Updated: September 14, 2021
Watch for Aphids in Melons
Several reports lately of very deformed watermelon plants, but also a few cucumber and cantaloupe fields. These distortions (fig. 1) most of the time are being caused by melon aphids Aphis gossypii Glover. Melon aphids are small and range in color from a light/dark green mottle (fig. 2), which is most common to whitish, yellow (seen during hot, dry weather), pale green, and dark green almost black forms. The legs are pale with just the tips of some parts black. The cornicles also are black. One trait of melon aphids that make them particularly difficult to manage is that unlike other aphids, their populations do not fade with higher summer temperatures. Immatures look like adults, only smaller.
Updated: September 3, 2021
Scout Sorghum for Key Insect Pests
Although sorghum faces relatively few pests compared to our other grain crops, it is not a “plant and forget” crop. Sorghum is often grown on marginal ground, in areas with greater deer pressure, dryland fields, and as a rotational component for managing weed and disease pressure. Sorghum is generally a minor component of a farming operation, and as such is easy to overlook during the season, especially now as other pests are requiring more attention and corn is nearing harvest. However, there are two significant insect pests that need to be scouted for to avoid potential losses and both are active right now on Delmarva.
Updated: September 3, 2021
September IPM Insect Scouting Tips
Soybeans: Continue scouting for corn earworm, stink bugs, and soybean looper in double-crop fields. Defoliation thresholds at R5 are 15% and between 20 and 30% at R6. Corn earworm pheromone trapping information for Maryland can be found at https://extension.umd.edu/resource/corn-earworm-pheromone-trapping. NC State Extension has a good CEW threshold calculator can be used to help decide if it is worth treating: https://www.ces.ncsu.edu/wp-content/uploads/2017/08/CEW-calculator-v0.006.html. Stink bug thresholds are 5 bugs per 15 sweeps until the soybeans reach the R7 stage, after which treatment for stink bugs is not necessary.
Updated: September 2, 2021
Insect Pest Management in Potato
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.