Laboratory Rearing of the Garden Weevil, Phlyctinus Callosus Boheman (Coleoptera: Curculionidae), and the Effect of Temperature on Its Growth and Survival.

Abstract

Age-specific life and fecundity studies on the weevil Phlyctinus callosus (Boh.) (a polyphagous pest in gardens in parts of southern Australia, especially Victoria) revealed that mortality was greatest in the immature stages and that high temperatures were lethal to eggs (>30 deg C) and larvae (>25 deg C). The intrinsic rate of natural increase was greatest at 20 deg C, and the greater proportion of its value was accounted for early in the egg-laying period. Larvae could be reared on carrot roots in the laboratory; 76% of larvae reared in this manner to the pupal stage passed through 7 instars, 12% through 6, and 12% through 8. Head-capsule width was a suitable criterion for identifying the instars. Eggs could be stored for as long as 12 weeks at 5 deg C with no loss of viability. These results are discussed in relation to control measures against the weevil.