MANAGEMENT OF ORIENTAL FRUIT MOTH AND PEACH TWIG BORER
Control strategies for these species have typically involved the use of organophosphate insecticides. However, with over use, they developed resistance to organophosphate insecticides and the use of synthetic pyrethroids often results in increased costs for mite control later in the growing season. The use of synthetic sex pheromones for disruption of mating is targeted at adult moths instead of hatching larvae. Accurate prediction of the emergence of moths from the overwintering populations is critical to timing CheckMateŽ applications. The use of degree-day models, pheromone traps and field observations are helpful detecting the earliest emergence of the overwintering generation. By preventing mating and subsequent egg laying, insect populations can be dramatically reduced to below economically damaging levels. In situations with high pressure (problem blocks or some organic blocks), pheromone mating disruption and an accurately timed insecticide spray targeted at larval populations can be used together in an Integrated Pest Management strategy.
INSECT BIOLOGY*
Oriental fruit moth (Grapholita molesta) and peach twig borer (Anarsia lineatella) are pests of deciduous fruits. The greatest economic losses occur on peaches and nectarines. The insects may also attack apples, pears, plums, apricots, cherries and almonds. There are normally three to four generations of oriental fruit moth and two to three generations of peach twig borer in the northern fruit production areas of the United States. As many as four generations of PTB and five or six generations of OFM occur in the southern states and in California. Early in the season, larvae bore into the tips of tender twigs causing them to wilt and die. Although oriental fruit moth mine deeper into a shoot than peach twig borer larvae, distinguishing between the two can be difficult unless the larvae is still present in the twig. The oriental fruit moth larva is white or pink with a brown head; the peach twig borer larva is dark brown with a black head. Later in the season the larvae of both will prefer mature fruit. |
