Red pine needle midge

Red pine needle midge - Larva in a needle sheath of red pine
  • Latin name: Thecodiplosis piniresinosae Kearby and Benjamin
  • French name: Cécidomyie du pin rouge
  • Order: Diptera
  • Family: Cecidomyiidae


Eastern Canada



Damage, symptoms and biology

Browning of the current year's needles in September is the primary symptom that can be used to confirm the presence of the red pine needle midge. Premature shedding of the needles can be observed later in the fall and during the winter.

Early scouting can help to detect the insect, especially during heavy infestations. Affected needles are much shorter than normal ones, and the tissues of the needle sheath will have become necrotic and hardened, owing to the hollowed out needle base.

Adults emerge between late May and early June and lay their eggs on the developing shoots which are still covered by bud scales. Single eggs or egg clusters can be found at the base of new needles bundles. The young larvae bore into the needle sheath before it matures and feed between the two needles or on their surface between sheath and needles.

In October, larvae fall to the ground and overwinter in the larval stage in the litter.

Life cycle (East of the Rockies)

Life cycle (East of the Rockies)
Stage/Month J F M A M J J A S O N D

Other information

The red pine needle midge has been recorded in North America since 1932, particularly in red pine plantations.

It only causes major damage occasionally and on a very localized scale. However, during heavy infestations, lateral and terminal shoots may die if they lose more than 75% of their needles. Although this insect does not threaten the survival of trees, tree growth will be reduced if large insect populations persist for two or three years.

A shady, cold site will delay adult emergence and vigorous trees with rapidly elongating annual shoots hinder egg-laying.

Canadian Forest Service Publications

Red pine needle midge

Diet and feeding behaviour

  • Phyllophagous : Feeds on the leaves of plants.
    • Gall-forming: Induces the formation of galls and feeds on their tissues.
Information on host(s)

Main host(s)

Red pine

  • Red pine needle midge Larva in a needle sheath of red pine
  • Red pine needle midge Red pine branches partially stripped of their needles after an attack
  • Red pine needle midge Red pine branches severely damaged
  • Red pine needle midge Red pine plantation severely damaged
  • Red pine needle midge Damage on slightly affected needles of red pine
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