The currant fruit-fly, Epochra canadensis Loew, in Manitoba ; and, Optimum feeding temperatures for the dark-sided cutworm, Euxoa messoria Harris

Abstract

The currant fruit fly, Epochra canadensis, Loew attacks red and white currants (Ribes rubrum L.), flowering currant (Ribes aureum, Pursh) and probably black currant (Ribes nigrum L.) in Manitoba, Instances have been reported of injury to black currants but it was impossible to verify these reports. In other parts of America where this insect is found, black currants and also gooseberries are included in the list of host plants. The currant fruit fly is probably the most destructive insect attacking red and white currants in Manitoba. The damage is caused by the females ovipositing in the partially grown currants. The developing maggots cause many of the currants to ripen prematurely and drop from the bushes. Other infested currants may remain on the bushes until the unifested fruit is ripe. Usually, however, there is a heavy drop from the bushes before the uninjured portion of the fruit is ripe. In some instances as much as fifty per cent of the currant crop falls from the bushes due to the injury caused by this insect. If small white maggots are found within the prematurely ripening currants one may be certain of the identity of the insect as no other insect attacks this fruit in a similar manner in Manitoba....