bbca target weeds

BBCA - Target Weeds - Nov 2008

Biotechnology and Biological Control AgencyBB A

Target WeedsNovember 2008




Fig. 1. C. basicorne. Root and crown-boring weevil

Fig. 2. The stem–boring and leaf–feeding flea beetle Psylliodes chalcomerus

Fig. 3. Effect of the attack of the eryophyid mite Aceria solstitialis on YST buds

Fig. 12. Sap-feeding lace bug Tingis grisea

Russian thistle, Salsola spp.

Fig. 4. Anthypurinus biimpressus. stem-boring weevil, found in Tunisia.

Fig. 5. Baris przewalskyi. Root-boring weevil, found in Kazakhstan.

Fig. 6. Eriophyoid mite galls in Eastern Turkey.

Fig. 7. Stem boring larva of Lixus sp. in Central Turkey.

Yellow starthistle is an annual weed of primary concern in the Western USA, where it spreads over 9 million hectares of pastureland, non-cultivated and natural areas.

During 2000 BBCA started a biocontrol program for YST in co-operation with USDA-ARS EBCL and PWA with the specific objective to select biocontrol agents attacking the weed at the early developmental stages.

Between 2001 and 2005, five new agents (fig. 1-3) were selected; among them the weevil Ceratapion basicorne completed the host specificity screening and a release petition was submitted in 2005. Three other agents are currently under study.

Salsola spp. represent one of the most troublesome weeds in the drier regions of western North America. It infests range and semi-arid pasture lands as well as cropland, agricultural, residential and industrial areas. As a crop weed it can cause yield losses of greater than 50% in spring wheat.

A project for the selection of new biocontrol agents for Russian thistle was started in 2003 in co-operation with USDA-ARS EBCL and PWA. At the present time, 4 potential biocontrol candidates have been selected (fig. 4-7);

Preliminary studies on the biology and host specificity of selected organisms are ongoing.

Yellow starthistle, Centaurea solstitialis (YST)



Fig. 8. S. foveola. Root-boring buprestid beetle.

Fig. 9. Symira nervosa. Leaf and stem-feeding moth.

Rush skeletonweed, Chondrilla juncea (RSW)

Perennial pepperweed, Lepidium latifolium

Perennial pepperweed is a herbaceous, semi-woody mustard of Eurasian and Central Asian origin that is aggressively invading natural habitats and pastures in North America.

BBCA started opportunistic field surveys for the selection of new biocontrol agents in 2003. Numerous associated organisms were found; four of them were preliminarily selected (fig. 12-14).

A co-operative project for the selection and evaluation of new PPW biocontrol agents, involving BBCA and CABI Bioscience Switzerland is in preparation.

Rush skeletonweed is mainly a threat to rangeland but also to well-drained soil wheat cultivation areas in NW North America.

In rangelands and croplands infestations, rush skeletonweed displaces native or beneficial forage species and outcompetes with crops for limited resources, particularly nitrogen.

The work on RSW was started in 2003-2004 in cooperation with EBCL and USDA Forest Service; Dedicated exploration trips have been conducted in the presumed native range. As a result several new potential biocontrol agents have been selected and are currently under study. Among them, highest priority was given to the buprestid beetle Sphenoptera foveola (fig. 8) and the noctuid moth Schinia cognata (fig. 10-11).

Fig. 12. A new root-boring Melanobaris species found in Turkey.

Fig. 13. Open field test with Lasiosina deviata in Turkey.

Fig. 14. Plant attacked by the mite Metaculus lepidifolii

Fig. 10 -11. Flower feeding moth Schinia cognata.



Scotch thistle is a biennial weed, of Eurasian and Central Asian origin that is aggressively invading natural habitats and pastures in North America.

BBCA started opportunistic field surveys for the selection of new biocontrol agents in 2007. Numerous associated organisms were found; three of them were preliminarily selected (fig. 15-17).

Preliminary host range tests have been carried out with the weevil T. briesei. One hundred of L. latus adult weevils were collected in Central Turkey and shipped to the USDA ARS quarantine facility in Albany, Ca for first host range tests.

Fig. 15. The root-boring weevil Trichosirocalus briesei found in Spain.

Fig. 16. The root-boring moth Eublemma amoeana in Turkey.

Fig. 17. Seed-feeder weevil Larinus latus in Turkey.

Scotch thistle, Onopordum acanthium

Russian olive, Eleaegnus angustifolia

Russian olive is a fast growing tree of moderate size of Eurasian and Central Asian origin. Introduced in North America as a desiderable ornamental shade tree, it became a serious weed problem in pastures, meadows and waterways.

A co-operative project for the selection and evaluation of new RO biocontrol agents, involving BBCA and CABI Bioscience Switzerland started in 2007, and so far has been targeted on explorations in Turkey, China and Iran for potential biocontrol candidate agents. Three of them, two beetles and an eriophyoid mite, have been selected for host range tests.

Fig. 18. The defoliator flea beetle Altica sp. found in China.

Fig. 19. The stem boring beetle Scolytis sp. found in Iran.

Fig. 20. Plant attacked by the mite Aceria angustifoliae in Turkey

Next year will follow the footsteps of last years, improving BBCA efforts in terms of new disciplines and new projects. Regarding new disciplines, in particular, we will enhance our screening improving genetic aspects of work. The target for 2009 will be to help EBCL in the clarification of several taxonomic question marks on some of the new potential biocontrol agents, having 4 weevil species and one eriophyoid mite in our pipeline. For the classic approach, our goal will be to be involved on 4 different projects for EBCL (Russian thistle, Scotch thistle, saltcedar and YST), one together with EBCL and CABI (perennial pepperweed), and two under the supervision of CABI (Russian olive and Russian knapweed).

Regarding the “historical“ projects, our work on YST will be focussed on the final data for the screening and the petition of the stem-boring flea beetle Psylliodes chalcomerus, in cooperation with Lincoln Smith; in addition, we are planning the second year of open field host range test with the eriophyoid mite Aceria solstitialis in Plovdiv, Bulgaria, in cooperation with Dr. Vili Harizanova and Dr. Atanaska Stoeva.

Laboratory bioassays with 3 species/biotypes of Lixus spp. nr. incanescens found on Russian thistle in Turkey, Italy and Iran will be carried out in our facilities to evaluate the oviposition and the larval host range in no-choice conditions: the approach includes not only host range observations in or lab, but also molecular analysis with the progeny. An open field test with a population from Kapadokya is planned for the late spring/early summer in Central Turkey.

We will start the second year for Scotch thistle, continuing the screening of the root boring weevil Trichosirocalus briesei, carrying out host range bioassays as well genetic analysis. In addition we will work together with Lincoln Smith on two populations of the flea beetle Psylliodes sp. near chalcomerus, associated with Onopordum acanthium in Italy and Turkey. In cooperation with Maurizio Biondi (University of L’Aquila, Italy) and Alessio De Biase (Università of Rome, Italy) and under the supervision of Lincoln Smith, we will provide to Albany, CA adults of the seed feeder weevil Larinus latus, collected in central Turkey. Perennial pepperweed project will be focussed on the final steps for the host range screening of the stem boring fly Lasiosina deviata, together with a preliminary screening of an eriophyoid mite in Central Turkey.

BBCA will continue to work on collections and preliminary rearing observations on the root galling weevil Liocleonus clathratus on saltcedar, in cooperation with Nada Carruthers, USDA APHIS PPQ, Albany, CA.

Field open field host range multiple choice tests will be carried out with the noctuid moths Schinia cognata and Simyra nervosa on Rush skeleton weed in Bulgaria, in co-operation with the University of Plovdiv and Jeff Littlefield, Montana State University, Bozeman, MT. Additional explorations will be performed in Slovakia, Turkey and Iran in order to detect additional potential biocontrol agents.

Two open field tests will be carried out on the eriophyoid mites Aceria acroptiloni and A. angustifoliae, on Russian knapweed and Russian olive respectively in Iran and Turkey, evaluating the host specificity and the impact on seed production and germination rate.

Plans for 2009



BCA or Weed 2009 2010 2011

Psylliodes chalcomerusTW: Yellow starthistle

complete DNA analysessubmit petition

Tingis griseaTW: Yellow starthistle

complete HR tests in lab and field start impact tests

complete impact testssubmit petition

Aceria solstitialisTW: yellow starthistle

complete HR tests in open field condition submit petition

Psylliodes chalcomerusTW: Scotch thistle

start HR tests in field and labstart impact and crossing tests

continue DNA analyses and tassonomic studies

complete HR tests in field and labcomplete impact and crossing tests

continue DNA analyses and tassonomic studies

complete DNA analyses and tassonomic studies

Trichosirocalus brieseiTW: Scotch thistle continue HR tests in lab complete HR tests in lab

start quarantine studiescomplete quarantine studies

submit petition

Eublemma sp.TW: Scotch thistle

foreign explorationsstart biology studies

start HR tests

continue biology studiescontinue HR tests

complete HR testscomplete biology studies

Anthypurinus biimpressusTW: Russian thistle

foreign explorationscontinue biology studies

continue HR tests

complete HR testsstart impact tests

complete biology studies

complete impact testsstart quarantine studies

Gymnancyla sp.TW: Russian thistle start HR tests continue HR tests complete HR tests

Lixus sp.TW: Russian thistle


start HR tests

continue foreign explorationscontinue biology studies

continue HR tests

complete biology studiescomplete HR tests

Cosmobaris sp.TW: Russian thistle

foreign explorations and collectionsstart genetic analyses

foreign explorations and collectionscontinue genetic analyses

Sphenoptera foveolaTW: Rush skeletonweed

Simyra nervosaTW: Rush skeletonweed


continue HR tests

complete biology studiescomplete HR tests start quarantine studies

Schinia cognataTW: Rush skeletonweed


continue HR tests

complete biology studiescomplete HR tests start quarantine studies

Oporopsamma sp.TW: Rush skeletonweed


start HR tests


continue HR tests


Lasiosina deviataTW: Perennial pepperweed

foreign explorationscontinue HR tests

complete HR testsstart quarantine studies

complete quarantine studiessubmit petition

Psylliodes sp.TW: Perennial pepperweed


start HR tests


continue HR tests


Oporopsamma sp.TW: Rush skeletonweed


start HR tests


continue HR tests


Aceria angustifoliaTW: Russian olive


start HR tests


continue HR tests


Scolytis sp.TW: Russian olive


start HR tests


continue HR tests


Milestones 2009-2011 for Prioritized Candidate Biocontrol Agents



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