Density has more influence than drought on spruce budworm (Choristoneura fumiferana) performance under outbreak conditions

•Higher insect densities increased defoliation of 1-year-oldfir shoots.•Higher insect densities reduced spruce budworm %survival.•Higher insect densities reduced adult male wing length.•Higher insect densities reduced female mass but only on droughted trees.•Overall, drought had minimal influence on defoliation and insect performance.