Cephalcia lariciphila (Wachtl, 1898)

Cephalcia lariciphila

First reported in Britain in 1972 in Wales. The species rapidly spread to larch plantations in England and Scotland. The species mates at ground level shortly after emerging from leaf litter in the spring. Mated females climb tree trunks or fly to the crown of the trees to lay eggs. Adults are black with off-white markings on the head, thorax and sides of the abdomen. The tibia and some basal antennal segments are reddish.
Larvae spin a silk tube and feed on the young shoots. When full grown (around July) the larvae drop or decend on silk and burrow to where the leaf litter meets the underlying soil. They overwinter as a prepupa and pupate in early spring.

Size: approx. 10 - 12mm

Status: Widespread

Distribution: England, Scotland, Wales

Flight period: Univoltine, April to June

Plant associations: Larix spp (larches)

References:

Benson, R.B., 1952. Handbooks for the Identification of British Insects. Hymenoptera, Symphyta, Vol 6, Section 2(a-c), Royal Entomological Society, London

Liston A, Knight G, Sheppard D, Broad G, Livermore L (2014) Checklist of British and Irish Hymenoptera - Sawflies, ‘Symphyta’. Biodiversity Data Journal 2: e1168. https://doi.org/10.3897/BDJ.2.e1168

Billany D J, Brown R M (1980) The Web-spinning Larch Sawfly, Cephalcia lariciphila Wachtl. (Hymenoptera: Pamphiliidae) A New Pest of Larix in England and Wales. Forestry 53(1)