I must admit, I was a little jealous to hear that the Brood X cicadas that everyone’s been talking about in New York, New Jersey, Pennsylvania and Maryland would not extend as far north as Massachusetts. So I was surprised, and quite delighted, to discover this Magicicada (periodic cicadas) in my yard last week. Unlike some of the swarm-like photos coming out of NY/NJ, I found just a single female beside its exuvia – the cast-off outer outer skin of the cicada nymph after its final molt. I’ve since located six other exuviae around the yard, and have seen two instances of birds catching one of these juicy morsels. 

Periodical cicadas fall into two groups based on the length of their lifecycle: 13-year or 17-year. Within the 17-year cicada group, there are three species: Magicicada septendecim, M. cassini and M. septendecula. The ones pictured here are likely M. septendecim, which is also called the Pharaoh cicada. It is native to the United States and Canada and is the largest and most northern species of 17-year periodical cicadas. Although cicadas are common on Cape Cod every summer, what you’re probably used to seeing (and hearing!) are various species of annual cicadas. Annual and periodical cicadas differ in a number of ways. Some differences are visual: the annual cicadas are primarily patterned in greens and browns with dark black eyes, while the periodical cicadas have striking red eyes, black bodies and bright yellowish wing veins. The most important difference, however, at least from an ecological standpoint, is their timing. Despite their name, even annual cicadas have lifecycles that span many years, but because the lifecycles of the individuals within a particular population are staggered, some annual cicadas emerge each year, although in varying numbers. In contrast, the periodical 13- or 17-year cicadas have populations in which all the individuals have synchronized their life cycles. 

There are different regional populations of the periodical cicadas – identified as different “broods”. This is why Brood X can emerge in the mid-Atlantic, while New England isn’t “scheduled” for a significant cicada emergence until 2025 (Brood XIV). But apparently, not wanting to miss the 2021 party, some Pharaoh cicadas are not waiting. While it’s mind-blowing enough to consider that millions of a tiny underground nymphal insects can count exactly 17-years before emerging en masse, it’s even crazier to me to find out that if they are going to be “early” or “late”, they will be off by exactly 4 years. And here they are, popping up in great enough numbers on the upper Cape to be noticed not only by nature-nuts like me, but by folks on numerous local Facebook groups wondering “what these crazy bugs are”. As you can see in the screen shot of M. septendecim iNaturalist observations in Massachusetts this year, however, the emergence seems fairly localized to a few towns on upper Cape Cod. I wonder what it is about this region that’s causing the early arrivals…

If you do happen to find one of these red-eyed beauties this summer, please take the time to post your observations to iNaturalist or Cicada Safari; your input will help researchers track where and when cicadas are emerging. Don’t worry about picking them up – they can’t hurt you. They do not sting or bite. If you can, get a photo of both the back and underside of the insect. Not only with you be able to tell whether your individual is a male or a female (the one pictured below is a female, as evidenced by the long ovipositor at the end of her abdomen), but a clear view of the striped patterning on the underside is required for species identification. 

In addition to their mass emergences, cicadas are probably best known for their loud song, particularly on hot summer days. It’s only the males that sing, however, as they use their song as a means to attract a mate. The loud buzzing songs produced by cicadas are generated by special membrane-like organs called “tymbals” located on their abdomens. Whether you love them or hate them, cicadas are quite beneficial to the ecology of the region. Their underground activities during their 17-year nymphal stage create tunnels in the soil that act as a natural aeration system. An emergence of a large number of cicadas provides a feast for all sorts of insectivorous animals. And, after the cicadas die their decaying bodies contribute nitrogen and other nutrients to the soil.