Tracking Mormon Crickets

Latest Research Findings, Reports, and Publications for this Project

Outbreaks of insect pests are common and can have devastating effects on natural and agricultural ecosystems. Little is known about the causes of these outbreaks, not to mention the causes of en masse migrations during outbreaks. Our research has focused on flightless Mormon crickets (Anabrus simplex  (Tettigoniidae)), a katydid species that forms large, mobile groups (migratory bands) during outbreak periods. Working with collaborators from Kent State University and the University of Toronto at Mississauga, we have been studying the process of migratory band formation and movement to facilitate the development of predictive models for Mormon cricket migration. We utilize radiotelemetry, a valuable tool for understanding animal movement patterns, to quantify movements of individual Mormon crickets under natural conditions.

To date, we have tested hypotheses about: (1) movement differences between insects in outbreak and non-outbreak populations; (2) wind direction as a cue determining band movement direction; and (3) the role of social interactions in migratory band formation and movement.  Our results indicate that Mormon crickets in outbreak populations exhibit collective movement patterns and travel much further than those in non-outbreak populations. Wind direction plays little if any role in determining the direction of migratory band movement.

Social effects have a major effect on both the distance and direction traveled by band members. In addition, we have shown that migratory band membership benefits individual insects by greatly reducing their probability of being killed by predators.  This suggests that migratory band formation has evolved as an anti-predator strategy that confers substantial protection to insects within the group.

Dr. Sword's research on Mormon cricket migration was featured on the National Geographic Channel.  Click here to see the video.

Contributing Scientist:  Vice Sword (Ecologist)


 

Latest Research Findings/Reports

Radiotracking Mormon Crickets By: Gregory A. Sword (Ecologist), Patrick D. Lorch, & Darryl T. Gwynne Download this Poster (PDF: 4.93 MB) Insect outbreaks can have devastating effects on natural and agricultural ecosystems. Little is known about the causes of these outbreaks, not to mention the causes of en masse migrations during outbreaks. Our work focuses on flightless Mormon crickets (Anabrus simplex (Tettigoniidae)), a katydid species that forms large, mobile groups called migratory bands during outbreaks in the western US.

The following recent publications are available to download in .PDF format:   Lovejoy, N.R., Mullen, S.P., Sword, G.A., Chapman, R.F., and Harrison, R.G. 2006. An ancient trans-Atlantic flight explains locust biogeography: molecular phylogenetics of Schistocerca. Proc. R. Soc. B., 273: 767-774. (518KB)   Simpson, S.J., Sword, G.A., Lorch, P.D., and Couzin, L.D. 2006. Cannibal crickets on a forced march for protein and salt. PNAS, 103(11): 4152-4156. (623KB)   Simpson, S.J., Sword, G.A., and DeLoof, A. 2005. Advances, controversies and consensus in locust phase polyphenism research. Journal of Orthoptera Research, 14(2): 213-222. (470KB)