Summary: | The peachtree borer, <i>Synanthedon exitiosa</i>, and lesser peachtree borer, <i>S. pictipes</i>, are economically important indirect pests of peach in West Virginia. The purpose of this 3-year study was to compare the efficacy of mating disruption and post-harvest trunk sprays of chlorpyrifos insecticide for control of this pest complex in a commercial peach orchard. Overall, Isomate PTB-Dual disruption dispensers applied at a rate of 371/ha significantly disrupted the male mate-finding behavior of <i>S. exitiosa</i> and <i>S. pictipes</i>. In addition, the infestation of peach trees by <i>S. exitiosa</i> larvae did not vary significantly between mating disruption and insecticide treated plots. Hot-spot maps of <i>S. exitiosa</i> infestation showed significant spatial clusters of infestation predominately near the perimeter of all orchard plots, or where trees were missing within and/or between rows. The generation of standard deviational ellipses revelated that the location of <i>S. exitiosa</i> infestations in orchard plots remained relatively constant between years, and were generally oriented in a north and easterly direction, which coincided with the prevailing wind direction. Although our data indicated that mating disruption can provide growers with an effective non-chemical alternative to chlorpyrifos trunk sprays, several variables may affect its long-term success in West Virginia peach orchards; most notably the presence of high population densities, problems with maintaining adequate pheromone coverage, and the need for area-wide implementation.
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