A New Nomenclature for the Broods of the Periodical Cicada

by Charles Lester Marlatt

Explore the intricate map of cicada broods across time, place, and season.

This edition details how the western and eastern groups of the 17-year race connect, and how new broods emerge from retardation or acceleration in appearance. It presents the relationships among major broods and the ongoing effort to verify records across decades.

From the relationship of 13-year and 17-year swarms to the identification of new broods, the book offers a grounded look at how scientists trace patterns, confirm sightings, and map colonization. It uses historical records to show why some reports are uncertain and how researchers pursue clarity over time.

Clear explanations of how broods relate within the 17-year and 13-year races. Discussion of new broods and what retinal records or letters contribute to the picture. Examples of how scientists assess confidence in historical sightings and updates. Context for why verification matters when mapping cicada populations. Ideal for readers curious about insect life cycles, historical record-keeping, and the science of periodical cicadas.

12 pages, Paperback

Published August 24, 2018

About the author

From Wikipedia: Charles Lester Marlatt (1863–1954) was an American entomologist. Born in 1863 at Atchison, Kansas, he was educated at Kansas State Agricultural College (B.S., 1884; M.S., 1886), where he was assistant professor for two years. He is the person who introduced the ladybug insect Chilocorus similis into the United States to control the San Jose scale insect,[1] which was first discovered in San Jose, California in 1880 by John Henry Comstock and named by him. Marlatt worked for the Bureau of Entomology, United States Department of Agriculture. In 1912 he was appointed chairman of the Federal Horticultural Board. He was president of the Entomological Society of Washington in 1897–98 and of the American Association of Economic Entomologists in 1899.

His 1907 description of periodic cicadas remains a classic in the field. In this article, Marlatt proposed a grouping of periodic cicadas into 30 different broods, each given a Roman numeral. Broods I–XVII assigned brood numbers for each of 17 sequential calendar years to 17-year cicadas. Broods XVIII–XXX assigned 13 sequential calendar years to 13-year cicadas. Subsequent research has established that, in fact, not every year produces a brood of periodical cicadas. There are only 15 distinct broods, not 30, but Marlatt's scheme continues to be used.[2]