Insect control in peanuts
Scouting for insect pests is a critical component of an integrated pest management (IPM) system. Scouting involves correct identification of pest species, determination of infestation levels, and reliable estimation of crop damage. Once scouting confirms the presence of insect pests, a well-planned monitoring program can assist in making management decisions. Remember that “no treatment” is also considered an IPM tactic when treatment is not justifiable.
This article is intended to provide information about scouting techniques for some soil-dwelling insect pests of peanuts; however, this is not an all-inclusive list of insect pests, and sampling methodologies may require modifications depending on location, crop type, growth stage, sampling time, cost, etc. Note that soil sampling is not a perfected method, and a scout may have to check the foliage in conjunction with soil or roots to complement soil sampling. The experience of a scout can also affect accuracy of sampling.
Various sampling methods are described in this publication. The germinating seed bait technique is detailed in this article, and some critical details about overwintering stages and insect behavior are included in order to assist field scouts. Refer to ANR-1351 for soil insect pest identification.
The Alabama IPM pheromone trapping project is a new team endeavor started in 2009 that is aimed at monitoring about a dozen critical insect pests of peanuts (and vegetables) in order to generate insect advisories for farmers. Alabama insect pest advisories for both peanuts and vegetables can be found at www.aces.edu/go/85 and www.agfax.com.
Burrower Bugs (Hemiptera: Cydinidae)
About six species of burrower bugs have been reported from peanut farmers in several states. The predominant species is Pangaeus bilineatus, and it may cause direct kernel injury. Adult bugs hide under rocks, crop stubble, volunteer plants, and decaying wood for winter protection. Read more about burrower bugs and scouting methods.
Whitefringed Beetles (Coleoptera: Curculionidae)
This insect (Naupactus sp.) is a native of South America. It was first reported from Florida in 1936, but it is now present in over a dozen states, its dispersion facilitated by commercial activities. Larvae or grubs move to a depth of 10 to 12 inches for overwintering. Grubs move within 3 to 4 inches of soil to pupate. Eggs laid in soil can also overwinter. Read more about whitefringed beetles and scouting methods.
Southern Corn Rootworms (Coleoptera: Chrysomelidae)
The southern corn rootworm (SCRW), Diabrotica undecimpunctata howardi, is the immature form of the spotted cucumber beetle. Read more about southern corn rootworm and scouting methods.
Lesser Cornstalk Borer (Lepidoptera: Pyralidae)
The lesser cornstalk borer (LCB), Elasmopalpus lignosellus, is one of the major insect pests of peanuts in some parts of Alabama. Research indicates that LCB is better able to survive dry soil conditions in which its natural predators cannot thrive. This anomaly results in a greater incidence of LCB in the soil. Read more about lesser cornstalk borer and scouting methods.
Wireworms (Coleoptera: Elateridae)
Wireworms have become the major insect pest of peanuts under certain cropping conditions. Several species of wireworms occur in peanut fields, so an independent description for all species is not provided in this publication. Wireworms can cause significant late-season loss of peanut pods. Read more about wireworms and scouting methods.
Germinating Seed Bait Technique for Intensive Sampling Advantages
The germinating seed bait technique has been shown to be the most cost-effective relative sampling technique for a variety of subterranean insect pests. The seed bait technique can complement or replace an absolute sampling method such as spade sampling, which could be laborious and time-consuming in an intensive sampling program. The germinating seed bait technique has been used successfully in agronomic crops, vegetable crops, pasture, and fields under the Conservation Reserve Program; this method is relatively easy to set up and remove. Materials Untreated corn/wheat/sorghum seeds, water, black polyethylene trash bag, shovel, large resealable plastic bag (optional). Read more about Germinating Seed Bait Technique for Intensive Sampling Advantages.