Parasitoidism by Brachymeria pandora (Hymenoptera: Chalcididae) in Pupae of Danaus erippus (Lepidoptera: Nymphalidae) in an Urban Savanna Area

Abstract

The Chalcididae comprises parasitoid wasps that attack various invertebrate groups. Within the family, some Brachymeria species specialises in infecting pupae of Lepidoptera. Here, we quantitatively describe the relationship between Brachymeria pandora and the Southern Monarch butterfly, Danaus erippus, in urban areas of Cuiabá, Mato Grosso, Brazil. A total of 109 pupae of D. erippus were collected on the exotic plant Calotropis procera. The collected pupae were found in different stages (live, dead, emerged or parasitised). Live pupae were kept in the laboratory under controlled conditions, dead pupae were dissected, and the remaining pupae were preserved. Parasitism prevalence was 62.7%, and mean intensity was 12.1 parasitoids per infected pupa. The sex ratio was 1:2.17 (male to female), although unisexual broods of males and females were recorded. We observed remarkable differences in the number of pupae found throughout the year, parasitised or not. The record of B. pandora parasitising D. erippus pupae is currently limited to individuals associated with the exotic plant C. procera, as no data are available for populations using native host plants. The high prevalence of B. pandora on D. erippus indicates a strong capacity for population control, reinforcing the need for monitoring parasitic interactions in order to conserve the population of butterflies in urban environments.