Cannibal females invaded the Office of Teaching and Learning Services last winter, but don’t worry — they didn't bite. Rather, they were part of a photographic exhibit that documented the unusual mating behaviour of hump-winged grigs.
Grigs (genus Cyphoderris) are large, flightless relatives of crickets whose mating system provides a glimpse into the operation of Darwinian evolution in the wild.
A 2017 NSERC Individual Discovery Grant allowed Dr. Kevin Judge, assistant professor in the Department of Biological Sciences, to study whether changes to the environment — deforestation, pine beetle infestations and fires — could be linked to important evolutionary factors, like mate selection and cross breeding between species. Over the course of his research, Kevin has taken thousands of photos of grigs.
“Photography is a way of observing,” he says. “I love sitting and observing specimens and being in nature. Photography goes along with that, and being interested in biology helps you ask good questions. Just observing and keeping your mind open provides so much fodder for research.”
Male grigs sing by rubbing their front wings together, a behaviour that attracts receptive females and repels rival males. Once a female approaches a potential mate, she mounts his back and begins to feed on his hind wings. The loss of wing tissue and blood is not fatal to the male, and may serve to distract the female while the male grasps the female and attempts to copulate. The resulting male wing wounds offer an intimate window into the mate choices of female grigs. Kevin studies the wounded males to determine what characteristics (including body shape and size) make them attractive to females.
“The term ‘cannibal’ is technically true, but when you hear the term, you think of death,” explains Kevin. “The males don’t die. They display adaptations to their wings that suggest that they’ve evolved to sustain this damage from mating, and it may even be a characteristic that evolved in males in order to feed females.”
Kevin says that being a researcher gives him direction in the photos he captures. He also uses his camera as a magnifying lens and note-taking device, which enables him to continue making observations long after leaving the specimen’s natural environment.
“There’s an art to photography and part of that comes from being interested in the animals themselves and trying to capture their beauty.”
Kevin shares a few of his favourite photos from the “Cannibal Females” display.
An adult female Cyphoderris monstrosa feeding on a small insect. (Photo has been cropped.)
A mating pair of Cyphoderris strepitans (the female is mounted on the male’s back).
A female (left) and male (right) Cyphoderris buckelli mating in the lab. The male has grasped the female’s abdomen with his gin-trap organ.
A recently mated female Cyphoderris buckelli with spermatophore (the white mass at end of her abdomen) attached.
Ventral view of a female Cyphoderris buckelli. The irregularly spaced black spots are puncture marks caused by the male’s gin-trap during mating.
A male Cyphoderris buckelli. (Photo has been cropped.)