Trail Following as a Rare Phenomenon among Non-social Lappet moth Larvae (Lepidoptera: Lasiocampidae)

Abstract

[Article] Within the Lasiocampidae sociality among caterpillars occurs quite frequently. FITZGERALD & COSTA [1986] suggested that sociality might originate in the ability of solitary ancestral species to mark and follow trails whereas other authors emphasize adaptations to adult morphological constraints as most important selective factors. In this laboratory study we tested whether solitary caterpillars of seven species of Lasiocampidae are able to mark their pathways and follow these trails during a second encounter (solitary trail following). Only caterpillars of Dendrolimus pini (Linnaeus 1758) proved to be able to recognize previously marked trails again. In D pini trails are . marked by dragging the tip of the sternum of the last abdominal segment along the substrate. No silk is used for additional marking in contrast to reports from other non-social larvae in Lepido­ ptera which exhibit trail following behaviour. This study suggests that solitary trail following is of minor importance for the evolution of sociality in the Lasiocampidae.