OBSERVATIONS OF GERANOMYIA RECONDITA (DIPTERA: TIPULOIDEA: LIMONIIDAE) LARVAE FEEDING ON EPIPHYLLOUS LIVERWORTS IN COSTA RICA

Abstract

Geranomyia recondita larvae live in a jelly mass on the leaf surfaces of understory plants. The feeding behavior of these larvae was observed by laboratory feeding trials utilizing three species of epiphyllous liverworts (Lejeuneaceae) in La Selva Biological Station, Costa Rica, and complemented with field observations of movement over the leaf surface and size variation of the jelly mass in which the larvae live. Although only 30% of the G. recondita larvae fed on the liverworts that were offered to them, the results indicate that they are capable of feeding on live liverworts. The larvae primarily accepted Lejeunea and never accepted Leptolejeunea, suggesting that they avoid liverworts containing aromatic compounds. Larvae were also observed feeding on other epiphylls that were present on the surface of the leaf. The area of the jelly masses was negatively correlated with ambient temperature, suggesting that G. recondita larvae are more active at night, since the masses were larger at that time, possibly allowing them to forage over greater distances on the surface of the leaf.