These mites overwinter in protected sites as eggs, immatures or adults depending on food hosts and habitat. Immatures and adults move to emerging plant hosts in the spring. They create webbing on the underside of leaves where they puncture cells to feed on cell contents. This feeding causes stippling, yellowing or browning of the leaves. Leaves may dry and drop which can further reduce crop yields.
Infestations start at the field edge and move inwards. Extended hot, dry conditions favour rapid population build up and exacerbate feeding injury.
For more information on the twospotted spider mite, check out our Insect of the Week page!
Twospotted spider mite – adult closeup
David Cappaert, Michigan State University, Bugwood.org
|Twospotted spider mite - stippling damage on bean|
Whitney Cranshaw, Colorado State University, Bugwood.org