An Insight: Spruce budworm outbreak model

The spruce budworm (Choristoneura fumiferana) is one of the most harmful invasive insects in the Eastern United States and Canada's spruce and fir forests. The majority of the time, the number of budworms remains minimal. However, every forty years or so, the population of budworms grows to large proportions, wreaking havoc on the forest and killing many trees before returning to pre-explosion stages. These outbreaks seem to have occurred on a daily basis for hundreds, if not thousands, of years, according to evidence.