Leads: David Kerns and Gus Lorenz Project #3: How to effectively manage SCA in the presence of other pests? Leads: David Kerns and Gus Lorenz Robert Bowling, David Buntin, Jeff Gore, Brian McCornack and Ali Zarrabi

Objectives Determine the efficacy of insecticide mixes towards multiple pests in sorghum. Determine the impact of insecticide mixes targeting multiple pests on beneficial insects.

Design & Methods Headworm Midge Yield and adjust to 14% moisture Replicated, small plot, RCB (4-5 replicates) Two test options Targeting SCA + Headworms Targeting SCA + Midge Application timing on one or both pest complexes as available; emphasis on midge test where midge are problematic SCA and beneficials Sampling of leaves (10 upper, 10 lower) per plot, estimate number of SCA count beneficals. Precounts, 2-3 DAT, and 7, 14, 21 DAT Headworm Bucket sample 10 heads per plot, count and ID. Precounts, 2-3 DAT and 7 DAT. Midge Precounts of adults visually from 20 panicles/plot. 12 DAT, remove and bag 10 heads/plot, count emerged adults 7-12 days later. At soft dough estimate percentage damage kernel. Yield and adjust to 14% moisture

Locations Researcher Test site Target pests Hybrid Bowling Corpus Christi, TX SCA + headworm DKS38-88 Buntin Plains, GA 83P17 Gore Stoneville, MS DKS54-00 Kerns Winnsboro, LA M75GB39 Lorenz Marianna, AR 84P80 McCormack South Haven, KS DKS37-07 Nutech 623 Zarrabi Lane, OK KS 585 SCA + midge

Headworm Tests Trt SCA insecticide SCA Insecticide 1 Untreated 2 Transform 1 oz/ac or Pyrethroid (Baythroid XL 2.8 fl-oz or Karate Z 1.92 fl-oz/ac) 3 Blackhawk 3.3 oz/ac 4 Belt 3 fl-oz/ac 5 Sivanto 4 fl-oz/ac Prevathon 14 fl-oz/ac 6 Lannate 2.4LV 16 fl-oz/ac 7 Diamond 9 fl-oz/ac OK location used Transform first application and Sivanto on a second application

SCA Populations

SCA Transform

SCA Sivanto Prime

Headworm Populations

Headworms Transform or Sivanto

Midge Tests Trt SCA insecticide SCA Insecticide 1 Transform 1 oz/ac or Untreated 2 Pyrethroid (Baythroid XL 2.0 fl-oz or Karate Z 1.2 fl-oz/ac) 3 Blackhawk 1.5 oz/ac 4 Sivanto 4 fl-oz/ac Lorsban 1 pt/ac or Lannate 2.4 LV 1 pt/ac 5 Diamond 6 fl-oz/ac

Sorghum Midge

Sorghum Midge No yield response

Sorghum Midge No yield response

Sorghum Midge No yield response

Beneficial Populations

Beneficials Transform

Beneficials Sivanto Prime

Beneficials Sivanto Prime

Key Learning Points Neither Transform nor Sivanto Prime appear to impact the efficacy of insecticides targeting headworm complex. Pyrethroids may negatively impact SCA control achieved by Transform but did not appear to affect Sivanto Prime as much. Blackhawk, Belt, Lannate and Prevathon all offered good headworm control. Diamond was ineffective (timing issue?) and Pyrethroids were inconsistent (probably due to resistance in some area).

Key Learning Points (cont.) Good sorghum midge tests are difficult to achieve. Sorghum midge is probably over-emphasized as a pest (too many automatic sprays). Were unable to assess midge/SCA treatment combinations. Under low to moderate pest pressure, Blackhawk, Lorsban and Pyrethroids all appeared be effective in preventing midge injury. Diamond was inconsistent; higher rates may be effective.

Key Learning Points (cont.) SCA arthropod natural enemies were not numerous. Lady beetles appear to the dominant natural enemy of SCA. Where mixed with Transform; Belt, Prevathon, Lannate and Diamond all has fewer predators than the untreated at 2 DAT. Blackhawk and Pyrethroids did not severely impact lady beetles at 2 DAT.

Next Steps Determine economically feasible insecticide mixes for multi-pest targets. Comprehensive study of impact of natural enemies on SCA populations. Specifically designed and focused. How important are they? What are the impacts of insecticides have on them? Sorghum midge education. Are they as common a problem as they are made out to be?

Questions?