Biological Control Agents and Their Roles

Revised: 
March 2016

Classical biological control agents introduced into the Pacific Northwest for the management of weeds and the general role of each biocontrol species.

Species

Role

Aceria malherbae

bud/leaf gall mite

Agapeta zoegana

root-boring moth

Agrilus hyperici

root-boring beetle

Aplocera plagiata

defoliating moth

Aphthona cyparissiae

root/defoliating flea beetle

Aphthona czwalinae

root/defoliating flea beetle

Aphthona flava

root/defoliating flea beetle

Aphthona lacertosa

root/defoliating flea beetle

Aphthona nigriscutis

root/defoliating flea beetle

Aulacidea acroptilonica

gall wasp

Bangasternus fausti

seedhead weevil

Bangasternus orientalis

seedhead weevil

Botanophila seneciella

seedhead fly

Brachypterolus pulicarius

flower beetle

Bradyrrhoa gilveolella

root-boring moth

Bruchidius villosus

seed beetle

Calophasia lunula

defoliating moth

Chaetorellia acrolophi

seedhead fly

Chaetorellia australis

seedhead fly

Chrysolina hyperici

defoliating beetle

Chrysolina quadrigemina

defoliating beetle

Cyphocleonus achates

root-boring/gall weevil

Cystiphora schmidti

stem/leaf gall midge

Diorhabda carinulata C

(formerly D. elongata)

leaf beetle

Eriophyes chondrillae

bud gall mite

Euhrychiopsis lecontei E

stem weevil

Eustenopus villosus

seedhead weevil

Exapion fuscirostre

seed weevil

Exapion ulicis

seed weevil

Galerucella calmariensis

leaf beetle

Galerucella pusilla

leaf beetle

Gymnetron antirrhini

seedhead weevil

Hadroplontus litura

(formerly Ceutorhynchus litura)

crown/root weevil

Hyles euphorbiae

defoliating moth

Hylobius transversovittatus

root-boring weevil

Jaapiella ivannikovi

shoot tip gall midge

Larinus curtus D

seedhead weevil

Larinus minutus

seedhead weevil

Larinus obtusus

seedhead weevil

Leucoptera spartifoliella

twig mining moth

Longitarsus jacobaeae

root/defoliating flea beetle

Mecinus janthiniformis
(
formerly M. janthinus)

stem-boring weevil
(Dalmatian toadflax)

Mecinus janthinus

stem-boring weevil
(yellow toadflax)

Metzneria paucipunctella

seedhead moth

Microlarinus lareynii

seed weevil

Microlarinus lypriformis

stem weevil

Nanophyes marmoratus

flower bud weevil

Oberea erythrocephala

stem-boring beetle

Phrydiuchus tau

crown/root weevil

Pterolonche inspersa

root-boring moth

Puccinia chondrillina

rust fungus

Puccinia jaceae var. solstitialis

rust fungus

Rhinocyllus conicus A

seedhead weevil

Sphenoptera jugoslavica

root-boring/gall beetle

Spurgia esulae

shoot tip gall midge

Subanguina picridis

stem/leaf gall nematode

Terellia virens

seedhead fly

Tetranychus lintearius

spider mite

Trichosirocalus horridus A

root/crown weevil

Tyria jacobaeae B

defoliating moth

Tyta luctuosa

defoliating moth

Urophora affinis

seedhead gall fly

Urophora cardui

stem gall fly

Urophora quadrifasciata

seedhead gall fly

Urophora sirunaseva

seedhead gall fly

Urophora stylata

seedhead gall fly

A Rhinocyllus conicus and Trichosirocalus horridus are not recommended. They attack native thistles.

B Tyria jacobaeae is not recommended east of the Cascades, particularly in Idaho. It attacks several native plant species.

C Diorhabda carinulata (formerly D. elongata) interstate shipment permits have been suspended.

D Larinus curtus may be infected with a disease that can reduce insect populations. It should not be redistributed to avoid spreading the disease to healthy L. curtus populations.

E Euhrychiopsis lecontei is a native insect, and thus, not a classical biological control agent. The weevil is co-evolved with native milfoil, Myriophyllum sibiricum, but also attacks Eurasian watermilfoil, M. spicatum. It is naturally-occurring at many lakes in the Pacific Northwest and weevil releases often augment inadequate native populations. It is currently only available commercially.