Aquilegia sawfly

The larval stage of aquilegia sawfly can completely defoliate Aquilegia in early summer.

Aquilegia sawfly damage

Quick facts

Common name Aquilegia sawfly
Latin name Pristiphora rufipes
Plants affected Aquilegia
Main symptoms Foliage is eaten by pale green caterpillar-like larvae
Caused by Larvae of a sawfly
Timing May-September

What is aquilegia sawfly?

Aquilegia sawfly has caterpillar-like larva of a sawfly that eats the leaves of aquilegia plants.

Symptoms

Aquilegia sawfly larvae feed in large groups so damage can occur very quickly. Be alert for early signs from early May:

  • Pale green caterpillar-like larvae with yellowish brown heads and up to 1cm long. They feed on the edge of leaves whilst lying with most of the body beneath the leaf blade
  • Complete defoliation may occur, affecting the appearance and vigour of infested plants

Control

Non chemical

Search for the larvae and remove them from the underside of damaged leaves.

Chemical

  • If infestations are too heavy for hand picking, control may be achieved by spraying with pesticides
  • Organic pesticides, such as those containing pyrethrum (e.g. Bug Clear Gun for Fruit and Veg, Defenders Bug Killer, ecofective Bug Killer) will control young larvae but larger larvae are more tolerant of these insecticides
  • Synthetic pesticides containing deltamethrin (e.g. Bayer Sprayday Greenfly Killer, Bayer Provado Ultimate Bug Killer), lambda-cyhalothrin (e.g. Westland Resolva Bug Killer), cypermethrin (e.g. Py Bug Killer) or the systemic insecticide acetamiprid (e.g. Bug Clear Ultra) may give some control of larger larvae
  • Plants in flower should not be sprayed due to the danger to pollinating insects
  • Inclusion of a pesticide product does not indicate a recommendation or endorsement by the RHS. It is a list of products currently available to the home gardener

Download

Pesticides for gardeners (Adobe Acrobat pdf document outlining pesticides available to gardeners)

Biology

Adult aquilegia sawfly are black-bodied insects, up to 5.5mm 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 then causes more foliar damage. By mid-summer, the stems may have been stripped of foliage. Larvae of the second generation overwinter in pupal cocoons in the soil.

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