scholarly journals Diversity, host ranges, and potential drivers of speciation among the inquiline enemies of oak gall wasps

Author(s):  
Anna KG Ward ◽  
Sofia I Sheikh ◽  
Andrew A Forbes

ABSTRACTAnimals that exploit an extended phenotype (e.g., residences, resources, etc.) of other animals are called inquilines. Not strictly parasites, inquilines may nevertheless possess specialized traits that adapt them to particular dimensions of the extended phenotype of their “host”. These adaptations to host traits can in turn lead to fitness tradeoffs that restrict the host range of an inquiline such that shifts to novel hosts might trigger inquiline diversification. Speciation via host shifting has been studied in many animal parasites, but we know far less about the role of host shifts in inquiline speciation. Synergus (Hymenoptera: Cynipidae: Synergini) is a speciose but taxonomically-challenging group of inquilines that feed on the tissue of galls induced by oak gall wasps (Hymenoptera: Cynipidae: Cynipini). Currently too little is known about Nearctic Synergus diversity or host associations to evaluate whether and how host use affects their diversification. Here, we report on a large collection of Synergus reared from galls of 33 oak gall wasp species in the upper Midwestern United States. We integrated DNA barcodes, morphology, ecology, and phenology to delimit putative species of Synergus and describe their host ranges. We find evidence of at least 23 Synergus species associated with the 33 gall wasp hosts. At least five previously described Synergus species are each a complex of two to five species, while three species fit no prior description. We also find strong evidence that oak tree section and host gall morphology define axes of specialization for Synergus. Without over-interpreting our singlegene tree, it is clear that the North American Synergus have experienced several transitions among gall hosts and tree habitats and that host-use is correlated with reproductive isolation, though it remains too early to tell whether shifts to new hosts are the initiators of speciation events in Synergus inquilines of oak gall wasps, or if host shifts occur after reproductive isolation has already evolved.

2020 ◽  
Vol 4 (6) ◽  
Author(s):  
Anna K G Ward ◽  
Sofia I Sheikh ◽  
Andrew A Forbes

Abstract Animals that exploit living spaces of other animals (inquilines) may have specialized traits that adapt them to extended phenotypes of their ‘hosts’. These adaptations to host traits may incur fitness trade-offs that restrict the host range of an inquiline such that shifts to new hosts might trigger inquiline diversification. Speciation via host shifting has been studied in many animal parasites, but we know less about the role of host shifts in inquiline speciation. Synergus Hartig (Hymenoptera: Cynipidae: Synergini) is a speciose but taxonomically challenging genus of inquilines that feed inside galls induced by oak gall wasps (Hymenoptera: Cynipidae: Cynipini). Here, we report on a large collection of Synergus reared from galls of 33 oak gall wasp species in the upper Midwestern United States. We integrated DNA barcodes, morphology, ecology, and phenology to delimit putative species of Synergus and describe their host ranges. We find evidence of at least 23 Synergus species associated with the 33 gall wasp hosts. At least five previously described Synergus species are each complexes of two to five species, while three species fit no prior description. We find evidence that oak tree phylogeny and host gall morphology define axes of specialization for Synergus. The North American Synergus have experienced several transitions among gall hosts and tree habitats and their host use is correlated with reproductive isolation. It remains too early to tell whether shifts to new hosts initiate speciation events in Synergus inquilines of oak gall wasps, or if host shifts occur after reproductive isolation has already evolved.


Author(s):  
Kelly L. Weinersmith ◽  
Andrew A. Forbes ◽  
Anna K.G. Ward ◽  
Pedro F. P. Brandão-Dias ◽  
Y. Miles Zhang ◽  
...  

AbstractCynipid gall wasps play an important role in structuring oak invertebrate communities. Wasps in the Cynipini tribe typically lay their eggs in oaks (Quercus L.), and induce the formation of a “gall”, which is a tumor-like growth of plant material that surrounds the developing wasp. As the wasp develops, the cynipid and its gall are attacked by a diverse community of natural enemies, including parasitoids, hyperparasitoids, and inquilines. Determining what structures these species-rich natural enemy communities across cynipid gall wasp species is a major question in gall wasp biology. Additionally, gall wasps are ecosystem engineers, as the abandoned gall is used by other invertebrates. The gall-associated insect communities residing on live oaks (Quercus geminata Small and Q. virginiana Mill.) are emerging as a model system for answering ecological and evolutionary questions ranging from community ecology to the evolution of new species. Documenting the invertebrates associated with cynipids in this system will expand our understanding of the mechanisms influencing eco-evolutionary processes, record underexplored axes of biodiversity, and facilitate future work. Here, we present the community of natural enemies and other associates of the asexual generation of the crypt gall wasp, Bassettia pallida Ashmead. We compare the composition of this community to communities recently documented from two other cynipid gall wasps specializing on live oaks along the U.S. Gulf coast, Disholcaspis quercusvirens Ashmead and Belonocnema treatae Mayr. B. pallida and their crypts support a diverse arthropod community, including over 25 parasitoids, inquilines, and other associated invertebrates spanning 5 orders and 16 families.


2020 ◽  
Vol 113 (5) ◽  
pp. 373-388 ◽  
Author(s):  
Kelly L Weinersmith ◽  
Andrew A Forbes ◽  
Anna K G Ward ◽  
Pedro F P Brandão-Dias ◽  
Y Miles Zhang ◽  
...  

Abstract Cynipid gall wasps play an important role in structuring oak arthropod communities. Wasps in the Cynipini tribe typically lay their eggs in oaks (Quercus L.), and induce the formation of a ‘gall’, which is a tumor-like growth of plant material that surrounds the developing wasp. As the wasp develops, the cynipid and its gall are attacked by a diverse community of natural enemies, including parasitoids, hyperparasitoids, and inquilines. Determining what structures these species-rich natural enemy communities across cynipid gall wasp species is a major question in gall wasp biology. Additionally, gall wasps are ecosystem engineers, as the abandoned gall is used by other invertebrates. The gall-associated insect communities residing on live oaks (Quercus geminata Small and Quercus virginiana Mill.) are emerging as a model system for answering ecological and evolutionary questions ranging from community ecology to the evolution of new species. Documenting the arthropods associated with cynipids in this system will expand our understanding of the mechanisms influencing eco-evolutionary processes, record underexplored axes of biodiversity, and facilitate future work. Here, we present the community of natural enemies and other associates of the asexual generation of the crypt gall wasp, Bassettia pallida Ashmead. We compare the composition of this community to communities recently documented from two other cynipid gall wasps specializing on live oaks along the U.S. Gulf coast, Disholcaspis quercusvirens Ashmead and Belonocnema treatae Mayr. B. pallida and their galls support a diverse arthropod community, including over 25 parasitoids, inquilines, and other associated arthropods spanning 5 orders and 16 families.


2012 ◽  
Vol 8 (4) ◽  
pp. 605-608 ◽  
Author(s):  
Scott P. Egan ◽  
Glen R. Hood ◽  
Jeff L. Feder ◽  
James R. Ott

Ecological speciation occurs when reproductive isolation evolves as a consequence of divergent natural selection among environments. A direct prediction of this process is that ecologically divergent pairs of populations will exhibit greater reproductive isolation than ecologically similar pairs of populations. By comparing allopatric populations of the cynipid gall wasp Belonocnema treatae infesting Quercus virginiana and Quercus geminata , we tested the role that divergent host use plays in generating ecological divergence and sexual isolation. We found differences in body size and gall structure associated with divergent host use, but no difference in neutral genetic divergence between populations on the same or different host plant. We observed significant assortative mating between populations from alternative host plants but not between allopatric populations on the same host plant. Thus, we provide evidence that divergent host use promotes speciation among gall wasp populations.


2021 ◽  
Vol 12 ◽  
Author(s):  
Dao-Hong Zhu ◽  
Cheng-Yuan Su ◽  
Xiao-Hui Yang ◽  
Yoshihisa Abe

The phage WO was characterized in Wolbachia, a strictly intracellular bacterium causing several reproductive alterations in its arthropod hosts. This study aimed to screen the presence of Wolbachia and phage WO in 15 gall wasp species from six provinces of southern China to investigate their diversity and prevalence patterns. A high incidence of Wolbachia infection was determined in the gall wasp species, with an infection rate of 86.7% (13/15). Moreover, seven species had double or multiple infections. All Wolbachia-infected gall wasp species were found to harbor phage WO. The gall wasp species infected with a single Wolbachia strain were found to harbor a single phage WO type. On the contrary, almost all species with double or multiple Wolbachia infections harbored a high level of phage WO diversity (ranging from three to 27 types). Six horizontal transfer events of phage WO in Wolbachia were found to be associated with gall wasps, which shared identical orf7 sequences among their respective accomplices. The transfer potentially took place through gall inducers and associated inquilines infected with or without Wolbachia. Furthermore, 10 putative recombination events were identified from Andricus hakonensis and Andricus sp2, which harbored multiple phage WO types, suggesting that intragenic recombination was the important evolutionary force, which effectively promoted the high level of phage WO diversity associated with gall wasps.


2015 ◽  
Vol 39 ◽  
pp. 962-964
Author(s):  
Serap MUTUN ◽  
Serdar DİNÇ
Keyword(s):  

2021 ◽  
Author(s):  
Louis Nastasi ◽  
Andrew Deans

Cynipidae (Hymenoptera: Cynipoidea) is a diverse group of wasps, many of which are capable of inducing plants to make novel structures, galls, that protect and nourish the wasps' larvae. Other cynipids, especially those species in Ceroptresini and Synergini, are understood to be usurpers of galls made by other cynipids. The North American cynipid fauna has not been fully cataloged since 1979, but there is renewed interest in revising the taxonomy and in doing research that sheds light on the mechanisms of gall induction, the evolution of this life history, and their ecological interactions more broadly. Significant taxonomic changes have impacted the group since 1979, thereby warranting a new catalog. The current state of knowledge of species classified in Aulacideini, Ceroptresini, Diastrophini, Diplolepidini, Phanacidini, and Synergini in the United States, Canada, and Mexico is summarized in catalog format. We report 323 names, including 170 valid species of rose gall wasps, herb gall wasps, and inquiline gall wasps, classified in 12 genera, from the United States, Canada, and Mexico. Current taxonomic status, distribution, host associations, and vernacular names are listed for each species. The catalog also includes the original description of galls for many species of gall-inducer, as well as atomized characterizations of different gall traits as key-value pairs. For most galling species without existing vernacular names, new vernacular names are proposed.


Zootaxa ◽  
2011 ◽  
Vol 2774 (1) ◽  
pp. 1 ◽  
Author(s):  
JOSE LUIS NIEVES-ALDREY ◽  
ENRIQUE MEDIANERO

This paper reports the first study of the inquiline oak gall wasp fauna of Panama. Samples were collected at 19 sites in Panama, and inquiline specimens were reared from 63 gall morphotypes, including six species of Quercus, mainly Q. salicifolia and Q. bumelioides. Two genera were found: Synergus, represented by 10 species, and the recently described genus Agastoroxenia Nieves-Aldrey & Medianero, with a single species, A. panamensis Nieves-Aldrey & Medianero. Synergus was recorded for the first time in Panama; Synergus mesoamericanus and Synergus nicaraguensis, which were formerly recorded from Guatemala and Nicaragua, have now been recorded in Panama, and eight new species of Synergus are described here: Synergus elegans, S. laticephalus, S. ramoni, S. rufinotaulis, S. luteus, S. gabrieli, S. baruensis and S. chiricanus. A key for the identification of the studied fauna is provided. An overall similarity cluster analysis of the inquilines of oak gall wasps of Panama, including one Neotropical and two Palaearctic species as outgroups, is included.


2020 ◽  
Vol 375 (1806) ◽  
pp. 20190541 ◽  
Author(s):  
Moritz Muschick ◽  
Víctor Soria-Carrasco ◽  
Jeffrey L. Feder ◽  
Zach Gompert ◽  
Patrik Nosil

Simpson's fossil-record inspired model of ‘adaptive zones’ proposes that evolution is dominated by small fluctuations within adaptive zones, occasionally punctuated by larger shifts between zones. This model can help explain why the process of population divergence often results in weak or moderate reproductive isolation (RI), rather than strong RI and distinct species. Applied to the speciation process, the adaptive zones hypothesis makes two inter-related predictions: (i) large shifts between zones are relatively rare, (ii) when large shifts do occur they generate stronger RI than shifts within zones. Here, we use ecological, phylogenetic and behavioural data to test these predictions in Timema stick insects. We show that host use in Timema is dominated by moderate shifts within the systematic divisions of flowering plants and conifers, with only a few extreme shifts between these divisions. However, when extreme shifts occur, they generate greater RI than do more moderate shifts. Our results support the adaptive zones model, and suggest that the net contribution of ecological shifts to diversification is dependent on both their magnitude and frequency. We discuss the generality of our findings in the light of emerging evidence from diverse taxa that the evolution of RI is not always the only factor determining the origin of species diversity. This article is part of the theme issue ‘Towards the completion of speciation: the evolution of reproductive isolation beyond the first barriers’.


2020 ◽  
Vol 49 (5) ◽  
pp. 1077-1087
Author(s):  
Claudia D Lyons-Yerion ◽  
James D Barbour ◽  
Judith A Mongold-Diers ◽  
Christopher J Williams ◽  
Stephen P Cook

Abstract Research over the last 15 yr has shown widespread pheromone parsimony within the coleopteran family Cerambycidae, with a number of highly conserved pheromone motifs, often shared within and across subfamilies, tribes, and genera. Our goals were to increase our understanding of the evolution of volatile pheromones within the Cerambycidae, their role in reproductive isolation and to identify pheromones for use in the development of lures for monitoring cerambycids. Over 3 yr, we tested 12 compounds known to be cerambycid pheromones as possible attractants at sites across Idaho. This study focused on species within the cerambycine genus Phymatodes (Tribe: Callidiini). We also collected and analyzed headspace volatiles of captured Phymatodes dimidiatus (Kirby). Our results demonstrate that (R)-2-methylbutan-1-ol is a male-produced volatile pheromone for P. dimidiatus. These results are consistent with prior research suggesting that (R)-2-methylbutan-1-ol and (R)-3-hydroxyhexan-2-one, individually or in a blend of both compounds, commonly serve as pheromones for Phymatodes spp. We captured Phymatodes starting in mid-May, continuing through mid-August. Our data indicate that flight periods of Phymatodes spp. in Idaho overlap. These species may be utilizing various mechanisms to ensure reproductive isolation, such as the production of different volatile pheromones, minor components, and/or proportions of components, utilizing different host species and/or host volatiles, differing daily activity periods, and/or occupying different heights in the tree canopy. Our results contribute to the basic understanding of the chemical and behavioral ecology of the Cerambycidae and can be applied to the development of pheromone lures for monitoring of economically important or endangered species.


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