Unfortunately that article refers to "Brood X" as being the name of a particular species of cicada. As it turns out Brood X consists of at least 3 different species, each with a different eye color and vibratory frequency and pattern. Some do the morning, some are Noonish, and others the afternoon.
17 years from now the descendants of Brood X will be up and about and they will also be called Brood X.
We can hear.
What is a "brood"? Groups of cicadas that share the same emergence years are called broods. Charles Marlatt, a bureaucrat working for the Department of Agriculture, designated all the cicadas that emerged in 1893 and at 17-year intervals thereafter as Brood I. The cicadas that emerged in 1894 were called Brood II, and so on. The cicadas that will appear in 2004 belong to Brood X, which is the largest of the 17-year broods.
You already did source it. My bad.