Vol. 61, 2022

(update: 2022.11.22)

The Arthropod Associates of 155 North American Cynipid Oak Galls

Anna K.G. Ward¹, Robert W. Busbee², Rachel A. Chen³, Charles K. Davis⁴, Amanda L. Driscoe², Scott P. Egan⁴, Bailey A.R. Goldberg¹, Glen Ray Hood⁵, Dylan G. Jones³, Adam J. Kranz⁶, Shannon A. Meadely-Dunphy⁷, Alyson K. Milks³, James R. Ott², Kirsten M. Prior³, Sofia I. Sheikh¹, Shih-An Shzu⁴, Kelly L. Weinersmith⁴, Linyi Zhang⁴, Y. Miles Zhang⁸, and Andrew A. Forbes^1,*

¹Department of Biology, University of Iowa, Iowa City, IA 52245, USA. *Correspondence: E-mail: andrew-forbes@uiowa.edu (Forbes).
E-mail: anna-k-ward@uiowa.edu (Ward); bailey-goldberg@uiowa.edu (Goldberg); sisheikh@uchicago.edu (Sheikh)
²Department of Biology, Texas State University, San Marcos, TX 78666, USA. E-mail: rwb77@txstate.edu (Busbee); amanda.driscoe@gmail.com (Driscoe); jimott@txstate.edu (Ott)
³Biological Sciences, Binghamton University, Binghamton, NY 13902, USA. E-mail: rchen78@binghamton.edu (Chen); djones41@binghamton.edu (Jones); amilks1@binghamton.edu (Milks); kprior@binghamton.edu (Prior)
⁴Department of BioSciences, Rice University, Houston, Texas 77005, USA. E-mail: ckd.ento.eco.evo@gmail.com (Davis); spe1@rice.edu (Egan); shihan.shzu@gmail.com (Shzu); kelly.weinersmith@gmail.com (Weinersmith); linyizhangecnu@gmail.com (Zhang)
⁵Department of Biological Science, Wayne State University, Detroit, MI 48202, USA. E-mail: glenrayhood@wayne.edu (Hood)
⁶Gallformers.org. E-mail: adamjameskranz@gmail.com (Kranz)
⁷Department of Biology, McGill University, Montreal, Quebec H3A 0G4, Canada. E-mail: shannon.meadleydunphy@mail.mcgill.ca (Meadely-Dunphy)
⁸Systematic Entomology Laboratory, USDA-ARS, c/o National Museum of Natural History, Washington, D.C. 20560, USA. E-mail: yuanmeng.zhang@gmail.com (Zhang)

Received 28 April 2022 / Accepted 25 July 2022
Communicated by Jen-Pan Huang

The identities of most arthropod associates of cynipid-induced oak galls in the western Palearctic are generally known. However, a comprehensive accounting of associates has been performed for only a small number of the galls induced by the estimated 700 species of cynipid gall wasps in the Nearctic. This gap in knowledge stymies many potential studies of diversity, coevolution, and community ecology, for which oak gall systems are otherwise ideal models. We report rearing records of insects and other arthropods from more than 527,306 individual galls representing 201 different oak gall types collected from 32 oak tree species in North America. Of the 201 gall types collected, 155 produced one or more arthropods. A total of 151,075 arthropods were found in association with these 155 gall types, and of these 61,044 (40.4%) were gall wasps while 90,031 (59.6%) were other arthropods. We identified all arthropods to superfamily, family, or, where possible, to genus. We provide raw numbers and summaries of collections, alongside notes on natural history, ecology, and previously published associations for each taxon. For eight common gall-associated genera (Synergus, Ceroptres, Euceroptres, Ormyrus, Torymus, Eurytoma, Sycophila, and Euderus), we also connect rearing records to gall wasp phylogeny, geography, and ecology - including host tree and gall location (host organ), and their co-occurrence with other insect genera. Though the diversity of gall wasps and the large size of these communities is such that many Nearctic oak gall-associated insects still remain undescribed, this large collection and identification effort should facilitate the testing of new and varied ecological and evolutionary hypotheses in Nearctic oak galls.

Key words: Cynipini, Gall, Diversity, Synergus, Torymus, Ormyrus.

Citation: Ward AKG, Busbee RW, Chen RA, Davis CK, Driscoe AL, Egan SP, Goldberg BAR, Hood GR, Jones DG, Kranz AJ, Meadely-Dunphy SA, Milks AK, Ott JR, Prior KM, Sheikh SI, Shzu SA, Weinersmith KL, Zhang L, Zhang YM, Forbes AA. 2022. The arthropod associates of 155 North American cynipid oak galls. Zool Stud 61:57.

Supplementary materials: Fig. S1 | Table S1 | Table S2