2013 insect update fall ext conf jan compressed

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!