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Dock sawfly

Ametastegia glabrata (Fallén)
Hymenoptera: Tenthredinidae

The adult is bluish black with red legs (A). The larva (B) is a smooth velvety green worm with white legs (3 pairs of true legs and 7 pairs of prolegs) and a dark head.


Mainly southern Canada and northern US south to PA and IL.


Attacks apple mainly. The larva digs brownish circular holes (C) on the surface of nearly mature fruit and creates short tunnels in the flesh. Larvae of only the last 1–2 generations are found in the trees.

Similar Species

The adult European apple sawfly (Hoplocampa testudinea) has an orange body, and the larva is white.


This insect causes few problems, most of which are related to the proximity of plants from the buckwheat family (dock, sorrel, knotweeds, bindweeds, etc.). An effective weed management program constitutes a good means of prevention.

Pest and Beneficials Search (search again)

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