Significance of Ovipositor Length in Life Cycle Adaptations of Crickets

Abstract

This paper was initially presented at a symposium at the 17th International Congress of Entomology held in Hamburg, German Federal Republic, on 21 August 1984. The significance of ovipositor anatomy in the evolution of life cycles of crickets [Grylloidea] is discussed. Adaptive radiation in different habitats is associated with interspecific variation in ovipositor length, and it is suggested that selection balance would establish such variation only when different amounts of benefit are gained in different species-specific habitats. Interspecific variations are also related to differences in life cycles; species with stable egg diapause tending to have longer ovipositors than those with only brief or no egg diapause. In some species ovipositor length is also related to latitude, the selection pressure for a longer ovipositor being directly proportional to the duration of diapause in predominantly univoltine populations, but favouring shorter ovipositors in nondiapausing summer generations in multivoltine populations.