288 ENTOMOLOGICAL NEWS GYNANDROMORPH OF HELICOVERPA ARMIGERA [LEPIDOPTERA : NOCTUIDAE] 1 A. Josephrajkumar, B. Subrahmanyam, V.V. Ramamurt h \ ~ ABSTRACT: A gynandromorphic moth was observed in a laboratory culture of the American bollworm, Helicoverpa armigera, with external characters of female on the left and of male on the right side. Dissection revealed the presence of a testis and an ovary on the trans-lateral posi-tions of the moth, respectively. A gynandromorph is an individual in which one part of the body is mascu-line and the other is feminine. Among insects, bilateral gynandromorphs are most frequent, in which the left and right halves are of different sexes (Mayr and Ashlock, 1991). However, anteroposterior gynandromorphs and forms with irregular mosaic-like distributions of sexual characters also are known (Richards andDavies, 1977). In Drosophila melanogaster of XX chromosomal constitution, a gynan-dromorph arises through the loss of one X chromosome in one of the early cleavage nuclei of the embryo, so that deficient (XO) cells form male tissue while those with a full complement of sex chromosomes yield female tissues (Wilbert, 1953). Gynandromorph also can result from the "double fertiliza-tion" of abnormal eggs possessing two nuclei, one of which gives rise to male and the other to female tissues (White, 1968). Some parasitic Hymenoptera yield many gynandromorphs at unusually high temperatures (Bowen and Stern, 1966). Lepidopteran gynandromorphs have been recognised in species with sexual dimorphism where the male has coloration and/or pattern elements that typi-cally differ from those of the female. Hence, notable sexual differences in phenotype appear on the two halves of the adult. An extraordinary hybrid gy-nandromorph containing wing-pattern genes from at least three subspecies of Heliconius melpomene (Lepidoptera : Nymphalidae) was reported by Emmel and Boender (1990). A rare gynandromorph of Nacophora quernaria (Lepi-doptera : Geometridae) from Florida showed a perfectly bilateral division be-tween the male and female with different antennae, the thorax, and the poste-rior anal tufts of the abdomen (Kutis and Heppner, 1990). At the Division of Entomology, Indian Agricultural Research Institute, New Delhi, a gynandromorph of Helicoverpa armigera arose for the first time in a laboratory colony reared on the artificial diet of Singh and Rembold (1992). Incidentally, this has been observed in a routine experiment with plumbagin, a napthaquinone of plant origin having insect growth regulatory activity, where the larva received a dose of 100p,g g-' applied topically. 1 Received August 25, (1997). Accepted December 17, 1997. 2 Division of Entomology, Indian Agricultural Research Institute, New Delhi -1 1 1 2 India. ENT. NEWS 109(4) 288-292, September & October, 1998
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