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Species Prionoxystus robiniae - Carpenterworm Moth - Hodges#2693

Carpenterworm Moth - Prionoxystus robiniae Prionoxystus robiniae - female Cossidae: Prionoxystus robiniae - Prionoxystus robiniae - female Carpenterworm Moth - Hodges#2693 - Prionoxystus robiniae - female Prionoxystus robiniaer carpenterworm moth - Prionoxystus robiniae Cossidae: Prionoxystus robiniae - Prionoxystus robiniae - female Prionoxystus robiniae? - Prionoxystus robiniae - male Carpenterworm Moth - Prionoxystus robiniae
Show images of: caterpillars · adults · both
Kingdom Animalia (Animals)
Phylum Arthropoda (Arthropods)
Subphylum Hexapoda (Hexapods)
Class Insecta (Insects)
Order Lepidoptera (Butterflies and Moths)
Superfamily Cossoidea (Carpenter and Clearwing Moths)
Family Cossidae (Carpenter and Leopard Moths)
Subfamily Cossinae
Genus Prionoxystus
Species robiniae (Carpenterworm Moth - Hodges#2693)
Hodges Number
Other Common Names
Carpenter Moth
Locust Borer
Synonyms and other taxonomic changes
Prionoxystus robiniae (Peck)
Orig. Comb: Cossus robinae Peck, 1818
Explanation of Names
Species name for a host plant, Black Locust, Robinia pseudoacacia (1).
Wingspan 43-85 mm; female larger than male. (2)
Adult: forewing in female mottled gray and blackish, slightly translucent; forewing in male less sharply mottled; hindwing in male yellow/orange with black outer border, no yellow in female (2). Large, might be mistaken for a sphinx moth.
Larva: body variably green to reddish with scattered black dots; head dark brown
Throughout NA (3); southern Canada and United States (Gerald Fauske). See Remarks.
Deciduous forests
mostly Mar-Jul (BG data)
Larvae bore in wood of living deciduous trees: locust, oak, chestnut, poplar, willow, maple, and ash. (3)
Life Cycle
Life cycle takes 3 to 4 years. (2)
Female deposits 450-800 eggs in groups in bark crevices, near wounds, or under vines, lichens, or moss. Young larvae bore to the inner bark and feed there until half grown. Then they bore into the wood, angling their tunnel upward in the sapwood and straight upward in the heartwood. In the Deep South, feeding is complete in 1 year. In the north, it may continue for 3-4 years. Tunnels are kept open and enlarged as the larvae grow; eventually they reach 18mm in diameter and 375mm in length. Mature larvae line their tunnels with loose, silky, yellowish-brown webs. Pupation occurs at the upper end of the tunnel. Before transformation to an adult, the pupa wriggles to the mouth of the tunnel and continues until its head and thorax are protruding. Once the adult as emerged, the pupal case remains in place, sticking out of the opening.(4)

eggs, early instar larvae, late instar larva, pupa, adult
Larvae are considered pests because their tunnels devalue hardwood lumber. (2)
According to Covell (5) (first edition), this species is native to Eurasia and was introduced to North America before 1879. However, that statement appears to be in error. Other references (e.g., Solomon and Hay, 1974) state this is a native North American species. In particular, a detailed taxonomic study of the Cossidae (Schoorl, 1990, p. 36) states that genus Prionoxystus occurs in "America", and does not mention any Eurasian members of the genus. (P Coin, a.k.a. Cotinis, 27 January 2011)
Print References
Covell, p. 423, plate 7, #6--female, #9--male (2)
Holland, p. 378 (1)
Solomon, J.D.; Hay, C.J. 1974. Annotated Bibliography of the Carpenterworm, Prionoxystus robiniae. Gen. Tech. Rep. SO-4. New Orleans, LA: U.S. Dept of Agriculture, Forest Service, Southern Forest Experiment Station. 13 pp. (PDF--1.8 MB)
Internet References
Moth Photographers Group - range map, photos of living and pinned adults.
USDA Forestry Images--Prionoxystus robiniae (Peck) (species account, with images)
Works Cited
1.The Moth Book
W.J. Holland. 1968. Dover.
2.Field Guide to Moths of Eastern North America
Charles V. Covell, Jr. 2005.
3.American Insects: A Handbook of the Insects of America North of Mexico
Ross H. Arnett. 2000. CRC Press.
4.Eastern Forest Insects
Whiteford L. Baker. 1972. U.S. Department of Agriculture · Forest Service.
5.Peterson Field Guides: Eastern Moths
Charles V. Covell. 1984. Houghton Mifflin Company.