Arthropod Management for Field Crops of the Agriculturally Diverse Central Region of Louisiana (2024)

Progress 01/01/13 to 12/31/16

Outputs
Target Audience:Extension agents, crop consultants, and farmers in Louisiana. Representatives of agrochemical, biotechnology, and seed companies in the southern United States. Scientists focusing on field crop production, insect ecology, and pest management in Louisiana and the southern United States. Changes/Problems:Nothing ReportedWhat opportunities for training and professional development has the project provided?Nothing ReportedHow have the results been disseminated to communities of interest?During the last year of the project, results were disseminated through four peer-reviewed journal articles, two reports in Arthropod Management Tests, one article in Louisiana Agriculture Magazine, four presentations at winter production meetings, five presentations at summer field days and production meetings, and four oral presentations at meetings of the Entomological Society of America. What do you plan to do during the next reporting period to accomplish the goals?Nothing Reported

Impacts
What was accomplished under these goals?Results from this research project have been used to develop refined arthropod management tactics for improved crop production practices in Louisiana. Objective 1: To refine traditional management tactics for arthropod pests in Central Louisiana field crops Research conducted during the last reporting period of the project determined the efficacy of selected insecticides for management of insect pests in sugarcane (3 experiments), soybean (2 experiments), grain sorghum (1 experiment), and corn (1 experiment). Over the four-year project period, soybean and corn results indicate that neonicotinoid seed treatments do notconsistantly have a measurable effect on yield. However, foliar applications ofinsecticides at the recommended rates provide satisfactory control of the redbanded stink bug in soybean. Grain sorghum results indicate that foliar applications of flupyradifurone (Sivanto), at labeled rates are very effective for sugarcane aphid management. Sulfoxaflor (Transform) is also an effective sugarcane aphid management tool. In addition, neonicotinoid seed treatments provide protection against the sugarcane aphid for several weeks in late-planted grain sorghum, sometimes delaying the need for foliar insecticides. Chlorantraniliprole (Prevathon) is the most effective insecticide for control of corn earworms and fall armyworms infesting sorghum seed heads. Sugarcane results indicate that diamide insecticides, flubendiamide (Belt) and chlorantraniliprole, provide sugarcane borer control levels at least as high as those provided by industry the standard tebufenozide (Confirm). Mexican rice borer control with insecticides is relatively more challenging than sugarcane borer control, and consistent benefits of insecticide use have not been demonstrated. During the 2016 growing season, the Louisiana sugarcane industry sustained a statewide outbreak of the West Indian canefly. Two field studies showed that lambda-cyhalothrin provides excellent control of the West Indian canefly. Lambda-cyhalothrin is a relatively inexpensive control option currently registered on sugarcane,andwas widely used in 2016. Two field studies also documented for the first time that acetamiprid (Strafer) and flupyradifurone can effectively control the West Indian canefly. Acetamiprid was granted a Section 18 Crisis Exemption label for use on sugarcane in 2016. The use of flupyradifurone will be reviewed in the future. Field experiments addressing the pest status of the threecornered alfalfa hopper in Louisiana soybeans during reproductive stages were conducted. Results indicate that threecornered alfalfa hopper adults are generally not associated with yield losses. However, initial data suggestsnymphs might be associated with yield losses. The current threshold will remain in the LSU AgCenter Insect Pest Management Guide until a new threshold is developed. However, Louisiana soybean crop consultants and growers have been made aware of the conclusions of this project. Objective 2: To determine the role of weed management and plant stress in the severity of arthropod pest problems in soybean. Over the 4-year project period, four field experiments evaluating two planting dates, three weed management levels, and two insect protection levels were conducted. Yield losses associated with insects and weeds were variable in the first three experiments. Data from the first experiment suggest that stink bug abundance and yield losses are relatively greater when weeds are managed. However, yield losses associated with insects were <5% and >35%, for the second and third experiments, respectively, with no apparent interactions with weed management. Samples and data from the 2016 experiment are being processed. The effects of irrigation regime and water salinity on soybean looper feeding in soybean were investigated in greenhouse and laboratory experiments. A method to consistently apply salt and drought stress to a large number of soybean plants in the greenhouse was developed. Reduced irrigation regimes and increased NaCl concentrations had inconsistent effects on relative growth rate and feeding preference of soybean looper larvae. Objective 3: To assess Mexican rice borer threat to Louisiana corn and grain sorghum. Mexican rice borer population monitoring with pheromone traps continued in 2016, with adults collected in Lafayette and West Baton Rouge Parish. Pheromone trapping during the four-year project have documented the geographical range expansion of the invasive species, which is now established in eleven parishes in south Louisiana. Results of four field experiments evaluating eight corn hybrids between 2013 and 2015 were analyzed. Results show that commercially available transgenic corn expressing Bt proteins targeting lepidopteran pests will reduce Mexican rice borer injury and infestations. However, Mexican rice borer infestations in non-Bt corn may require management.

Publications

Progress 10/01/14 to 09/30/15

Outputs
Target Audience:Extension agents, crop consultants, and farmers in Louisiana. Representatives of agrochemical, biotechnology, and seed companies in the southern United States. Scientists focusing on field crop production, insect ecology, and pest management in Louisiana and the southern United States. Changes/Problems:Nothing ReportedWhat opportunities for training and professional development has the project provided?Nothing ReportedHow have the results been disseminated to communities of interest?During the reporting period, results were disseminated through three peer-reviewed journal articles, two articles in Louisiana Agriculture Magazine, five presentations at winter production meetings, three presentation at a crop consultant meeting, four presentations at summer field days and production meetings, and two presentations at professional entomology meetings (1 oral presentation at the Annual meeting of the Entomological Society of America and 1 oral presentation at the Annual meeting of the Southeastern Branch of the Entomological Society of America). What do you plan to do during the next reporting period to accomplish the goals?Nothing Reported

Impacts
What was accomplished under these goals?Impact of the project All major field crops, including soybean, corn, sugarcane, winter wheat, grain sorghum and cotton are produced in Central Louisiana. Communities of arthropod pests attack these field crops, thus increasing production costs and decreasing yields. For example, yield losses and management costs associated with insect pests in Louisiana soybean were estimated at $53.80 per acre in 2014. Results from this research project are used to develop refined arthropod management tactics for improved crop production practices in Louisiana. Objective 1: To refine traditional management tactics for arthropod pests in Central Louisiana field crops Research conducted during the reporting period determined the relative efficacy of selected insecticides for management of common insect pests in soybean (4 experiments), grain sorghum (4 experiments), wheat (2 experiments), corn (1 experiment), and sugarcane (1 experiment). Soybean and corn results indicate that neonicotinoid seed treatments did not have a measurable effect on yield. However, foliar applications of recommended insecticides at the recommended rates provided satisfactory control of the redbanded stink bug in soybean. Grain sorghum results indicate that foliar applications of a new insecticide, flupyradifurone (Sivanto), at labeled rates are very effective for sugarcane aphid management. In addition, neonicotinoid seed treatments provide protection against the sugarcane aphid for several weeks in late planted grain sorghum. In wheat, aphid populations in the spring were low and yield data of experiments evaluating the efficacy of neonicotinoid seed treatments could not be collected because inclement weather severely damaged plots before harvest. Sugarcane preliminary observations suggest that a single aerial application of tebufenozide (Confirm), novaluron (Diamond), flubendiamide (Belt), or chlorantraniliprole (Prevathon) at 5 gallons per acre could not provide satisfactory control of Mexican rice borer infestations. Three field experiments releasing high densities of threecornered alfalfa hopper adults or nymphs on caged soybean plants, starting at the R1, R3, or R5 stages, were initiated. Two experiments were lost because inclement weather disturbed and broke field cages on multiple occasions. In the third experiment, adult and nymph infestations were not associated with yield losses. An additional field study conducted in 2015 compared plots treated with a recommended pyrethroid when threecornered alfalfa hoppers attained the recommended threshold with plots left non-treated (7 replications). Despite treating plots for threecornered alfalfa hoppers approaching the threshold twice in two weeks, differences in yield between treated and non-treated plots were not detected. Results suggest that the pest status of the threecornered alfalfa hopper in soybean is likely being overestimated under current Louisiana production practices Results support up-to-date region-specific insect management recommendations. Objective 2: To determine the role of weed management and plant stress in the severity of arthropod pest problems in soybean Samples and data from the second year of a field study addressing the impact of weed management on soybean insect abundance, injury, and yield loss were processed and analyzed. The experiment evaluated two planting dates, three weed management levels, and two insect protection levels. Yield data suggest that losses associated with weeds attained 24 and 46% for the early and late planting date, respectively. Yield losses attributed to insects only attained 5%, and did not change with the level of weed control. However, data from the first year of this study suggest that stink bug abundance and yield losses are relatively greater when weeds are well controlled. The third year of this field study was conducted in 2015. Samples and data are being processed at the time of this report. The second year of a greenhouse and laboratory study was conducted to conduct assays determining the effects of irrigation regime and water salinity on the soybean looper feeding on soybean. Two irrigation regimes and three water salinity levels applied to two soybean varieties were evaluated. Soybean looper larvae did not appear to be affected by irrigation regime. However, larvae preferred plants exposed to high and very high NaCl concentrations to those exposed to low concentrations. There was also weak evidence for faster larval growth on plants of one variety exposed to high NaCl concentrations. In addition to the greenhouse and laboratory study, a field study compared insect abundance in plots of soybean under four irrigation regimes. Plots were weekly irrigated starting at late vegetative growth, full bloom, pod set, or pod fill. Insect sampling conducted during pod fill did not detect differences among irrigation regimes. However, abundant rainfall and relatively low insect populations may have prevented the detection of differences among irrigation regimes. Results enhance knowledge on soybean agroecosystems and will assist in understanding how to adjust arthropod pest management in interaction with weed and stress management. Objective 3: To assess Mexican rice borer threat to Louisiana corn and grain sorghum. Mexican rice borer population monitoring with pheromone traps continued in 2015. Trapping efforts (> 80 pheromone traps) did not detect geographical range expansion of the invasive species, which is now established in eight parishes in southwest Louisiana. The third year of a field study evaluating eight hybrids confirmed that corn is susceptible to the Mexican rice borer. Mexican rice borer infestations when corn reached physiological maturity attained 0.15 larvae or pupae / plant in one non-Bt hybrid. Bt hybrids were generally less injured and infested than their non-Bt isoline although Mexican rice borers were observed feeding on plants of certain Bt hybrids (< 0.05 larvae or pupae / plant). Results suggest that commercially available transgenic corn expressing Bt proteins targeting lepidopteran pests will reduce Mexican rice borer injury and infestations. However, Mexican rice borer infestations in non-Bt corn may require management. Results provide information on the pest potential of the Mexican rice borer in Central Louisiana.

Publications

Progress 10/01/13 to 09/30/14

Outputs
Target Audience: Extension agents, crop consultants, and farmers in Louisiana. Representatives of agrochemical, biotechnology, and seed companies in the southern United States. Scientists focusing on field crop production, insect ecology, and pest management in Louisiana and the southern United States. Changes/Problems:Nothing ReportedWhat opportunities for training and professional development has the project provided?Nothing ReportedHow have the results been disseminated to communities of interest? During the reporting period, results were disseminated through four peer-reviewed journal articles, four presentations at winter production meetings, one presentation at a crop consultant meeting, one presentation at an Extension Agent training meeting, six presentations at summer field days and production meetings, and four presentations at professional entomology meetings (1 oral and 1 poster presentation at the Annual Meeting of the Entomological Society of America, 1 poster presentation at the Annual meeting of the Southeastern Branch of the Entomological Society of America, and 1 poster presentation at the International Working Group on Ostrinia and other Maize Pests Conference). What do you plan to do during the next reporting period to accomplish the goals? Continue work as planned.

Impacts
What was accomplished under these goals? All major field crops, including soybean, corn, sugarcane, winter wheat, grain sorghum and cotton are produced in Central Louisiana. Communities of arthropod pests attack these field crops, thus increasing production costs and decreasing yields.Results from this research project are used to develop refined arthropod management tactics for improved crop production practices in Louisiana. Research during the reporting period determined the relative efficacy of selected insecticides and adjuvants for management of common insect pests in grain sorghum (6 experiments), soybean (2 experiments), sugarcane (2 experiments), wheat (1 experiment), and bermudagrass pasture (1 experiment). Sulfoxaflor (Transform) is extremely effective for sugarcane aphid management in grain sorghum. In addition, neonicotinoid seed treatments provide protection for several weeks. In grain sorghum, sugarcane, and bermudagrass pasture, recently labeled diamides generally provide very good to excellent control of target lepidopteran pests. Three field experiments addressing the pest status of the threecornered alfalfa hopper in soybean showed that adult infestations for 14 days, starting at the R1, R3, or R5 stages, were not associated with yield losses. Two of these three experiments also included assessment of the impact of nymph infestations. Nymph infestations at the R1, R3, or R5 stages were not associated with yield losses in one experiment. However, an overall 560-lb/acre yield loss was detected in the other experiment. Samples from the first year of studies addressing the impact of soybean weed management and plant stress were processed and analyzed. Redbanded stink bug abundance and associated injury were greater where weeds were managed than where weeds were not managed. In addition, yield losses associated with insect infestations were greater where weeds were managed relative to where weeds were not managed. In the greenhouse and laboratory, the relative growth rate of soybean looper larvae was reduced when feeding occurred on soybean plants under a reduced irrigation regime. The second year of a field study determined the role of weed management in the severity of arthropod pest problems in soybean. In addition, the second year of a greenhouse and laboratory study was initiated to determine the role of plant drought and salt stress in the severity of arthropod pest problems in soybean. Samples are being processed. Mexican rice borer population monitoring indicated that after becoming established in southwest Louisiana, the invasive species has continued its spread toward major sugarcane, rice, and feed grain production areas. The insect has now been detected in Evangeline parish. The second year of a field study confirmed that corn is susceptible to the Mexican rice borer. Results of the study evaluating eight hybrids suggest that commercially available transgenic corn expressing Bt proteins targeting lepidopteran pests is effective in reducing Mexican rice borer injury and infestations. However, Mexican rice borer infestations in non-Bt corn may require management.

Publications

Progress 01/01/13 to 09/30/13

Outputs
Target Audience: Extension agents, crop consultants, and farmers in Louisiana. Representatives of agrochemical and seed companies in the southern United States. Scientists focusing on field crops insect ecology and pest management in Louisiana and the southern United States. Changes/Problems:Nothing ReportedWhat opportunities for training and professional development has the project provided?Nothing ReportedHow have the results been disseminated to communities of interest? During the reporting period, results were disseminated through two peer-reviewed journal articles, three presentations at winter production meetings, one presentation at a crop consultant meeting, four presentations at field days, and one oral and one poster presentation at the Annual meeting of the Southeastern Branch of the Entomological Society of America. What do you plan to do during the next reporting period to accomplish the goals?Nothing Reported

Impacts
What was accomplished under these goals? Impact of the project All major field crops are produced in Central Louisiana. Communities of arthropod pests attack soybean, corn, sugarcane, winter wheat, grain sorghum and cotton, thus increasing production costs and decreasing yields. Results from this research project are used to develop refined arthropod management tactics for improved crop production practices in Louisiana. Objective 1: To refine traditional management tactics for arthropod pests in Central Louisiana field crops Research conducted during the reporting period determined the relative efficacy of selected insecticides for management of common insect pests in soybean, sugarcane, grain sorghum, cotton, and bermudagrass. Research on the threecornered alfalfa hopper in soybean showed that ten-day infestations at the R1, R3, or R5 stages were associated with increased injury, but not yield losses. Re-evaluation of redbanded stink bug economic threshold in soybean continued. Results will support up-to-date region-specific arthropod management recommendations. Objective 2: To determine the role of weed management and plant stress in the severity of arthropod pest problems in soybean Field and greenhouse experiments were initiated to determine the role of weed management and plant drought and salt stresses in the severity of arthropod pest problems in soybean. Samples and data are being processed. Results are expected to enhance knowledge on soybean agroecosystems and assist in understanding how to adjust arthropod pest management in interaction with weed and stress management. Objective 3: To assess Mexican rice borer threat to Louisiana corn and grain sorghum. Mexican rice borer population monitoring indicated populations are increasing across newly invaded areas in southwest Louisiana. A field experiment confirmed that corn is susceptible to the insect. Commercially available transgenic corn expressing Bt proteins targeting lepidopteran pests is effective in reducing Mexican rice borer injury and infestations. However, Mexican rice borer infestation in non-Bt corn may require management.

Publications