Bumblebees Damage Plant Leave to Hasten Their Flowering

Environmental & Science Education
STEM
Behavior
Biological Evolution
Biodiversity
Edward Hessler

The natural world still holds a surprise or two, something never before observed. Bumblebees delivered one of those surprises.

They can force plant to flower by puncturing their leaves with one of their inimitable bites. A brief summary can be found in Scientific American (May 21).

Jim Daley, who wrote the article reports that "Study co-author Consuelo De Moraes, a chemical ecologist at the Swiss Federal Institute of Technology Zurich (ETH Zurich), says she and her colleagues were observing one species of bumblebee in an unrelated laboratory experiment when they noticed the insects were damaging plant leaves and wondered why. “Initially we wanted to see if they were removing the tissue or feeding on the plants or taking [leaf material] to the nest,” she says. And because previous research had shown stress could induce plants to flower, De Moraes and her colleagues also wondered whether the bees might be creating blooms on demand."

So they did a study in which "pollen-deprived bees" were placed in cages with tomato and mustard plants. The bees bit; the researchers used tools to bite plants as well. And then they waited and watched. Those flowers nipped in the bud so to speak bloomed several weeks earlier than those nipped artificially.

The laboratory is one thing but the great outdoors another so the researchers moved to the field. This time they selected a place where blooming plants were available but farther way than non-blooming plants closer to bee nests.

The findings suggest the bees’ behavior is an adaptation that maximizes pollen-foraging efficiency, but they do not definitively confirm that hypothesis, study co-author Mark Mescher says. Neal Williams, an entomologist at the University of California, Davis, who was not involved in the study, says the possibility is compelling and warrants more research. “'In order for something to be really defined and clearly understood as adaptive, we would want to be able to say the behavior was evolving because it contributed some relative fitness benefit to the colony,'” he says."

Daley's reporting may be read here. It is short and well, it is wonderful, too. In addition there are some photographs that show the bees at work, inflicting their "hurry-up" bites.