The common Gooseberry Sawfly is a common yet troublesome pest of Gooseberry, Red and White Currant bushes.
During early spring, the adult sawfly which have yellow bodies and black heads, emerge from pupae having spent the winter months underground.
They mate before the females fly off to lay their eggs on the underside of young leaves, usually within the centre of the bush and hidden from sight.
The young larvae then soon hatch and start voraciously feeding on the leaves, working their way upwards through the bush and defoliating the stems whilst they rapidly grow.
After 2 to 3 weeks these caterpillar-like larvae, which are green with black dots, are fully grown and they descend down into the soil to pupate.
If the climatical conditions are favourable, another two generations can occur before the end of the year.
Controlling Gooseberry sawfly in an environmentally friendly way, is relatively easy if you keep a regular eye on the bushes. Disappearing leaves will indicate the location of the larvae which can then be removed by hand.
Regularly turning over the soil around the base of the bushes, particularly during the winter months, will also help to reduce sawfly infestations by exposing the underground pupae to insectivorous birds and other predators.