Invasive Species Compendium

Detailed coverage of invasive species threatening livelihoods and the environment worldwide

Abstract

Study on the parasites of the cabbage seed weevil (Ceuthorrhynchus assimilis Payk.). I. Species composition and economic importance of the larval ectoparasites.

Abstract

Observations concerning the incidence and economic importance of the larval ectoparasites of Ceutorhynchus assimilis (Payk.), one of the main pests of winter rape in Poland, were carried out in 1967-69 and 1972-73. The dominant species was Trichomalus perfectus (Wlk.), which parasitised over 90% of the Ceutorhynchus larvae. Other pteromalid parasites found were Mesopolobus morys (Wlk.), Stenomalina muscarum (L.) and Habrocytus sp.; the eurytomid Eurytoma curculionum Mayr and the eupelmid Eupelmella vesicularis (Retz.) were also present. Parasitism rose steadily during the years of observation and by 1973 it had reached 68.1%. Although the parasite eggs are laid on the final instar of the host, the damage caused by a parasitised larva is about 28% less than that caused by a healthy one. The parasite complex is a major factor in the limitation of the populations of C. assimilis.