BIOTECHNOLOGY AND BIOLOGICAL CONTROL AGENCY
BIOTECHNOLOGY AND BIOLOGICAL CONTROL AGENCY
Projects
Centaurea solstitialis
Yellow starthistle (Centaurea soslstitialis) 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 2001 BBCA started a biocontrol program for YST in cooperation 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 (Ceratapion basicorne, Psylliodes chalcomerus, Aceria solstitialis) 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.
Lepidium latifolium
Lepidium latifolium (PPW, 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; some of them were preliminarily selected (Melanobaris spp.,Lasiosina deviata, Metaculus lepidifolii). A cooperative project for the selection and evaluation of new PPW biocontrol agents, involving BBCA and CABI Bioscience Switzerland is in preparation.
Taeniatherium caput-medusae
Taeniatherum caput-medusae is a winter annual of the family Poaceae, native to western Europe and north Africa, that infests rangelands and grasslands of several western states of U. S. Introduced in the late 1800s, it reproduces by seeds dispersed by wind, water and animals. Once established, this weed can reach high densities, outcompeting with native grasses and forbs. Moreover, senescent plants persist for a long time on the soil preventing the germination and survival of native species and contributing to fire danger in the summer. Foreign explorations for the selection of potential biocontrol agents in its native range are ongoing and a fungus isolated from the plant in 2001 is currently under study.
Salsola tragus
Salsola or Russian thistle 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 cooperation with USDA-ARS EBCL and PWA. At the present time, four potential biocontrol candidates have been selected. Preliminary studies on the biology and host specificity of selected organisms are ongoing.
LOREM IPSUM
Ambrosia artemisifolia
Common ragweed, Ambrosia artemisiifolia L., is an annual herbaceous species native to North America currently considered one of the most dangerous invasive alien species in Europe. It was first recorded in Europe in the mid-1800s, but it has become an increasing problem from the late 1920s. Common ragweed produces large quantities of high allergenic pollen that is responsible for asthma and allergic rhinitis in sensitized people of affected areas. Moreover, is an important agricultural weed of field and vegetable crops in North America, causing yield losses of 30%. Several insects have been examined as potential biocontrol agents of common ragweed since 1980s. Among them, the ragweed leaf beetle Ophraella communa, a promising biocontrol agent, recently found in many localities of southern Switzerland (Ticino) and northern Italy (Lombardia, Piemonte and Emilia Romagna). Since 2014 BBCA is member of COST SMARTER, Sustainable management of Ambrosia artemisiifolia in Europe.
Ailanthus altissima
Also called ‘tree of heaven’, Ailanthus altissima (Simaroubaceae) is an invasive pest plant native to China. It was introduced in Europe, United States, Australia and New Zealand since the 18th century. It’s very resistant, fast-growing, with extensive roots and prolific seeds. It has invaded both urban sites and forests, croplands and rocky or rugged grounds; its roots produces chemicals that inhibits growth of other species. Biocontrol programs have started in the US since 2006. In 2016 BBCA, in cooperation with the University of Bari (Italy) and the University of Belgrade (Serbia), has started a survey in several countries to identify potential biological control agents. Different symptoms have been recorded and the impact of eriophyid mites attack looks important. Eriophyd mite Aculus mosoniensis seems to be one promising biocontrol candidate.
Arundo donax
Giant reed, Arundo donax, is a perennial grass native to the Mediterranean area that has invaded the riparian habitats of southwestern U.S. and northern Mexico. The plant spreads by creeping rhizomes, growing rapidly and causing serious ecological problems such as loss of biodiversity, flood and debris risks and, most importantly, water loss and competition for water resources in arid regions. Two biological control agents, the arundo wasp Tetramesa romana and the Arundo scale Rhizaspidiotus donacis were released in U.S. respectively in 2009 and 2011 and have successfully established. At present, BBCA is involved in the screening of the arundo gall midge Lasioptera donacis, considered a potential specific candidate for biological control of giant reed. Moreover, explorations will be performed in order to select new potential agents in Caspian Sea area and to locate new arundo scale biotypes in further north locations in the northern hemisphere.
Chondrilla juncea
Rush skeletonweed, Chondrilla juncea, is a species of the family Asteraceae whose native range extends from Western Europe and Northern Africa to central Asia. It is currently a threat to rangeland and to wheat cultivations in NW North America because it displaces native or beneficial forage species and outcompetes with crops for limited resources. Three biocontrol agents have been already released in the U.S. to control this weed: the skeletonweed root moth Bradyrrhoa gilveolella, the rush skeletonweed gall midge Cystiphora schmidti and the rush skeletonweed rust fungus Puccinia chondrillina. BBCA is involved since 2003 in a research project finalized to the selection and study of new biocontrol agents for Chondrilla juncea and is currently carrying out explorations and host range bioassays with the root boring moth Oporopsamma wertheimsteini.
Isatis tinctoria
Dyer's woad (Isatis tinctoria, Brassicaceae) is native to the Central and Western Asia, but have been spread throughout all Europe because of its historical use in the production of the indigo dye. The plant is also listed as an exotic invasive species in Western US, and is being studied for a possible biological control program. Since 2016, a joint project between BBCA and CABI Switzerland, through explorations allowed the discovery of 2 potential natural regulators in its native range: an Eriophyd mite and a Curculionidae (Ceutorhynchus peyerimhoffi). In 2017, we also discovered that those regulators have been historically spread with the plant, as they can be found in Italy (Abruzzo); we therefore conducted host range testing for both natural regulators in this area.
Bromus tectorum
Cheat grass (Bromus tectorum, Poaceae) is a grass native to Europe, southwestern Asia and northern Africa. It has been introduced worlwide and is a severe threat in North America. In order to determine the geographic origin and identify possible candidate biological control agents, explorations started in 2015 and were conducted from Western Europe to Central Asia, with also some collection in North Africa (Italy, Armenia, Turkey, Kazakhstan, Iran, Bulgaria, Slovakia, Morocco, and more). Genetic analysis is being conducted in order to determine the origin of invasive populations in North America using different genotyping techniques. Explorations also allowed the discovery of 3 promising natural regulators: two eryophid mites and a rust which are currently tested for host specifity..
Onopordum acanthium
Scotch thistle, Onopordum acanthium, 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 (Trichosirocalus brisei, Larinus latus, Eublemma amoeana). 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.
Brassica tourneforti
Sahara mustard (Brassica tournefortii, Brassicaceae) is a winter annual crucifer that became invasive in the USA since the early 1900’s. It favors sandy and arid soils and now invades several deserts in southern states, e.g. California, New Mexico, Arizona, Nevada, Utah, and Texas. The first step of a biocontrol program, involving BBCA, the University of California (Irvine) and the USDA-ARS-EBCL, was initiated in 2015 to determine the geographic origin and identify possible candidate biological control agents. Explorations during the winter and spring of 2016 were conducted in Morocco, France, Italy, Israel, Jordan, Turkey, and Qatar. Genetic analysis is being conducted in order to determine the origin of invasive populations in North America using next-gen genotyping such as single nucleotide polymorphisms (SNPs) detected by a double digest RAD sequencing (ddRADseq) approach. In the meanwhile, field surveys in Spring 2016 allowed us to identify several natural enemies belonging to Coleoptera and Lepidoptera, mainly root galling weevils, a stem galling midge, a flea beetle and a stem mining moth.
