Cicada - Megatibicen pronotalis

Moved

Moved from Walker's Annual Cicada ("Northern-Western race" = "ssp. pronotalis").

… Bill Reynolds, 5 September, 2014 - 11:16am

Moved

Moved from Walker's Cicada.

… Bill Reynolds, 22 October, 2013 - 3:21pm

Moved

Moved from ID Request.

… Ron M., 5 September, 2009 - 5:37am

Tibicen pronotalis

Tibicen pronotalis (a.k.a. Tibicen walkeri & Tibicen marginalis).

This specimen is a nice green. A good percentage of individuals from s. Louisiana are more of a yellowish green (those in the New Orleans area are often greener). The dark pattern in the center of the pronotum is especially developed in populations west of the Mississippi River and typical of Louisiana.

bill

… Bill Reynolds, 3 September, 2009 - 4:16pm

distinctive feature differences

What features are good to look at to separate the green T. pronotalis vs. dealbatus? I appear to have some difficulty with those two.

… Andrew Williams, 3 September, 2009 - 4:24pm

Pictured here: Tibicen pronotalis

T. pronotalis vs. T. dealbatus
Good question!

Both species share not only similar appearance and size, but similar, if not identical calls. Interestingly, the two also share similar behaviors (i.e. calling well after sunset). Both taxa have been reported to call as late as 9:30 to 10:00 PM. Both species appear to e riparian in distribution - most assoscaited with waterways (creeks and rivers).

In all likelihood, these two taxa form a single species complex... = a large interbreeding continuum with blend zones across the Plains States. Both taxa are documented to occur in Kansas and Nebraska - as both states have pronotalis in the east and dealbatus in the west. I have been told by several people, incl. entomologists and naturalists, that there does in fact appear to be a blend zone between the two taxa across Texas, Oklahoma, Kansas up into Nebraska; however, I do not have any such specimens available for reference.

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

Distinquishing traits of T. dealbatus are as follows:

1) Greater pruinosity (white powdered wax) usually arranged in "dotted stripes" along the sides of the abdomen and dorsal abdominal midline.

2) Greater amounts of pruinosity on the thorax (mesonotum)

3) T. dealbatus is usually a bit more compact and has a narrower head by comparison

4) Regarding color, when T. dealbatus is green, it is typically a duller "pea green" - when tan, it is typically more of a sandy-brownish tan as opposed to a yellowish-green/tan seen in pronotalis.

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

All known material from this complex collected in Lousisiana falls under the taxon T. pronotalis for reasons described above.

bill

… Bill Reynolds, 3 September, 2009 - 4:42pm

I hope you don't mind...

But I added the above information to both info pages...

And thanks for the help :)

… Ron M., 3 September, 2009 - 5:06pm

thanks Bill

This is great info.

… Andrew Williams, 3 September, 2009 - 4:48pm

T. pronotalis-dealbatus group

I have seen a few pic's of really ambiguous specimens that could be difficult to assign.

There is no doubt the 2 are very closely related (sister species/taxa). One interesting note, despite the similarities, the blend zones appear to be rather narrow, suggesting something is in place to prevent swamping (=absorption of one taxon by the other).

bill

… Bill Reynolds, 3 September, 2009 - 4:54pm

maybe Tibicen dealbatus ?

If it is, you're the first for Louisiana, and best pictures of it. :)

… Andrew Williams, 3 September, 2009 - 4:06pm