North American oak gall wasp larval sequencing project

Hi all!

For those of you interested in oak galls, we have a cool opportunity starting this fall. is partnering with the Forbes lab at University of Iowa to writeg a grant to study the coevolution of inquilines, parasitoids, and inducers found in oak wasp galls in North America. We’re starting this fall with a pilot study to recruit participants and work out some of the kinks in the procedures. If you’re interested in participating, you can go out and collect any oak wasp galls on any oak species at any stage of development and mail them to the Forbes lab, where the larvae will be extracted and sequenced.

Here’s what you’d need to do to participate:

  1. Find an oak gall in the field and document the gall and its host tree to make an iNat observation

  2. Collect the 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 other tissue, or cut it 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.

  3. Label each distinct collection with the following information:
    iNat observation number
    Host tree species
    Location (including lat/long)
    Date of collection
    Collector name

  4. Within 2-3 days of collection, place them in a padded envelope or rigid container and mail them to this address:

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

And that’s it!

Here’s a few anticipated questions/issues:

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 (Sept 2-10), 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 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 understudied. 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.

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

Thanks, and happy gall-hunting!


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