screening rice lines for susceptibility to rice stink bug: Results from the Arkansas Rice Performance Tests. Pages 177-184. In B.R. Wells Rice Research Studies, 2002, Ark. Agric. Exp. Stn. Res. Series 504.
  • Rashid, T., Johnson, D. T., and Bernhardt, J. L. 2003. Feeding preference, fecundity, and egg hatch of rice stink bug, Oebalus pugnax (F.) (Hemiptera: Pentatomidae) on artificial diet, rice, and alternate host grasses. Pages 191-199. In B.R. Wells Rice Research Studies 2002, Ark. Agric. Exp. Stn. Res. Series 504.


Progress 01/01/02 to 12/31/02

Outputs
Lower rates of a seed treatment with thiamethoxam of 0.17 kg AI/ha did not give control of rice water weevil larvae statistically comparable to a seed treatment of 0.022 kg AI/ha of fipronil. A new formulation of zeta cypermethrin (Mustang Max) at a low rate 0.02 kg AI/ha gave control of rice water weevil adults statistically comparable to lambda cyhalothrin at 0.034 kg AI/ha. Residual activity of treatment with lambda cyhalothrin at 0.034kg AI/ha at 14, 10, 6, 2, and 1 days before permanent flood gave 43, 53, 57, 61 and 59% control of rice water weevils, respectively, when compared to an untreated check. Large field tests with fipronil seed treatment verified excellent control of grape colaspis with the lowest labeled rate, 0.022 kg AI/ha. A rice water weevil management system based on monitoring adults with aquatic barrier traps was tested with Cooperative Extension Service agents in two counties. The education/testing program will be expanded to include more agents in 2003. The new rice varieties Ahrent and Francis were compared to Bengal and Cocodrie in planting-date studies on field tolerance to infestation and damage by rice water weevils and other insects. Ahrent and Francis had larval infestations similar to those in Cocodrie but both had slightly less yield loss. Bengal had higher levels of infestation than the other varieties but no yield loss at any level of infestation. Bengal had the lowest number of whiteheads due to damage by rice stalk borers. Ahrent, Francis and Cocodrie had 5 to 7 times the number of whiteheads that were found in Bengal.

Impacts
Results from this project will continue to provide viable chemical, biological, or cultural options for growers to manage rice insect pests. The development, testing, and release of a management system based on monitoring adults will provide better timed and more efficacious application of adulticides to prevent excessive losses to rice yield from rice water weevils.

Publications

  • Bernhardt, J.L. and D.T. Johnson. 2002. Verification of a monitoring program for rice water weevil adults. Pp. 117-122. Ark. Agric. Exp. Stn. Res. Series 495.
  • Bernhardt, J.L., K.A.K. Moldenhauer, and J.W. Gibbons. 2002. Screening lines for susceptibility to rice stink bug: Results from the Arkansas rice performance tests. Pp. 123-132. Ark. Agric. Exp. Stn. Res. Series 495.
  • Rashid, T., D.T. Johnson, and J.L. Bernhardt. 2002. Comparison of different sampling techniques for Oebalus pugnax (F.) in rice. Pp. 133-137. Ark. Agric. Exp. Stn. Res. Series 495.


Progress 01/01/01 to 12/31/01

Outputs
Numbered chemicals were applied post-flood to assess control of rice water weevil (RWW) adults. When compared to the untreated, V10101 (Valent Corp) at 0.1, 0.16, and 0.2 kg AI/ha each had less than 40% control, the pyrethroid F0570 (FMC Corp.) at 0.019 and 0.024 kg AI/ha had 99% control, and the pyrethroid standard, lambda cyhalothrin (Syngenta), had 99% control. A seed treatment of thiamethoxam (Syngenta) at 200 but not at 100g AI/100 kg seed gave control of RWW larvae comparable to the standard seed treatment of ICON (fipronil, Aventis). F0570 at the above rates, lambda cyhalothrin (0.03 and 0.04 kg AI/ha), and methyl parathion (0.56 kg AI/ha) had comparable initial mortalities of rice stink bug adults. The latter two had little to no residual activity 12 to 24 hrs. after application, whereas F0570 had diminishing activity up to 96 hrs. An aquatic barrier trap for monitoring RWW adults was tested in commercial rice fields. Traps nearest the overwintering sites were the first to have RWW and adults then gradually dispersed over the remaining portions of fields. Trap catches indicated treatable densities of RWW as soon as 2 days after onset of permanent flood and 4 to 6 days before leaf-scar counts reached the treatment threshold. Studies to identify the necessary number of traps/field were continued. Studies that compared RWW infestation and yield loss indicated that Bengal had higher infestations than Cocodrie, Cypress, Wells, and Drew, but Bengal and Wells had no significant yield reductions when damaged by moderate to high densities of RWW larvae. Studies on the field susceptibility of rice varieties to RWW will be used to set insecticide application thresholds of adults that are captured in the aquatic traps. In other studies, the new rice variety Saber had similar infestation levels to Cocodrie, which is highly susceptible to whiteheads caused by the rice stalk borer.

Impacts
The development of use parameters for the aquatic barrier trap to monitor RWW adults will be of tremendous value to rice growers when trying to time post-flood applications of foliar insecticides. The currently registered foliar insecticides are effective when used during the short 10-day period immediately after permanent flood. The guesswork associated with previous methods (for example, leaf-scar counts) of monitoring adults is now removed and applications will be timed better by using the floating aquatic barrier traps.

Publications

  • Bernhardt, J. L. and D. T. Johnson. 2001. Verification of a monitoring program for rice water weevil adults. Pp.99-105. Ark. Agr. Exp. Stn. Res. Series 485.
  • Hix, R. L., D. T. Johnson, and J. L. Bernhardt. 2001. Trapping adult Lissorhoptrus oryzophilus (Coleoptera: Curculionidae) with aquatic barrier traps. Environ. Entomol. 30:770-775.


Progress 01/01/00 to 12/31/00

Outputs
ICON (fipronil) at .041 kg AI/ha was found to give control of extremely high densities of grape colaspis in large-field trials of drill-seeded rice. Loss of a rice planting (conventional tillage) that had seed treated with ICON was simulated and reseeded after minimum and no cultivation with untreated and ICON treated seed. Sufficient residual ICON was present to give control of rice water weevils (RWW) statistically equivalent to rice treated with a full rate (.041 kg AI\ha) of ICON. In addition, untreated non-cultivated (stale seed-bed) plots yielded 15% less than the untreated cultivated plots even when RWW densities were 27% less. An aquatic barrier trap for monitoring RWW adults was tested in commercial rice fields. The average number of adults/trap indicated treatable densities of RWW as soon as 2 days after onset of permanent flood and 4 days before leaf-scar counts reached the treatment threshold. Studies to identify the necessary number of traps/field and locations of traps were continued. Preliminary studies indicated differences among selected current rice varieties to have reduced yield when damaged by moderate densities of RWW larvae. In other studies, rice varieties Cocodrie, Jefferson, LaGrue and Cypress were found to be highly susceptible to whiteheads caused by the rice stalk borer while Wells, Bengal and Drew were much less susceptible.

Impacts
Impact: The development of an aquatic barrier trap for monitoring RWW adults will be of tremendous value to rice growers when trying to time postflood applications of foliar insecticides. The insecticides are effective when used during the short 10-day period immediately after permanent flood. The guesswork associated with previous methods (leaf-scar counts) of monitoring adults is now removed and applications will be timed better by using the floating aquatic barrier traps.

Publications

  • Bernhardt, J. L. and K. Moldenhauer. 2000. Screening rice lines for susceptibility to discolored kernels: Results from the Arkansas Rice Performance Tests. Pp.136-146. Ark. Agr. Exp. Stn. Res. Series 476.
  • Bernhardt, J. L. 2000. Control of rice water weevil in replanted rice with and without ICON 6.2FS treated seed, 1999. Arthropod Management Tests:2000. 25:290.
  • Bernhardt, J. L. 2000. Control of rice water weevil with Fury 1.5EC and Karate Z in drill-seeded rice, 1999. Arthropod Management Tests:2000. 25:290-291.
  • Bernhardt, J. L. 2000. Control of rice water weevil with ICON 6.2FS applied to dry and pred-germinated seed in water-seeded rice with pin-point flood, 1999. Arthropod Management Tests:2000. 25:291.
  • Hix, R. L., D. T. Johnson and J. L. Bernhardt. 2000. Swimming behavior of an aquatic weevil. Lissorhoptrus oryzophilus (Coleoptera: Curculionidae). Fla. Entomol. 83:316-324.
  • Hix, R. L., D. T. Johnson and J. L. Bernhardt. 2000. An aquatic barrier trap for monitoring adult rice water weevils (Coleoptera: Curculionidae). Fla. Entomol. 83: 189-192.
  • Hix, R. L., D. T. Johnson, J. L. Bernhardt and B. A. Lewis. 2000. An aquatic barrier trap for monitoring adult rice water weevils in flooded rice fields. Pp.147-157. Ark. Agri. Exp. Stn. Res. Series 476.
  • Hix, R. L., D. T. Johnson and J. L. Bernhardt. 2000. Researchers work on a rice water weevil aquatic barrier trap for better treatment decisions. Rice Journal 103(5):21.


Progress 01/01/99 to 12/31/99

Outputs
Fury (zeta-cypermethrin) at .067 and .056 but not .045 kg AI/ha gave control of rice water weevil (RWW) similar to Karate at .022, .034, or .045 kg AI/ha. ICON (fipronil) at .05 kg AI/ha gave excellent control of RWW when applied as a seed treatment to either dry or pregerminated rice seeded in water with pin-point flood. ICON at .041 kg AI/ha controled chironomids (bloodworms) in water-seeded rice with continuous flood and grape colaspis in large-field trials of drill-seeded rice. Loss of a rice planting with seed treated with ICON was simulated and reseeded with Icon treated seed after minimum cultivation seed. Sufficient residual ICON was present to control of RWW equivalent to rice treated with a half (.020 kg AI\ha) or a full rate (.041 kg AI\ha) of ICON. An aquatic barrier trap for monitoring RWW adults was tested in commercial rice fields and small plots. The number of adults captured was highly correlated to larval infestations and infers that the barrier trap can be used to time Karate and Dimilin applications shortly after permanent flood for control of RWW.

Impacts
Growers can now control two rice seedling pests; ICON will control rice seed midges in water-seeded rice and grape colaspis in drill-seeded rice. In replanted rice residual amounts of ICON from the first planting will control RWW. An aquatic barrier trap for monitoring RWW adults will allow rice growers to time applications of Karate and Dimilin. The guesswork associated with previous methods of monitoring adults is reduced and application timing will be improved with the use of the trap.

Publications

  • Bernhardt, J. L. and Moldenhauer, K. 1999. Screening rice lines for susceptibility to discolored kernels. Ark. Agr. Exp. Stn. Res. Series 468. PP.127-134.
  • Bernhardt, J. L. 1999. Screening rice lines for susceptibility to discolored kernels: Results of a statewide rice survey. Ark. Agr. Exp. Stn. Res. Series 468. PP.119-126.
  • Bernhardt, J. L. 1999. Control of rice water weevil with selected insecticides, 1998. Arthropod Management Tests:1999. 24:270-271.
  • Bernhardt, J. L. 1999. Control of rice water weevil with ICON, 1998. Arthropod Management Tests:1999. 24:271.
  • Bernhardt, J. L. 1999. Control of rice water weevil with Decis, 1998. Arthropod Management Tests:1999. 24:272.
  • Bernhardt, J. L. 1999. Evaluation of TADS 12253 for control of rice stink bug in a cage study, 1998. Arthropod Management Tests:1999. 24:272-273.
  • Hix, R. L., et. al. 1999. Trapping adult rice water weevils with floating cone and barrier traps. Ark. Agr. Exp. Stn. Res. Series 468. PP. 135-141.


Progress 01/01/98 to 12/31/98

Outputs
Fipronil (Icon), diflubenzuron (Dimilin), lambda-cyhalothrin (Karate) and cyhalothrin (Decis) controlled rice water weevil (RWW) when applied at proper times and rates to drill-seeded rice. Icon applied as a seed treatment as low as .022 kg(AI)/ha gave excellent control of RRW larve. Decis at .028 kg(AI)/ha gave control of RWW similar to Karate at .034 kg(AI)/ha. Icon applied as a seed treatment reduced whiteheads caused by the rice stalk borer (RSB), Chilo plejadellus, by 40 to 60 percent. Effects of cultural parctices (planting date, variety and seeding rate) on RWW and RSB were measured in the rice varieties Cypress, Bengal and Drew. Cypress was more susceptible to RSB than varieties Bengal or Drew, and Bengal had more RWW larvae than Cypress or Drew regardless of planting date or seeding rate. Several trap designs and colors without baits were tested in flooded rice for effectiveness in intercepting and capturing rice water weevil adults. Rice water weevil antenna gave an electrical response to hexanal a common rice plant volatile.

Impacts
(N/A)

Publications

  • Bernhardt, J.L. and Moldenhauer, K. 1998. Screening rice lines for susceptiblity to discolored kernels. Ark. Agr. Exp. Stn. Res. Series 460. PP. 103-110.
  • Bernhardt, J.L. 1998. Control of rice water weevil with dimilin, 1997. Arthropod Management Tests, 1997. 23:258.
  • Bernhardt, J.L. 1998. Control of rice water weevil and rice stalk borer with fipronil, 1997. Arthropod Management Test, 1997. 23:259-260.
  • Bernhardt, J.L. 1998. Control of rice water weevil with selected insecticides, 1997. Arthropod Management Test, 1997. 23:260-261.
  • Bernhardt, J.L. 1998. Evaluation of EXP61096A for control of rice stink bug in a cage study, 1997. Arthropod Management Tests, 1997. 23:260.
  • Hix, R.L., ET. AL. 1998. Development of an IPM monitoring program for rice water weevil adults. Ark. Agr. Exp. Stn. Res. Series 460. PP.95-102.


Progress 01/01/97 to 12/31/97

Outputs
Four insecticides were tested for control of rice water weevil in drill-seeded rice. Dimilin at a 0.21 (AI) kg/ha either in a split at 4 and 9 days or a single application at 4 days after permanent flood gave control comparable to a 0.28 rate. Fipronil at 0.036 (AI) kg/ha applied PPI gave 98% control and as a seed treatment gave 85% control. Whiteheads caused by rice stalk borer were 70 to 80 % less in EUP plots treated with fipronial. Fury gave 40 to 50% less control than Karate, fipronil or Dimilin. Karate CS had longer residual control than Karate EC. Karate EC and Furadan were tested in water-seeded rice plots heavily infested with rice water weevils. Two application of Karate had higher yields and better control than one. Two applications Karate applied within 16 days after permanent flood reduced rice water weevil densities by only 25% but yields were 1,200 lbs more than the untreated. Furadan applied 14 days after permanent flood had rice water weevil densities and yields the same as the untreated. Furadan applied 3 weeks after permanent flood resulted in densities reduced by 98% 2 weeks after application and yield was 1,000 lbs more than the untreated.

Impacts
(N/A)

Publications

  • BERNHARDT, J.L. ET AL. 1997. SCREENING FOR RICE STINK BUG RESISTANCE. ARK. AGRI. EXP. STAT. RES. SER. 456:67-74.
  • BERNHARDT, J.L. 1997. CONTROL OF RICE WATER WEEVIL WITH FIPRONIL, 1996A. ARTHROPOD MANAGEMENT TESTS: 1996. 22:286-287.
  • BERNHARDT, J.L. 1997. CONTROL OF RICE WATER WEEVIL WITH FIPRONIL, 1996B. ARTHROPOD MANAGEMENT TESTS: 1996. 22:287.
  • BERNHARDT, J.L. 1997. CONTROL OF RICE WATER WEEVIL WITH DIMILIN, 1996A. ARTHROPOD MANAGEMENT TESTS: 1996. 22:288.
  • BERNHARDT, J.L. 1997. CONTROL OF RICE WATER WEEVIL WITH DIMILIN, 1996B. ARTHROPOD MANAGEMENT TESTS: 1996. 22:288-289.
  • BERNHARDT, J.L. 1997. CONTROL OF RICE WATER WEEVIL WITH KARATE, 1996. ARTHROPOD MANAGEMENT TESTS: 1996. 22:289.
  • MOLDENHAUER, K.A., ET AL. 1997. BREEDING AND EVALUATION FOR IMPROVED RICE VARIETIES. ARK. AGRI. EXP. STAT. RES. SER. 456:17-21.


Progress 01/01/96 to 12/30/96

Outputs
One application of Karate at .034 (AI)kg/ha to drill-seeded rice at 5 or 10 daysafter permanent flood reduced numbers of rice water weevils larvae by 80 and 89%, respectively. A split application of Dimilin for a total of 0.28 (AI)kg/ha to drill-seeded rice at 3 and 9 days after permanent flood gave 97% control whereas a single application of a similar rate at 3 days after permanent flood gave 73% control. Dimlin applied at a similar rate in an EUP test gave 98% control when compared to the control. Fipronil applied PPI at 4 rates had an average of 89% control but an average of 62% when at 4 rates as a seed treatment. Fipronil applied PPI gave 96% control and as a seed treatment gave 94% control in an EUP test with extremely heavy rice water weevil infestations. Rice water weevil densities and damage were compared in drill and water seeded rice. Average density in untreated water seeded rice was twice that of untreated drill seeded rice, occurred earlier, and peaked 5 weeks after plants emerged from the water. Treatment of water seeded rice with Furadan when 60% of plants had leaf scars resulted in a 50% reduction of larvae but did not prevent an increase of larvae prior to internode elongation. Treatment of water seeded rice at a larval density of 10/core resulted in an 85% reduction of larvae with no increase later.

Impacts
(N/A)

Publications

  • BERNHARDT, J.T. 1996.
  • SCREENING INSECTICIDES FOR CONTROL OF RICE WATER WEEVIL. IN R.J. NORMAN AND B.R. WELLS (ED), ARK. RICE RES. STUD., 1995. ARK. AGR. EXP. STN. RES. SER. 453. PP. 88-94.
  • BERNHARDT, J.L, K.A. MOLDENHAUER, AND K.A. GRAVOIS. 1996.
  • SCREENING FOR RICE STINK BUG RESISTANCE. IN R.J. NORMAN AND B.R. WELLS (ED), ARK. RICE RES. STUD., 1995. ARK. AGR. EXP. ST. RES. SER. 453. PP. 95-100.
  • BERNHARDT, J.L. 1996.
  • CONTROL OF RICE WATER WEEVIL WITH FIPRONIL, 1995. ARTHROPOD MANAGEMENT TESTS: 1996. 21:280-281.
  • BERNHARDT, J.L. 1996. EVALUATION OF RICE LINES IN THE UNIFORM REGIONAL RICE NURSERY FOR INCIDENCE OF DISCOLORED KERNELS.
  • PROCEEDINGS, 26TH RICE TECH. WORKING GROUP.
  • SAN ANTONIO, TX. P. 119 (ABSTRACT).
  • DILDAY, R. H., ET AL. 1996.
  • EVALUATION OF JAPANESE CULTIVARS FOR GRAIN YIELD AND MILLING QUALITY. IN R.J. NORMAN AND B.R. WELLS (ED), ARK. RICE RES. STUD., 1995.ARK. AGR. EXP. STN. RES. SER. 453. PP. 36-40.
  • MOLDENHAUER, K. A., ET AL. 1996.
  • BREEDING AND EVALUATION FOR IMPROVED RICE VARIETIES. IN R.J. NORMAN AND B.R. WELLS (ED), ARK. RICE RES. STUD., 1995. ARK. AGR. EXP. STN.RES. SER. 453. PP. 41-45.
  • LEE, F. N., ET AL. 1996.
  • DISEASE RESISTANCE IN THE NEW LONG-GRAIN RICE CULTIVAR 'DREW'. IN R.J. NORMAN AND B.R. WELLS (ED), ARK. RICE RES. STUD., 1995. ARK. AGR. EXP. STN. RES. SER. 453. PP. 235-243.