Hylobius transversovittatus Goeze
Root-boring Weevil

Adult (left) and Larva of Hylobius transversovittatus
Photos by: Eric Coombs, OR Dept. of Agric. 

Hylobius transversovittatus adult.
Photo by: Bernd Blossey

Origin: European (1,2)

Life Cycle:
Overwintering State: The larvae are in the roots, while the adults are in the soil litter. (1)
Egg Stage:  The female will produce around 200 eggs in a year.  It takes about two or three months to lay the eggs and one to three eggs are laid in a day.  The eggs are laid into the stem or the soil nearby. (1)
Larval Stage:  It takes 1 to 2 years for the larvae to develop to full maturity. When mature, the larvae form a pupation chamber in the upper part of the root.  They will then come out as adults in mid to late summer. (2)
Pupil Stage: This part takes place in the upper root crown. (2)
Adult Stage: The adults are 4-5 mm long and usually red or brownish in color. They only are present in nocturnal situations and are present until late summer, and then they will go back to the egg laying stage before preparing for winter. (2)

Type of Damage to Host:
Plant Species, Stage: Lythrum salicaria, Larvae (2)
Location: They mine the roots. (2)

Host Impact (method/focus): They reduce seed reproduction.  Constant attacks will eventually kill the plant. (2)

Favorable Release Habitats: Areas highly infested in purple loosestrife (2)

Unfavorable Release Habitats: Areas without purple loosestrife present are not advised for release. (2)

How and Where to Collect, Transport, and Release: There are release sites in the states of New York, Pennsylvania, Maryland, Virginia, Minnesota, Oregon, Washington, Ohio, Indiana, Illinois, Iowa, Michigan, Wisconsin, South Dakota, Colorado and Montana.  There are also sites in southern Canada. (1) To collect, you must go two hours after dark and collect the adults.  The weevil will fall when it is touched. You can use the simple method of picking them by hand out of the habitat and putting them in a jar of some type. (2)

Redistribution: To redistribute, you must first cut a slight path through an area infested with purple loosestrife. Once available, release around 25 in a largely infested area.  This is advised only in late May until early July, or redistribution may not be possible.  (2)

Invasive Plants
Cornell University Biological Control
SANINET: Hylobius transversovittatus
Lethbridge Research Centre - Biological Control
Purple Loosestrife
Midwest Biological Control News
National Purple Loosestrife Research Initiatives
The Project
Biological Control of Purple Loosestrife
Ethan Frome 
Literature Cited:
(1) Weeden, C.R., Sheldon, A.M., Li, Y., and Hoffman, M.P., Cornell University Biological Control, February  9, 2000, [Online] Available, http://www.nysaes.cornell.edu/ent/biocontrol/weedfeeders/hylobius.html.

(2) Harris, P., Lethbridge Research Centre, December 12, 2000, [Online] Available, http://res2.agr.ca/lethbridge/weedbio/agents/ahyltra.htm.

By: Ryan Weightman  1/18/02

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