Biology subjects

Prior, K. M.

Publications and source records attributed to Prior, K. M..

5 recordsLinked to original sources

bioRxiv2022

Host-enemy interactions provide limited biotic resistance for a range-expanding species via reduced apparent competition

As species ranges shift in response to anthropogenic change, they lose coevolved or coadapted interactions and gain novel ones in recipient communities. Range-expanding species may lose or experience weak antagonistic interactions with competitors and enemies, and traits of interacting species will determine the strength of interactions. We leveraged a poleward range expansion of an oak gall wasp that co-occurs on its host plant with other gall wasp species and interacts with shared natural enemies (largely parasitoid wasps). We created quantitative host-parasitoid interaction networks by sampling galls on 400 trees. We compared network structure and function and traits of hosts and parasitoids in the native and expanded range. Interaction networks were less diverse in the expanded range, with low complementarity of parasitoid assemblages among hosts. While whole networks were more generalized in the expanded range, interactions with the range-expanding species were more specialized. This was not due to a loss of specialist enemies but weak apparent competition by shared generalist enemies. Phenological divergence of enemy assemblages attacking the novel and co-occurring hosts was greater in the expanded range that may contribute to weak apparent competition. Given the rate and extent of anthropogenic-driven range expansions, it is pressing to uncover how complex biotic interactions are reassembled.

ecology↗

bioRxiv2022

Historical forest disturbance results in variation in functional resilience of seed dispersal mutualisms

Mutualistic interactions provide essential ecosystem functions, such as promoting and maintaining diversity. Understanding if functionally important mutualisms are resilient (able to resist and recover) to anthropogenic disturbance is important to understand the capacity for diversity to recover. Animal-mediated seed dispersal supports plant population growth and community structure, and disturbance of this function can threaten plant diversity and contribute to low resiliency. Ant-mediated seed dispersal mutualisms are particularly sensitive to anthropogenic disturbance, as they rely on one to a few high-quality dispersal partners. In North American eastern deciduous forests (NAEDF), ants in the genus Aphaenogaster are "keystone dispersers" of 30-40% of understory forbs adapted to dispersal by ants (myrmecochores). The majority of present day NAEDF have regenerated from previous disturbance in the form of historical land use change (HLUC), due to clearing for agriculture. Previous studies have revealed that myrmecochore diversity is not resilient to HLUC. Here, we ask if seed dispersal mutualisms are resilient to HLUC and if decreases in mutualistic interactions with partners, Aphaenogaster sp., or increases in antagonistic interactions cause degradation of function. In a large-scale natural experiment (20 sites), we measured seed removal, the abundance of mutualistic partners and other invertebrates interacting with seeds, myrmecochore cover and diversity, along with ant habitat and forest structure. We found lower and more variable seed removal in secondary forests compared to remnant forests. A path analysis of all forests revealed that abundance of mutualists was the primary determinant of variation in seed removal, and that seed damage by antagonists (invasive slugs) negatively affected dispersal and was higher in secondary forests. In a path analysis of remnant forests, the link between mutualist abundance and seed removal was absent, but present in the secondary forest path, suggesting that seed dispersal is more variable and dependent on mutualist abundance in secondary forests and is stable and high in remnant forests. Here we show that functional resilience to HLUC is variable and may impede recovery of understory plant communities. This work provides key insights on the effects of anthropogenic disturbance on mutualistic interactions and how the resilience of critical ecosystem functions impacts diversity resiliency.

ecology↗

bioRxiv2022

The arthropod associates of 155 North American cynipid oak galls

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 wasp 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 animals. A total of 151,075 animals 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 animals 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.

zoology↗

bioRxiv2022

Speciation in Nearctic oak gall wasps is frequently correlated with changes in host plant, host organ, or both.

Quantifying the frequency of shifts to new host plants within diverse clades of specialist herbivorous insects is critically important to understand whether and how host shifts contribute to the origin of species. Oak gall wasps (Hymenoptera: Cynipidae: Cynipini) comprise a tribe of ~1000 species of phytophagous insects that induce gall formation on various organs of trees in the family Fagacae, -- primarily the oaks (genus Quercus; ~435 sp). The association of oak gall wasps with oaks is ancient (~50 my), and most oak species are galled by one or more gall wasp species. Despite the diversity of both gall wasp species and their plant associations, previous phylogenetic work has not identified a strong signal of host plant shifting among oak gall wasps. However, most emphasis has been on the Western Palearctic and not the Nearctic where both oaks and oak gall wasps are considerably more species rich and where oaks are more phylogenetically diverse. We collected 86 species of Nearctic oak gall wasps from 10 of the 14 major clades of Nearctic oaks and sequenced >1000 Ultra Conserved Elements (UCEs) and flanking sequences to infer wasp phylogenies. We assessed the relationships of Nearctic gall wasps to one another and, by leveraging previously published UCE data, to the Palearctic fauna. We then used phylogenies to infer historical patterns of shifts among host tree species and tree organs. Our results indicate that oak gall wasps have moved between the Palearctic and Nearctic at least four times, that some Palearctic clades have their proximate origin in the Nearctic, and that gall wasps have shifted within and between oak tree sections, subsections, and organs considerably more often than the analysis of previous data have suggested. Given that host shifts have been demonstrated to drive reproductive isolation between host-associated populations in other phytophagous insects, our analyses of Nearctic gall wasps suggest that host shifts are key drivers of speciation in this clade, especially in hotspots of oak diversity. Though formal assessment of this hypothesis requires further study, two putatively oligophagous gall wasp species in our dataset show signals of host-associated genetic differentiation unconfounded by geographic distance, suggestive of barriers to gene flow associated with the use of alternative host plants.

evolutionary biology↗

bioRxiv2022

Latitudinal gradient in species diversity provides high niche opportunities for a range-expanding phytophagous insect

O_LIWhen species undergo poleward range expansions in response to anthropogenic change, they likely encounter less diverse communities in new locations. If low diversity communities provide weak biotic interactions, such as reduced competition for resources or predation, range-expanding species may experience high niche opportunities. C_LIO_LIHere, we uncover if oak gall wasp communities experience a latitudinal diversity gradient (LDG) and weaker interactions at the poles that might create high niche opportunities for a range-expanding community member. C_LIO_LIWe performed systematic surveys of oak gall wasps on a dominant oak, Quercus garryana, throughout most of its range, from northern California to Vancouver Island, British Columbia. On 540 trees at 18 sites, we identified 23 species in three guilds (leaf detachable, leaf integral, and stem galls). We performed regressions between oak gall wasp diversity, latitude, and other abiotic and habitat factors to reveal if cynipid communities follow an LDG. To uncover patterns in local interactions, we performed partial correlations on oak gall wasps co-occurring on trees within regions. Finally, we performed regressions between abundances of co-occurring gall wasps on trees to reveal potential interactions. C_LIO_LIQ. garryana-gall wasp communities followed an LDG, with lower diversity at higher latitudes, particularly with a loss of detachable leaf gall species. Detachable leaf gall wasps, including the range-expanding species, co-occurred most on trees and had weak interactions in the northern region. Abundances of the range-expander and detachable and integral leaf galls co-occurring on trees were negatively related, suggesting antagonistic interactions. Overall, we found that LDGs create communities with weaker antagonistic interactions at the poles that might facilitate ecological release in a range-expanding community member. C_LIO_LIHere, we uncover how regional and local scale patterns and processes create high niche opportunities for a range-expanding community member. This research provides insight into how biogeographical patterns in communities and species interactions influence the outcome of range expansions. Given the ubiquity of LDGs, these outcomes might be expected in other phytophagous insect communities. C_LI

ecology↗