Aquilegia sawfly larvae feed in large groups and can defoliate aquilegia plants quickly. Watch for early signs from early May:

• Pale green caterpillar-like larvae with yellowish brown heads and up to 1 cm long. They feed on the edge of leaves whilst lying with most of the body beneath the leaf blade
• Complete defoliation can sometimes occur, plants usually recover
• The adult insect is a black, grey winged insect about 5 mm in length

Sawflies are a part the biodiversity a healthy garden supports.

• Where possible tolerate populations of aquilegia sawfly, plants often recover from defoliation and may not be affected every year
• Encourage predators and other natural enemies of sawfly in the garden, such as birds, wasps and ground beetles
• Check plants regularly from May for the presence of larvae to prevent a damaging population developing
• Remove by hand if required and where practical

Adult aquilegia sawfly are black-bodied insects, up to 5.5 mm long, with two pairs of blackish grey wings and light brown legs. They appear similar to small flies but are in the same order of insects as bees, ants and wasps, the Hymenoptera. They emerge in late spring.

The larvae feed on the underside of the leaves, making large holes from the leaf edge. They take about two weeks to complete development before entering the soil to pupate. Adults emerge from the pupa after a couple of weeks and soon lay eggs. A second generation of larvae can then cause more defoliation. By mid-summer, the stems may have been stripped of foliage, plants will usually recover. Larvae of the second generation overwinter in pupal cocoons in the soil.