Celtis leaf galls - Pachypsylla

Moved

… Chris Mallory, 18 December, 2016 - 10:34am

Expert opinion

Dr. John Moser, who researches hackberry gallmakers and arthropod associates, says of this image: "The flower-shaped galls are unfamiliar to me. Perhaps they are P. celtidisasterica Riley 1980. The nipple-shaped galls may be P. celtidismamma." He confirms that the ones in this image are immature P. celtidismamma:

I just did a Google search, and it seems that there is only one reference to Pachypsylla celtidisasterica in the whole internet (well, I guess there are two now!). Felt (1) attributes star-shaped or flower-shaped leaf galls, 1/4" in diameter, to P. astericus Riley, clearly the same species. That name only got three hits, and they were all different versions of the same thing, "The Comparative Morphology of the Zoocecidia of Celtis occidentalis," by Bertram W. Wells (1916). The pertinent passage:

"The author concurs with Crawford (4, p. Ill) in his monograph of the Psyllidae, when he asserts that the following species of Pachypsylla erected by Riley (28) in the Fifth Rep't of the U. S. Ent. Comm., viz.: P. astericus, umbilicus, pubescens, globulus and curcurbita and P. rohweri Ckll, are 'only variations of the species of P. mama, since the insects are said to be similar and the differences in the galls are not great.' These species evidently represent intermediate forms between P. mama Riley and P. vesiculum Riley, though they are much closer to the former than the latter. The writer has noted the wide variation obtaining among the P. mama forms. The above named species will not be included in this paper, since their validity is rightly doubted."

The one reference to Pachypsylla celtidisasterica, though (Folia Biologica 2002), indicates that that species has a different chromosome number from P. celtidismamma, so apparently they are distinct.

… Charley Eiseman, 30 December, 2010 - 3:16pm

Moved

Moved from Unidentified Galls.
Thanks, I had (obviously) completely forgotten about the ones you found. And this is maybe supporting evidence for your idea that the two are different stages of the same thing. I don't think the big ones on my leaves looked like this on the other side though:

… Charley Eiseman, 20 December, 2010 - 12:06pm

Maturity?

Maybe some of mine had matured to the point where they opened to allow the adult out. My "immature" ones weren't open.

Should yours be linked?

… John R. Maxwell, 20 December, 2010 - 12:12pm

That one...

looks a lot like Pachypsylla celtidisvesiculum (1) ...but you could well be right that it's an immature example of one of the other ones.

It sure would be nice if a psyllid specialist could be tracked down to help sort this stuff out.

I guess I can link mine--the photos are of different leaves, but they were all in the same area.

… Charley Eiseman, 20 December, 2010 - 12:22pm

Raising

I hope to collect more this year. They are near the parking lot of a local bar/restaurant. ;-)

… John R. Maxwell, 20 December, 2010 - 12:33pm

I'll try to do the same

The fuzzy type I referenced below shows up reliably on a tree in my friends' yard in Burlington, VT.

… Charley Eiseman, 20 December, 2010 - 1:11pm

An expert would help

I still lean towards these, but I have no idea.

… John R. Maxwell, 20 December, 2010 - 12:30pm

You could be right...

The galls that I typically see in New England look like this:

and (1) labels these as Pachypsylla celtidismamma. (So does (2), but that doesn't prove anything...) (1) also shows smooth galls that look the one you linked to (and mine from Tennessee, and yours), and these are simply labeled as Pachypsylla. Looking at other online sources, there are plenty of examples of galls like this that are labeled as P. celtidismamma, and the drawings for this species in some of my books sort of look like this too. In (3), the photos for P. celtidismamma show warty-looking galls (and they're described as warty too) that seem like they might be different from either of the above.

… Charley Eiseman, 20 December, 2010 - 1:09pm

All of these

should at least stay together

… John R. Maxwell, 19 December, 2010 - 3:18pm