Springtails: Because of the lull in pest activity, we thought this might be a good opportunity to go over a few details for identifying some insect pests and damage that you may encounter in the coming days. The first two pictures are of springtail feeding damage on cabbage and a springtail at a feeding site on squash. The feeding damage of springtails resembles that of flea beetles but does not penetrate all the way through the leaf. The thin layer of tissue that remains will eventually fall out and appear more like the typical shot-holing caused by flea beetles. The appearance of the damage on the leaves may be a better ID tool because both flea beetles and springtails can be difficult to spot in the field. Springtails are grayish in appearance and look like a small piece of dirt on the leaf. However, when disturbed the springtails will jump off the leaf much like the flea beetles. Typically, springtails will only be present under wet and high humidity conditions, such as we've been experiencing in the last several weeks. Infestations are typically limited to relatively small areas of a field and rarely cause economic damage. For further information refer to the VegEdge fact sheet.

Bean leaf beetle: The next two pictures are of bean leaf beetle (BLB) damage and adult BLB. BLB damage starts as small shot-holes in the unifoliate or trifoliate leaves and feeding continues until entire areas of the leaf are eaten and can lead to stand loss with high BLB populations. There are few insect pests that will defoliate snap bean leaves in this manner in Minnesota. So, if this damage appears in your field BLB is the likely candidate. Adult BLB can vary in color from yellowish to brown to red. Although it is most common to see beetles with four black spots on the wings, the adults can also have no spots. Therefore, the best characteristic to use for ID is the small black triangle that is present behind the head of the beetles. This distinguishes BLB from other common beetles you may see in the field such as northern and western corn rootworm and southern corn rootworm (also known as spotted cucumber beetle). For further information refer to the VegEdge fact sheet.

Pest identification is critical to making proper pest management decisions. Knowledge of the damage symptoms of the typical pests in a crop can help to differentiate not only which pest is causing damage but also if the damage is being caused by an insect, disease, nutrient or pesticide.