High Parasitism Rates of a Rare Ladybird Platynaspis luteorubra (Goeze, 1777) (Coleoptera: Coccinellidae) - a Reason of its Rarity?

摘要

Larvae of a rare, myrmecophilous ladybird Platynaspis luteorubra (Goeze, 1777) were collected in three regions in central and northern Poland (Mazovian Lowland, Masurian Lakeland and Gdańsk Shoreland) to check their parasitism by the hymenopteran parasitoid Homalotylus platynaspidis Hoffer, 1963. The larvae were parasitized in all the three regions, and the recorded parasitism rates were surprisingly high, ranging between 0.56 and 0.69. This suggests that the constantly high parasitoid pressure may be the main force maintaining numbers of P. luteorubra at low levels. H. platynaspidis has not previously been reported from Poland. The reported records represent the northernmost known localities of this species in central and western Europe.