OVIPOSITION PREFERENCE OF DARKWINGED FUNGUS GNATS (DIPTERA, SCIARIDAE) AMONG TRIFOLIUM SPECIES

We examined the oviposition preference of darkwinged fungus gnats, Bra dysia spp., on 14 Trifolium cultivars representing seven species and s eedling mortality following fungus gnat larval feeding. Variation in f ungus gnat oviposition preference was detected for interspecific Trifo lium cultivars but not for intraspecific cultivars. In a replicated fr ee-choice greenhouse' test, subterranean clover, T. subterraneum L., w as preferred significantly over other tested species, followed by crim son clover, T. incarnatum L.; arrowleaf clover, T. vesiculosum Savi; r ed clover, T. pratense L .; kura clover, T. ambiguum Bieb.; white clov er, T. repens L.; and ball clover, T. nigrescens Viv. All Trifolium sp ecies were susceptible to feeding by fungus gnat larvae; we have also observed the death of 20 white clover seedlings by as few as six fungu s gnat larvae. Fungus gnats may pose a serious threat to cool-season p asture legumes. Field surveys and population studies are needed to det ermine the importance of fungus gnat feeding in reducing the pasture p ersistence of cool- and warm-season forage legumes.