Black cutworm

There were more intense catches with black cutworm this last week. With the number of storms this year, we have had many black cutworm moths caught. There have been reports of black cutworm over threshold in many areas of the state.

When your corn reaches the V6 stage of growth black cutworm does not continue to feed. If the corn is younger than V6, it is best to get out and scout fields. The threshold is 5% or more of the plants have been cut is the point to employ management. For more information, please few the following website:

Black Cutworm Damage

Black Cutworm

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

Field Corn Pheromone Trapping Interactive Map

Black Cutworm Degree Day Accumulations by Location

*Intense Catch is over 15 moths in a week.

Black Cutworm Degree Days (Base 50⁰ F) Lifecycle Growth Stages

Degree Days               Stage                           Feeding Activity

0                                  Moth Capture              Egg Laying

90                                Eggs Hatch

91-311                         1st to 3rd Instar           Leaf Feeding

312-364                       4th Instar                     Cutting Begins

365-430                       5th Instar                     Cutting Begins

431-640                       6th Instar                     Cutting Slows

641-989                       Pupa                            No feeding

Potato Leafhopper

There have been reports of potato leafhopper in alfalfa in NYS. They do not overwinter in NYS and ride on storms from the south. Once here they lay eggs on alfalfa and many other host plants. When the nymphs hatch is when the damage occurs. You want to avoid damage by scouting now. If you see the V-shaped yellowing of the leaf tips it is too late. The damage on yield and quality has happened.

For more information on potato leafhopper in alfalfa view the following site:

https://cals.cornell.edu/field-crops/forages/insects-forage-crops/potato-leafhopper

potato leafhopper damage

Alfalfa Weevil

While there may still be a few fields with alfalfa weevil larvae most of them have pupated and will not be feeding on alfalfa until the next season. 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 cocoon-at this stage of development feeding ends for the season.

Soybean Aphids

Soybean aphids have been reported in western NYS. These were not at threshold. It is thought that the 1^st generation of soybean aphids migrating off buckthorn to soybeans are controlled by the insecticide seed treatment on soybeans. For more information on soybean aphid, view the following website:

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

Soybean Aphid

Stagonospora blotcin Triticale

Stagonospora blotch has been reported on triticale on the lower leaves. We see this common disease in most fields of small grains each year. See the following website for more information: https://cals.cornell.edu/field-crops/small-grains/diseases-small-grains

Stagonospora blotch