Cicada ID - Tibicen - BugGuide.Net

In support of Tibicen canicularis

"I am tending to agree with you and Elias that this is indeed canicularis. Based on the diagnostics at hand. I'd also like to add the extreme lack of a bold black mask between the compound eyes."

Gerry
_______________________________________________________________

Thanks for your time and commentary.
bill

… Bill Reynolds, 30 September, 2009 - 11:37am

Moved

Moved from Linne's cicada.
I'm moving this back to genus, since there isn't agreement on species (if it's even possible for sure). If one of you experts, feels strongly enough to have it moved back to one of the species, I will do so. Thanks for all the discussion.

… Heidi Genter, 29 September, 2009 - 7:17pm

Tibicen canicularis

This photo supports T. canicularis. In my experience with a multitude of specimens captured here in NY, I have never come across a Tibicen linnei with light eyes. The golden pubescence seen on this specimen also supports T. canicularis but this criteria alone is not 100% diagnostic.

… Elias Bonaros, 28 September, 2009 - 11:18pm

Tibicen sp. (canicularis)

I agree with your observations Elias. We have several "linnei" complex members across the southeast and all seem to have "darker eyes" by comparison. Of the many specimens I have collected, incl. those in the mid-Atlantic and Ohio River basin, all "linnei" have had eye characteristics as you decribed - providing correctly id'd in the field (id can be tricky). Certainly, all those I've collected while calling the known "linnei songs" have had dark eyes (no exceptions yet).

However, this individual has been placed under linnei due to wing characteristics.

What is your take?

I think continuing to apply certain linear measurements on images of cicadas in situ will continue to be an issue (most images lack the perfect flat wing position necessary to run a "valid line bisection test" or other wing comparisons)

...and as much as it pains me to admit, I do from time to time use the wing diagnostics and line bisection test myself, but not as the single deciding factor.

… Bill Reynolds, 29 September, 2009 - 4:04pm

Moved

Moved from Tibicen.

… Heidi Genter, 1 September, 2009 - 10:04am

Moved

Moved from ID Request.

… Heidi Genter, 28 August, 2009 - 12:32am

Tibicen sp. (likely T. canicularis)

There are 4 species of cicadas that can often times be very difficult to differentiate without the specimen in hand. These include T. robinsonianus, T. linnei, T. canicularis and T. pruinosus.

-----------------------

In cases such as this, I look at the possibilities, total number of traits, and work backwards by a process of compare-contrast and via the process of elimination .

This cicada is green, well patterned, light eyes and a somewhat curved costal margin - the latter is suggestive of linnei. However, T. linnei, pruinosus and robinsonianus almost always have darker eyes than the cicada here. T. canicularis often has light colored eyes - tan & slate just like this cicada. Additionally, the pruinosity (that bronzy glitter effect) is much more typical of T. canicularis.

Regarding the curvature of the costal margin, that's thin ice given only an image vs. the specimen, and considering the fact that there can be trait overlap between and among several of these taxa. NOTE: image perspective from this angle is the worst possible angle for wing shape diagnostics!

According to the lit. and per. comm., T. canicularis is the most widespread and abundant late summer species in the upper mid-West.

-----------------------
f.y.i./t.m.i.

In general, there are several morphometric/allometric diagnostics that can be used on the specimen(s) in hand or images taken at the right angle/perspective. It is important to keep in mind that these measurement based diagnostics are not ABSOLUTES!

In general, images pose an even greater problem because of photographic distortion, "lensing", and the application of linear measurements applied to a 3-D object but imposed on a 2-D field (issues of angle and perspective).

… Bill Reynolds, 27 August, 2009 - 12:31pm

Tibicen linnei

Despite the angle, one can see clearly that the costal margin is slightly concave past the midlength, which is characteristic only of this species (which is also fairly common in the mid-West).

… Andy Hamilton, 1 September, 2009 - 9:35am

Thank you

and I appreciate your detailed analysis, as well as the tips for what shots help to ID. I don't photograph cicadas often where I live, but it will be helpful if I do.

… Heidi Genter, 28 August, 2009 - 12:36am