Forest Pest Insects in North America: a Photographic Guide

Saddleback looper

Ectropis crepuscularia (Denis and Schiffermüller) (Lepidoptera: Geometridae)

Orientation to pest

Saddleback looper, Ectropis crepuscularia (Denis and Schiffermüller, is a native North American looper present across southern Canada, the adjacent tier of U.S. states, and the eastern United States. This species is a generalist, feeding more on conifers in western North American and all of Canada, but on various hardwood species in the eastern United States. Adults fly in spring, when they lay their eggs. Larvae are solitary feeders able to mimic twigs. Young larvae often begin feeding first on groundcover species and understory shrubs. Larvae later move up trees where they complete development. Mature larvae drop to the soil to pupate in the litter, where they overwinter. There at least two generations per year over much of the eastern United States. Larvae of this species are generally economically damaging. However, outbreaks in British Columbia and Alaska have occurred.

Hosts commonly attacked

In Canada and the western United States, saddleback loopers feed mostly commonly on conifers, including hemlock (Tsuga), true firs (Abies), spruce (Picea), and larch (Larix). In the eastern United States, broadleaf trees are the main hosts, including apple (Malus), ash (Fraxinus), birch (Betula), dogwood (Cornus), maple (Acer), oak (Quercus), poplar (Populus), walnut (Juglans), and willow (Salix).


This geometrid is found in a band across North America including southern Canada and the adjacent tier of US states. In the eastern United States, it is also found south to Florida.

Images of saddleback looper

Larva of saddleback looper Connecticut Agricultural Experiment Station Archive, Connecticut Agricultural Experiment Station, 768x512 / 1536x1024
Figure 1. Larva of saddleback looper

Important biological control agents related to this pest species

No information on the natural enemies of this species was found.

Web links for information on saddleback looper