Review of Insect Problems in

Field Crops in 2013

Janet Knodel, Venkata Chapara

and Patrick Beauzay

Extension Entomology

Fall Extension Conference

October 22-25, 2013

Forages – Alfalfa Weevil

Increasing numbers in ND,

especially SW, SC and NC!

Reduces crop yield, crop quality, protein

content, and digestibility

Primarily on 1st cutting

Occasionally re-growth of 2nd cutting

Field Damaged by Alfalfa Weevil

Frosted Appearance

Alfalfa Weevil

Sampling – Stem Counts• Bucket 30-stem method

• Select 30 stems from 5 sites• Beat stems into bucket• Determine average # of

larvae/stem (see next 2 slides)• Determine average height of

alfalfa

Nominal Threshold (not as accurate)

IF, 30-40% damaged stems

Alfalfa Weevil IPM in ND• Early harvest!

• Do not apply insecticide unless weevils are at ECONOMIC THRESHOLD levels

– Before 1st Cutting

• Calculated ET for larvae/stem from 30-stem bucket method (or nominal threshold = 30-40% of stems damaged)

– After 1st cutting, 50% of crowns have weevil feeding or 8 or more larvae/ft2 (6/ft2 on sandy soil); and larvae are suppressing regrowth

• E1676 „IPM of Alfalfa Weevil in ND‟

Red Sunflower Seed Weevil

Adult

• Increasing pressures in SC, SW and NC ND

• Studies with Prevathon (new sunflower insecticide) from

Dupont for control of RSSW

• Rynaxypyr® new mode of action

• Ryanodine receptor activator (IRAC Group 28)

• Active against a broad range of chewing insects

• 2013 data being tabulated for NSA Forum in Jan. 2014

Larva

Drop into soil to overwinter

European Corn Borer

Female moth

Egg mass at“black-head “ stage

Newly laid egg mass

Increasing problem in

NC Region of ND

where non-Bt corn is

grown

European Corn Borer

Entry hole in stalk

Tunneling ECB larva

ECB pupa in stalk

Corn Borer Damage . . .

• Shot-hole damage to whorl

Greatest Yield Impact: physiological

loss from tunneling damage that stops

flow of sap, water, nutrients through

stalks (> all the above combined).

• Broken stalks

• Dropped ears

Corn Rootworms in Corn

Western Corn RootwormDiabrotica virgifera virgifera LeConte

Northern Corn RootwormDiabrotica barberi Smith

Corn Rootworm - Damage

Goose-necked Corn

⅛-½ inch long

Corn Rootworm Damage

Photo courtesy by Dr. Joel Ransom, NDSU Extension Cereals

This photograph was taken near Arthur, ND in 2013!

Western Corn Rootworm

Diabrotica virgifera virgifera

• Gassmann et al. 2011 Field-Evolved Resistance

to Bt Maize by Western Corn Rootworm

PloS ONE 6(7): e22629

– Cry3Bb1 protein

– Iowa

– 2012 - Illinois, Minnesota, Nebraska

– Continuous corn > 3 years

– Relied on a single Bt trait for control CRW

– Increased lodging and root feeding on Bt

hybrids with CRW-resistant trait

North Dakota in 2012-2013

• Increasing numbers of adult

WCRWs in SE ND

• Concerned about CRW resistance

to Bt corn (not been documented in

ND yet)

• Study funded by ND Corn Council to

examine Bt-traits and efficacy

against CRWs in ND

– In collaboration with Dr. Ransom and

Dr. Boetel

‘High’ Risk Corn Fields for

CRW Resistance

• Continuous corn for more

than 3 years

• Same Bt trait (e.g., Cry3Bb1)

for more than 3 years

• Lots of volunteer corn in

soybean fields (good food

source for resistant CRW)

CRW Trap Survey in ND

• Monitoring for adult CRWs

• Determine species and

abundance

• Pherocon AM (yellow trap)

• Scentry Multigard (green trap)

• Mid-August to September

• Results being tabulated

Soybean Aphid• „Hot‟ spots in 2013, mainly eastern ND

• ND Soybean Council Study to determine „best‟

pest management strategies:

– Seed treatments (insecticides and fungicides)

– Different modes of action (OP, pyrethroid and

neonicotinoid) for foliar insecticide application

– Different timings (R1, ET of 250 aphids/plant, 100

aphids/plant)

– Rag1 aphid-resistant variety

• Results will be presented at “2014 Getting It

Right Soybean Production Meetings” at Velva,

Mohall and Wishek.

• 2013 Wheat

Midge Risk

forecast was for

low populations

in 2013 due in

part to drought

of 2012

• 2013 soil

samples are

being collected

for laboratory

counting of

cocoons

New Insect Pest Detections in 2013

• Spotted wing Drosophila (see next slide)

• Japanese Beetle

– Not detected in pheromone traps (not overwintering)

– Re-introduced again in 2013 from trucks from MN

nursery with JB-infested nursery stock

– Stark, Burleigh, Ward, Grand Forks and Cass

• Cereal Leaf Beetle

– Confirmed in 3 new counties

• Ward County at NCREC in Minot, Burke County near

Flaxton, and Renville County near Mohall

– Export concern of cereal hay to Canada and CA

Spotted-wing Drosophila (fruit fly)

• First detection in CA in 2008

• Attacks healthy fruits

– Raspberries

– Strawberries

– Other soft & hard fruits

• Confirmed in ND in 2013

– 13 counties so far

– Burke, Burleigh, Cass, Cavalier, Grand Forks, Foster,

Stark, Logan, McLean, Mercer, Morton, Pembina, Stark

Protect our Pollinators!

New EPA Bee Advisory Box on

pesticide labels to help

protect pollinators

„New‟ Extension Publications

• E1676 IPM of Alfalfa Weevil in ND

• E1640 Dry Bean Grower Survey of

Production, Pest Problems and

Pesticide Use in MN and ND

• E1143 ND Field Crop Insect

Management Guide

• PP1635 Dutch Elm Disease in ND: A

New Look

• A1636 Growing Lentils in ND

• E1634 Emerald Ash Borer Biology and

IPM in ND

• E1631 IPM of Japanese Beetle in ND

Upcoming Extension

Entomology Publications

• Spotted wing Drosophila

• European Corn Borer (revised)

• Corn Rootworms

• Spider mites in Soybean, Dry Bean and Field

Corn

• Cereal Leaf Beetle (revised)

• Honey bee & pesticide safety (revised)

• Grasshoppers (revised)

• Wireworms (revised)

NDSU Crop & Pest Report• Free to subscribers with email but MUST SIGN-UP ON WEBSITE!!!

(Do not need to re-sign up if you subscribed in 2013)

• Remember to sign-up and encourage others!

– http://www.ag.ndsu.edu/cpr/

Thank you!