Insect identification and scouting
Sticky wing pheromone traps are very useful for detecting moth activity at a low cost. Typically, the moth counts in traps provides a forecast for caterpillar activity in crops in the coming days (caterpillars must be confirmed by direct counts in the crop). Based on sticky wing pheromone counts from 14 locations across Alabama (mix of commercial farms and research stations with peanuts and/or horticultural crops), we have some clear trends on increasing moth activity that are summarized here.
Counts and Trends
Over the past 15 days, we have collected the following from various locations:
- 13 tobacco budworm (TBW) moths
- 8 corn earworm (CEW)
- 92 beet armyworm (BAW)
- 14 fall armyworm (FAW)
- 25 cabbage looper (CL)
- 3 soybean looper (SL)
- 416 lesser cornstalk borer (LCB)
- 55 squash vine borer (SVB) moths
Clearly, there is lot more beet armyworm activity compared to the fall armyworm that typically migrate late to row crops like peanuts. We have noticed a high number of cabbage looper caterpillars feeding in vegetable crops which corresponds to the high moth numbers seen in sticky wing traps.
LCB is a good indicator species for drought and stress conditions. The high moth numbers is a sign of increased risk to crops like peanuts later in the season. LCB is a hidden threat in peanuts and can cause high crop damage to late-stage peanuts; irrigation for improving soil moisture significantly reduces the threat.
Squash vine borers have a limited host plant range and can reduce yields as caterpillars bore into the stem. The vine borer moth is a red moth that behaves like a wasp, trying to lay eggs at plant bases. Vine borer activity is favored by the drought conditions experienced over the past several weeks. Even with one or two generations of these moths, the damage to commercial crops or garden crops can be significant. So, stay alert and keep reading IPM pest alerts throughout the summer.
While looking for caterpillars and other insect pests, don’t forget to take into account the beneficial insect populations that are critical for small insect control, such as aphids, whiteflies, thrips, spider mites, and others that often take on pest status this time of year.
Rampant use of organic or conventional insecticides only aggravates pest species. For detailed insect pest management information, refer to the Southeastern Vegetable Production Guide or the Peanut IPM Guide after confirming infestation. Contact an Alabama Extension regional agent for assistance with crop scouting and pest identification services. Stay connected with pest outbreaks and management recommendations by subscribing to the Alabama IPM Communicator newsletter.