Montana Field Guide

The forewing upperside of the Spurge Hawkmoth (Hyles euphorbiae) is pale yellow-gray to lavender-gray, with a dark brown spot at the center of the costa and at the wing base, and a dark brown band running from the wing tip to the inner margin. The costal and outer margins may be dusted with pink or gray. The hindwing upperside is black with a pale greenish outer margin and a pinkish brown median band which becomes white at the inner margin. The wing span is about 64 -77 mm (Opler et al. 2010).

The larvae are also conspicuously colored, with a pronounced tail or "horn" near the rear end. Young larvae are variously patterned with green, yellow, and black. Older larvae have a distinctive red, black, and yellow pattern with a double row of white spots on each side and white speckles (Balaban and Balaban 2005).

Adult Spurge Hawkmoths are present beginning in early to mid-summer (Batra 1983). The females lay eggs singly or in small clusters on spurge leaves. (Opler et al. 2010). After hatching, larvae consume leafy spurge leaves and flowers. Mature larvae enter the soil to pupate. There are one or two generations per year, with soil-inhabiting pupae as the overwintering stage (Batra 1983).

The larvae of the Bedstraw Hawkmoth (H. gallii) are somewhat similar. However, the Bedstraw Hawkmoth has a single row of spots, and the Spurge Hawksmoth has a double row of spots (Balaban and Balaban 2005).

Disturbed meadows and valleys with dense stands of leafy spurge (Opler et al. 2010).

The larvae feed on various species of Euphorbia in the spurge family Euphorbiaceae. Adults feed on flower nectar (Opler et al. 2010).

Melissa Maggio-Kassner is the coordinator for the Montana Biological Weed Control Project. She can be reached at (406) 258-4223 or mmaggio@missoulaeduplace.org

Useful Links:
Montana Invasive Species website
Montana Biological Weed Control Coordination Project
Montana Department of Agriculture - Noxious Weeds
Montana Weed Control Association
Montana Weed Control Association Contacts Webpage.
Montana Fish, Wildlife, and Parks - Noxious Weeds
Montana State University Integrated Pest Management Extension
Weed Publications at Montana State University Extension - MontGuides