Annual Cycle of Gonad Maturation, Characteristics of Copulating Pairs and Egg-laying Rates in Cavernicolous Crickets, Particularyly Hadenoecus subterraneus (Insecta: Orthoptera)

Abstract

-Monthly collections, fresh and dry weight determinations, and analysis of reproductive components were made of cave crickets Hadenoecus subterraneus and camel crickets Ceuthophilus stygius from caves in or near Mammoth Cave National Park, Ky. from April 1986 to March 1987. Minimal spermatophore frequency (50%) in adult male H. subterraneus occurred in September with essentially all mature males having spermatophores from October through May. Minimal occurrence of mature ova in adult female H. subterraneus was found in July and occurrence peaked in January and February. Cave crickets probably reproduce in all months with peak reproduction in January and February. Both sexes of C. stygius contain mature gonads only from August through October when nonparasitized, gravid females contain 25.5 ? 4.2 mature ova (weight = 10.6 ? 2.5 mg/egg). When spermatophores are present, mature males of both species invariably have two. Mature ova in H. subterraneus are seasonally consistent at 6.1-7.4 ova/female (weight = 5.4 mg/ egg) except for one winter sample from Sophy's Avenue of Mammoth Cave where females averaged 18.1 ova/female. Crickets of both sexes and species are mature when their hind femur length ?20.0 mm. Cave crickets in copulo of both sexes have higher wet carcass weights and markedly lower crop contents, and females contain the same number of mature ova (6.1 ova/female) as other gravid adults. Caged adult female cave crickets laid more ova in the 1st 2 days of captivity than in later successive 2-day periods and created many false oviposition holes throughout the testing period. Peak egg-laying frequency occurred in December and February tests. Estimated annual egg production in cave crickets ranges from 96 to 371.