Amorbia humerosana

Status

NATIVE

DOMESTIC SURVEY

Taxonomy

Amorbia humerosana Clemens (Tortricidae: Tortricinae: Sparganothini)

Common names: white-lined leafroller moth, dusky leaf-roller

Adult Recognition

FWL: 10.5–16.0 mm

Head, thorax gray; forewing with ground color gray, usually with a darker gray triangle along the outer two-thirds of the costa; inner margin often suffused with red-orange scaling; darker speckling over much of forewing; male with forewing costal fold absent; hindwing gray. Some southern populations are more gray-yellow in coloration with a darker brown costal triangle. A median abdominal pit is present on segment 2.

Male genitalia are characterized by a long, thin uncus; large, setose socii; and large, membranous valvae. Female genitalia are characterized by a sterigma with well-developed lateral lobes; a ductus bursae with a well-sclerotized median portion; and a band-like signum on the wall of the corpus bursae. 

Larval Morphology

Frost (1926b), Craighead (1950)Craighead (1950):
Craighead, F. C. 1950. Insect enemies of eastern forests. United States Department of Agriculture, Miscellaneous Publications. 657: 1-679., MacKay (1962a)MacKay (1962a):
MacKay, M. R. 1962a. Larvae of the North American Tortricinae (Lepidoptera: Tortricidae). Canadian Entomologist, Supplement 28: 1-182., and Chapman and Lienk (1971)Chapman and Lienk (1971):
Chapman, P. J., Lienk, S. E. 1971. Tortricid fauna of apple in New York (Lepidoptera: Tortricidae); including an account of apple's occurrence in the state, especially as a naturalized plant. Spec. Publ. Geneva, NY: New York State Agricultural Experiment Station. 122 pp. described the larva of Amorbia humerosana. The following account is summarized from the review in Powell and Brown (2012)Powell and Brown (2012):
Powell, J. A., Brown, J. W. 2012. Tortricoidea, Tortricidae (part): Tortricinae (part): Sparganothini and Atteriini. In: Hodges, R. W. (ed.). The Moths of North America, fascicle 8.1. Wedge Entomological Research Foundation, Washington, D.C., 230 pp..

Mature larva approximately 25 mm in length; light to dark brown, sometimes nearly black; prothoracic shield pale brown, black on lateral margins; legs light brown; prothoracic pinacula brown; body pale green with large, paler green pinacula; anal shield brown; anal fork well-developed.

Pupa 11–12 mm in length, chestnut brown; spiracles large and conspicuous; mid-dorsal pit on A2-7.

For more information on Amorbia larvae, including a more detailed account of chaetotaxy, please consult the fact sheet and keys on LepIntercept.

Similar Species

Few other North American tortricids are similar in size or appearance to Amorbia, and this is one of the few tortricid genera in which the adults lack ocelli. The three Amorbia species treated here can be separated by the combination of two characters: forewing color and number of median dorsal pits on the abdomen. Amorbia humerosana is gray, oftentimes with a brownish band on the inner margin and has a single median dorsal pit on the second abdominal segment. Both A. emigratella and A. cuneanum are yellow-orange or yellow-brown, but A. cuneanum has a median dorsal pit on segment 2 whereas A. emigratella has median dorsal pits on segments 2–6.

The lateral bands on the prothoracic shield can be used to distinguish late instar Amorbia larvae from those of many other tortricids. Early instars lack the distinctive dark bands, and morphological identification of early instar larvae may be difficult or impossible.

Distribution

Amorbia humerosana is distributed across Canada and the eastern United States, from Nova Scotia to Alberta, south to Florida and eastern Texas.

Biology

The following account is summarized from Chapman and Lienk (1971)Chapman and Lienk (1971):
Chapman, P. J., Lienk, S. E. 1971. Tortricid fauna of apple in New York (Lepidoptera: Tortricidae); including an account of apple's occurrence in the state, especially as a naturalized plant. Spec. Publ. Geneva, NY: New York State Agricultural Experiment Station. 122 pp. and Powell and Brown (2012)Powell and Brown (2012):
Powell, J. A., Brown, J. W. 2012. Tortricoidea, Tortricidae (part): Tortricinae (part): Sparganothini and Atteriini. In: Hodges, R. W. (ed.). The Moths of North America, fascicle 8.1. Wedge Entomological Research Foundation, Washington, D.C., 230 pp..

Female lay eggs on the upper surface of the leaves of host plants in May and June. Larvae hatch in 11–18 days, depending on temperature. Development takes between 51–95 day, with an average of 60 days. Overwintering occurs in the pupal stage. Adults occur primarily in May and June, but are active earlier in the year in Texas and Florida. There is a single generation per year throughout most of its range, but a second generation may occur further south.

Larvae are highly polyphagous leaf-rollers on a large number of plants and has been reported as an occasional pest of apple (Malus spp.).

Plant Associations

View full screen host table here

Links

Additional photos and distribution map in North America available at Moth Photographers Group.