Pterolonche
inspersa
Grey-winged
root moth
Insect:
moth (Lepidoptera: Pterolonchidae)
Photos Links:
Adult
Type of Agent: Insect:
Moth
(Lepidoptera: Pterolonchidae) (3)
Origin: The original source of this
species is in Austria, Greece, and Hungary. The
native
distribution are France, Spain, the former USSR, Greece, Hungary,
Bulgaria,
Turkey, Romania, and Italy. (1)
Life Cycle:
Over wintering: They
over winter as larva. (1)
Egg Stage: The eggs are deposited on a lower
leaf surface in small groups or singly. The eggs are oval, black,
and .04 mm long and .03 mm wide. Incubation is about 12 days. (3)
Larval Stage: The larvae feed on the center, or
cortex, of the root
of the plant. Larvae spin a silken tube to cover the area where
they are feeding and to provide an exit for the emerging adult.(2)
Pupal Stage: Pupation occurs from early to the middle
of July inside the root. (1,3)
Adult Stage: The adults are in the field in late July to
early
August. Mating and egg laying occur right after the larvae
becomes
an adult. The adults last for 15 to 16 days. (1,2)
Appearance
The adult is a white to brownish grey moth measuring a 1.9
to 2.5 mm wingspan and 8 mm in length. Their wings are narrow and
have no distinct markings. (1,2,3)
Effects
Destructive
stage: Larval (1)
Plant species attacked:
Diffuse knapweed, (Centaurea diffusa,) spotted knapweed, (Centaurea
maculosa,) and squarrose knapweed, (Centaurea squarrosa.) (1)
Site of Attack: central
vascular tissue of the roots (1)
Damage to host: The larva damages the roots by feeding
on them. The plants become shorter and produce less
flowers. The attacked roots become swollen and spongy. The
roots are then more susceptible to viral, bacterial, and fungal
infections. (1,2,3)
Releases
First introduced into U.S: 1986,
Idaho, Oregon, and Utah. (3)
Now established in: Oregon,
but has not been recovered since 2000. (3)
Habitat: Hot, dry areas with limited vegetation. The
insect does
not do well at higher elevations and habitats with rainfall. (3)
Availability: Is not yet
available. (2,3)
Stages to Transfer: Adult
(3)
Redistribution: No good
redistribution techniques have been established yet. (3)
How to Collect: Use a sweep
net when they are out on the plants. To release the insects,
simply sprinkle them from jars on the knapweed leaves, or swing your
arm around with the container open to let them out. (1)
Useful Links
1)
http://www.for.gov.bc.ca/HFP/PUBS/INTEREST/Bioagent/diffuse.htm
2)
http://www.aphis.usda.gov/oa/pubs/knapwpub.pdf
3)
http://res2.agr.ca/lethbridge/weedbio/agents.htm
4)
http://www.mtweed.org/Bio_control/Biocon2.pdf
5)
http://scarab.msu.montana.edu/mchr/11mch010.htm
6)
http://pi.cdfa.ca.gov/weedinfo/CENTAURE2.htm
7)
http://tncweeds.ucdavis.edu/esadocs/documnts/centdif.html
8)
http://www.efn.org/~ipmpa/Noxknapw.html
9)
http://www.3rivers.net/~tomelpel/weedsinfo/Centaurea_spp.htm
10)
http://www.oda.state.or.us/Information/biennialReport/08.html
Literature Cited
1. Rees, Norman, et. al., Ed., Biological Control of Weeds
in the West, Western Society of Weed Science, in Cooperation with
USDA ARS, MT Dept. of Ag, and MT State Univ., Color Printers, Bozeman,
MT, Feb., 1996.
2. Lang, R.F Biological Control: A Guide to Natural
Enemies
in North America, (online) available:
http://www.nysaes.cornell.edu/ent/biocontrol/weedfeeders/pterolonche_inspersa.html
, Page last modified: Feb. 9, 2000 Text last modified: April 18, 1997.
3. Story, J.M. and Coombs, E.M. "Pterolonche inspersa."
Biological Control. Ed.
Eric Coombs, Janet Clark, Gary Piper, and Alfred Cofrancesco Jr.
Corvallis Oregon: Oregon State University Press, 2004. 221-222
Updated by:
Hilary Palakovich 3/17/05
By:
Traci Henningsen
1/ 14/ 02
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