פברואר 9, 2024

Live oak bud gall

Texas live oak (Quercus fusiformis) and Southern Live Oak (Quercus virginiana) in Austin and Houston have a small, persistent bud gall that was, to my knowledge, never reported before I observed it in 2022. You can see the observations here; so far @jeffdc, @currenfrasch, and I are the only ones who have reported it on iNat.

I was quite confused about the phenology of the gall last year. However, I've been tracking them as they developed across the last year in relatively large numbers, and it makes a bit more sense now. They start developing on buds at the tip of new growth in July and grow slowly. Their phenology closely matches agamic generations of galls like Disholcaspis cinerosa and Druon quercuslanigerum. By October the larva is visible but only occupies the tip of the gall; by December, the larva has eaten the gall tissue. The specimens I collected in Austin were still larval on January 1 but had pupated by February 4. I'm not sure exactly when they'll start to emerge but I think it's likely to happen over the next two months.

I'd love to have people look for this gall over the next few months to 1) assess the limits of its range and 2) collect more galls to guarantee we can rear adults and create a more diverse specimen set for the description. I would be surprised if it isn't found in DFW and throughout Texas, possibly into Oklahoma. I'd also expect it to be present on live oaks as far east as Florida but I'm less confident of that. It would be very interesting to know if it's found on Quercus geminata.

To look for it, scan large numbers of branch tips looking at the end of last year's growth, (ie, not the new spring growth if you're looking after budbreak). They're hard to distinguish from normal buds at first so you may be fooled but they are more conical, larger, and grey rather than brown. It helps to have something to magnify the branch tips at least a bit. In Austin, I've found them in 3 places but they are far more abundant on a couple trees than the others. It may take some looking to find a good site for them.

הועלה ב-פברואר 9, 2024 02:49 לפנה"צ על ידי megachile megachile | תצפית 1 | 2 תגובות | הוספת תגובה

דצמבר 31, 2023

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

הועלה ב-דצמבר 31, 2023 08:33 אחה"צ על ידי megachile megachile | 6 תגובות | הוספת תגובה

אוגוסט 19, 2023

Cynipini and Associates Larval Sequencing Pilot Study

We have an exciting opportunity coming up in the world of oak gall research!

TL;DR: we're looking for volunteers to collect oak wasp galls, put them in a sealed container, label them clearly and carefully, and mail them within 2-3 days to:

Andrew Forbes
The University of Iowa
434A Biology Building
Iowa City, IA 52242

Long version:

If you’ve posted many gall observations by now, there’s a good chance I’ve asked you to return to a site to collect a gall and rear adults. Rearing adults of the inducing wasp is important because it’s the only way taxonomists can describe an unknown species. We’ve had a remarkable amount of success with this so far, and I was able to bring dozens of specimens reared by iNat users to taxonomists this July at the International Gall Symposium thanks to those efforts.

But if you’ve been involved in this process, you know that rearing has a ton of failure points. You might not know the gall is worth collecting until you leave the site. You don’t know when the gall will be mature enough to viably collect. The gall could mold or dry out or you might rear parasitoids or inquilines instead of the inducer.

For this new project, we don’t have to worry about any of that. The goal is to study the whole community at each point in time using genetic sequencing of larvae. We’re trying to determine when different species show up in galls and which species of parasitoid and inquiline are associated with which inducers. In other words, no more waiting and no need to rear (we will still want to rear plenty of things but galls collected too early or too late to rear inducers are now valuable too).

We are currently working on a grant proposal that will get us some funds to support this work in the lab and in the field for the next few years. This fall, we’re conducting a pilot study to find issues and opportunities in the workflow we hope to expand in the grant. Here’s what we’d like you to do, starting now and extending into Gall Week (9/2-10) and beyond.

Collect oak galls and place them in a sealed container so they don’t dry out (ziploc bags work, or a plastic condiment cup with a lid). If the gall is detachable you can remove it from the plant; if it’s integral, you can either put the whole leaf or host tissue or cut as needed to fit in your container. Ideally each container should contain only one gall species, but multiple galls of a species can go together if they share a host, date, and location.
Label each distinct collection with the following information:
iNat observation number
Host tree species
Location (including lat/long)
Date of collection
Collector name

Within 2-3 days of collection, place them in a padded envelope or small box and mail them to this address
Andrew Forbes
The University of Iowa
434A Biology Building
Iowa City, IA 52242

If you can’t get the galls mailed out in a short timeframe and are confident/curious to try it, you can also dissect the larvae out yourself and put them in 0.5-2 mL vials (eg) of 95% ethanol and store them in the freezer. If there are people who are willing to consolidate collections and do this dissection in bulk, let me know and we can mail vials prefilled with ethanol to you.

DO NOT put dry galls in the freezer--this will destroy the larvae and make it impossible to preserve them for shipment. It may be possible to keep the fresh galls in the fridge to keep the larvae alive longer to consolidate a larger shipment collected over several days, but we haven’t experimented with this. It would be valuable if someone wanted to try it.

It’s your responsibility to make sure that you collect only where it is legally permissible to do so--make sure you avoid collecting in National Parks or similar locations. Most municipal parks should be fine but it’s always good to double check. Use your judgment in terms of collection effort, but generally speaking your ability to affect populations of these insects is negligible.

If anyone is planning to organize any events for Gall Week, you could consolidate collections and make a single shipment from your area, which would save a lot of money overall. Broadly speaking, if you are going to make a shipment, it would make sense to try to collect enough galls of enough species to make it worth the postage.

In terms of priorities: I’ve made a few posts in the past about things I’m especially interested in, but really there are just too many species and generations to list. Anything listed as “Undescribed” on gallformers.org is a top priority and we can’t get too many. A few of the most common species (all the Belonocnema species, Bassettia pallida, and Druon quercuslanigerum on live oak, Amphibolips confluenta and Philonix fulvicollis in the eastern US) are no longer needed, but many other very abundant galls are still of interest. Generally speaking, err on the side of assuming that something is worth collecting, unless you have a specific plan to do something else with it later.

I’m unfortunately not going to have a ton of time to guide everyone on this individually, so I’m hoping that this project provides the space for new and existing members of the wonderful gall community to take initiative on their own and to support each other. That said, feel free to tag me or message me with questions and I’ll try to help.

You can also tag Dr Forbes at @aforbes10 or contanct him by email at andrew-forbes@uiowa.edu or tag Guerin Brown at @moneykittens. They'll be the ones receiving and processing your specimens.

הועלה ב-אוגוסט 19, 2023 05:59 לפנה"צ על ידי megachile megachile | 9 תגובות | הוספת תגובה

יולי 16, 2023

European Cynipini in North America

To date, 3 species of cynipini native to Europe have been reported in North America, all on Quercus robur:

Neuroterus anthracinus (agamic): BC, WA, OR, QC, ON
Neuroterus anthracinus (sexgen): BC

Neuroterus quercusbaccarum (agamic): QC
Neuroterus albipes (agamic): QC

Of those, only Neuroterus anthracinus on the west coast has been confirmed by multiple recent records. Ideally, these are the questions I'd like to answer:

Do these species all still occur in NA? If so, where are the limits of their range? We'd start by checking planted/feral Quercus robur trees near the known sites and moving outward. Just photographing the galls and the host tree would be sufficient for this.

Can we close the life cycle for each? These are known from Europe so it shouldn't be hard to find them.

What other species might be present on Quercus robur?

Can we confirm these genetically? That could be done by cutting out larvae and shipping them for sequencing.

Can we confirm them anatomically? That requires obtaining adult inducers (ideally of both generations) from each species present. This will mean collecting and rearing many galls.

What parasitoids and inquilines are found on these galls? Did they bring some with them from Europe, or have any native ones moved to take advantage of them, or did they "escape" their enemies? This may be something we can achieve by sequencing larvae as well, but ideally we would collect and rear many galls to study this.

I'm hoping to recruit people to take the lead on filling in some of these gaps. I'm going to tag those who have observed the galls or other observers in the areas and ask you to either return to these sites to make additional observations or try to point me to local observers who can do so in your stead. Feel free to contribute as much or as little as you'd like.

Given the nature of the question, I think it's likely we can find funding from the Canadian government or potentially from other labs to cover some of the costs of materials and shipping, but I can't promise that yet.

@krisskinou is the only one who has reported quercusbaccarum or albipes on the continent. Those observations were made on a Quercus robur in Papineauville, where @jonathan_mack @cramnaejvallieres and @cecropiabmantis are top observers. I suspect these are also found throughout Quebec as well but I can't be sure.

For both species, the agamic galls appear on the lower side of the leaves in the late summer and early fall; the sexual generation can be found on flowers and young leaves in the spring. See: https://bladmineerders.nl/parasites/animalia/arthropoda/insecta/hymenoptera/apocrita/cynipoidea/cynipidae/neuroterus/neuroterus-quercusbaccarum/

and

https://bladmineerders.nl/parasites/animalia/arthropoda/insecta/hymenoptera/apocrita/cynipoidea/cynipidae/neuroterus/neuroterus-albipes-reflexus/

For Neuroterus anthracinus, @adam1420 and @krisskinou are the only observers in eastern NA. It is almost certainly found across Ontario and Quebec by now, on urban Q robur. Possibly in the US as well.

The two generations of N anthracinus can be seen here: https://bladmineerders.nl/parasites/animalia/arthropoda/insecta/hymenoptera/apocrita/cynipoidea/cynipidae/neuroterus/neuroterus-anthracinus/

More generally, @nsouc @mossy_stone @mhking @donaldasutherland @nikolett6ttn @mws @richardlbaxter may be in a good position to check for these as experienced cynipini observers in Ontario, along with @leoguy in Quebec.

In the western part of NA, @earley_bird @skesau @bastefanidis @kurtsteinbach @brnhn have all reported N anthracinus repeatedly. If you have trees you can conveniently track and sample from, we'd love to have you do that. It's possible there are other species present in the northwest as well.

Thank you all for your time and attention! At this point I'm just making the suggestion and gauging interest; I can add more specific info on rearing and collecting as we move forward.

הועלה ב-יולי 16, 2023 07:36 אחה"צ על ידי megachile megachile | 4 תגובות | הוספת תגובה

ינואר 23, 2023

Florida Amphibolips hosts

Amphibolips galls are typically visually apparent in both generations and relatively easy to rear especially in their sexual generation. Douglas Castillejos, an entomologist in Mexico, is sequencing wasp specimens from any Amphibolips species we can get him.

One mystery I'd like to solve is the host relationships of each putative species. This mystery is most severe in Florida, where several similar gall types are reported from many similar and often-confused host species. For this post I'm focusing on globular or spindle-shaped leaf and bud galls.

My hypothesis is simply that each host has a single species of gall wasp, which induces a spindle-shaped sexgen leaf/bud gall in the spring and a globular bud gall in the late summer-fall, persisting over the winter. This hypothesis is contradicted extensively by current literature and iNat observations, but I'm speculating that much of this is due to a combination of gall variability and mistaken host IDs.

I don't know if it's even worth listing specifically what we already do and don't think we know. At this point, I'd look for agamic galls on overwintered twigs from now into April (adults can likely be cut out already) and then collect sexgen galls on new growth in May. Priority here is to document the gall inside and out (at collection and then at emergence) and to document the host so its ID can be confirmed by experts.

I'm especially keen to get adults from galls on these hosts:

Quercus laurifolia
Quercus phellos
Quercus pumila
Quercus myrtifolia
Quercus inopina
Quercus hemisphaerica
Quercus incana

What would be ideal ultimately is to get an adult from any pair of these gall types on a single host: cinerea, spinosa, and murata (all apparently agamic, overwintering now). cinerea galls are round and smooth, dark green-purple with white spots, spinosa galls are green and pointed and have raised protrusions, and murata galls are pointed and smooth and tan.

@laurasea @ryancooke @knotwood @eickwort @noaboa @cocokitty

That said, any Amphibolips adults reared from any host would be valuable additions to our understanding and to Douglas' genetic phylogeny of the genus.

הועלה ב-ינואר 23, 2023 08:50 אחה"צ על ידי megachile megachile | תגובה 1 | הוספת תגובה

Amphibolips confluenta and quercusinanis hosts

Amphibolips confluenta/quercusspongifica (afterward just confluenta for convenience) and quercusinanis are two of the most commonly observed oak wasp galls in the eastern US. They're visually apparent and short-lived sexual generation galls with a relatively high success rate in rearing. Douglas Castillejos, an entomologist in Mexico, is sequencing wasp specimens from any Amphibolips species we can get him.

One mystery I'd like to solve is the host relationships of each putative species.

According to the literature, quercusinanis is found on Quercus rubra and coccinea. All of the nearly 4000 observations we have fall within the range of Q rubra, from Minnesota to Nova Scotia. We have no putative records of it on coccinea and it seems possible that the lit reports are all just repeating an ambiguous host ID from Osten Sacken. IMO this is likely exclusive to Q rubra (as Weld lists it).

A confluenta is listed on many hosts. Of those, Quercus rubra is the apparent type host, and is among the host relationships reported by Weld and many others. However, I am becoming skeptical this is valid. Walsh collected extensively and concluded inanis was found on rubra and confluenta on velutina, exclusively, and I think he may be right.

That said, iNat reports provide a couple strong reasons to think Q rubra is a host. We have several matching observations reportedly on Q rubra made by competent oak identifiers. Galls ID'd as A confluenta have also been reported frequently in Nova Scotia, where Q rubra is the only candidate host. But I've mistaken Q velutina for rubra many times myself, and looking more closely at the NS observations, while some look like confluenta on the outside, not a single one has an unambiguously spongy interior. Conversely, spongy A confluenta galls are abundant throughout Minnesota, where Q velutina is essentially absent.

My hypothesis is that none of these are actually A confluenta on Q rubra. I'm speculating that the NS galls are variant quercusinanis and that the MN spongy galls are actually on Q ellipsoidalis, a close cousin of velutina. Q ellipsoidalis is understudied and not a recorded host of confluenta.

To test this hypothesis, I would love to get:

From Nova Scotia (@benarmstrong @benkendrick @ianmanning)

  • more cross-sections of galls to confirm the absence of spongy interiors
  • adults reared from bumpy galls with minimal to no exterior spotting.

From Minnesota (@guidingguida @kimcwren @csledge)

  • adults reared from a gall confirmed to be collected from Q ellipsoidalis
  • definitive documentation of a spongy gall on Q rubra

In these areas, I'd collect mid June and expect adults late June-early July, but your observations will help confirm those timelines.

Additionally, confluenta is also reported from:

Q buckleyi and shumardii - These are the common hosts in Texas. Not closely related to velutina so I'd like to rear one of these myself this year to confirm that this is in fact the same species. In Austin they're predicted to emerge in April.

Q coccinea - Maybe. This host is also closely related to velutina and ellipsoidalis. There are some putative iNat observations that seem plausible. But Q velutina is extremely variable and it is not easy to reliably distinguish the two.

Q ilicifolia - Checked into this and found a couple observations that seem reliable on this host. https://www.inaturalist.org/observations/118725687

Q marilandica, palustris, falcata - Dubious pending reconfirmation. We have a few putative iNat observations each without clear host documentation. It seems more likely to me that these hosts have distinct Amphibolips species.

Any Amphibolips adults reared from any host would be valuable additions to our understanding and to Douglas' genetic phylogeny of the genus.

@jeffdc @kimberlietx @calconey for your interest

הועלה ב-ינואר 23, 2023 07:05 לפנה"צ על ידי megachile megachile | 5 תגובות | הוספת תגובה

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