Hyles euphorbiae
leafy spurge hawkmoth
Lepidoptera
Sphingidae
Biological Control Links Photos: Adult Moth Young Larvae Larvae
Hyles euphorbiae larvae. Photo from USDA-ARS, Sidney, MT.
Origin: The native range of the hawkmoth includes Germany, France, Hungary, and Switzerland. (3)
Life Cycle: Adult moths come out beginning in early to mid-summer. After mating, females lay small groups of eggs on leafy spurge foliage (a cluster of leaves). After hatching, larvae eat the 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. (5)
Overwintering state: In the overwintering stage the hawkmoth spends its time as a pupae in the soil. (5)
Egg stage: Up to 150 light green spheres, 1 mm diameter, laid singly or in clusters of up to 50. The eggs are round and a green fluid can be seen at first through the transparent egg covering in younger eggs. (13)
Larva stage: This is the first stage where the hawkmoth is a leaf feeding catipeller. (2) The larva usually hatch during June and again in August. The larva have their own color which is a dark black or a blackish green. Then after it sheds its skin, the color turns to a yellow with dark brown and orange streaks with some speckles of white. (13) Within two to three weeks they really start to grow. They will weigh two to three grams. Feeds little below 15°C, but at 32°C a generation is completed in 6 weeks. (14)
Pupil stage: The pupa will be light tan, smooth and, covered with short, fine dark lines. Larva excavate a hole in the soil or litter 2.5 to 8 cm (1 to 3 in) deep. (12) This stage will last all winter, but in the summer will last only 15 to 20 days to produce the second yearly generation. Pupa are about 4 to 5 cm (1.6 to 2 in) long. (14)
Adult stage: The adults are about 25 to 30 mm long. The first generation will appear from June to July and the second in late August through September. Their wingspan is 5 cm (2 inches). They are a furry brown color, and their wings are very distinctive. (14)
Damage to Host: The hawkmoth is damaging to the target weed in the larval stage. They will feed on the leaves and the bracts (a leaf on the stem) of leafy spurge. (13) They produce noticeable foliage damage when in dense groups. However, the feeding is not a great threat to leafy spurge plants because of their extensive root reserves, and therefore, the hawkmoth is generally ineffective as a biological control agent. (14)
Host impact: The hawkmoth eats the bracts and the leaves late in the growing season, making it a non-effective biological control agent. Also, the population tends to scatter and apparently will crash (drastically lower in numbers) periodically because of outbreaks of an NPV virus. (6)
Release habitats: The hawkmoth was introduced into Montana in 1966. (12) They seem to like areas around trees were leafy spurge flourishes. There is not a lot of impact where there are birds, squirrels and other small animals, because they will eat the eggs and/or pupa. (13)
When to transport: You need to collect and transport when they are in the larval and pupil stage. You can also transfer a mated female to prevent them from being threatened or eaten. (14)
How to collect: To collect adults, you can use sweep nets and/or black lights to attract the moth in late June and July. The large showy larvae can be hand picked and transported in a cooler with foliage. (6)
Redistribution: Collect the larva from plants in July and September and keep them fed with fresh leafy spurge. They can also be shipped as a moth, but make sure they also will have food. The container should be kept cool. When you collect the insect, make sure you do not damage the wings. (14)
Purchasing: To purchase a biological control agent call or mail: Biological Control of Weeds, Inc. 1418 Maple Drive • Bozeman, MT 59715 Phone 406-586-5111 FAX: 406-586-1679.
Comments: The hawkmoth only chews the bracts, leaves, and young stems, usually well after flowering, which will not kill the plant. They are well established in the Jefferson River Valley South of Whitehall in Jefferson and Madison Counties but, are ineffective as a biological control agent. The populations of larvae seem to be quite widely scattered in this area. However, they are large, impressive larvae and make a good educational introduction to biological weed control. (6)
Bibliography:
(1) Pittaway, Tony. Leafy spurge hawkmoth: tpittaway.tripod.com/sphinx/h_eup.htm
(2) Hansen, Rich. Leafy spurge hawkmoth [Online] Available: http://www.nysaes.cornell.edu/ent/biocontrol/weedfeeders/hyles.html
(3) Northern Prairie Wildlife Research Center. Leafy spurge hawkmoth: www.npwrc.usgs.gov/resource/distr/lepid/moth/usa/1064.htm
(4) Oehlke, Bill. Leafy spurge hawkmoth: www.silkmoths.bizland.com/heuphorb.htm
(5) www.leps.it/indexjs.htm?speciespages/hyleseupho.htm
(6) Breitenfeldt, Todd, Personal Interview, Biology Teacher, Whitehall School, Box 1109, Whitehall, MT 59759 (406)-287-3862. 9-1-99.
(7) Norhern Plains Agriculture Research Lab. Leafy spurge hawkmoth: www.sidney.ars.usda.gov
(8) Leafy Spurge Biological Control Information and Photo Resource Gallery. Leafy spurge hawkmoth: www.team.ars.usda.gov
(9) Forestry Images. Leafy spurge hawkmoth: www.forestryimages.org
(10) Moths of North Dakota. Leafy spurge hawkmoth: www.ndsu.nodak.edu/ndsu/ndmoths/names/7892.htm
(11) Rosebud County Weed District. Leafy spurge hawkmoth: www.hysham.com/rosebudweed/
(12) Anderson, Gerald. Hyles euphorbiae: www.sidney.ars.usda.gov/scientists/nspencer/spurge/ihyles.htm
(13) N/A. Leafy Spurge Biological Control Plan: www.ag.state.co.us/DPI/publications/leafyspurge.html
(14) Tomas, Vince. Leafy Spurge Hawkmoth: www.mcn.net/~rosebudweed/leafy1.html.
By: Travis Henningsen, Published by: Crystal Raue - 2/13/2000 . Updated By: Nathan Dillon - 3-18-2005.
Travis
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