Cicada - Neotibicen linnei

I think their is mass intogre

I think their is mass intogression of the pruinosus complex and T.linnei. wen i look at theese T.linnei i have found they key out to be pruinosa in almost every aspect exept they call like T.linnei. I think if we could find allopatric populations of linnei the bisection test would hold up like expected along with the operculae and ventrel stripe. now wen you find T.linnei sympatric with any pruinosus complex i think this bisection test falls apart alot due to intogression. the problem is that most T.linnei are sympatric with the pruinosus complex? i have found that regions having alot faster rapid calling linni examples seem to show more T.linnei traits. esp in the northern parts of illinois.i would love to find out why theese hybrids are only found in T.linnei habitates if they are infact hybridizing on such a large scale? Here in most parts of centrel IL T.linnei and its hybrid/backcoss are not sympatric with pruinosus in urban areas and this brings up a huge WHY? if theese are infact hybrids than why are they not sympatric with pure pruinosa in urban areas if they possess the same genetics? there is still no proof theese are hybrids but it looks that way and i will be looking into this for 3 months. i say lets find allopatric T.linnei and compaire them with sympatric populations? i am not shure were T.linnei is allopatric though?

… slikk03, 3 July, 2011 - 6:39pm

Tibicen linnei ?

With regards to these 4 images, there has been a long running debate on the "correct" identification of this cicada. The separation of Tibicen linnei from Tibicen winnemana may at times be impossible without the specimen in hand (lit. & per. comm.)! At the time these discussions were held, the reservoir of reference specimens from this part of NC was slim and the full extent of variability not fully observed. Subsequent collecting efforts and comparisons have been a bit more revealing and at the same time confounding (i.e. there seems to be sufficient evidence to support rather extensive hybridization between winnemana & linnei in this area - per. observ. & per. comm.)!!!

If you carefully read all of the comment streams, you will see there is debate on which characters weigh heviest in the correct identification. I have listed a brief synopsis of characters discussed below and the points raised during the debate. Unfortunately both arguments have strong points and validity.

1) The black face mask is variable in both taxa (Unrevealing)
2) Line bisection test can be variable in both taxa (Unrevealing)
3) Dorsal coloration and distribution of Black pigmentation can be variable in both taxa (Unrevealing)
4) Brown maculations along the dorsum of the abdomen can be variable in T. winnemana, even absent (hence unrevealing in this case)
5) T. linnei can possess slight brown edging to the abdominal tergites (Unrevealing)
6) T. linnei is a bit more gracile in appearance as compared to winnemana (a dorsal aspect is needed to best observe this character, as seen here). This cicada is rather slender when viewed from above and suggestive of linnei.
7) Perhaps the ventral aspect would be the best character in this case, unfortunately it is not available.

Of the 4 images, it is the dorsal aspect that is most suggestive of T. linnei (gracile). Although there appears to be slight tan maculation(s) along the dorsum, it is not sufficient for adequate separation as both taxa may possess small amounts of brown to none at all.

Please note, the cicada in this image shares similar dimensions and build. Although not completely typical of most linnei (per. comm.), in all liklihood it too belogs to this taxon.

For the reasons listed above, I am placing this series of images back under Tibicen linnei.

Identification of cicadas is not absolute even when series of specimens are in hand. Identification of images can be even more difficult and I am always willing to admit a mistake. I am also constantly reviewing not only other cicada images, but my own, in attempt to continue learning and adding to my knowledge base and the resources here on bugguide.

In this case I am willing to concede and place this series back under linnei since more recent comparisons and females of winnemana have become available.

bill

My pencils still have erasers and my keyboard a backspace button ;)

… Bill Reynolds, 29 September, 2009 - 12:25pm

Moved

Moved from Tibicen winnemana.

… Bill Reynolds, 29 September, 2009 - 10:44am

Moved

Moved from Linne's cicada. Thanks for your help on this. I appreciate the difficulty in this sort of identification.

… Cotinis, 28 October, 2008 - 6:33pm

Tibicen winnemana (T. pruinosus winnemana)

This may well be one of the most difficult, but several things strike me concerning this image.

First, the black stripe across the face is slightly interrupted by green along the top margin. Although typical of Tibicen pruinosus complex (Not T. linnei) to have green intrusion into the black stripe ("mask"), there is usually a little more green intrusion than seen here.

Second, The bow in the wing is not quite as defined as I'd like to see in a T. linnei. Again similar to the wing structure of female T. winnemana (T. pruinosus winnemana) - ?

Third, There is reduced black and the definition of the pattern is not so delineated ("lateral reds touch dorsal greens") - again typical of T. winnemana - ?

I'm going with Tibicen pruinosus group for this id.
Tibicen winnemana

… Bill Reynolds, 28 October, 2008 - 5:41pm

Disagree

Sorry Bill but I have to disagree on this particular specimen. Try this exercise:

1). Note the midline wing vein in the forewing.
2). Draw a straight line following the same angle as the midline wing vein across the length of the forewing and see which cell it bisects on the tip of the wing.
3). If it bisects the last marginal cell then it is T. linnei.

I have tried this exercise on many T. linnei specimens I have on hand and found it to be 100% accurate. I even took the liberty of snagging a few T. linnei images from Bugguide and drew a line then uploaded them to my server for you to compare. Clickhere here and here. As you can see in the three examples (I even used this image in one of my examples)in every instance the yellow line bisects that last marginel cell.

You can have a slight interruption of green in the upper portion of the black stripe but it is the thickness of the stripe that is indicative and in this specimen the intrusion is very little.

Compare the face in this series of images to the face of this confirmed T. linnei in the guide:

As you can see there is a slight intrusion of green along the schlerotized portions.

Lacking a ventral view for this specimen to indicate a black stripe on the abdomen, I think that this is enough to confirm that this is indeed T. linnei

… Gerry Bunker, 28 October, 2008 - 11:43pm

Tibicen "CONUNDRUM" cont'd

Thanks again for the response.

I ran the suggested test on my T. linnei, and all passed as T. linnei with a clear bisection (~half way through the final cell)!

I ran the test on all of my T. pruinosus collected west of the Appalachians and they passed - at best with only a very slight bisection at the cell tip!

Now the down side - Ooops.
I ran the test on the T. winnmena, and here are the results.
The males revealed that the final cell was bisected, however the line only crossed the last bit of the cell (~1/4). in the females it bisected the latter third of that cell (??) - Not to unlike your image here. (http://www.mechaworx.com/images/cicada_3.jpg)

Clearly the second 2 images of your bisection test cut the cell into 2 ~equal halves, just as I saw in all of my T. linnei specimens (AL, NC, & TN). However the image above seemingly cuts approx. 2/3's into the final cell for that specimen (http://www.mechaworx.com/images/cicada_3.jpg)
...What do we do now?

I wouldn't normally be bothered by this, except for the fact I collected the T. winnwmanas while calling - the unmistakeable call of the pruinosus group....Plus, all the other traits obviously deviate form T. linnei.

For now I'll agree that the specimen presents a problem and that your points hold true - but then again so do a few of mine ;)

There's always next year and I'll be sure to grab a bunch - of all. We definitely need more T. winnemana!!!

… Bill Reynolds, 29 October, 2008 - 11:25am

Notes on the Wing Bisection Test

I guess the real question to identification pertains to 1) the original identification of the specimen in hand and/or 2) how we factor and consider all the collective traits.

I looked at the Cicadas of Michigan site (see below) for detailed reference to the wing bisection test, and although most of the cicadas I measured fell within the ranges expected - a few did not. It is the point of bisection, not the fact it bisects. Apparently if the line intersects either before the Sc + C jnc. or directly on the Sc + C junction, you would expect to have T. linnei. If the bisection of the cell lies just after the junction or further down it is expected to be some other Tibicen species.

Now based on practical application - Apparently, this test typically holds true (particularly with Midwestern Cicadas), however in conversation with Dr. Marshall at the Univer. of Conn., there have been cases involving eastern species in which this test seemingly fails.

http://insects.ummz.lsa.umich.edu/fauna/michigan_cicadas/michigan/key.html

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Gerry,
I respect your knowledge, opinion, and perspective more than you'll ever know. My above comment is actually a reiteration of an earlier post.

"Ok, with this additional picture and scale on the other image, and using the Michigan Cicadas key, this cicada keys out to be T. linnei. However, I have been instructed to be careful when using this key as there may be subtle regional variations. But the wing shape with the bent costal margin is key for T. linnei and this bend is only indicative of the species."

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This opens another can of worms!

… Bill Reynolds, 29 October, 2008 - 12:16pm

Wing Bisection

Hey Bill

As you previously indicated when you ran this line bisect test on your T. linnei specimens, you found it to be reliable for T. linnei, that is it bisected the final cell by about half. That is the same result that I noted when trying this test on my T. linnei specimens from Kansas, Ohio, Illinois, Pennsylvania and New York. They all seemed to follow the same example. That is the last marginal cell was bisected by half.

Ok that being said, when I ran this same test on my T. pruinosus specimens from Kansas and Illinois, I also found that it bisected the last marginal cell as in T. linnei but it wasn't by 1/2 and the line ended up being closer to the junction where the last cell and second to last cell meet. (Nowhere near Sc+C as indicated by the Michigan Cicadas Key)

Question, is there proper nomenclature for the naming of the cells and wing veins of a cicada? I would be very interested if there was one, it would make talking about this subject easier. Maybe we should come up with something?

Anyway, what does this tell us? Well, for one thing I think it is safe to say that if the last marginal cell is bisected by half then that is a pretty good indication that a specimen in question is indeed T. linnei when lacking a ventral view.

Note: this will only work when determining T. linnei from other species similar in morphology. It may be that for example in T. dorsatus, the medial wing vein bisects the last marginal cell by half in that species but because of the obvious other morphological differences between, T. linnei and T. dorsatus we can rule it out as a key.

What it also tells us is that there are regional variations in T. pruinosus only.

As you know we discovered last night that the Specimen that I thought was Winnemanna was not Winnemanna at all but is probably another T. pruinosus so I can safely say that I have no experience with Winnemanna species but if the wing shape is similar in appearance with my single T. latisfaciatus specimen then I can tell you that the line also bisects at about the same area as T. pruinosus.

So with all that being said and sighting my previous example on this specimen, the last marginal cell is bisected by half making this specimen T. linnei.

… Gerry Bunker, 29 October, 2008 - 6:33pm

Nice Ocelli!

Nice shot showing the three ocelli in the center of it's head and between the two compound eyes. Very difficult to get a good shot of those.

… Gerry Bunker, 22 June, 2005 - 3:49pm