THE TWO-SPOTTED SPIDER MITE, Te-tranychus urticae Koch, is a persistent and destructive pest of pears in California. Bartlett pears are particularly susceptible to this mite, and severe defoliation can occur in relatively short periods of time. Contributing to the severity of mite infestations is the presence of weed hosts, such as morning glory (bindweed), around the base of tree trunks. These weeds can support large numbers of mites which will move up into the foliage when the weeds dry out or are treated with herbicides. Further complicating the mite control picture, is the necessity for chemical control of the codling moth, Laspeyresia pomonella (L.), which can result in the supression of naturally occurring or introduced mite predators.