No firm evidence of immunological costs of insect oviposition and copulation: A test with dragonflies (Zygoptera)

Abstract

The immune response is a costly trait as investment in immunity is frequently tradedoff against life history components. In insects, for example, experimental tests haveprovided evidence that oviposition and copulatory activities impair immune abilityin the form of encapsulation ability. Here such tests are replicated by using four zygopteranspp., viz. Argia joergenseni, Calopteryx splendens, C. virgo and Hetaerinaamericana having encapsulation, phenoloxidase and nitric oxide activity 1 three keycomponents in the insect immune response 1 as dependent variables. The results provideno consistent results. Only in A. joergenseni there was any evidence of ovipositionactivity (or, in the case of H. americana, submergence) affecting encapsulation,but neither in C. splendens nor in H. americana did copulation have any such effect.In H. americana, nitric oxide activity was lower in // that had been submerged butthere was no effect on phenoloxidase activity. Thus, former observations indicatingthat oviposition and copulation negatively affect the immune response, cannot begeneralized.