25 January 2024

Map of the periodical cicada broods


Coming to our neighborhood this summer.  Via Neatorama, where note is made of the coincidence of a 13-year brood and a 17-year brood this year.

Image credit USDA Forest Service.

5 comments:

  1. I can't believe those puppies are limited to just that area?

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    1. I think I understand your objection. These are maps of concentrations of each brood. If a yellow "Brood X" flew into the green "Brood VIII" area before going back underground, it would emerge on its own schedule not sync'd with the VIIIs, and be considered one of the "ordinary, occasional" cicadas that everyone sees/hears every summer.

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    2. Thnak you for the xplanashun!

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  2. I noted the absence of Brood XI and Brood XII and had to check it out.

    Brood XI was in CT, RI, and MA, last seen in 1954 and have since been labeled as extinct. Brood XII is labeled as "spurious" (false or incomplete) by entomologists.

    The 13 and 17 year broods that will emerge this year will cross paths mainly in northern Illinois.

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  3. The emergence of large cicada broods affects wildlife and plant life. We often see trees damaged when these large broods emerge and attribute it to the cicadas. Recent studies look at the changes in the food web due to birds changing their eating habits, eating fewer tree-damaging caterpillars when the cicadas are available. More caterpillars means more tree damage, especially to oak trees. The emergence of 2 broods this year is expected to provide opportunities for more research. Bird populations also tend to increase in the years after a large brood emergence, which leads to fewer caterpillars for a period of time.

    https://mediarelations.gwu.edu/unearthing-ecological-impacts-cicada-emergences-north-american-forests

    The study is published in Science magazine, possibly available at some libraries.

    https://www.science.org/doi/10.1126/science.adi7426

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