Insect Pest - Beetles

IPM Threshold Guide for Vegetable Crops

Insect Pest Management in Peppers

Insect Pests of Tomato

IPM Threshold Guide for Agronomic Field Crops

Potato production in Maryland continues to grow and has more than doubled in the last 5 years, while in surrounding states it has declined. About 50% of the potatoes harvested in Maryland are for the fresh market while the other half goes for processing. Because of its value growers frequently apply pesticides too often in order to protect their investment. This often leads to the development of insect resistance, environmental contamination, worker and food safety concerns and poor management of pests.

The Asian Longhorned beetle (ALB), native to eastern China and Korea, is a wood-boring pest which feeds on a number of hardwood trees, eventually killing them, impacting both urban trees and forested sites. Wildlife habitat will be impacted due to loss of forest shelter and food sources. Industries such as such as lumber, maple syrup, nursery, commercial fruit, and tourism will feel an economic impact.

In order to capture the range of pest pressures and growing conditions in Maryland, we replicated our study across 3 UMD research farms (Keedysville, Beltsville, and Queenstown) and over 3 years (2020-2022). At each location we planted one field of a Bt hybrid and one field of a similarly-yielding non-Bt hybrid as early as possible in the growing season (Table 1). In 2020 our Bt hybrid was LC1196 VT2P (Local Seed, Memphis, TN) which expresses Cry1A.105/Cry2Ab2 proteins. In 2021 and 2022 we planted P1197YHR (Pioneer Hi-bred International. Johnston, IA) which contains Cry1Ab and Cry1F proteins. We planted P1197LR (Pioneer Hi-bred International, Inc. Johnston, IA) for our non-Bt hybrid all three years. All hybrids had excellent yield potential and were grown with standard no-till practices. In each field we established 3 replicates of 3 treatments at planting: 1) an untreated control, with bare seed and no in-furrow product, 2) an in-furrow pyrethroid treatment using Capture LFR® (active ingredient: bifenthrin, rate: 13.6 fl oz/acre), and 3) an NST treatment using Poncho® (active ingredient: clothianidin, rate: 0.25 mg/seed). Each replicate consisted of 24 rows of corn at 30 inch row spacing, and was 200 feet long.

Samples of sweet potatoes from southern Maryland and the Eastern Shore have shown feeding damage from either wireworms or white grubs. Wireworms bore shallow holes into the surface of sweet potato roots. Multiple species of wireworm can attack sweet potato.

There have been problems in our vegetable fields with three pests, which include striped cucumber beetles, leafhoppers and twospotted spider mites. I think most of the problems we are having with these three comes from our mild winter as each has had an outbreak population after a mild winter sometime in the last 12 years.

The cool, wet spring weather we have been experiencing favors slugs, so be on the lookout for slug damage. Slug damage may easily be confused for sap beetle feeding, but management of these pests is very different, so it is important to correctly identify the problem. Both pests can be common in matted row production. Authors: Sankara Ganesh, Maria Cramer, and Kelly Hamby, Department of Entomology, University of Maryland, College Park