Parasitism in Relation to Pupation in Lucilia sericata Meig

Abstract

IN NATURE of April 19, p. 598, Holdaway and Evans make reference to the stage in which the hibernation of Lucilia sericata Meig. takes place. Their observations show that although “both larvæ and puparia were recovered from the soil surrounding baits exposed in the autumn and examined towards the end of the season”, that 87.4 to 92.2 per cent of these puparia (plus larvæ pupated within eight days of collection) were parasitised. From these facts it is evident that in Toulouse, France, from which station the letter is addressed, the normal mode of hibernation of Lucilia sericata, excluding the influence of parasitism, is in the larval stage, and thus is similar to that found by me in North Wales in 1928–1929 (NATURE, May 18, 1929, vol. 123, p. 759). In the latter case, and again last winter, when observations on the hibernation of Lucilia sericata have been confirmed, not a single puparium appeared among the hibernating larvæ.