query: What is the wingspan of the eastern spruce budworm?
passage: Choristoneura fumiferana
The moths will emerge from the pupae within 8 to 12 days, during mid-June to August. Adult spruce budworm are medium-sized (15mm in length) and dichromatic, exhibiting gray and rust colors.[12] The wings have silvery patches and are 21mm to 30mm in wingspan.[11] Peak activity occurs during the later afternoon and early evening.[37] After emerging, the adults will mate and lay eggs in July or August.[11][38]
passage: Choristoneura fumiferana
Massive outbreaks of spruce budworm occur irregularly throughout the range, but populations of this insect can remain at an endemic level for long periods.[47] In 1943, a continuing outbreak in Ontario and western Quebec caused heavy mortality, particularly in stands of balsam fir. Half of the 25 million cords (90,615,000 m3) of balsam fir standing in 1931 were estimated to have died or been injured beyond recovery. Millions of cords of white spruce were also probably killed. Atwood noted increased difficulty of logging in affected stands as well as an increased risk of fire.[51]