Assessing the Mating Status of Male Obliquebanded Leafrollers <I>Choristoneura rosaceana</I> (Lepidoptera: Tortricidae) by Dissection of Male and Female Moths

Abstract

We tested several methods for assessing the mating status of male obliquebanded leafrollers, Choristoneura rosaceana (Harris) (Lepidoptera: Tortricidae). In four experiments, we established that the technique developed to determine mating status of male spruce budworms, Choristoneura fumiferana (Clemens) (Lepidoptera: Tortricidae), can be used for C. rosaceana pop- ulations in western and eastern North America. Section seven of the primarysimplex of the ductus ejaculatorius appeared opaque, with either a white or yellow coloration in virgin C. rosaceana males, but was clear for up to 6 days after copulation in mated males. This technique was used successfully to determine the mating status of males captured in pheromone-baited traps during the Þrst sight of C. rosaceana in two consecutive seasons. In three laboratoryexperiments, we determined that the presence or absence of sclerotized bars on the surface of spermatophores dissected from female C. rosaceana is a reliable indicator of the mating status of the femalesO partner. Spermatophores produced byvirgin males had sclerotized barring, whereas those from once-mated males did not. This technique was used to demonstrate that the mating status of males mated to tethered, virgin females did not differ between pheromone-treated and nontreated control plots.