Andricus petiolicola/frondosus group

Genetic evidence increasingly suggests that Andricus quercuspetiolicola is the sexual generation corresponding to an agamic gall with a cell surrounded by leafy bracts. As part of the cynipini larval sequencing work Gallformers is doing with the Forbes, Hood, and Prior labs, I'd like to get some additional specimens to fill in some gaps in our knowledge of this group; this post is a summary of what we know and what we're missing. If you're not familiar with the larval study, it means that you can collect these galls at any point in development (before emergence) and we should be able to get useful info from them.

The sexgen gall in this group is distinctive because it always occurs on petioles/midribs of young leaves in the spring and has a pronounced inward dimple (or more rarely a corresponding outward projection).

The agamic gall has a hairless white or mottled larval cell nestled within a rosette of wide or narrow, short or long, leafy bracts. The appearance of this gall varies by host (short/narrow bracts on stellata, alba, bicolor, margaretiae, and thicker leafy bracts on macrocarpa, prinoides, muehlenbergii).

Eastern NA:

Quercus macrocarpa - we expect to see quercusfrondosus reported in Edmonton, AB but so far is hasn't been @jasondombroskie. Otherwise the ranges are a perfect match. We have COI from frondosus and UCE from petiolicola on this host.

Quercus alba - we have COI from the ~frondosus (though on alba it's somewhat different--short bracts and mottled cell) and petiolicola on this host and UCE from petiolicola. Ranges show good overlap but we're missing the frondosus gall in Minnesota @csledge.

Quercus bicolor - we have UCE from petiolicola but no COI from either generation. Range looks reasonable

Quercus chapmanii - sexgen is called Callirhytis parvifoliae though we've been calling them petiolicola anyway. Reported frequently in Florida. The presumed agamic is Andricus cinnamomeus/stropus, which has never been reported on iNat. We need specimens from both gens for sequencing. Are cinnamomeus and stropus actually different?

Quercus lyrata - we need specimens from both gens for sequencing. The agamic gall is called "Andricus stropus" but is presumably identical; genes will tell us if so. @esummerbell @little_metal_weirdo something to collect if you see them. Range maps are thin for these but look right.

Quercus margaretiae - we need specimens from both gens for sequencing. The sexgen gall is called Callirhytis parvifoliae (a name we haven't been using) and the agamic gall is called "Andricus stropus." We need genes to say if these are actually different species. @kimberlietx something your group could likely find in DFW. I found both when I came up in April; they're the only records of either on this host.

Quercus michauxii - we need specimens from both gens for sequencing. petiolicola reported a few times in DC area, no records in the lit or on iNat of the frondosus type. @jeffdc @esummerbell something to look for on buds of this species

Quercus montana - we need specimens from both gens for sequencing. petiolicola reported a ton on iNat, but no records in the lit or on iNat of the frondosus type. A big unexplained gap.

Quercus muehlenbergii- we need specimens from both gens for sequencing. range a bit bigger for petiolicola than frondosus; worth looking for these in more places.

Quercus prinoides - we need specimens from both gens. Both rarely reported on this host.

Quercus stellata - common host for both. We have UCE from petiolicola but need specimens from both for COI. The oddity on stellata is that we see both the "stropus" type agamic gall with narrow bracts and the "frondosus" type with wide leafy bracts. Would be great to get specimens from both and compare genes.

SW and CA: for all the remaining hosts, we need specimens of both generations. In the west, the sexgen is called Andricus reticulatus and the presumed agamic gall is undescribed (q-turbinella-thistle-head-bud-gall). The host and geographic ranges of the rosette are much more limited than reticulatus.

@joshuacde @stevejones @austinrkelly

Quercus engelmanni - galls like reticulatus are known from the LA area but we have no candidate for the agamic generation. Very keen to see how this "reticulatus" relates genetically to the ones from the southwest. @anudibranchmom

Quercus oblongifolia, rugosa, turbinella - known hosts of reticulatus and the rosette in the lit.

Quercus ajoensis, arizonica, toumeyi, gambelii, vaseyana - known to have something like reticulatus, missing records of the rosette

I'm somewhat skeptical of the gambelii records and would like to get better observations and genes to confirm

Quercus pungens - known to have the rosette gall, missing records of reticulatus

Mexico: also need specimens of all of both gens from any host here. The sexgen is called Andricus sphaericus. No agamic candidates are known from any host

Quercus deserticola, glabrescens, laeta, obtusata, rugosa - sexgen known, no candidates for the agamic

Posted on Δεκέμβριος 31, 2023 0833 ΜΜ by megachile megachile


I can try to rear adults of the A. reticulatus sexgen next year, though I don't recall ever finding the rosette in NM. Do you think reticulatus is a synonym for A. quercuspetiolicola or just related?

Αναρτήθηκε από joshuacde 5 μήνες πριν

You can try to rear some but let's start with just getting the larvae sequenced first. And that is exactly the question we need genes to answer--I don't really know how we draw the species boundaries; clearly they're closely related but will probably end up having separate names but not sure.

Αναρτήθηκε από megachile 5 μήνες πριν

Fantastic, will keep an eye out for these!

Αναρτήθηκε από esummerbell 5 μήνες πριν

I know of at least one tree where I’ve seen the sexgen on Q lyrata, will look out for fresh galls in the spring

Αναρτήθηκε από esummerbell 5 μήνες πριν

I know A. reticulatus and the thistle-head-bud gall on Q. turbinella from Rackensack Canyon nearby and can make regular visits this year.

Αναρτήθηκε από stevejones 5 μήνες πριν

I have a mental map of local Q. Lyrata ready to go. I look forward to the season!

Αναρτήθηκε από little_metal_weirdo 5 μήνες πριν

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