New Garden Pests Loom

There’s plenty of information out there about most common garden insects that are considered bests, such as the emerald ash borer or the Asian lady beetles (ladybugs). But now there are two more problem insects coming over the hill that diligent gardeners should be on the lookout for and educate themselves on. Now, new garden pests loom.

The first of the new invaders is the brown marmorated stink bug, “Halyomorpha halys,” is an invasive (non-native) pest originally from Asia. It was first found in Pennsylvania in 1998 but has steadily spread across the United States. It was first detected in Wisconsin in 2010 and by 2016 populations had caused damage to a wide range of fruit and vegetable crops, specifically apples, sweet corn, tomatoes, and pumpkins.

There are native stink bugs, some of them are beneficial, and they have natural predators. Therefore, they do not reach the destructive populations of the brown marmorated stink bug. Hence, it is important to correctly identify the brown marmorated stink bug before taking action. Size, distinctive bands on the abdomen and smooth shoulders are all distinguishing features. The website stopbmsb.org has clear photos to help differentiate between the species.

Brown marmorated stink bug adults look for warm places to overwinter. Inside houses, barns and in secluded garden areas are a prime home to a cold brown marmorated stink bug. Eggs are laid in the spring and a single female can lay nearly 500 eggs in her lifetime. They feed by piercing the fruit and sucking out the juices. Not only does this damage the fruit, but it leaves it susceptible to disease.

The brown marmorated stink bug can be removed by hand picking or vacuuming when populations are low. If numbers escalate, chemical control may become necessary. By all means, keep them out of the house. Install weather stripping around doors, caulk cracks and put screens over the chimney or other entry points. Under no circumstances should a person crush a brown marmorated stink bug. They come by their name legitimately since the odor they omit is offensive and will linger for days.

A second and yet even more problematic insect is the spotted wing drosophila, “Drosophila suzukii.” This invasive insect also hails from Asia. It was first discovered in the continental United Stated in California in 2008. It spread rapidly and by 2010 was in many Wisconsin counties.
Spotted wing drosophila is a type of vinegar fly, commonly referred to as “fruit flies.” The biggest difference is that fruit flies feed on dead or damaged fruit. The female spotted wing drosophila has a serrated ovipositor, or a sharp keister, that allows her to cut into healthy fruit and lay her eggs. This pest poses a hazard to most berries and tree fruits; however, they seem to have a special affinity to raspberries.

Traps made with a 32-ounce container, dish soap, water, and yeast are particularly effective with spotted wing drosophila. (See hort.uwex.edu/articles/spotted-wing-drosophila for further information.) They are attracted to damaged fruit, so keep the raspberry patch meticulously clean, tossing out each and every damaged fruit. Harvest frequently to keep fruit from over-ripening.