Identification
"harnedi" diverges from nominate "davisi" as follows:
1) The wing shape of "harnedi" is described as broader and rounder by comparison (similar to that of T. auriferus)
2) There is a greater degree of infuscation along the apical margins/cells of the forewings in "harnedi" (i.e. the smoky grey coloration is visible in 6 to 7 wing cells apically & less restricted to the apical wing veins as seen in nominate "davisi")
3) "harnedi" typically lacks the dark pigmentation often seen along the edges of the abdominal sternites in many specimens belonging to the nominate race "davisi" (NOTE: this character is subject to notable variation in the nominate race across the davisi range)
4) "harnedi" is described as being more robust than nominate "davisi" (however...this "frame of reference" can be called into question since davisi varies significantly across its range - southern and coastal types are often quite large by comparison with inland populations)
5) "harnedi" is described as being a very bright green dorsally (per. observation - esp. in males)
6) In the few living & fresh examples of "harnedi-like" types reviewed, the eye color was "light" and similar in color to that of T. auriferus (eye color may include tan, grey, light bluish-grey/slate, or pale purplish-tan). I have not yet seen any living/fresh specimens with dark eyes.
Song is "indistinguishable" from davisi & auriferus: Best described as a loud, high-pitched whine with a slight vibration (~like a power saw cutting wood) - usu. lasting several seconds before fading at the end
Range
Known from areas along the Mississippi River (eastern & western banks)
incl. e. Arkansas, n. & w. Mississippi, and w. Tennessee. Likely found in adjacent states to those mentioned.
NOTE: The following information is based on per. observ., Bill Reynolds:
Cicadas fitting this description also occur as far east as the Tennesse River Valley of nw. Alabama. Although the infuscations of the apical wing cells seem to be slightly less than seen in specimens collected nearby to the west (Specimens collected from adj. ne. Mississippi & s. Tennessee), wing shape and other traits appear more congruent with "harnedi" than with nominate "davisi" to the south and east. Refer to the image below comparing wing structure and infuscation patterns.
Larger sample sizes could shed more light on the relationships between and among these taxa (davisi, harnedi & auriferus). Unfortunately, the points of parapatry &/or sympatry (i.e. overlap/blending) remain undefined - ??.
(Populations from nw. Alabama may represent a possible intergrade zone with the nominate form davisi ?? - but details are still UNKNOWN?)
Habitat
Tibicen davisi harnedi can be found in rural areas/farmlands where there are open fields and lots of early successional growth incl. short-leaf pines, long-leaf pines & mixed hardwoods.
Life Cycle
eggs usually laid in dead twigs, wood or bark (occassionally eggs will be laid in living stems and twigs)
eggs hatch and nymphs burrow into the soil
nymphs feed on the sap in roots for several years (nominate davisi populations prefer Pines - while the host preferences of T. davisi harnedi appear divergent??)
Final instar nymphs emerge and develop into winged adults (emergence for this species usu. occurs at night - between 9:00PM & Mid-night)
Remarks
Tibicen davisi harnedi Davis 1918
T. davisi, T. davisi harnedi and T. auriferus are very closely related taxa. T. davisi harnedi shares several morphological characteristics with T. auriferus and may be more closely related to that species.
See Also
Most often confused with the following:
"Southern Dog-day Cicadas"
Loosely & informally referred to as the "Southern Dog-day Cicadas" (
"coined", Bill Reynolds), the following taxa are mostly "southern" in distribution and appear to be closely related. These cicadas share several traits, incl. elongated opercula in the males, rapid trill and/or clicking calls, and unusually wide heads relative to body dimension (head widths usu. exceed thoracic widths).
(*appears to be the most divergent member within this group - ??)
"Green Tibicen Species"
Collectively, yet informally, referred to as the "Green Tibicen species" (per. comm.), the following cicadas are often difficult to differentiate and all appear to be very closely related. Genitalic analysis of the males suggest these species are very closely related and morphological differences between and among the species are slight. It is also thought (based on observations) that several of these may be involved in complex hybrid zones; however, more work is needed to substantiate and better understand these observations.
Tibicen pruinosus pruinosus var. fulvus Beamer 1924 [syn. T. pruinosa var. fulva], "Pale Scissor(s) Grinder Cicada"