Drepana bilineata

(Packard, 1864)

warty birch caterpillar

Drepana bilineata is a in the Drepanidae, commonly known as the warty birch caterpillar. Its larvae are notable for their specialized , using two distinct signals— drumming and anal scraping—to defend feeding territories on birch leaves. The species exhibits territorial where resident caterpillars signal more frequently than intruders and win the majority of conflicts. This represents one of only two described examples of vibrational communication in Drepanoidea caterpillars.

Psoricoptera gibbosella (2) (48707218658) by Ben Sale from Stevenage, UK. Used under a CC BY 2.0 license.

Bucculatrix albedinella (2) (48707557106) by Ben Sale from Stevenage, UK. Used under a CC BY 2.0 license.

Nemapogon ruricolella variatella TBC (2) (48707554876) by Ben Sale from Stevenage, UK. Used under a CC BY 2.0 license.

Pronunciation

How to pronounce Drepana bilineata: /ˈdrɛpənə ˌbaɪlɪˈniːətə/

These audio files are automatically generated. While they are not always 100% accurate, they are a good starting point.

Images

Habitat

Larvae occur on birch (Betula) leaves, where they establish and defend individual feeding territories. The specific microhabitat involves the leaf surface itself as both food source and territory boundary.

Distribution

Records from Vermont, USA; broader North American distribution likely but not fully documented in available sources.

Diet

Larvae feed on birch (Betula) leaves.

Host Associations

Betula - larval food plant and territorial substrateBirch leaves serve as both the food source and the defended territory for larval stages

Behavior

Larvae produce two distinct types of substrate-borne vibrational signals during territorial encounters: drumming (striking the leaf with open mandible edges) and anal scraping (dragging specialized oar-shaped setae against the leaf surface). Residents signal at higher rates than intruders, with signaling frequency increasing as intruders approach. Territorial conflicts typically resolve within minutes, with residents winning 61% of contests, intruders winning 6%, and 33% ending in ties after 30+ minutes. The does not appear to practice size assortative mating in its stage.

Similar Taxa

Drepana arcuataThe only other Drepanoidea caterpillar with described ; differs in territorial and signaling patterns, potentially related to differential investment in silk leaf mats and shelters