NYS IPM Field Crops Pest Report-May 8, 2023

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Contents

Black cutworm and True armyworm

There have been intense catches of black cutworm and true armyworm moths with our field corn pheromone-trapping network in both Eastern and Western NY. We have caught a lot of black cutworm moths near Amenia, NY in Dutchess County. There have been several intense catches of black cutworm and true armyworm near Seneca Castle and Linwood in Western NY. There have not been enough degree days yet for he eggs to hatch. It is best to keep a close eye on fields over the next few weeks. Remember if your corn is not planted yet and you till the soil and moths have laid eggs it will have little to no effect on the insect in the field. The moths will lay eggs on grassy weeds in fields. Once the weeds have been eliminated, they can focus on your corn. Make sure to get out and scout for both these insect pests. Black cutworm and true armyworm can do a lot of damage if in high numbers and undetected.

Information on Black Cutworm

https://cals.cornell.edu/field-crops/corn/insects-corn/cutworms

photo of a black cutworm Moth

Black Cutworm Moth-Photo by Jaime Cummings

photo of Black Cutworm Damage

Black Cutworm Damage

Information on True Armyworm

https://cals.cornell.edu/field-crops/corn/insects-corn/armyworms

this is a photo of true armyworm

True Armyworm

The is damage by armyworm on corn plants in the 2nd leaf stage. They feed form the edge of the leaf into the midrid

True Armyworm Damage

Field Crops Pheromone Trapping Network Interactive Map

 

Black Cutworm Degree Day Accumulations

*Location for Intense Catches

Black Cutworm

(Base 50)

Life Stage

Seneca Falls

Seneca County

April 20

 

25 Egg Laying and Egg Development

Amenia

Dutchess County

April 28

40 Egg Laying and Egg Development

Seneca Falls

Seneca County

April 26

13 Egg Laying and Egg Development

Amenia

Dutchess County

May 3

36 Egg Laying and Egg Development

Seneca Falls

Seneca County

May 3

13 Egg Laying and Egg Development

Linwood NY

Livingston County

May 4

13 Egg Laying and Egg Development

*Intense Catch is over 15 moths in a week.

True Armyworm Degree Day Accumulations

*Location for Intense Catches

True Armyworm

(Base 50)

Life Stage

Seneca Falls

Seneca County

April 20

 

25 Egg Laying and Egg Development

Seneca Falls

Seneca County

April 26

13 Egg Laying and Egg Development

*Intense Catch is over 15 moths in a week.

 

Alfalfa Weevil

Alfalfa weevil adults should be in fields laying eggs. There should be very few larvae present in fields. In the next week or so larvae should be present. Start gearing up to scout alfalfa fields.

For more on alfalfa weevil please view the link to management information:

https://cals.cornell.edu/field-crops/forages/insects-forage-crops/alfalfa-weevil

This is a photo of alfalfa weevil. They have a snout and a dark strip down their back

Alfalfa Weevil Adult

This is a photo of the hole alfalfa weevil chew a hole in a stem to lay eggs.

This is a photo of alfalfa weevil eggs.

Alfalfa Weevil Degree Day Accumulations from March 1 to May 8

Weather Station Location Alfalfa Weevil Life Stage
Arkport 170 Egg Laying
Bergan 166 Egg Laying
Canton 150 Egg Laying
Ceres 164 Egg Laying
Conesus Lake 184 Egg Laying
Corwin 137 Egg Laying
Geneva 173 Egg Laying
Highland 280 Hatching
Ithaca 201 Egg Laying
Kinderhook 230 Egg Laying
Laurens 156 Egg Laying
Northport 327 2nd Instar
Peru 151 Egg Laying
Red Hook 234 Egg Laying
Versailles 196 Egg Laying
Watertown 140 Egg Laying

 

Alfalfa Weevil Life Stage Development

Growing Degree Days for peak (50%) occurrence of stage

Stage of Life Cycle Degree Days *
eggs hatch 280
Instar 1 315
Instar 2 395
Instar 3 470
Instar 4 550
Cocooning 600
Pupa 725
Adult Emergence 815

*48 degree F base temperature