Contarinia pseudotsugae Condrashoff, 1961
douglas-fir needle midge
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
larvae in opened gall
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.
larva and pupa are described in much detail by Condrashoff (1961a).
spatula (from Hielscher, 2017a)
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)
Burton, Carbonnelle, Ellis & Schneider (2019a), Condrashoff (1961a, 1962a), Eppo (2018), Hielscher (2017a).