Cereal Leaf Beetle (Oulema melanopus)

Cereal leaf beetle adults are starting to show up in small grains fields. They seem to prefer oats but can also cause damage in wheat and other small grains. They are laying eggs on leaves. The following photo is what to look for when scouting small grain fields.

This graphic helps better understand when to scout for the pest:

For more information on Cereal Leaf Beetle:

https://cals.cornell.edu/field-crops/small-grains/insects-small-grains

Black cutworm (Agrotis ipsilon) and True Armyworm (Mythimna unipuncta)

There was only one new location with an intense catch last week. This was black cutworm in Dutchess County in Eastern NY. Larvae should be present in the next week or so from the early intense catches.  Make sure to get out and scout for the larvae feeding on corn. This is a nocturnal pest so it is best to look under the soil around the base of the plant or crop residue. When they get to the 4^th instar is when they start cutting plants. The threshold to control is when they reach 5% of the corn plants cut in the field. Your insecticide seed treatments are supposed to control this pest early in the season.

Information on Black Cutworm

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

Information on True Armyworm

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

Field Crops Pheromone Trapping Network Interactive Map and Data

Black Cutworm Degree Day Accumulations and Life Stages

*Location for Intense Catches	Black Cutworm Degree Days (Base 50)	Life Stage
Seneca Falls Seneca County April 20	75	Egg Laying and Egg Development
Amenia Dutchess County April 28	99	1-3 Instar-Leaf Feeding
Seneca Falls Seneca County April 26	54	Egg Laying and Egg Development
Amenia Dutchess County May 3	96	1-3 Instar-Leaf Feeding
Seneca Falls Seneca County May 3	54	Egg Laying and Egg Development
Linwood NY Livingston County May 4	64	Egg Laying and Egg Development
Amenia Dutchess County May 10	64	Egg Laying and Egg Development

*Intense Catch is over 15 moths in a week.

True Armyworm Degree Day Accumulations and Life Stages

*Location for Intense Catches	True Armyworm Degree Days (Base 50)	Life Stage
Phelps Ontario County April 20	75	Egg Laying and Egg Development
Phelps Ontario County April 30	54	Egg Laying and Egg Development

*Intense Catch is over 15 moths in a week.

Alfalfa Weevil (Hypera postica)

Alfalfa weevil adults are present in fields and are laying eggs. Only the Hudson Valley and Long Island have 1^st to 2^nd instars at 50% occurrence of the life stage. This does not mean that fields in your area might have a small number of larvae that have hatched. They are not at the peak of that life stage yet. When scouting look for the hole in the leaves. The larvae feed on the buds before they unroll into leaflets. When they unroll it reveals the small holes in the leaflet.

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

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

Alfalfa Weevil Degree Day Accumulations from March 1 to May 15

Weather Station Location	Alfalfa Weevil	Life Stage
Arkport	225	Egg Laying
Bergan	231	Egg Laying
Canton	204	Egg Laying
Ceres	209	Egg Laying
Conesus Lake	239	Egg Laying
Corwin	207	Egg Laying
Geneva	225	Egg Laying
Highland	373	Leaf Feeding-1st instar
Ithaca	247	Egg Laying
Kinderhook	304	Egg Laying
Lafayette	245	Egg Laying
Laurens	200	Egg Laying
Northport	433	Leaf Feeding 2nd Instar
Peru	219	Egg Laying
Red Hook	315	Leaf Feeding-1st instar
Versailles	250	Egg Laying
Watertown	186	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