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Accelerations FAQs Periodical Periodical Stragglers

What are stragglers?

Periodical cicadas often emerge in years before or after they are expected to emerge. When periodical cicadas don’t emerge on schedule we call them stragglers, regardless of whether they show up early or late. Typically cicadas with a 17-year lifecycle will emerge 4 years early, and cicadas with a 13-year cycle will emerge 4 years late.

Probability of Straggling chart from Chris Simon
This image indicates the probability of Magicicada straggler emergences. Courtesy of cicada researcher Chris Simon.

People hear the word straggler and assume it means something that lags behind, but that is a laggard. A straggler can mean something that has deviated from an expected date/time or moved away from others of its kind. That said, periodical cicadas that emerge early can also be called precursors, but in the scientific literature, they are called stragglers.

Visit Brood Chart to see when stragglers will be most likely.

Extremely likely stragglers in the next few years:

2020: Brood XIII 4 years early.
2021: Brood XIV 4 years early.
2025: Brood I 4 years early.

Likely stragglers in the next few years:

2020: Brood X 1 year early.
2021: Brood IX 1 year late.
2022: Brood X 1 year late.
2023: Brood XIII 1 year early.
2024: Brood XIV 1 year early.

Accelerations

An acceleration occurs when periodical cicadas straggle in numbers significant enough to sustain future generations. In other words, a large population of a 17-year brood emerge in just 13 years, they avoid being eaten by predators, they mate and reproduce, and then 17 years later their offspring emerge in large enough numbers to reproduce and sustain their population. This is one reason why two different broods might exist in the same area. 1

It is thought that Brood X was formed when a group of Brood XIV accelerated 4 years (they emerged in 13 years, rather than 17). Then Brood VI came from Brood X, and Brood II came from Brood VI. Brood XIV -> X -> VI -> II is called the “main sequence”1.

Accelerations may have been more prevalent and successful (successful in terms of sustaining future generations) in the past when much of eastern North America was forests, and there was no human intervention or destruction of habitat to interfere.

References

1 Monte Lloyd & Jo Ann White. Sympatry of Periodical Cicada Broods and the Hypothetical Four-Year Acceleration. Evolution, Vol. 30, No. 4. (Dec., 1976), p. 795.

Here’s a paper that discusses 13-year Magicicada emerging 4 years early: David C. Marshall, Kathy B. R. Hill, and John R. Cooley “Multimodal Life-Cycle Variation in 13- and 17-Year Periodical Cicadas (Hemiptera: Cicadidae: Magicicada),” Journal of the Kansas Entomological Society 90(3), 211-226, (1 July 2017). https://doi.org/10.2317/0022-8567-90.3.211

19 replies on “What are stragglers?”

This is really interesting. I live in Southwest Virginia in the Brood I area. In December 2011, our 12-year old family dog, Lulu, died. When my son and I dug her very large and deep grave in our backyard, we found several nymph stage cicadas in the soil from the grave. I had seen anything like this, but I thought this might mean an emergence of cicadas would happen the following spring. Sure enough, in May 2012, our yard and woods came alive with many thousands of cicadas. I can’t wait until 2029 to see them again!

Indianapolis, IN. Northeast side of the city. It’s deafening.
coordinates: 39.9108959, -86.0285935
N39° 54.6538′, W086° 1.7156′

I found a ‘cicada island’ in the north-central part of Baltimore City. It’s about a mile long and maybe 6-9 blocks wide. Very loud continual chorus, and thousands of shells around the trees in the neighborhoods. Adults are very active now. The area seems to be in full Brood X emergence.

Hi Doug,

Could you please report the exact coordinates of either end of the “cicada island” to this site and let us know how long it lasts? This will be very useful expecially when we map Brood X in four years. Thanks! Chris

It has been a week now since I have seen the first cicada in my area and have only seen just a few. My question is how long does it take for them to emerge? Is it days or even weeks from seeing the first one? I know they last 4-6 weeks possibly longer. I can only hope that what we have here is all that we’re going to get until 2021! Also will this effect the amount that will come in 2021?

Usually they’re all out of the ground within 1 to 2 weeks. Cold or rainy weather can prolong the time it takes from them to emerge. The total event — from the first nymph to crawl from the ground to the last one to die — typically takes 4 to 6 weeks. Again, the weather can prolong or shorten an event. If you only have a few this year, you’ll likely have many more in 4 years.

We have quite an emergence in the Dublin, Ohio area (near Columbus). There are easily hundreds in my yard. I made a recording of their call. It is so loud that we can’t sleep. I wish I could post the recording.

Do stragglers undergo one less molt–i.e. the Brood X stragglers that are emerging this year (2017)–do they molt to adult form on their 4th molt (as opposed to the 5th molt for 2021)? OR rather, do the stragglers molt at a more rapid pace throughout their nymphal stage–every three years instead of four? Part B: are (13-year–4 years early) adult stragglers smaller on average than the on-time (17-yr) adults?

I believe they go through the same number of molts/instars. They’re also the same approximate size (based on personal experience). Basically something triggers them to follow the lifecycle of their closely-related 13-year sister species.

Just saw many emerging in a yard in our neighborhood in Newark, DE. May 14,2017. They are emerging from what must be the roots of a tree cut down in early spring. They are crawling all over the grass looking for a tree to climb.

We seem to have the same thing. We cut down 2 trees within 20 feet of each other. There are easily 100+ nymphs in this area. I even had one climb up my ankle the other day as I stood in the lawn

We’re enjoying a ‘mass’ emergence of
Brood X stragglers in Central MD this evening. A wonderful Mother’s Day ‘gift!’

The emergence began here in Fairfax County, VA a few days ago. Today’s persistent cool rain has seen dozens of them come out of their shells from under the leaves in our patio planter.

as of 26 april, 2017, prince george’s county, maryland- many nymphs in tunnels, waiting! may be as good as my 2000, 4-year accel. counted almost 3000 sheds. will count sheds again.
see: john zyla’s paper, april, 2004, pp. 488-490. proc. ent. soc. of washington.

I’ve lived in/around D.C. for nearly 50 years but this is my first experience with stragglers. On Monday we found one adult on our porch and were bewildered because we knew it hadn’t been 17 years. This morning I see nymphs all over the place.

Also, many birds that can not BELIEVE their luck.

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