Effect of host age on life cycle and morphological characteristics ofGlyptapanteles liparidis(Hymenoptera: Braconidae), a parasitoid ofAcronicta rumicis(Lepidoptera: Noctuidae)

Abstract

AbstractThe life cycle ofGlyptapanteles liparidiswas 23.75 ± 1.26, 21.95 ± 2.44 and 20.83 ± 0.78 days when fed on the first, second and third instar larvae ofAcronicta rumicis, respectively. Although insufficient numbers hindered statistical analysis, the life cycle ofG. liparidisappeared to be shortest, 19 days, when fed on fourth instar larvae. The life cycle ofG. liparidistends to shorten as the larvae ofA. rumicisfed upon are more advanced. The body length, forewing length and head capsule width of femaleG. liparidisfed on first instar larvae ofA. rumiciswere greater than those of males, while the antennae of males were longer than those of females. When fed on second instar larvae, there was no difference in body length and head capsule width between males and females, but the male antennae were longer than the female, and the female forewings were longer than the male. When fed on third instar larvae, there was no significant difference in head capsule width between the sexes, but female body length and forewing length were greater than the male, and the male antennae were longer than the female. On the whole, females were bigger than males in terms of body length and forewing length, while antennae of the males were longer than those of the females. There was no difference in head capsule width between males and females. Body length, antenna length, forewing length and head capsule width of male and femaleG. liparidiswere relatively larger when fed on first instar larvae ofA. rumicisthan when fed on second and third instar larvae.