Family common name: common sawflies
Genus: Eriocampa Hartig, 1837
The Tenthredinidae are the most species-rich family and are found throughout the world, in all continents but Antarctica. They are known as the “common sawflies.” They can generally be recognized by a cylindrical body and long, segmented antennae. Otherwise, they come in a variety of colors, sizes, and forms (Goulet 1992).
Sawflies in the Allantinae subfamily are mostly black and shining, sometimes with other colors. They have agricultural importance as some species are pests on cultivated and ornamental plants (Smith 1979a). They can be distinguished from other subfamilies by wing venation (Smith 2003a).
There are 28 described species worldwide. Three species occur in North America, two of which are introduced from Europe/West Asia (Taeger et al. 2010).
In North America, Eriocampa feeds on Juglans nigra (black walnut), Alnus rubra (red alder), A. incana (speckled alder) and A. glutinosa (black alder). In Europe, E. ovata is also recorded on Ulmus (elm) and Corylus (hazel) (Smith 1979a).
The female Eriocampa lays an egg into the midrib of the leaf. After hatching, the larvae feed externally on the leaves. Larvae are known to secrete a white substance in long trails while feeding, which appears similar to bird fecal matter on the foliage. At maturity they drop to the ground and spin a cocoon in leaf matter at the base of the plant (Mackay and Wellington 1977, Smith 1979a).
North America: Eriocampa juglandis is common in the eastern half of the United States north into Ontario. Eriocampa ovata was introduced to the Northeast and Northwest, possibly independently, and now ranges in New England and the Great Lakes area as well as in Washington, British Columbia, and Alaska (Smith 1979a, Discover Life 2019).
Map data from: GBIF.org (29 October 2019) GBIF Occurrence Download Eriocampa
Details about data used for maps can be found here.