Below is a brief discussion of the seasonal activity of thrips and some major caterpillar pests based on moth catches from sticky wing pheromone traps that have also been summarized in the graphs. For detailed peanut insect pest scouting and control recommendations, please refer to the Alabama Peanut IPM Guide.
Thrips as an early season peanut pest is a common issue throughout Alabama. In the research plots in Headland have been severely affected by thrips with damage ratings in untreated check plots nearly 80% loss of terminal leaves in the three-week old plants.
Peanuts with soil treatments such as Thimet, Admire Pro, Velum, and Orthene in single rows looked remarkably healthier compared to the untreated check (see picture below). Foliar treatments for thrips include Radiant (spinetoram), Besiege (premix), and Orthene (acephate).
Check your plant condition and thrips pressure before using foliar treatments as they can also wipe out beneficial insects.
Lesser cornstalk borer (LCB): This year we have found plenty of lesser cornstalk borer in Headland before the rains. On June 8, we counted nearly 11 LCB larva from 40 samples during the dry spell. Moth numbers were 109 during the week.
On June 15, LCB moth counts reduced to 94 and only three caterpillars collected from the plot survey after the prolonged rain. LCB really like dry sandy soil, so watch those peanuts by pulling them out across several locations and watch for larvae and/or webbing.
Armyworm update: Beet armyworm (BAW) moths are definitely on the move to peanuts and other crops in South Alabama. Moth numbers are around 28 to 34 moths per week for the past two weeks. You may start seeing caterpillars emerging from egg masses deposited by females on the lower surface of leaves (see picture below).
Look at the terminal leaves while scouting for thrips and other insects as many insects lay eggs on those soft leaves. Fall armyworm (FAW) moth numbers near peanut fields has been low at this point; they could mainly infesting hay and pasture fields. July and August are typical times when we see migration of several different species of armyworms to peanuts.
Last but not the least, watch for corn earworms and tobacco budworms. Corn earworms appear to be more active compared to the budworms and it is important to correctly identify the species. If your peanuts are small and insect pressure is low, then it is wise to ease up on foliar treatments so that you have control options when you really need them.
Spraying with quick knockdown chemicals hurts the natural enemies (e.g., ground beetles, assassin bugs) that may be providing you good control of small caterpillars.
For any further information about peanut insects, check out the Alabama Peanut IPM website or call 251-331-8416. Stay in touch with your agronomic crop regional extension agent for immediate assistance.