July 25, 2022

NYS IPM Weekly Field Crops Pest Report-July 25, 2022

Potato Leafhopper in Alfalfa

There have been a few reports of potato leafhopper (PLH) in alfalfa over threshold this last week. If you see V-shaped yellowing you have caught it too late. It is best to harvest the field or if the alfalfa is short clip it and scout the regrowth. Once the alfalfa shows the damage the field has lost yield and quality. Avoid large infestations by getting out and scouting your fields now!

For more information on thresholds and management, view the following video:

IPM for Potato Leafhopper on Alfalfa

A photo of potato leafhopper damage to alfalfa

Potato Leafhopper damage

A photo of potato leafhopper damage to alfalfa

Potato leafhopper damage

Western Bean Cutworm

So far this season western bean cutworm catches have been low. However, they are coming. Last year’s peak flight was this week. Unless they explode this week, the peak flight will be the first part of August. Western bean cutworm prefers laying eggs on corn at this stage.  Make sure to get out and scout your pretassel corn. You are scouting for small larvae and eggs laid on the leaves.

For more information, view the following website: https://cals.cornell.edu/field-crops/corn/insects-corn/western-bean-cutworm

Western Bean Cutworm Eggs on Corn Leaf-Photo by Mike Hunter

Western Bean Cutworm Eggs on Corn Leaf-Photo by Mike Hunter

Photo by Mike Hunter-1st instar western bean cutworm larvae

Photo by Mike Hunter-1st instar western bean cutworm larvae

Field Corn Pheromone Trapping Network Interactive Map

 

Fall Armyworm

Fall Armyworm catches have been very low so far this season. We have a limited number of traps across the state. So far, we have only caught a few moths. For more information please view the following website: https://extension.entm.purdue.edu/fieldcropsipm/insects/fall-armyworm.php

This is a phot of fall armyworm damage to fields corn. There are a lot of long hole elongated up and down the leaf from larval feeding.

Fall Armyworm Damage

Soybean Aphids on Soybeans

Soybean aphids populations have been low to moderate this last week. It is best to get out and scout for aphids from the R1-R6 stage of growth. For more information, view the following website:

https://cals.cornell.edu/field-crops/soybeans/insects-soybeans/soybean-aphid.

 

This is a photo of light green tiny soybean aphids on a soybean leaf

190 soybean aphids on the leaflet

Spider Mites on Soybeans

Spider mites have been reported on soybean in areas of the state that has been dry and hot. There have not been reports of them being over threshold. It is important to get out and scout for them in areas of the state that stay hot and dry.  For more information please view the following website: https://cals.cornell.edu/field-crops/soybeans/insects-soybeans/two-spotted-spider-mites

This is a photo of spider mites on soybeans.

Spider mites on soybeans-Photo by Mike Stanyard

Foliar Diseases of Field Corn

There have been minor reports of foliar diseases of field corn. Gray Leaf Spot, Northern Corn Blight,

and Eye Spot have been found in corn fields in Western NY. For more information on diseases of corn please view the following website: https://cals.cornell.edu/field-crops/corn/diseases-corn

This is Gray Leaf spot on Corn. It has little match stick like lesions.

Gray Leaf spot on Corn

This is a photo of Northern corn leaf blight. It has long cigar like lesions running up and down the leaf. The range from a 1/2 inches to  5 inches long.

Northern corn leaf blight