A YELLOW PUPAL BODY, SEX-LINKED MUTANT IN THE TOBACCO BUDWORM, HELIOTHIS VIRESCENS (LEPIDOPTERA: NOCTUIDAE)

Abstract A sex-linked mutant of the tobacco budworm, Heliothis virescens (F.), has been isolated. The wild-type pupae are brown, and the mutant pupae are yellow-bodied. The mutant (yb) could aid in sexing large numbers of tobacco budworms since > 98% of the female pupae from ± ♀ × yb/yb ♂ are yellow but all male pupae are brown. Data on mating frequency, fertility, and F1 survival of six mating types between ± or yb females and yb/yb, ±/yb, or ±/± males indicate that selection favors the wild-type genotype. When heterozygous males were crossed with either female genotype, the effect on fertility was similar to that produced by homozygous mutant males. Also, when heterozygous males were crossed with mutant females the effect on mating was similar to that produced by homozygous males. However, when heterozygous males were crossed with wild-type females, mating frequency was intermediate between that of the homozygous mutant and that of the homozygous wild-type. Survival of larvae from mutant females was lower than survival of larvae from wild-type females.