Kingston - Surprising findings from an international research team – including Geological Sciences and Geological Engineering professor Kurt Kyser – provide the first evidence of a “vegetarian” spider.

"Stable isotope analyses in the high-tech laboratory at Queen's proved conclusively what had been observed in the field: these spiders were indeed primarily vegetarian," says Dr. Kyser.

Until now, the eight-legged arachnids have been considered strict carnivores, trapping their prey in webs or hunting them. But the researchers have discovered a spider species that feeds mostly on the leaves of the acacia plant.

"Our findings show that we still have much to learn from biological systems which may appear to be very familiar," says Dr. Kyser, who is director of the university's Facility for Isotope Research laboratories.

Called Bagheera kiplnigi, the small, jumping spiders were first identified in Costa Rica by Eric Olson of Brandeis University, and then in Mexico by Christopher Meehan of Villanova University. The two researchers linked up with Queen's PhD student Matt Reudink, who was working on his thesis under Biology professor Laureen Ratcliff, with the assistance of Dr. Kyser.

The Queen's isotope lab facilities confirmed that the primary component of the spider diet came from "Beltian bodies" -leaf-tip structures produced by acacia shrubs that normally serve as a food reward for ants living in the acacia plants.

"Biologists have been studying the relationship between ants and acacia trees for more than 50 years, but none had recognized that a small spider with peculiar eating habits was part of the system in certain places," says Dr. Kyser, noting the eclectic backgrounds of the researchers in the group: biologists, a policy maker, a forensic scientist and an earth scientist.