Photo credit: N. canicularis (Dog-Day cicada) and N. davisi (Southern Dog-Day cicada) by Paul Krombholz.
Dog-day cicada is the common name given to Tibicen (now Neotibicen) type cicadas in North America. These cicadas are called “Dog Day” because they are typically observed during the “Dog Days of Summer“, which fall somewhere between late July to early September, or once the “Dog Star” Sirius appears in the morning sky. All Neotibicen species are present during the month of August in North America.
Dog-day cicadas are known for their green, brown, black & white coloration that provides them with excellent camouflage in the trees they inhabit.
Dog-day cicada is used generally to describe most Neotibicen, but a few species are explicitly named Dog-day:
Neotibicen canicularis aka the Dog-day cicada. Canicularis is Latin for “of the dog star”, and the dog star is Sirius. Found in AR, CT, DC, IL, IN, IA, KS, ME, MB, MD, MA, MI, MN, MO, NE, NB, NH, NJ, NY, NC, ND, NS, OH, ON, PA, PE, QC, RI, SC, SD, TN, VT, VA, WV, WI. Season: August-October.
Neotibicen davisi, aka the Southern Dog-day cicada. There are two sub-species. Found in AL, DE, DC, FL, GA, LA, MD, MA, MS, NJ, NY, NC, PA, SC, TN, TX, VA, WV. Season: July-October.
Neotibicen superbus aka the Superb Dog-day cicada. Found in AR, KS, LA, MO, NM, OK, TX. Season: June-August.
Photo credit: Neotibicen superbus by Sloan Childers
These cicadas do not actually appear the moment Sirius rises, and when they do appear depends on your location and the weather. Neotibicen canicularis will appear in Arkansas before it appears in Quebec. That said, if you are curious when Sirius will rise in your area, search for “heliacal rising of sirius” — it varies about a day per degree of latitude. Neotibicen, depending on the species, can be found from May to December (December in Florida), but all Neotibicen species are present during the month of August in North America.
Update #12 Last week I traveled west to look for stragglers in Ohio and Indiana. I found exuvia (cicada skins) north west of Indianapolis, Indiana; exuvia in Cedar Springs, Indiana; active, mating periodical cicadas in several small towns north-west of Columbus, Ohio; and exuvia & a few adults in Princeton, NJ. See a map of my sightings.
Periodical cicadas have been spotted in the Hudson Valley of New York state.
This year “precursors” to Brood X are emerging or will emerge in small to large numbers in D.C., Delaware, Georgia, Illinois, Indiana, Kentucky, Maryland, Michigan, Missouri, New Jersey, New York (Long Island), North Carolina, Ohio, Pennsylvania, South Carolina, Tennessee, Virginia, and West Virginia. Magicicada.org has the most up-to-date map from Brood X.
Note: because of the significant number of cicadas emerging ahead of time, this might be an acceleration event. Periodical cicada accelerations occur when a significant group of an established brood emerge in years ahead of the main brood, and sometimes the accelerated group are able to reproduce and create what is essentially a new brood. Brood VI was likely part of Brood X at one point of time1. We’ll have to see if the Brood X stragglers are able to survive predation, and reproduce in significant numbers to sustain future populations. They are certainly trying.
Don’t panic! Less that one percent of a Brood straggles. If you had 10,000 cicadas in your yard back in 2004, you can expect a less-frightening or more manageable dozens or hundreds (okay, maybe 1,000s). :)
Brood VI is also emerged this year?
Brood VI also emerged this year in North Carolina, South Carolina and Georgia. These cicadas emerged on schedule, and are not stragglers. It is believed that Brood VI descended from Brood X through acceleration (mentioned above).
Stragglers are periodical cicadas that emerge in years before or after the brood they belong to is expected to emerge. Typically 17-year periodical cicadas emerge 4 years early (see the probability chart). While stragglers might not produce enough offspring to produce future generations, straggling is something periodical cicadas do — it is hard-wired into their DNA. The 4-year interval is also typical.
Stragglers are not a new phenomenon. William T. Davis documented accelerations of cicada populations back in the 1800s, which was reported by C.L. Marlatt in the 1898 document The Periodical Cicada. An Account Of Cicada Septendecim, Its Natural Enemies And The Means Of Preventing Its Injury.
Mr. W. T. Davis records the occurrence of scattering individuals on Staten Island in both 1890 and 1892, neither of which is a Cicada year. These may have been of accelerated or retarded individuals, but possibly represent either remnants of broods or insignificant broods not hitherto recorded.
In the case of W. T. Davis’s observations, Brood II would have emerged in 1894 in Staten Island, so 1890 would have been a 4-year straggler/processor/acceleration, and 1892 a rare 2-year acceleration.
The term “straggler” throws people off, because most people are familiar with the definition of straggler that means “something that falls behind the main group”. These cicadas are clearly ahead of the main group, not falling behind. Straggle can also mean “to wander from the direct course or way” (Merriam-Webster), “to trail off from others of its kind” (Merriam-Webster). In terms of cicadas, scientists and naturalists have been using the term “straggler” for over a century, so it has stuck around. For now, don’t worry about the term, just know that it means periodical cicadas that are not emerging on schedule.
It makes sense that climate variations would trigger periodical cicadas to emerge ahead of time. Periodical cicadas take cues from the seasonal cycles of their host trees. An unusual climate event, like a hot fall or winter, might cause trees to signal cicadas that additional years have passed, and cause them to shift to emerge early. In the paper, How 17-year cicadas keep track of time, Richard Karban was able to show that you can speed up the time it takes for a periodical cicada to emerge by artificially altering the seasonal cycles of their host trees2. It’s likely that the Brood X stragglers emerging now were set on their path to emerging 4 years early not this year or the last, but many years ago.
Metropolitan areas like Washington D.C., called “HEAT ISLANDS” (read this article), can often be much hotter than surrounding rural areas due to human activity. The effects of living within a heat island may have disrupted the seasonal cycles of the cicadas’s host trees, and therefor the cicadas themselves. Localized climate change will be considered as a contributing factor to their early emergence. If we find considerably less stragglers in rural areas than city areas, then we could draw a conclusion that local climates are contributing to straggling.
Other than climate (in the long term), weather (in the short term), and a natural propensity to straggle or accelerate, population density is another reason why cicadas will straggle. If there is a high density of them underground, vying for limited resources, some might emerge a year or so before or after the main Brood.
1 Monte Lloyd &J o Ann White. Sympatry of Periodical Cicada Broods and the Hypothetical Four-Year Acceleration. Evolution, Vol. 30, No. 4. (Dec., 1976), pp. 786-801.
2 Richard Karban, Carrie A. Black and Steven A. Weinbaum. How 17-year cicadas keep track of time. Ecology Letters, (2000) 3: 253-256.
A new subspecies of the Similar Dog-Day Cicada has been described in the paper A new Neotibicen cicada subspecies (Hemiptera: Cicadidae) from the southeastern USA forms hybrid zones with a widespread relative despite a divergent male calling song by David C. Marshall and Kathy B. R. Hill (Zootaxa, Vol 4272, No 4). The cicada is named Neotibicen similaris apalachicola.
This cicada lives in Florida, Georgia & Alabama, and hybridizes with the other Similar Dog-Day Cicada sub-speces, Neotibicen similaris similaris. The document is available on biotaxa.org.
A morphologically cryptic subspecies of Neotibicen similaris (Smith and Grossbeck) is described from forests of the Apalachicola region of the southeastern United States. Although the new form exhibits a highly distinctive male calling song, it hybridizes extensively where it meets populations of the nominate subspecies in parapatry, by which it is nearly surrounded. This is the first reported example of hybridization between North American nonperiodical cicadas. Acoustic and morphological characters are added to the original description of the nominate subspecies, and illustrations of complex hybrid song phenotypes are presented. The biogeography of N. similaris is discussed in light of historical changes in forest composition on the southeastern Coastal Plain.
If you’re in DC, DE, IN, IL, KY, MD, MI, MO, NJ, NY, OH, PA, TN, or VA. head over to our Brood X straggler page.
Update #7: I traveled to Wisconsin last week and spent a few days looking for cicadas in the southern part of the state (Madison, Baraboo, Janesville, Cedar Bluff, Dodgeville) but unfortunately I did not see or hear any. :(. So far this year though, Brood VI was spotted in GA, NC, SC, OK, OH and perhaps NY….
Brood VI (6) 17-year cicadas (“locusts”) will emerge in the spring of 2017. The main group will emerge in South Carolina, North Carolina and Georgia. Other lesser groups should emerge in Ohio & Wisconsin. And possibly other states/locations as well.
When: Generally speaking, these cicadas will begin to emerge when the soil 8″ beneath the ground reaches 64 degrees Fahrenheit3. A nice, warm rain will often trigger a emergence. So, definitely May, but something might happen in April if we have a particularly hot spring.
1889 document: Dade (Trenton), Elbert (Elberton), Floyd (Rome), Habersham (Turnerville), Hill (Virgil), Paulding (Brownsville), Rabun, Spalding (Experiment), White (Tesnatee). 7
Best bet: Buncombe (Asheville), Burke, Caldwell, Henderson, McDowell, Polk, Wilkes6.
1889 document: Alexander (Mount Pisgah, Taylorsville), Bladen, Buncombe (Asheville), Burke (Morganton), Cabarrus, Caldwell (Lenoir, Hickory), Catawba (Claremont, Maiden), Henderson (Westfeldt Park, Horse Shoe), Iredell, Lincoln (Denver, Lincolnton), Macon (Franklin), McDowell (Greenlee), Moore, Montgomery, Pender (Long Creek), Polk (Columbus, Saluda, Mill Spring), Rabun (Highlands), Randolph, Rutherford, Swain (Whittier), Transylvania, Union (Waxhaw), Washington, Wilkes (Moravian Falls, Wilkesboro).7
Best bet: Oconee, Pickens6.
1889 document: Oconee (Stumphouse Mountain which is near Westminster).7
Wisconsin seems like a sure thing as well.
Best bet: Columbia, Dane, Rock, Sauk (Baraboo)5
1889 document (aside from those mentioned above: Burnett (Spooner), Columbia (Madison), Crawford (Towerville), Dane (Janesville), Fond du Lac (Ripon), Green Lake (Dartford), Marquette (Harrisville), Sauk (Baraboo), Sawyer (Hayward), Washburn (Shell Lake), Waushara (Auroraville). 7
Best bet: Hamilton (Hyde Park, Delhi, Finneytown, Green Township, Anderson). 5
Most, if not all cicadas sing during the day, but what time of day they sing depends on the species and the weather. There are over 3,000 species of cicadas, and each has its own unique behavior.
Typically, cicadas do not sing at night, but there are exceptions. Most of the time when you hear an insect at night, it’s a cricket or katydid.
Most cicadas love the sun, so rain, and cloudy skies will decrease the likelihood they will sing. Temperature also effects whether or not they will sing. If it is too cold, or too hot cicadas won’t sing. Tolerance for temperature depends on the species.
Cicadas, depending on the species, will sing depending on the number and proximity of other cicadas in their area. Periodical cicadas, when there are enough in a given area, will synchronize their songs forming a chorus (a group effort to attract females).
When they sing during the day, under perfect conditions, depends on the species. Each species has its favorite time to sing, for example, in North America: