We provide evidence for conspecific acoustic communication in caterpillars.
Larvae of the common hook-tip moth, Drepana arcuata (Drepanoidea), defend
silk nest sites from conspecifics by using ritualized acoustic displays. So
unds are produced by drumming the mandibles and scraping the mandibles and
specialized anal "oars" against the leaf surface. Staged interactions betwe
en a resident and intruder resulted in escalated acoustic "duels" that were
typically resolved within minutes, but sometimes extended for several hour
s. Resident caterpillars generally won territorial disputes, regardless of
whether they had built the nest, but relatively large intruders occasionall
y displaced residents from their nests. All evidence is consistent with aco
ustic signaling serving a territorial function. As with many vertebrates, r
itualized signaling appears to allow contestants to resolve contests withou
t physical harm. Comparative evidence indicates that larval acoustic signal
ing may be widespread throughout the Lepidoptera, meriting consideration as
a principal mode of communication for this important group of insects.