New Soybean Pests and IPM Study Results 2016

Transcription

1 New Soybean Pests and IPM Study Results 2016 Dr. Moneen Jones, Research Entomologist

2 Soybean Podworm Induced Resistance to Compare Management Strategies We treated newly hatched, first instar SPW larvae with a diet consisting of SPW diet from Southland Products mixed with the LC 25 dose of three different chemicals: (chlorpyrifos, lambda-cyhalothrin, and a pre-mix of chlorpyrifos+lambdacyhalothrin) and a rotation of chemicals (chlorpyrifos, lambda-cyhalothrin). The treatment of chlorpyrifos took six generations to reach 50% mortality and subsequently took three generations on untreated diet to bring the larvae back to susceptibility with an 85% mortality rate. The treatment of lambda-cyhalothrin took seven generations to become resistant and four generations to return to susceptibility. The larvae treated with the rotation of chemicals took seven generations to become resistant and five to return to susceptibility. The pre-mix of two chemicals took only 5 generations to see 50% mortality and four generations to return to an 85% mortality rate. For each resistance population, biochemical enzymes were quantified for comparison with lab/susceptible, and this data is pending.

3 BASELINE DATA FOR SPB SUSCEPTIBILITY TO KEY INSECTICIDES B. Dose response curves for chlorpyrifos, chlorpyrifo s+lambda cyhalothrin, lambda cyhalothrin, zeta -cypermethrin, indoxicarb, and bifenthrin Insecticide n Slope ± SE z 2 LD 25 95% CL Lower -Upper LD50 95% CL Lower -Upper LD 95 95% CL Lower -Upper Chlorpyrifos+Lambda cyhalothrin ± Chlorpyrifos ± Lambda cyhalothrin ± Zeta -cypermethrin Indoxicarb Bifenthrin ± ± ±

4 Thrips Management Strategies Selected insecticide seed treatments were evaluated for control of thrips in soybean at Lee Farm, Fisher Delta Research Center, Hayward, Missouri. Soybeans were planted on 23 May. The test was arranged in a RCB design with 4 replicates. Individual plots were 13 x 40 ft and planted at a rate of 1560 seeds per plot. Treatments were applied to the seed before planting. Plots were sampled with a standard black shake sheet and by hand beginning at V2. On each date, 10 samples were taken from the center two rows of all plots. Insect control and damage was evaluated 5 July 43DAP (days after planting), 13 July 51DAP, and 21 July 59DAP. Data were subjected to ANOVA and means were separated using a protected LSD.

5 Thrips Management Strategies - Results All seed treatments besides Poncho/Trilex/Votivo had lower number of thrips than the untreated seed at 43 DAP. At 51DAP, there were no significant differences in thrips control between seed treatments. However, at 59DAP, CruiserMaxx, CruiserMaxx/Avicta, Intego Suite/Nipsit, Acceleron DX109, 309, 409, or Acceleron DX109, 309, 409/Poncho had significant lower number of thrips. At 59DAP, CruiserMaxx/Avicta, Intego Suite/Nipsit, Acceleron DX109, 309, 409, and Acceleron DX109, 309, 409/Poncho had significantly fewer thrips than the check plots.

6 Thrips Management Strategies - Results Rate amt. per July 5 July 13 July 21 treatment 43DAP 51DAP 59DAP Treatment Thrips Thrips Thrips Formulation Total Total Total* Trilex oz/cwt 1.0b 3.0a 0.7a Poncho/Trilex/Votivo 1.28/1/2oz/cwt 1.2ab c 2.3a 0.7a CruiserMaxx 3oz/cwt 0.4c 3.2a 0.5ab CruiserMaxx/Avicta 3/2.5oz/cwt 0.3cd 2.5a 0.3b Intego Suite/Nipsit 3.37oz/cwt 0.3cd 2.4a 0.3b Acceleron DX109, 309, /0.8/2oz/cwt 0.2cd 2.6a 0.3b Acceleron DX109, 309, 409/Poncho 0.4/0.8/2/1.28oz/cwt 0.1d 1.9a 0.3b Untreated check 1.6a 3.4a 0.7a

7 Spray App: Insecticide Efficacy Enter date, location, and pest densities - Finished Step 3: Enter date, location, timing and pest observations in field. Setup History Current Preferences Date Location Home Stage Square Thrips A L M H Plant bug A L M H Armyworm A L M H Aphid A L M H Cutworm A L M H Grasshopper A L M H Bollworm A L M H Tobacco budworm A L M H Cabbage looper A L M H Spray No. 1 Appl. Date Priority Cost Application Type: Ground Application Type: Ground or Aerial Volume: Low Volume: Low or High Setu p Spray No. Appl. Date Priority Histor y Curren t Cost Preferenc es Application Ground Application Type: Ground or Type: Volume: Low Aerial Volume: Low or High Bollworm: +++ Tobacco budworm: +++ Cabbage looper: +++ Product: Belt A.I.: Flubendiamide REI: 12 hours PHI: 28 days MOA: 4A ENE: Medium Add Save Guide Note: calendar Pop-up Note: Pop-up calendar FREE DOWNLOAD: BOOTHEELAGPESTMANAGEMENT.COM

8 ipipe: Next Generation Pest Information Platform An Evolutionary Step for the Agricultural Community ipipe evolved from NAPPFAST* and ipmpipe** IT platforms. ipmpipe Spray App is NOW connected to this platform App available for free download at bootheelagpestmanagement.com ipipe was expanded to include crop consultants, company reps, and others. Copyright 2014 ZedX Inc. *NAPPFAST: NCSU/APHIS Plant Pest Forecast System ** ipmpipe: Pest information platform for extension and education

9 Kudzu Bug in Missouri 8/28/16 Did you know?

10 Gray Looper It s Discovery in Missouri Soybeans

11 Gray Looper Adults In 2010, Mississippi growers had difficulty controlling gray looper in soybean, and they are accustomed to having this moth in their state. In 2010, in Mississippi, loopers infested 1.7 million acres of soybeans and caused a 19% total loss plus cost of control to producers (Musser et al. 2011). For those growers and crop consultants of Missouri who have not seen this moth, gray looper (GL) moth (Rachiplusia ou) is a Noctuid that resembles the Silver Y moth in its characteristic winged Y pattern. This moth is not currently monitored in the state of Missouri Moth is a generalist feeder that consumes soybean AND cotton with equal preference

12 Larval Characteristics The larvae resemble the soybean looper The primary larval character that differs the two species involves the absent/vestigial prolegs (the squishy legs) on abdominal segments 3 & 4. The prolegs are vestigial on A3 and A4 in the soybean looper and totally absent on A3 and A4 in the gray looper (personal communication, Paul Goldstein, USDA). Needless to say it is difficult to distinguish between these two larvae unless you have a trained eye. The issues that we have with soybean looper and insecticide tolerance may very well be because it is a different moth species in the field that we know very little about

13 Moths PER Trap PER Day Flight in Missouri Phenology of gray looper moth in Southeast Missouri. Counts represent moths per trap, per day of trapping period (May October 2015) Gray Looper Moths in Southeast Missouri Soybean Dunklin Mississippi New Madrid 3 Pemiscot 2 1 Scott Stoddard 0

14 Leaf Damage a single 4th instar larvae can devour a leaf completely in 24 hours 3rd instars can finish a leaf in 2 days Research is NECESSARY More information is needed on gray looper biology and economics. Because it starts its first flight in May: Do later generations cause overall more damage than soybean loopers? What is the ratio between moth species in an average cotton field? Can they be controled with the same chemicals? Do we need to re-think our management thresholds?? There are loads of questions that need to be answered, but we need to start somewhere.

15 Thank you! Any Questions?