Poplar Sawfly - Cladius grandis

7-9mm. Orange bodied with a black head and the top of thorax black. Though the sides of the thorax are orange, the underside is black. The base of the wings and the costa is yellow-orange and the stigma is dark brown with even darker margins.

Larvae feed on poplars and willows and found underneath the leaf. Early instars are pale green with some yellow, and have two rows of black spots. The larvae become increasingly yellow in later instars.

Adult, Larva and leafmine (when the host plant is identified)

Any habitat with trees of the Poplar family

May to August usually two broods.

Eggs are laid in a double row along the side of the leaf petiole. The larvae are very distinctive, both in terms of colour and their style of feeding. The colouration of the larvae changes as they mature. When fully grown, the larvae are 20 mm long. The hairy prepupal larva is yellowy-orange all over with black spots and a black head. The larvae feed gregariously but not by clinging to the edge of the leaf as most sawfly larvae do. Poplar sawfly larvae lie side by side on the underside of the leaf and start feeding at the tip end of the leaf. They gradually eat their way backwards but stop when their rear ends reach the basal edge of the leaf. At that point they migrate to another leaf and repeat the process.

Fairly widespread but local in its distribution in Britain

Rare in Leicestershire and Rutland.