Catalog Home Page

Laboratory trials of the efficacy of the Crown Weevil Mortadelo horridus (Coleoptera: Curculionoidae) for the biological control of Slender Thistles Carduus pycnocephalus and C. tenuiflorus in Southwestern Australia

Wenziker, K.J., Calver, M.C. and Woodburn, T.L. (2003) Laboratory trials of the efficacy of the Crown Weevil Mortadelo horridus (Coleoptera: Curculionoidae) for the biological control of Slender Thistles Carduus pycnocephalus and C. tenuiflorus in Southwestern Australia. Biocontrol Science and Technology, 13 (7). pp. 655-670.

Link to Published Version: http://dx.doi.org/10.1080/09583150310001606255
*Subscription may be required

Abstract

The hypothesis that larval crown weevil (Mortadelo horridus Alonso-Zarazaga and Sanchez-Ruiz) can suppress vegetative growth, seed set and viability in the winter annual slender thistles (Carduus pycnocephalus L. and C. tenuiflorus Curt.) was tested in laboratory gardens. Different densities (eight and 16) of M. horridus larvae and eggs were inoculated onto slender thistle rosettes between one and four times. Controls received no eggs or larvae. Larval feeding destroyed the apical meristems of treated plants, producing multi-crowned rosettes and significant declines in leaf area in both species, irrespective of the number of larvae. Treated thistles bolted at the same time and had a 4-fold increase in stem number compared to controls. The stems of control plants were up to one-third taller and thicker than attacked plants. Relative to controls, the leaves of treated plants had significantly fewer spines, decreased leaf area and decreased leaf perimeter, with less deeply lobed leaf margins. The total number of capitula produced by control and experimental groups was not significantly different, but consideration of fertile capitula only revealed a reduction in fertile capitula production following weevil attack. This was most marked in C. pycnocephalus. Control plants also produced significantly wider capitula. No control plants died, compared to 17 and 26% of the attacked plants of C. pycnocephalus and C. tenuiflorus, respectively. Implications for biocontrol of slender thistles are discussed.

Publication Type: Journal Article
Murdoch Affiliation: School of Biological Sciences and Biotechnology
Publisher: Carfax Publishing Ltd.
Copyright: (c) Taylor & Francis Ltd
Notes: Erratum: Laboratory trials of the efficacy of the crown weevil Mortadelo horridus (Coleoptera: Curculionoidea) for the biological control of slender thistles Carduus pycnocephalus and C. tennuiflorus in Southwestern Australia (Biocontrol Science and Technology 13:7 (655-670)) http://dx.doi.org/10.1080/09583150310001655729
URI: http://researchrepository.murdoch.edu.au/id/eprint/861
Item Control Page