SEX, TRAPS and TIMING - PROGRESS in BLUEBERRY IPM
Dean Polk, Cesar Rodriguez-Saona, and Rob Holdcraft
Fruit IPM Agent, Rutgers Fruit R&E Center, 283 RT 539, Cream Ridge, NJ 08514; Specialist in Blueberry & Cranberry Entomology; and Technician, Marucci Center for Blueberry & Cranberry R & E, 125 A Lake Oswego Rd, Chatsworth, NJ 08019
Pheromones are an important tool for use in various IPM practices. Insect sex pheromones have been discovered and synthesized for many common insect pests. This presentation will focus on what pheromones are, and how they work, and include a brief list of commercial sources for pheromone products. Traps, insect phenology models are discussed, along with progress on mating disruption of Oriental beetle in blueberries.
Semiochemicals are chemicals that influence interactions between organisms. They are divided into ‘allelochemicals’, which mediate behavior, and ‘pheromones’, which mediate behavior. Pheromones can be either ‘releasers’ or ‘primers’. The former initiate an immediate behavioral change, such as alarm, sexual or aggregation behavior, while primers can initiate changes in sexual or physiological development. Common pheromone groups include alcohols, aldehydes, amines, carboxylic acids, esters, and keytones, such as that from the Oriental beetle. Female insects have rather simple antennae compared to most males – well illustrated with many moths. Pheromone molecules are emitted by a virgin female and picked up by sensory organs in the male’s antennae (fig 1). The ‘odor’ is often carried by air currents and ‘sensed’ by the male as it flies through the plume. The ‘on/off’ signal the male receives enables it to find the point source/female for mating.
Figure 1. Male silk moth antennae and sensory organs. (From Howse et. al., 1998)
Various sex pheromone traps include wing, delta and unitraps. Traps are baited with an emitter containing the pheromone and usually monitored 1-2 times per week to track male flight, population density, or the first sustained flight or biofix point. Degree day based models often need a biofix point at which to start degree day accumulations, so that developmental stages and spray timing can be predicted. Sex pheromones and traps are available from the