Latin name: Phyllocoptes gracilis
Reason for Concern:
1) A problem primarily in blackberries (including ‘Logan’ and ‘Boysen’ berries).
2) Berries turn red, brown and dry, causing poor fruit quality that can lead to processor downgrading.
3) Late maturing varieties are particularly susceptible to damage as late mites migrate from winter cane buds to the fruit.
The whole fruit may be dry or have dry patches. Mites are about 1/100“long: use a hand lens or microscope. The body is sausage-shaped with 2 pairs of legs; yellow to brown in color and nearly transparent. Eggs, deposited in expanding leaf buds, are round, transparent.
Overwinters in exposed colonies of 200+ near cane buds of the previous season’s growth. In spring as leaflets separate, mites enter expanding leaf buds and lay eggs. Females lay about 80 eggs in a month’s time. Mites hatch and pass through 2 development stages taking 1 to 2 weeks. All stages of mite are present during summer and early fall with many overlapping generations each year. Mites overwinter as adult females in bark cracks and under bud scales.