Progress 04/21/14 to 09/30/18
Outputs
Target Audience:Ranchers, producers, and pest managers. Changes/Problems:Project Director resigned to take another position as of July 1, 2018. What opportunities for training and professional development has the project provided?The project provided an opportunity to train one graduate student (MS), Lee W. Noel, in the field of Integrated Pest Management. A training of Wyoming Weed and Pest district personnel in the use of recently labeled pyrethroid insecticides against rangeland grasshoppers has been accomplished at their annual spring workshop in 2017. How have the results been disseminated to communities of interest?Results were reported during the following events: - Entomology seminar at the University of Wyoming (April, 2017) - Annual meeting of the Entomological Society of America (Denver, November 2017) - International training on locust and grasshopper management in Uzbekistan and Azerbaijan within framework of FAO UN - Results of the project have been delivered to pest and land managers of 17 western states at the annual meeting of the National Grasshopper Management Board (Denver, Jan. 2017 and Feb., 2018) What do you plan to do during the next reporting period to accomplish the goals?
Nothing Reported
Impacts
What was accomplished under these goals?
Field tests were conducted to determine how to incorporate a pyrethroid insecticide into the Reduced Area and Agent Treatments strategy (RAATs) for grasshopper management. Pyrethroids are based on the plant derived insecticide pyrethrin. Pyrethroids are less toxic to mammals than the much older but still registered broad spectrum insecticide options for grasshopper control. There was no guidance on how to best apply pyrethroid class insecticides with RAATs. RAATs typically reduces the amount of insecticide needed to achieve economic control of grasshoppers and Mormon crickets by 50%. Aerial RAATs applications of the third generation pyrethroid insecticide, lambda-cyhalothrin, resulted in reductions of pest grasshopper populations to below the economic injury level. The rate of insecticide, best spray adjuvants, and total volume per acre treated optimized for RAATs were determined to guide stakeholders that may need to control grasshopper infestations. By reducing both the toxicity and exposure to pesticide utilized, the hazard to human and environmental health is also reduced, a goal of Integrated Pest Management. In addition to the synthetic insecticide research, field trials and laboratory bioassays, in cooperation with a USDA-ARS-NPARL microbiologist specializing in the development of fungal pathogen of insects, were conducted to help develop bio-pesticides compatible with RAATs. A major goal of IPM is to target only the pest insects and leave beneficial insects unharmed. The focus of the research was on fungi species in the genus Metarhizium. Species of this fungi from the Old World have been found that are very specific to grasshoppers and then successfully developed into bio-pesticides. A graduate student worked on the project which resulted in a completed thesis. A lot of useful information regarding the selection criteria of native candidate fungal pathogens that can be effective under field conditions was gained. An application method that was developed to apply the fungal spores resulted in high rates of infection of the field treated grasshopper populations. However, the species of native Metarhizium fungi available for testing did not prove to be lethal when grasshoppers could raise their body temperature through sun exposure. Laboratory and field cage tests of fungal spores applied via grasshopper bait show great promise in reducing the amount of bio-pesticide needed to successfully infect grasshoppers. Bait formulation of biopesticide also reduces exposure of non-target animals to the fungal pathogen. Knowledge gained from this work will help guide the future development of a fungal biopesticide product that is pest insect specific and can meet Organic Materials Review Institute standards.
Publications
- Type:
Theses/Dissertations
Status:
Published
Year Published:
2017
Citation:
Noel, L.W. Biological Control of Rangeland Pest Grasshoppers Orthoptera: Acrididae) Using Bait Formulation of a Fungal Pathogen Metarhizium robertsii DWR2009 (Hypocreales: Clavicipitaceae)
- Type:
Conference Papers and Presentations
Status:
Other
Year Published:
2017
Citation:
Presentations at the 13th Annual UW ENTO Short Course in March 2017.
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Progress 10/01/16 to 09/30/17
Outputs
Target Audience:Ranchers, producers and pest managers. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?The project provided an opportunity to train one graduate student (MS), Lee W. Noel, in the field of Integrated Pest Management How have the results been disseminated to communities of interest?Results were reported during the following events: - Annual meeting of the National Grasshopper Management Board (Denver, January 2017) - Entomology seminar at the University of Wyoming (April, 2017) - Annual meeting of the Entomological Society of America (Denver, November 2017) - International training on locust and grasshopper management in Uzbekistan and Azerbaijan within framework of FAO UN What do you plan to do during the next reporting period to accomplish the goals?
Nothing Reported
Impacts
What was accomplished under these goals?
Experiments were performed in the laboratory to test the efficacy of wheat bran bait with an active ingredient of Metarhizium robertsii DWR2009 fungal spores against pest grasshoppers. Tests were conducted at the USDA-ARS insectary in Sidney, Montana on 3rd and 4th instar Melanoplus sanguinipes and Melanoplus differentialis grasshopper nymphs that were reared in the laboratory. Three separate tests were carried out for each species. Treatments of wheat bran bait with a consistent concentration of 2.75 x 1011 and ~90% viable spores were administered in doses of 5 lb./ac (5.6 kg/ha), 10 lb./ac (11.2 kg/ha), and 20 lb./ac (22.4kg/ha). Exposure time to the bait was either 1, 3, or 6 days. Grasshoppers were monitored daily for mortality throughout the duration of their exposure to the bait plus 14 days after exposure ended. Overall mortality as well as the time taken to achieve 50% mortality (median survival time) was calculated in each treatment. When analyzing the three different bait dosages for M. sanguinipes nymphs, statistically significant differences (p<0.05) were found in the 50% survivorship times for the three treatments. The 5 lb./ac treatment (n=113) reached 50% mortality at 9 days after treatment, the 10 lb./ac treatment (n=114) reached 50% mortality at 8 days after treatment, and the 20 lb./ac treatment (n=117) achieved 50% mortality in its cohort on an average of 7 days after treatment. Statistically significant differences (p<0.05) in total mortality were found between each treatment, suggesting that mortality depended on the amount of bait, with 20 lb./ac causing the most mortality. There was no statistically significant difference found between the 5 lb./ac and 10 lb./ac treatments using chi-square tests of independence. For M. differentialis, the 5 lb./ac bait dosage (n=132) achieved 50% mortality on average by the 11th day after treatment, while the 10lb./ac (n=129) and the 20 lb./ac treatments (n=133) each reached 50% mortality by the 9th day after treatment. There was a statistically significant difference between the 5 lb./ac treatment and the 10 lb./ac treatment as well as between the 5 lb./ac treatment and 20 lb./ac treatment groups. There was no statistically significant difference (p<0.05) between the 50% survivorship times of the 10 lb./ac and 20 lb./ac treatments. The second set of experiments analyzed overall grasshopper mortality and rate of mortality when exposure time to each bait dosage was changed. The M. sanguinipes data showed no significant differences (p>0.05) in time taken to achieve 50% mortality among the groups with 1 day of exposure to the bait (n=114, 7 days taken to achieve 50% mortality), 3 days of exposure to the bait (n=114, 7 days), and 6 days of exposure to the bait (n=116, 7 days). Both the 3 day exposure and 6 day exposure caused significantly more mortality (p<0.05, ~90%) than the 1 day exposure (~79%) in separate pairwise comparisons, but there were no significant differences (p>0.05) in the levels of mortality caused by the 3 and 6 day exposure times. Similarly for M. differentialis, there were no significant differences (p>0.05) in time taken to achieve 50% mortality between the 1 day of exposure time (n=132, 10 days taken to achieve 50% mortality), 3 days of exposure time (n=131, 9 days), and 6 days of exposure time (n=131,9days) to the three different bait dosages. There were also no significant differences (p>0.05) found in the levels of mortality caused by 1 day exposure (~68% mortality), 3 day exposure (~73%), and 6 day exposure (~79%) periods.
Publications
- Type:
Theses/Dissertations
Status:
Published
Year Published:
2017
Citation:
Noel, L.W. Biological Control of Rangeland Pest Grasshoppers Orthoptera: Acrididae) Using Bait Formulation of a Fungal Pathogen Metarhizium robertsii DWR2009
(Hypocreales: Clavicipitaceae)
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Progress 10/01/15 to 09/30/16
Outputs
Target Audience:
Nothing Reported
Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?Entomology Short Course training on grasshopper biocontrol. How have the results been disseminated to communities of interest?Results were disseminated via Entomology Short Course What do you plan to do during the next reporting period to accomplish the goals?
Nothing Reported
Impacts
What was accomplished under these goals?
For goal (3): The commercial Metarhizium brunneum F52 was evaluated against field populations of grasshoppers, primarily Aulocara elliotti, in an improved pasture in Wyoming. Our evaluation was a ground application of F52 against a population of mixed species of mostly adult grasshoppers on four replicate 0.91 ha (2.25 ac) plots of rangeland for a total of 4 ha (10 ac). Each plot was surrounded by a chemical pesticide barrier to prevent grasshopper migration. One rate of F52, 6x1012 conidia/ha (2.5x1012/ac), was tested, which rate was based upon recommendation by the registrant, commensurate with the pathogenicity of F52 for several grasshopper species. In addition, we similarly tested an unregistered fungus, M. robertsii DWR346 (under study by APHIS PPQ and ARS for control of Mormon crickets), at the same rate and volume of carrier. There were no significant reductions in grasshopper numbers 7, 14 or 21 days post-treatment, due to failure of the pesticide barriers to prevent extensive migration into and among plots. There was significant mortality of grasshoppers collected immediately after sprays and subsequently incubated for 14 days in the laboratory where the insects could not efficiently thermoregulate (100% corrected mortality) with 38-41% prevalence of overt mycosis among dead insects, and 2 days later (94-100% corrected mortality, with 81-85% prevalence of mycosis). Bioassays of sprayed vegetation taken immediately after spraying yielded a corrected mortality of 42-57% (80% prevalence of mycosis). Similar bioassays of samples taken two days later 31-33% (89-90% prevalence of mycosis); lower efficacy may have been due to a rain event the night after fungus applications. Thermal data collected during the trial indicated that grasshopper body temperatures were too high for fungal infections to develop normally (>39° C), for at least 3 hours daily most days, and as much as 7 hours/day. The extensive migration and these temperature data may help explain lack of any fungal efficacy.
Publications
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Progress 10/01/14 to 09/30/15
Outputs
Target Audience:Wyoming ranchers, farmers, landowners and pest managers Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?Results of the trials were included in the annual Entomology Short Course for Weed and Pest specialists. Successfully completing the course, the attendees earn Continuous Education Units for their professional development. How have the results been disseminated to communities of interest?Results were presented at the annual National Grasshopper Management Board meeting in Denver, CO. What do you plan to do during the next reporting period to accomplish the goals?
Nothing Reported
Impacts
What was accomplished under these goals?
For goal (3): The purpose of the current trial was to obtain a second year's worth of data about the efficacy of Met52EC against grasshoppers. Specifically, our goals were to (1) determine field efficacy of Metarhizium brunneum F52 (Novozymes NZBPC2102) against a mixed population of grasshoppers on rangeland; and (2) determine persistence of infectious residues on sprayed vegetation subsequent to application. In addition, we concurrently and similarly evaluated another fungus, Metarhizium robertsii DWR346, which is under study by USDA ARS. The desired outcome was to reduce grasshoppers from outbreak proportions (>30/yd2) to below threshold (<15/yd2), ideally within 1-2 weeks of application. Initial grasshopper populations ranged from 33 to 69 grasshoppers per yd2, which value is considered greatly above economic threshold. Final mortality among the grasshoppers collected immediately after treatments was very high, 64% among the oil carrier control insects, and 100% among grasshoppers from the two fungal treatments. Final fungus-associated mortality was significantly higher than the controls (ANOVA F2,11=7.42, p = 0.0125). Nevertheless, the rate at which mortality accumulated (Figure 4) was much more indicative being greater among grasshoppers from fungus-treated versus carrier control plot. In addition, the prevalence of Metarhizium mycosis was 38-41% among grasshoppers from fungus-treated plots, versus 0% from the control plots. These two sets of data indicate that there was substantial infection of the grasshoppers, and subsequent death from mycosis when the grasshoppers could not properly thermoregulate.
Publications
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Progress 04/21/14 to 09/30/14
Outputs
Target Audience: Ranchers and farmers in Wyoming and other western states where grasshoppers present economic problems to agriculturists. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided? On-the-job training of Wyoming Weed and Pest personnel in the use of pyrethroid insecticides against rangeland grasshoppers has been accomplished. How have the results been disseminated to communities of interest? Results of the project have been delivered to pest and land managers of 17 western states at the annual meeting of the National Grasshopper Management Board. What do you plan to do during the next reporting period to accomplish the goals? Continue to work on research objective (1); start working on research objectives (2) and (3)
Impacts
What was accomplished under these goals?
(1) Efficacy of pyrethroid insecticides within the RAATs context was evaluated in the field. Aerial application of insecticide Warrior II (active ingredient lambda-cyhalothrin) yielded the following results: treatment(volume/coverage) pre-treatment gh density per square m 4 d post-treatment gh density per square m/efficacy 21 d post-treatment gh density per square m/efficacy untreated 16.4 16.1 13.9 2 gal/100% 22.9 1.25/94% 2.3/88% 2 gal/50% 17.7 3.0/83% 4.4/71% 1 qt/50% 23.75 8.9/62% 4.8/76% 14 fl.oz/50% 18.8 9.3/50% 5.9/63% Based on these results, the RAATs applications of 1 qt and 14 fl.oz of Warrior II could be recommended for further evaluation and practical application against rangeland grasshoppers.
Publications
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