Gynandromorph in fall armyworm, Spodoptera frugiperda (Lepidoptera: Noctuidae)

Gynandromorph in fall armyworm, Spodoptera frugiperda (Lepidoptera: Noctuidae)

Gynandromorphism is a phenomenon in which an individual develops with sexual mosaic of male and female traits. It is a rare phenomenon that has been reported in certain group of organisms viz., arthropods, birds, reptiles, amphibians, mammals. Gynandromorphs are expressed generally in two ways, bilateral and non-bilateral (sexual mosaics). In insects, bilateral gynandromorphs are most frequent, wherein left and right halves are of different sexes. As a routine, we were rearing the S. frugiperda for reproductive physiology experiments, while looking for the adult emergence from pupae, serendipitously we observed an adult with an uncertainty in wing morphology suggesting it to be a gynandromorphy. Detailed examination of morphological and anatomical structure of gynandromorphic moth revealed that wing pattern of left and right side resembled that of male and female, respectively and in thorax, patagium on left side was prominent like male while on right side it was inconspicuous like female depicting the bilateral type. Dissection of gynandromorphic moth genitalia revealed that genital structure is asymmetrical with male genitalia structures observed on one half and female genitalia structures on the other half, male structures are well developed representing, distinct uncus, valvae, aedeagus, tegumen, and ampulla as compared to the female