Insect Pest - Invasive

Soybean: Scout for the usual defoliators, including bean leaf beetle, Japanese beetle, and caterpillars. The treatment threshold is 15-20% defoliation for bloom to pod fill. Note that defoliation percentages should be based on the entire soybean plant or canopy, not just the top leaves or worst leaves. University of Nebraska Extension has a nice guide for defoliating insects in soybeans (https://croptechcafe.org/defoliating-insects-in-soybeans-thresholds-training-and-tools/). Adult Dectes Stem Borer will be emerging over the next several weeks. Chemical control is not recommended since it would require multiple applications to reduce larval infestations, which is not economical. However, if a high number of adults are found, harvesting that field as soon as it matures will reduce losses associated with lodged plants.

I have seen and have gotten reports of stinkbug damage in tomatoes over the past few days. Stinkbug feeding damage is called cloudy spot in tomato fruit (fig. 1). It occurs when the adult or immature stinkbug puts its needle- like mouth part into the fruit and removes material from a large number of cells.

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. 

A few blueberry and cherry growers in central Maryland have reported fruit damage to their crop from Spotted Wing Drosophila (SWD) this week. If you grow any small fruit such as blueberries, cherries, blackberries, raspberries it would be best if you check these crops for the presence of SWD.

Podisus maculiventris, better known as the spined soldier bug (Figure 1), is a close relative of the invasive brown marmorated stink bug (BMSB, Figure 2). However, the spined soldier bug is not only deemed nonthreatening to crops, gardens, and ornamentals, but is beneficial to their health. It is important to identify which type of stink bugs you are dealing with before you move forward with pest management.

Growers and an alert county agent, Ben Beale, have found what most likely will be an infestation of spotted wing drosophila (SWD) in cherries in southern Maryland (St. Mary’s County). I say "most likely" because I have the cherries and the maggots but it is very difficult to identify SWD from other fruit or vinegar fly maggots.

The invasive spotted-wing drosophila (SWD) is the key insect pest of soft-skinned fruit across the United States. With the recent wet weather, we have been experiencing higher than normal spotted wing drosophila (SWD) pressure.

Fruit and Vegetable News, Volume 12, Issue 4 (July 15, 2021)

Spotted-wing drosophila (SWD, Drosophila suzukii) is a small fly that lays its eggs into ripening and ripe soft-skinned fruit, causing direct damage and wounds that other pests and pathogens can use. Although they prefer fully colored ripe fruit, they are capable of infesting fruit that is just starting to turn color and will do so when populations are high.

Timely Viticulture is an electronic newsletter designed to remind grape producers of seasonal vineyard needs and considerations throughout the year.