Erik Etzler

Erik Etzler's paper on the survival of nymphal tree crickets

Erik Etzler's research on nymphal tree crickets was published in Ecology Entomology : Sex differences in survival: viability selection in nymphal tree crickets from a conopid fly parasitoid

https://doi.org/10.1111/een.12989

Erik Etzler, PhD student in Prof. Darryl Gwynne's lab, explained that:

Stylogaster neglecta

"Parasites are a far more common hazard than most people would like to think, and a large source of mortality for many animals. After discovering a new host-parasite relationship between the parasitoid fly Stylogaster neglecta and juveniles of the cricket Oecanthus nigricornis, we investigated whether certain types of crickets were more vulnerable to parasites than others. We sampled crickets across Ontario and dissected them to count the number of internal parasites. We found that male crickets are more likely to contain internal fly parasites than females, as well as contain more parasites on average. In addition, larger juvenile crickets were more likely contain internal parasites than smaller juvenile crickets, and had more internal parasites as well. When we examined the males more closely, we found a non-linear relationship between body size and parasite status, with intermediate sized males being more likely to contain parasites. Possible causes for this finding may include sex differences in cricket immune function, riskier behaviour of male as they acquire resources, as well as the effects of S. neglecta flies specifically targeting males and larger crickets. This work further reveals how parasitism does not always affect the sexes equally.”

Prof. Gwynne mentioned that: “Erik’s work is such a nice local story set in UTM’s old field on the far side of the lower football field. Years ago our lab had noted these unusual maggots emerging from our nymphal tree crickets. Erik took this bit of natural history (detailed further in his first paper)and developed it into a terrific MSc project showing that close to 50% of “youngster” tree crickets were doomed to death-by-maggot and, now in this paper, actually documenting an intriguing sex difference in the this action of survival selection (natural selection) on the crickets."

U of T News featured Erik's research this summer:

U of T Mississauga grad discovers little-known parasitic fly is killing local crickets

 

Read this paper »