David Owens, Extension Entomologist; firstname.lastname@example.org
Early Season Moth Activity
|Trap Location||True Armyworm per night||Black Cutworm per night|
|Smyrna, DE (Wilson)||—||5.4|
|Kenton, DE (Owls Nest)||3.4||1.0|
|Pearson’s Corner, DE||0.5||0.4|
Keep checking alfalfa fields for weevils and aphids. Aphid pressure needs to be high, around 50-100 per stem without natural enemies before a treatment is advised. If going out with an insecticide, pay attention to pre-harvest intervals. Lorsban works well against weevils but has longer PHIs than other insecticides and is rate dependent. Virginia reports very high aphid counts in fields treated earlier, especially when treated with a pyrethroid. Alfalfa recommendations can be found here: http://extension.udel.edu/ag/insect-management/alfalfa/.
Generally, cooler weather favors aphids. I don’t see how the weather could favor aphids any more by being cool than what we have had the past couple of weeks. Aphid counts continue to remain high in some fields. This week, reports have come in of small sawflies and early instar armyworm presence. Cereal leaf beetle egg lay has hit its peak, and eggs are beginning to hatch out. We are still seeing some fields with unusually high aphid activity. Although not a concern for right now, this is also a good time to remember some products have long pre-harvest intervals. You can find threshold and insecticide recommendations by scanning Crop cards passed out at Delaware Ag Week with a QR reader or by following this link: http://extension.udel.edu/ag/insect-management/small-grains/
There have been reports of corn infested with aphids, probably from nearby small grain. In most cases, seed treatment on the corn should provide good control of these aphids until natural enemies build up in the small grain and begin to control the source population.