Earlier, Rose and Lindquist (1985)[2] had noted that severe injury to spruce is unusual, and had been recorded only from a number of locations in Yukon Territory.

Other outbreaks have occurred in Yukon Territory in 1968 and 1969 (Tripp et al. 1970),[3] in Connecticut in the early 1970s (Stephens 1985),[4] and in New Brunswick and Nova Scotia in 1981 and 1982 (Magasi 1983).

Pupation usually occurs from mid-May to early June, and the 2-winged reddish-brown adult midge emerges through a conspicuous hole in the gall formed in the previous year’s shoot.

Gall formation becomes noticeable within 10 days as a series of small, semi-globose swellings, which render the infected twig twice its normal diameter.

The data were used to derive a sequential sampling plan for the classification of damage cause by spruce gall midge, of use to foresters and pest managers (Brandt 2000).