The relative importance of larval and adult nutrition in the isotopic profile of the spermatophore produced by the male true armyworm moth (Mythimna unipuncta) (Haworth).
Abstract
The wings of true armyworm (Mythimna unipuncta) are metabolically inactive tissue and as their isotopic profiles are determined by resources obtained during larval development, they provide information on natal origin of immigrants. The majority of female immigrants are mated so could the isotopic profiles of spermatophores dissected from her reproductive tract provide information about the natal origin of her mates? However, as spermatophores are produced by metabolically active male accessory glands and could use resources obtained from larval and adult feeding I conducted experiments to determine the relative importance of these two dietary sources on the isotopic profiles of spermatophores. Laboratory results showed H from both dietary sources affect the isotopic profiles of spermatophores so they provide no reliable information about the origin of the female’s mates. However, this could be a model system to examine turnover rates of resources obtained during larval and adult stages in a migratory species.