ON THE BIOLOGY OF CERTAIN SPECIES OF HOLCOCNEME1 KON. (HYMENOPTERA‐SYMPHYTA)

SUMMARYFour representatives of the genus Holcocneme Kon. occur more or less commonly in Britain. H. caeruleocarpa Htg. breeds on Salix and Populus. It oviposits in pocket‐shaped incisions in the leaves, and the eggs have an incubation period of 8–9 days. The young larvae are dark with the head black, older larvae are green with the head brown. A typical body segment has six annulets with dorsal setae on the second and fourth and the caudal segment has prominent cylindrical pseudocerci rounded at the apex. Females have five and males have four larval stadia, and pupation takes place in dark brown cocoons in the soil. There are two or three generations during the year, and the insects pass the winter in the cocoons. Parthenogenetic reproduction produces males. Holcocneme lucida Panz. breeds on species of Prunus and lays its eggs in shallow incisions along the veins on the under surface of the leaves. The incubation period is 7–10 days. The larvae are yellowish green with the head brown. A typical body segment has six annulets of which the second and fourth are setiferous; the caudal segment bears prominent pseudocerci that are broader at the apex than at the base. Females have five l