Juniper Webworm (Dichomeris marginella)

Taxonomy

Domain	Eukarya
Kingdom	Animalia
Phylum	Arthropoda
Subphylum	Hexapoda
Class	Insecta
Subclass	Pterygota
Infraclass	Neoptera
Superorder	Holometabola
Order	Lepidoptera
Superfamily	Gelechioidea
Family	Gelechiidae
Subfamily	Dichomeridinae
Genus	Dichomeris

Scientific Name

Dichomeris marginella

Common Name

juniper webworm

Maier, C.T.; Lemmon, C.R.; Fengler, J.M.; Schweitzer, D.F.; Reardon, R.C.; Caterpillars on the Foliage of Conifers in the Northeastern United States. Morgantown, WV. USDA Forest Service. Forest Health Technology Enterprise Team Connecticut Agricultural Experiment Station. FHTET-2004-01. March 2004. 151 p.

Description

Very light brown body with dark middorsal and subdorsal stripes. Brown head; orange-brown prothoracic shield with light anterior margin and with narrow, dark brown spot at hind margin. Brown middorsal stripe narrower than dark brown subdorsal stripe. Up to 14 mm.

Food

Common and creeping junipers.

Life Cycle

One generation. Partly grown caterpillar overwinters in a silken case in the webbed foliage. Mature caterpillar present in May and June.

Comments

After hatching, the young caterpillar mines foliage. The mature caterpillar hollows needles while it dwells in a communal web of dead needles and frass (see below). It forms a pupa in a silken cocoon in the webbed foliage. The juniper webworm also infests non-native junipers that are used in landscaping. This introduced species is native to Europe.