Archived content - Cicada (33 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)
10D-1. Small Species (Subgenus Cryptotympana)
Tibicen Canicularis (Harris), Dog-day Cicada
Adults: Head 11-12.5 mm wide; overall length (wings folded) 4.0-4.8 cm; male opercula short, projecting 3.5-4.5 mm beyond hind leg base, not pointed as in T. linnei; uncus 1.5 times as long as wide, weakly tapered to broadly rounded tip. Upper side black variegated with pale green, including a broad, green 'collar' between wing bases. Underside pale green, sides usually appearing floury, with broad black band down middle of abdomen.
Song: A loud, continuous buzz rising to a crescendo and then dying away after about a minute, strikingly similar to the noise of a buzz-saw. This is the loudest of our cicadas. T.W. Harris, who gave both the scientific and common name to this species, notesFootnote 1:
"During many years in succession … I have heard this insect, on the 25th of July, for the first time in the season, drumming in the trees, on some part of the day between the hours of 10 in the morning and 2 in the afternoon. It is true that all do not muster on the same day; for at first they are few in number, and scattered at great distances from each other; new-comers, however, are added from day to day, till, in a short time, almost every tree seems to have its musician, and the[y] … may be heard in every direction. This circumstance, however, does not render it any the less remarkable that the first of the band should keep their appointed time with such extreme regularity."
To this account must be appended this note: their time of occurrence is temperature-dependent. Thus they usually gather the first week of July in inland situations, and have been heard as early as June 20th when an unusually hot summer is encountered.
Although this species usually appears each year, 1992 had an unusually cool and wet summer, with maximum temperatures hardly ever exceeding 25° C. Adults did not begin to sing until early October, when maximum temperatures were about 20° C. This must have caused a population "crash" that year. Accordingly, the Dog-day Cicada brood of 2000 did not begin singing until August (representing early emergence of the 2001 brood) in southern Ontario, and in 2005 they did not begin singing in Ottawa until mid July, although that year there were frequent days since early June that exceeded 25° C. This "natural experiment" suggests that the Dog-day Cicada usually has an eight-year cycle, with northern populations having a 13-year cycle.
Range: Pine woods of Nova Scotia and Prince Edward Island westward through southern Québec, Ontario and Manitoba; also found in vicinity of Prince Albert, Saskatchewan. Found in the northeastern USA, south to Ohio and the Appalachian Mountains, but records from more southerly areas at low elevation are often misidentifications of other cicadas, principally T. davisiFootnote 2 and T. pruinosus Say.
Tibicen Linnei (Smith and Grossbeck), * Angled Harvestfly
Adults: Head 12.5-14 mm wide (eyes more prominent than in T. canicularis); overall length (wings folded) 4.2-5.1 cm; front wings distinctly angled near midlength, with leading edge (lower edge when wings folded) straight beyond the angle; male opercula pointed, projecting 5-6 mm beyond hind leg base; uncus almost twice as long as wide, nearly parallel-margined to broadly rounded tip. Colour as in T. canicularis.
Song: Short, loud burstsFootnote 3 with lower note at end of each: "zeeger, zeeger, zeeger." It is heard in late afternoon and evening from late July to October.
Range: Louisiana to Florida, north to Nebraska, Minnesota, southern Ontario and Massachusetts.
Tibicen Robinsonianus Davis.
Adults: Head 12.5-13.5 mm wide; front wings less strongly angled. Are hard to distinguish from both T. linnei and T. canicularis; sometimes the only distinguishing feature to separate it from the latter is the position of the marginal crossvein, which is centrally located in canicularis but more basally positioned in linnei and robinsonianus.
Song: Also intermediate, being a longer buzz than in linnei but divided into segments: "a long-drawn-out slow zape, zape, zape continued for from one to two minutesFootnote 4". It is heard from July to September, the same time period as the Dog-day Cicada, but usually sings late in the afternoon until dusk, as does T. linnei.
Range: Hardwood forests of eastern North America, from Louisiana to Florida, north to Minnesota and Maine. In Canada restricted to oak-hickory and beech-maple woods of southern Ontario, from Belleville west to Sarnia; common around Niagara Falls and Chatham. This northern form occurs only where the ranges of T. linnei and T. canicularis overlap, and thus appears to be a hybrid, linnei × canicularis. Whether it is a self-perpetuating species is not known.
Tibicen Pruinosus (Say), (?=T. Latifasciatus Davis, Cicada Winnemanna Davis), Silverbelly
Adults: Head 13-14.5 mm wide; overall length (wings folded) 4.6-5.3 cm; wings pointed, with leading edge nearly straight; male opercula projecting 7-8 mm beyond hind leg base; uncus twice as long as wide, parallel-sided or slightly widening towards broadly rounded tip. Colour as in T. canicularis, but usually with contrasting white patches at base of abdomen on upper side, woolly coat on underside whiter, and dark stripe down underside of abdomen paler. Several colour varieties have been named, but as these all have the proportions of T. pruinosus they might not be biologically distinct.
Song: A high-pitched whine, rising and falling, with pulsationsFootnote 5 at intervals, variously rendered as z-zape, z-zape, z-zape or za-wie, za-wie, za-wie; often heard at dusk. In the southern USA "the recorded songs of T. pruinosus all sound more rapid -ear-ear-ear-ear-. What I hear around here is much slower - eeeearrrrr-eeeeeeaarrrrrrr-eeeeeeeeaarrrrrrr, etc. In fact the song is exactly like the song of T. latifasciata." The variety of song types recorded suggest that this may be a complex of several species or subspecies that have not yet been associated with a particular scientific name.
Range: A common species of the southern USA and ranges from Texas to Florida, but its northern limits are uncertain due to records confused with T. canicularis and T. linnei. It has been photographed as far north as the southern shore of Lake Erie. In the south its range abuts or overlaps with the forms currently considered as subspecies latifasciata and winnemanna.
- Date modified: