California gall wasp, Andricus quercuscalifornicus (Hymenoptera, Cynipidae, Cynipini), a new species for Canada discovered through community science

Abstract

Biodiversity-focused community (a.k.a., citizen) science datasets can be valuable tools for understanding the distribution of species. These data are often generated by the public and curated by experts. While curating the Cynipoidea records on the community science platform iNaturalist.org, I found an observation of the first record of Andricus quercuscalifornicus (Bassett) (Hymenoptera: Cynipidae) for Canada. The record was contributed by a hobby naturalist who photographed a gall in her neighbourhood park in Victoria, British Columbia (BC), and uploaded the record to iNaturalist. I visited the park, collected and reared the inhabitants out of the galls, and identified the adults morphologically. At around the same time, another gall was found independently in nearby Saanich, BC. The galls from both Victoria and Saanich were collected from recently planted Quercus garryana saplings on municipal land, and the trees may have been transplanted while already infested with A. quercuscalifornicus. More research is needed to understand if A. quercuscalifornicus arrived in BC naturally or if it was introduced through the horticultural industry. This record provides another example of how community science can contribute valuable information to our understanding of species ranges.