Pollinator-Plant Mismatches

As temperatures continue to warm and weather patterns keep shifting, some plants are blooming much sooner than they used to.

- Susan M. Brackney

Certain insects are emerging off of their usual schedules, too. The result? Potentially significant disruptions to the life cycles of some of our most industrious pollinators and a decoupling of critical plant-and-pollinator relationships.

“The plants and the insects are responding to different phenological cues,” says Daniel Herms. Formerly a professor and department chair at The Ohio State University Department of Entomology, Herms presently works as vice president of research and development for the Davey Tree Expert Co. He has been monitoring phenological events — natural occurrences synchronized to the weather and the seasons — for nearly 40 years.

“[Plants and insects] respond to temperature differently,” Herms says. “They’re in different niches, and each niche is being affected differently by climate change.”

Generalists vs. Specialists 

In part, that degree of impact depends on the relationships insects have with the plants on which they rely. For instance, moths and butterflies tend to be generalists when it comes to their nectar sources. This makes them less susceptible to missed windows of opportunity with specific flowering plants.

“If they’re mismatched with one nectar plant, well, then they just go over to a different nectar plant,” Herms says. (That said, though, they are much more limited in terms of the host plants on which they’ll lay their eggs.)