Wheat Insect Update. Dr. Janet Knodel Extension Entomologist Crop Outlook and Int l Durum Forum November 6, 2007 Minot, ND Wheat Insect Updates

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1 Wheat Insect Update Dr. Janet Knodel Extension Entomologist Crop Outlook and Int l Durum Forum November 6, 2007 Minot, ND 2007 Wheat Insect Updates Wheat stem maggot Wheat stem sawfly Hessian fly Orange wheat blossom midge 1

2 Wheat Stem Maggot Meromyza americana Fitch Diptera: Chloropidae Adult fly 1/5 inch long Three black stripes on thorax Bright green eyes Larva Maggot (headless and legless) 1/16 inch long Wheat Stem Maggot Life Cycle Two generations per year June - Adult emerges and lays eggs July Maggot (larva) and pupa Late July into early August 2 nd generation of adults emerge and lays their eggs on wild grasses or volunteer grain Overwinters as maggot in lower parts of grass stems 2

3 Wheat Stem Maggot Hosts: Wheat, rye, barley, grass weeds (quackgrass, wheat grass, bromegrass, green and yellow foxtail, bluestem grass) Damage Larva rasps and tears the stem causing white heads White heads do not produce grain Presence of white heads has not been correlated to level of damage/yield loss. 3

4 Wheat Stem Maggot - IPM Crop rotation with non-susceptible crops Control of grassy weed and volunteer small grains Resistant Varieties None Delayed planting Tillage Fall or Spring Biological Control Parasitic wasps Bracon meromyzae Gahan Coelinidea meromyzae (Forbes) Chemical Control -? Insecticide Timing Trial Hettinger REC, Eric Eriksmoen HRSW, Variety Reeder, planted on May 1 st Four spray timings: June 13 th (5 leaf & jointing) June 20 th (early boot) June 26 th (heading) July 5 th (flowering) Mustang Max insecticide at 3 fl oz/a Counted white head on July 20 th from 200 heads Harvested July 27 th (unreplicated strips of 100 ft per plot) 4

5 Wheat Stem Maggot Insecticide Timing Study - Hettinger Treatment % White heads Yield* (bu/a) TW* (lbs/bu) Untreated check 8.3 a June 13 5-leaf & Jointing 1.3 cd June 20 E. boot 2.7 bc June 26 - heading 0.7 d July 5 - flowering 3.7 b Means followed by the same letter do not significantly differ (P=0.05, LSD). *Unreplicated data. Wheat Stem Maggot Insecticide Timing Study Todd Kautsman, Mott Grain Location - NE of Mott, ND HRSW, Variety Parshall Treatment Warrior (2.56 fl oz/a) + Quilt (12 fl oz/a) June 14 th at flag leaf Counted white heads on 500 heads 5

6 Wheat Stem Maggot Insecticide Timing Study Mott Grain Untreated: >12% White heads Treated: <1% White heads 13 bu/a yield increase! Wheat Stem Maggot Research Needs IPM Basic Biology - number of generations Plant stage(s) injured Field monitoring/scouting techniques Economic thresholds Impact of planting date Evaluation of hybrids for resistance Solid-stem varieties Chemical control and timing Impact on small grain production in the region 6

7 Wheat Stem Sawfly Adult Egg Pupa Larva Distribution of Wheat Stem Sawfly 7

8 Lodging caused by Wheat Stem Sawfly Wheat Stem Sawfly Insecticide Timing Study - Hettinger Treatment % Stem Infested Larvae* Yield* (bu/a) TW* (lbs/bu) Untreated check June 13 5-leaf & Jointing June 20 E. boot June 26 - heading July 5 - flowering *Unreplicated data. 8

9 Wheat Stem Sawfly Research Needs IPM Field monitoring/scouting techniques Economic thresholds Evaluation of hybrids for resistance Solid-stem varieties Degree of solidity necessary for resistance Chemical control and timing Impact on small grain production in the region Hessian Fly 2 generations per year Overwinter as prepupa ( flaxseed ) Female can lay 300 eggs over 3-5 day lifespan Larvae feed 7-14 d, inject toxic saliva Adults weak fliers Photos courtesy S. Blodgett, Montana State University; and Nebraska Extension Service 9

10 Hessian Fly Damage Stunt plant growth Stems break at headfilling stage Reduce tiller number 2nd brood cause poorly filled heads/low test weight 10

11 Orange Wheat Blossom Midge Sitodiplosis mosellana (Gehin) Increase in field observations of adult wheat midge during 2007 Increase in non-ipm spraying 2007 Soil Survey for Cocoons New factsheet Entomology Extension Factsheets Revised Wheat Stem Insect and Management Practice Biology and Management of Barley Thrips Grasshopper Biology and Management Wireworm Management for North Dakota Field Crops New Orange Blossom Wheat Midge 11

12 EPA Proposed Chlorpyrifos (Lorsban, Nufos, Warhawk, ) Cancelation Public Comment Period Open on or before: December 17, 2007 Important insecticide in wheat / durum Orange wheat blossom midge Small grain aphids Submit comment to: Docket ID # - EPA-HQ-OPP nent/main Farming isn t just a hobby or a job for those who grow hard red spring wheat and durum wheat. It is a family-owned business, a home and more importantly a way of life. ND Wheat Commission 12