Survey of gooseberry mite infestation in Ribes L.

During Dec.1997 and Jan. 1998, the gooseberry mite, Cecidophyopsis grossula riae Collinge, was observed to infest 48 currant and gooseberry (Ribes L.) cultivars in a field plantation in Corvallis, Ore. The mite was observed on 29 black currant, (Rabes nigrum L., two red currant [Ribes rubrum L. and R . sativum (Rchbch.) Syme], 12 gooseberry [R. uva-crispa L., R. oxyacanthoid es var. setosum (Lindley) Sinnot], and three R. xnidigrolaria Bauer cultiva rs and the hybrid R. nigrum x R. pauciflorum Turez. ex Pojark, A range of m ite infestation levels was observed, with some cultivars not being infested , some with light infestation, having 1 to 100 adult mites per bud, and som e heavily infested, with more than 100 mites per bud. On lightly infested b uds, the mites were inside bud and leaf scales; in heavily infested buds, m ites mere also observed on floral primordia. Scales of infested buds were o ften loose and appeared more open than noninfested ones. Mite distribution varied by branch within a plant. Black currant cultivars with the heaviest infestation of C. grossulariae were of Scandinavian, Russian, Scottish, and Canadian origin. The Russian black currant cultivar Tunnaja was the most h eavily infested with more than 1000 mites per bud. Floral primordia mere da maged in heavily infested buds.