Initial development of an attracticide formulation against the oriental fruit moth, Grapholita molesta (Lepidoptera: Tortricidae)

Abstract

Six different attracticide formulations (LastCall OFM) were tested for attractiveness and toxicity to the Oriental fruit moth, Grapholita molesta (Busck). Oriental fruit moth pheromone was incorporated into the formulation at rates of 0.016, 0.16, and 1.6%, with and without the insecticide permethrin (6.0%), for a total of six different formulations. Formulations containing 0.016 and 0.16% pheromone were equally attractive to male moths, and both were significantly more attractive than formulations containing 1.6% pheromone. The presence of 6% permethrin in the formulations did not influence trap capture and there was no pheromone X insecticide interaction effect. Comparison of the most attractive formulations in a wind tunnel bioassay showed a significant effect of pheromone dose and a pheromone X insecticide interaction effect on the proportion of males that took off from the release device and contacted the attracticide droplet. There was no pheromone dose, insecticide, or pheromone X insecticide effect on the proportion of males that exhibited wing fanning, locking-on to the pheromone plume, and upwind-oriented flight behaviors in the wind tunnel. A second wind tunnel experiment revealed that a greater proportion of male Oriental fruit moths conducted all behaviors to calling virgin females compared with attracticide formulations containing 0.016 and 0.16% pheromone and 6% permethrin. Toxicity of the attracticide formulations was determined at 3 and 24 h after exposure in the laboratory and in the wind tunnel. Almost all of the males exposed to formulations in the laboratory bioassay and 66.4% of males exposed in the wind tunnel showed signs of pyrethroid poisoning by 3 h after exposure, and significant mortality was observed at 24 h after exposure. This research showed that attracticide formulations containing 0.016 and 0.16% pheromone and 6% permethrin were effective in attracting wild and laboratory-reared Oriental fruit moths and exposing them to insecticide through source contact. Further work is necessary to determine if LastCall OFM formulations are competitive with calling virgin females under field conditions and whether treatment with LastCall OFM will result in reduced mating frequency and ultimately population control.