Thrips obscuratus: A Pest of Stonefruit in New Zealand

Abstract

The biology and economic importance of Thrips obscuratus in New Zealand are discussed. In spring, feeding by adults and larvae on nectarine ovaries and small fruits results in irregularly shaped blocks of russet and fruit distortion. T. obscuratus infests nectarines and peaches at harvest when adults feed and oviposit on fruits. Feeding damage on mature fruit is minor, but the main economic concern is contamination of export fruit. Adults and larvae are found throughout the year where food plant flowers are available, in stone fruit populations numbers peak in midsummer. There is no reproductive diapause so continuous generations can occur. Natural enemies do not appear to have a significant impact on population size.