Sunday, July 8, 2007

Missed the cicadas? More to come


Are you disappointed that you never saw any periodical cicadas? Wait until 2024 and hold onto your hat, says biology professor John Cooley of the University of Connecticut at Storrs. That year, Brood XIII will be back in the Chicago area and Brood XIX -- the largest brood in geographic extent -- will simultaneously emerge all the way from Missouri to Virginia. "The show of a lifetime," Cooley calls it. "It's a once-in-221-year event!"

Just imagine the road trip.

You don't have to wait 17 years; you can plan a visit next May to Kentucky, Tennessee or West Virginia for the emergence of Brood XIV. Visit a few distilleries and see the cicadas.

XIX cicadas are the same species of the genus Magicicada as our XIII ones, but are on a different schedule: 13 years instead of 17. Scientists are not 100 percent sure why the Magicicadas emerge on two different schedules, but 13-year broods tend to be more southerly. XIV, down there in Tennessee, is a 17-year brood, though. So go figure.

Maps of all the broods for vacation planning purposes can be found at the Periodical Cicada Page of the University of Michigan Museum of Zoology.

Of course, as in Chicago this year, the cicadas in future emergences likely will not be found everywhere in the areas shown on those maps.

That may be partly because some of the old cicada territory has been paved over. But the brood maps themselves are pretty shaky. They are old and are based on reports from local residents over a number of emergences, Cooley says. "In the old days, this was accomplished with postcards or reports to USDA extension agents." People may not have known what they were seeing and probably often got their insects confused.

And "the absence of a report did not mean that cicadas were absent -- it only meant that nobody had reported cicadas as present." Some people may not have bothered to report them if they weren't especially astonished or freaked out.

This year, Cooley and other scientists were charging all over Chicago and surrounding counties in May and June trying to map the Brood XIII emergence more precisely. So, with your help, the scientific community hopes to give us a much more precise (though not perfect) idea of where to look for cicadas in 2024.