PARASITISM OF THE ORIENTAL FRUIT MOTH, GRAPHOLITHA MOLESTA (LEPIDOPTERA: TORTRICIDAE), IN AN UNSPRAYED PEACH ORCHARD ON THE NIAGARA PENINSULA, ONTARIO

Abstract

Eight species of insects parasitic on the Oriental fruit moth, Grapholitha molesta (Busck), were reared from host larvae collected in a peach orchard that was unsprayed since 1962. Macrocentrus ancylivorus Rohwer was the dominant species and parasitized between 40 and 50% of first and second generation larvae from 1964 to 1966. Despite this the parasite did not appear to be a controlling factor in these years and population fluctuations of the fruit moth resulted from other causes. In 1967 parasitism rose sharply to 61% in the first generation and 74% in the second. Low adult emergence in the second generation was related directly to the increased parasitism. Effectiveness of the parasite depended both on its numbers and degree of synchronization with the development of the moth population. To determine its total effect parasitism must be measured throughout each generation of the fruit moth, because in most years it tended to reach a maximum early in the generation and then gradually decline.

TRAPPING ADULT MACADAMIA NUT BORER, CRYPTOPHLEBIA OMBRODELTA (LOWER) (LEPIDOPTERA: TORTRICIDAE)

“…flight, malaise, and sticky traps were ineffective under the conditions tested. Bait traps also failed to catch adults although such traps have been used to monitor other tortricid populations (Phillips and Dustan 1970;Van Leeuwen 1943). Whilst some ofthese traps may have caught larger numbers had they been tested for longer in higher density areas, their use as a general monitor of adult C .…”