Contarinia pseudotsugae Condrashoff, 1961

douglas-fir needle midge

on Pseudotsuga

large number of larvae below a Pseudotsuga menziesii; Belgium, prov. Antwerp, Kalmthout, 12.xii.2020 © Igor Vandamme: apparently the larvae leave their galls more or less synchronously.

Pseudotsuga menziesii, België, prov. Antwerpen, Balen, de Most 30.ix.2018 © Carina Van Steenwinkel

detail

larvae in opened gall

spatula

parasite

Galls on the youngest shoots. In a needles lives one,sometimes more, pale yellow larva. Locally the needle turns yellow, pink or purple and swells, mainly at the underside. There is one generation; in the autumn the larva leaves the gall through a triangular opening, hibernates as larva in the soil and pupates in the spring. Especially multiply infected needles drop prematurely.

host plants

Pinaceae, monophagous

Pseudotsuga menziesii.

larva, pupa

larva and pupa are described in much detail by Condrashoff (1961a).

spatula (from Hielscher, 2017a)

notes

Three Contarinia species live in western North America on P. menziesii, viz., next the locally most common C. pseudotsugae also C. constricta Condrashoff, 1961 and C. cuniculator Condrashoff, 1961. In 2015 infestations by C. pseudotsugae, have been found in the Netherlands, Belgium and France, soon followed by Germany, but there still is uncertainty if perhaps also C. cuniculator has become established in Europe.

Pseudotsuga menziesii needles with typical galls of Contarinia pseudotsugae (1), C. constrica (2), and C. cuniculator (3); A: upper side, B: underside (from Condrashoff, 1962a)

references

Burton, Carbonnelle, Ellis & Schneider (2019a), Condrashoff (1961a, 1962a), Eppo (2018), Hielscher (2017a).