Convergence in the ovipositor system of Platygastroidea

The ovipositor system of some scelioninae wasps is extended without the use of musculature, and presumably operates by changes in hydrostatic pressure. The platygastrinae genus, Gastrotrypes, is distantly related to Scelioninae and exhibits a convergent form of ovipositor extension without the use of musculature. We here describe the ovipositor system of Gastrotrypes in detail, compare it to the Scelio-type ovipositor system found in Scelioninae, and discuss the phylogenetic implication of plasticity and convergence in this character system.