Upright webspinning sawfly

Upright webspinning sawfly - Lateral view of mature
larva, on ponderosa pine.
  • Latin name: Acantholyda verticalis (Cresson)
  • French name:
  • Order: Hymenoptera
  • Family: Pamphiliidae
Description

Distribution

British Columbia, Alberta

This species occurs throughout central and southern British Columbia; it also extends to Alberta and to California.

Micro-habitat(s)

Needle

Damage, symptoms and biology

Acantholyda verticalis is a relatively uncommon innocuous solitary defoliator.

Mature larva up to 18 mm long. Head, light tan with a pair of seven segmented antennae and rows of brown spots in two patches over the crown. Body, yellowish green with prominent purplish brown middorsal, midventral and spiracular stripes; yellow subspiracular stripes. A pair of jointed appendages occur at the posterior end.

This species overwinters as a prepupal larva in earthen cells. Adults emerge in spring or early summer. Larvae construct silken webs and are active from June to July. Mature larvae drop to the soil in late July to August and construct earthen cells.

Canadian Forest Service Publications

Upright webspinning sawfly

Diet and feeding behaviour

  • Phyllophagous : Feeds on the leaves of plants.
    • Webworm: Spins a silk shelter in which to hide or feed.
Information on host(s)

The principal host of Acantholyda verticalis are lodgepole pine and ponderosa pine; other hosts include western white pine and Monterey pine.

Main host(s)

Lodgepole pine, Monterey pine, ponderosa pine, western white pine

Photos
  • Upright webspinning sawfly Lateral view of mature larva, on ponderosa pine.
  • Upright webspinning sawfly
  • Upright webspinning sawfly Lateral view of mature larva, on ponderosa pine.
  • Upright webspinning sawfly Lateral view of mature larva, on ponderosa pine.
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