Malacosoma americana

870017.00 — 7701 — Malacosoma americana (Fabricius, 1793) — Eastern Tent Caterpillar Moth

Larval Host(s)

Presumed main host
on Block Island:

Known hosts:
Prunus serotina

Polyphagous (woody plants)


The population of this species on Block Island seems to be highly cyclical. In 2016, the caterpillars caused mass defoliation of black cherry (Prunus serotina) across the island in May; this was before I made any effort to track species abundances at lights. At the Hunt property, an estimated 40–50 individuals were recorded each night July 2 and 3, 2017, but there were never more than about 10 in a night at the same location throughout 2019. Numbers were even lower in 2020, with a maximum of four individuals in a night, and were probably even lower in 2021 based on more limited surveying during the narrow flight window.

Sex Differences

Antennae bipectinate in both sexes, but with much larger pectinations in male.


  • Species Page at Moth Photographers Group
  • Barcode of Life (BOLD) - Caution: Some specimens shown may not be sequenced. DNA barcode provides evidence of relatedness not proof of identification.
  • Franclemont, J. G., 1973. Moths of America North of Mexico, Fascicle 20.1: p. 76; pl. 9.29-37. order or free PDF
  • Species Page at BugGuide