Percent infestation and seed consumption of Centaurea solstitialis L. (Asteracea: Cardueae) by Eustenopus villosus and Larinus curtus (Coleoptera: Curculionidae) in Washington, USA

Publication date: Available online 27 March 2019Source: Biological ControlAuthor(s): Steven E. Woodley, Benjamin A. Zamora, Todd CoffeyAbstractA 2-year field study (2014-2015) was conducted to determine the levels of Eustenopus villosus (Boheman) and Larinus curtus (Hochhut) infestation and seed consumption of the invasive plant Centaurea solstitialis L. (Asteraceae: Cardueae) in the steppe of southeastern Washington, USA, a marine-modified continental macroclimate. Mature terminal C. solstitialis flowerheads were collected and dissected to determine abundance of each weevil species and level of seed consumption by both species. Data were analyzed by year to assess climatic influences on insect prevalence and feeding activity. Results showed that E. villosus infested 40% of the flowerheads in 2014 and 39.5% in 2015. Larinus curtus infested 16.7% in 2014 and 23.3% in 2015. In 2014, 5.8% of the flowerheads were infested by at least one E. villosus and one L. curtus in the same flowerhead and 9.9% in 2015. Eustenopus villosus and L. curtus consumed similar percentages (76.1% and 75.4%, respectively) of total seed production per flowerhead of C. solstitialis. Infestation levels of E. villosus and L. curtus in southeastern Washington are lower than in the Mediterranean macroclimates in California and northern Greece. Mean seed consumption was also lower in southeastern Washington compared to northern Greece, with no data specific to California. Lower levels of infestation and seed...

Source: Biological Control - March 28, 2019 Category: Biology Source Type: research