With farmers across several states enduring drought conditions, it’s prime time for spider mites to make their move. These sucking, biting pests can damage the crop’s photosynthetic abilities, thereby hurting yields. In addition, any stressor opens the crops up to more disease.
“Proper identification of the mite species present in a field is essential for making control recommendations and selecting an appropriate pesticide,” according to the University of Nebraska Extension (UNL). One mite is harder to control than the other, and certain pesticides can even increase that mite’s population.
There are two types of spider mites to monitor: Banks grass mite (BGM) and two-spotted spider mite (TSM). TSM is the more troublesome and harder to control of the two species. Because mites are so small, typically requiring a magnified glass to see them, you cannot rely on appearance alone to differentiate them.
Here are some of the ways to distinguish between TSM and BGM, according to UNL.
Two Spotted Spider Mite
- Dark green in two distinct spots on the front half of the body
- Rounded body
- Spider-like silk webbing, typically produces more webs than BGM
- Hosts include many grass species, soybeans, fruit trees, vegetables and ornamentals
- Mid- to late-season pest
- Feeds on entire plant
- Overwinters in primarily alfalfa and other broadleaves along crop field borders
- Has resistance so control is more difficult
Banks Grass Mite
- Dark green pigment spots extend down length of body
- Elongated body
- Spider-like silk webbing
- Hosts are almost exclusively grass, such as corn and sorghum
- Early season pest
- Attacks lower leaves mostly, moves upward as infestation grows
- Overwinters in crowns of winter wheat and native grasses
- Moderately susceptible to common miticides
“When the weather in June, July and August is especially hot and dry, mites can reach damaging numbers,” UNL continues.
