Developmental Time, Oviposition Behavior, and Incidental Mortality by Coccygomimus disparis (Hymenoptera: Ichneumonidae), a Parasite of the Gypsy Moth (Lepidoptera: Lymantriidae)

Abstract

Abstract When reared in the gypsy moth, Lymantria dispar (L.), developmental time of the introduced parasite, Coccygomimus disparis (Viereck), was found to vary according to host stage, age, and sex. Development took longer when oviposition occurred in host prepupae than in pupae. When oviposition occurred in female pupae, development was more rapid in older hosts than young hosts. When oviposition occurred in male pupae, developmental time did not differ with host age. Development proceeded more rapidly in male hosts than female hosts. In addition, male parasites developed more rapidly than female parasites. Drilling times by ovipositing females were similar for host pupae of both sexes, and host feeding did not render hosts unsuitable for development of parasite progeny. Parasitization of drilled hosts was 63% (56% yielded adult parasites and 7% contained dead parasites), and 12% successfully transformed into adult moths. The remaining 25% died, probably due to oviposition trauma or some other consequence of parasite attack. The frequency of this incidental mortality was especially high (41%) in hosts that were visited by parasites for more than 10 min. Total parasite-induced mortality, as adjusted by Abbott′s formula, was 87.7%.