Grass pest moths detected

Apamea moths are flying now. Larvae are cutworm pests of grasses.

Apamea cutworms can be serious pests of grasses. There are a few different species that are common in this region. Two of them have fun common names.

A. cogitata, the thoughtful Apamea

and its more unfortunate contrary:

A. dubitans, the doubtful Apamea

The current activity of this common group of moths is not of direct concern. Rather, it is the active, overwintering larvae that are considered pests because they feed on grass roots.  A. dubitans and A. cogitata could be similar to the congeneric A. devastator, which only has 1 generation per year. I made a post about them in February.

In western Oregon, glassy cutworm (Apamea devastator) moths emerge in late June, peak in July, and larvae take 100-120 days to develop, depending on daylength1. The species we caught in traps this week (thoughtful and doubtful) are less well-studied. But I wager a guess that we could begin to see larvae in fields by about mid-September.

Fun fact: “cogitare” translates from Latin as “to think”. One of Francis Bacon’s most famous works “Cogitata et visa” (“Thoughts and Conclusions”) was written in 1612. In it, he posed that philosophy and science have common interests.

1 Kamm, 1990. Biological observations of glassy cutworm in western Oregon. Pan-Pac.Ent. vol. 66