Over the course of the summer of 2023, Quebec experienced its worst wildfire season on record. By its end, some 4.5 million hectares of the province’s boreal forest were burned. While the effects of the toxic smoke on humans have been thoroughly studied, our knowledge of the impact on local fauna — including insects — is lacking. A new study led by Concordia researchers is among the first to look at how exposure to wildfire smoke affects the development of lepidoptera: the order of winged insects that includes moths and butterflies. The paper… shows that smoke exposure during larval development caused significantly higher rates of wing deformities in spruce budworm and forest tent caterpillar moths, two species that periodically strip the leaves off millions of hectares of Canadian forest when the insects’ populations boom. …Smoke-exposed spruce budworm moths were twice as likely to develop wings that the researchers classified as folded, crumpled or missing.