Life cycle (Apple Sawfly)

• Adults emerge on sunny days around the blossom time of apple.
• After mating, eggs are laid throughout the blossom period singly in the side of the receptacle of apple flowers.
• The eggs hatch in 1-2 weeks, longer in cold weather.
• The young larva burrows into the receptacle, often just beneath the skin causing characteristic ribbon scars.
• When larvae are semi-mature, they often move to another fruitlet (often within the same truss) boring into the ovary and feeding on the pips.
• When larvae are fully fed in late June or early July, they enter the soil to form a cocoon at depths down to 25 cm.
• The larvae overwinter in cocoons before pupating 3-4 weeks before emergence the following spring.