Biology of Larinus curtus Hochhut (Coleoptera: Curculionidae), a European Weevil for Biological Control of Yellow Starthistle Centaurea solstitialis L (Asteraceae), in the United States

The biology of the weevil Larinus curtus Hochhut was studied in the field in northern Greece and in the laboratory in Rome, Italy, and in Thermi, near Thessaloniki, Greece. The species is univoltine, and adults overwinter in ground litter. Eggs are inserted into the flowers of yellow starthistle (Centaurea solstitialis L.) where the larvae feed mainly on developing achenes, destroying on average over 96% of the seeds in infested flowerheads. Overwintered adults lived up to 84 days, females laid up to 70 eggs each, eggs hatched 4.2 ± 0.6 days after being laid, larvae required 17 to 20 days to develop through the four instars, and pupal development required 4 to 5 days under laboratory conditions. Six percent of 360 seedheads collected on July 13 and 28, 1988 were infested with L. curtus larvae and up to 89% of the larvae were parasitized. The species is recommended for the biological control of C. solstitialis in the United States.