Life tables for the carrot fly, Psila rosae.
Abstract
Life tables are presented for 4 consecutive generations of Psila rosae on carrots in southern England, and are analysed using key factor analysis. Of the 6 factors studied, k0 (loss in potential natality) and k2 (early larval mortality) were key factors. Parasitism (by Chorebus gracilis, Aleochara sp. and Kleidotoma psiloides) and egg mortality due to predation were relatively small. The population of P. rosae declined dramatically during the study, and this was attributed chiefly to an increase in k2 under abnormal environmental conditions. Life tables for P. rosae are compared with those for other dipterous pests of annual crops.