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United States Department of Agriculture

Agricultural Research Service

Research Project: Biological Control of Invasive Terrestrial and Riparian Weeds in the Far Western U.S. Region, with Emphasis on Thistles, Brooms and Cape-ivy

Location: Exotic and Invasive Weeds Research

Title: Taxonomic status of Trichosirocalus species (Curculionidae) attacking Carduus, Cirsium and Onopordum species

Authors
item Cristofaro, Massimo -
item DE Biase, Alessio -
item Colonnelli, Enzo -
item Belvedere, Silvia -
item Paolini, Alessandra -
item La Marca, Alessandra -
item Di Cristina, Franca -
item Lecce, Francesca -
item Smith, Lincoln

Submitted to: International Symposium on Biological Control of Weeds
Publication Type: Abstract Only
Publication Acceptance Date: January 14, 2014
Publication Date: N/A

Technical Abstract: The genus Trichosirocalus Colonnelli includes some host-specific weevil species or biotypes with a relatively narrow host-range limited to some thistles of the subfamily Carduinae. An Italian population of T. horridus (Panzer) was introduced in 1974 into the USA, and a population from Germany was introduced to Canada in 1975, then to New Zealand in 1985 and Australia in 1993, primarily to control Carduus nutans L. The species T. briesei Alonso-Zarazaga & Sánchez-Ruiz, mainly distributed in Central Spain, was introduced into Australia in 1997 to control Onopordum acanthium L. A third weevil species that is associated with Cirsium spp., T. mortadelo Alonso-Zarazaga & Sánchez-Ruiz, was recently described, although several taxonomists question its validity. In order to clarify the status of these three taxa, a multidisciplinary approach has been performed combining behavioral host-range tests, morphological analyses and molecular-genetic analyses, based on mitochondrial (CO1) and nuclear (EF1a) markers. The differences between weevil ecotypes collected on different thistle species in Europe and Asia (Spain, France, Italy and Georgia), in the USA (Oregon), in Australia and in New Zealand, have been evaluated. First results support the existence of only two clearly distinguished species (p distance on CO1 ˜ 11%), T. briesei which develops on Onopordum, and T. horridus which can use both Carduus and Cirsium as host plants.

Last Modified: 12/29/2014
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