Poplar Budgall Mite
Eriophyes parapopuli (Keifer)
Cottonwood, particularly the variety 'Siouxland'
Damage and Diagnosis
Life History and Habits
Biology of this mite is not well known. The mites overwinter primarily within the galls produced the previous season, as well as in protected areas around buds. In spring feeding within the old galls continues and mites begin to move to and feed on the new buds. As the buds develop, they become distorted and cover the mites. Reproduction appears to occur throughout the growing season.
There are two nymphal stages plus the adult stage. Ten to 14 days are required to complete one generation.
Predator mites are commonly associated with poplar budgall mites and presumably are important natural controls. Hard winters, which can kill the galled tissues, also appear important in limiting populations. Serious infestations rarely are sustained for long due to these natural controls.
Chemical control is difficult. The mites emerge from the galls over an extended period so repeat applications would be necessary to maintain adequate control. If attempted, sprays should be initiated before bud break. Dormant oil sprays may control mites and mite eggs near bud scales, but fail to sufficiently penetrate old galls.
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