Archived content - Cicada (31 of 46)
Archived content is provided for reference, research or recordkeeping purposes. It is not subject to the Government of Canada Web Standards and has not been altered or updated since it was archived. Please contact us to request a format other than those available.
C. A Fascinating Fauna (Continued)
Cicada species occurring in more than one region of the world are marked with an asterisk (*).
10C. Periodical Cicadas (Magicicada)
Periodical Cicadas(genus Magicicada, formerly Tibicina) are easily recognized by the contrasting eyes, usually red (rarely, bluish white) which stand out from the bluish-black head and thorax; face with parallel ridges on midline; forewings orange; legs and most of underside of abdomen orange to black. Head as wide as thorax with eyes prominent; tymbals concealed only by wings; male abdomen appearing inflated, at base narrowly overlapped by short, broadly rounded male opercula projecting 3 mm beyond hind leg base, nearly touching each other; male terminal segment with uncus small and forked on lower edge, theca bearing saw-like double semi-circular discs at tip. Song a low call in spring (May through June). Nymph flattened, pale brown with darker eyes and often black patches on the thorax.
All the species of genus Magicicada are found in eastern North America. They differ in coloration, size, song, mating behavior, and habitat preference, but they are evidently very closely related since allozyme studies found no alleles unique to any species. They have been found to hybridize in nature, but rather infrequently (1%) and these seldom establish breeding populations. Occasional individuals are found in the field which appear to be hybrids.
There are now recognized to be three species, all in eastern North America, although formerly there were thought to be as many as seven species, of which three have 17-year life cycles and three (or four) identical ones have 13-year life cycles. Now it is thought that 13-year cicadas are not distinct species of cicadas but are actually 17-year cicadas that have switched their development time to 13-year cycles. Thirteen-year cicadas are mostly found in the lower Mississippi Valley from Illinois to Louisiana, and on the piedmont south of Virginia.
Magicicada septendecim (L.), Seventeen-Year Locust
Adults: Head 7.5-8.5 mm wide; overall length (wings folded) 3.5-4.2 cm, largest of the periodical cicadas. Underside light orange to dark reddish, usually barred with black; 13-year populations (subspecies tredecim Walsh & Riley and neotredecim Marshall & Cooley) are usually orange on the underside and 17-year populations (typical septendecim) are usually black with varying widths of orange stripes.
Song: Most commonly in the morning: two hollow-sounding notes, low pitched, lasting 1-3 seconds, which rises and gets louder, and then falls again, as in "pharaoh". Where populations of subspecies neotredecim overlap those of subspecies tredecim, male calling songs (and female song preferences) are more distinct than where the populations occur separately. In this overlap zone (Arkansas to Indiana), M. neotredecim songs are much higher-pitched, while M. septendecim subspecies tredecim songs are slightly lower-pitched. This "character displacement" indicates an incipient speciation event, possibly caused by an isolated 17-year founding population becoming a 13-year population, and then competing with other 13-year populations as it spreads southeastwards. Character displacement is rare between subspecies of the same species, but may happen in populations with low vagility (such as periodical cicadas).
Range: Forests of eastern USA, from Louisiana to Georgia, north to Cape Cod, northern New York state, southern Michigan, southern Wisconsin and Iowa; more commonly found on hills rather than valley bottoms. Recently, it has been reported in Canada from southern Ontario (Grand Bend). One Canadian record, from 1885, is from Montebello, Quebec (on the Ottawa River) but this has not been reported since, 2005 (brood X) having been the most recent opportunity to find it. The population has probably died out. The site is too far from the nearest recorded population (in Vermont; itself probably eradicated) to be merely a record of a stray individual. This site is also not on a direct rail line from the USA, and thus the population is unlikely to have been introduced by transportation.
The typical subspecies (17-year cycle) is generally found more northerly, westerly, and at higher elevation from subspecies tredecim (13-year cycle). The latter is found from North Carolina, Tennessee and Arkansas southwards, and is also widespread throughout Illinois and Missouri, whereas the typical subspecies is found in northern Illinois west to eastern Nebraska and Kansas, and north of North Carolina and Tennessee (but also in the Appalachian mountains south of Virginia and Tennessee).
Reports of this species from Montana, Idaho and Wyoming are based on records from the 1800s that are probably from misidentified specimens of Okanagana.
Outbreak years: The exact regularity of outbreaks makes predictions precise. For this species they occur every 17 years. Adults of the most widespread brood (Brood XIV) last appeared in 1991, so the next major outbreak will be in 2008. This will affect mostly southern Ohio and locations southwards, but also a few scattered counties in Pennsylvania. Broods of greater significance to Canada are those affecting adjacent Michigan: Brood VI that appeared in 2000 will reappear in 2017, and Brood X which was last seen in 2004 will come again in 2021.
Economics: Seventeen-year locusts can occur in enormous numbers over a 6-week period. It is this rather than the individual damage by feeding and egg-laying that makes them a major, if local, pest. A single fruit tree may support over 1500 larvae; their exit holes may be so dense as to honeycomb the ground surface; and females by the thousand gather in a small area, drawn by the singing of the males.
Eggs are laid in early summer, but do not hatch until late in the season. Thus the danger of accidentally importing living eggs extends throughout most of the growing season. Moreover the chance is very great of importing, at any time of year, sufficient living larvae in the earth of root balls to start a local colony.
Magicicada septendecula (Alexander & Moore)
Adults: Head 7-8 mm wide; overall length (wings folded) 3-4 cm; underside black; this species overlaps both other species in form and timing of emergence, and can only be distinguished by its song. Its 13-year populations (subspecies tredecula Alexander & Moore) are physically indistinguishable from the typical (17-year) subspecies. As such, it is only possible to distinguish this form by the timing of its brood emergence.
Song: Most common around noon: a series of brief, high pitched chirps lasting 15-30 seconds.
Range: Forests of eastern USA, co-occurring with M. septendecim and having a similar distribution of its 13- and 17-year subspecies. This, together with its intermediate size and song characteristics, suggests that the species is of hybrid origin, representing septendecim × cassinii.
Magicicada cassinii (Fisher), * Dwarf Periodical Cicada
Adults: Head 6.5-7.5 mm wide; overall length (wings folded) 2.8-3.5 cm; smallest of the periodical cicadas; underside black, or with faint orange stripes, these broken on the midline. Its 13-year populations (subspecies tredecassini Alexander and Moore) are physically indistinguishable from the typical (17-year) subspecies.
Song: Most common in late afternoon: a series of ticks or a trill, followed by a shrill, whining buzz, that has been likened to the sound of a pull-and-release toy car that is pulled back and let go. Males may sing in concert.
Range: Forests of eastern USA, from Texas to North Carlina, north to southern Iowa and east to Long Island, usually found together with M. septendecim, but not approaching the Canadian border; more common in valley bottoms than on hills. Subspecies tredecassini has a similar range to that of Magicicada septendecim subspecies tredecim, whereas the typical (17-year brooded) subspecies is more southerly in the west, being abundant in Kansas, and the only periodical cicada recorded from Texas and southern Oklahoma.
See Picture Guide
- Date modified: