I hate insects—virtually any creepy, crawly bug. It’s a childhood phobia that has followed me into adulthood.

As organic gardeners know firsthand, insects are highly adaptable. Mother Nature has bestowed the power to survive significant environmental shifts, including climate changes.

But like something out of a Halloween horror flick, new University of Washington research suggests insects’ ability to adapt to global warming carries an unexpected consequence: more of them. This phenomenon will have widespread effects on agriculture, public health and conservation.

“Enhanced population growth rates for butterflies might be a good thing, but enhanced growth rates for mosquito populations are much more dubious,” says biology doctoral student Melanie Frazier, lead author of the research published in the October edition of The American Naturalist.

Evolutionary adaptation to climate warming will have a profound ecological impact because rates of population growth will eventually alter entire ecosystems. Some species could evade warmer temperatures by moving to cooler habitats, or they might alter their seasonal activity patterns, Frazier notes. Others might not be able to adapt adequately and could become extinct. But those that do adapt should have elevated rates of population growth.

“No matter which scenario plays out for a given species, local ecosystems will be profoundly altered,” says Frazier, whose research was funded by grants from the Environmental Protection Agency, National Science Foundation and National Cancer Institute.