Sex Discrimination by Morphological Traits for Larvae and Pupae of Potato Tuber Moth, Phthorimaea operculella (Lepidoptera: Gelechiidae) Using Binocular Microscope

Abstract

The potato tuber worm, Phthorimaea operculella (Zeller) (Lepidoptera: Gelechiidae), is one of the most destructive potato pests in the world. Sexual differentiation is sometimes required to conduct investigations on sex-specific responses, mating, pesticide resistance inheritance, and sterile, Insect-Inherited, Sterility Technique and Control Tactics. The goal of this study was to use a binocular microscope to determine distinct morphological traits of immature stages male and female larvae (L.) and pupal stage (p.). We present a straight forward approach for sexing P. operculella in this paper. Male larvae were distinguished by the presence of dark-colored gonads that were plainly visible through the cuticle. The sex of a male pupa can be determined using a Binocular microscope by the appearance of dark-colored gonads on the dorsal side. Furthermore, the morphology of the genitalia opening at the end of the abdominal segment distinguishes males from females.