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Graham N Stone - One of the best experts on this subject based on the ideXlab platform.
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From Inquilines to Gall Inducers: Genomic Signature of a Life-Style Transition in Synergus Gall Wasps.
Genome biology and evolution, 2020Co-Authors: Erik Gobbo, Graham N Stone, Tatsuya Ide, Yoshihisa Abe, Nicolas Lartillot, Jack Hearn, Christopher W. Wheat, Fredrik RonquistAbstract:Gall wasps (Hymenoptera: Cynipidae) induce complex galls on oaks, roses, and other plants, but the mechanism of gall induction is still unknown. Here, we take a comparative genomic approach to revealing the genetic basis of gall induction. We focus on Synergus itoensis, a species that induces galls inside oak acorns. Previous studies suggested that this species evolved the ability to initiate gall formation recently, as it is deeply nested within the genus Synergus, whose members are mostly Inquilines that develop inside the galls of other species. We compared the genome of S. itoensis with that of three related Synergus Inquilines to identify genomic changes associated with the origin of gall induction. We used a novel Bayesian selection analysis, which accounts for branch-specific and gene-specific selection effects, to search for signatures of selection in 7,600 single-copy orthologous genes shared by the four Synergus species. We found that the terminal branch leading to S. itoensis had more genes with a significantly elevated dN/dS ratio (positive signature genes) than the other terminal branches in the tree; the S. itoensis branch also had more genes with a significantly decreased dN/dS ratio. Gene set enrichment analysis showed that the positive signature gene set of S. itoensis, unlike those of the Inquiline species, is enriched in several biological process Gene Ontology terms, the most prominent of which is "Ovarian Follicle Cell Development." Our results indicate that the origin of gall induction is associated with distinct genomic changes, and provide a good starting point for further characterization of the genes involved.
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Catalogue of parasitoids and Inquilines in cynipid oak galls in the West Palaearctic
Zootaxa, 2013Co-Authors: R. R. Askew, Graham N Stone, Karsten Schönrogge, George Melika, Juli Pujade-villar, José Luis Nieves-aldreyAbstract:A quantitative catalogue of the parasitoids (almost exclusively Chalcidoidea) and Inquiline Cynipidae recorded in the western Palaearctic from galls induced on Quercus by Cynipidae (Cynipini) is presented. Quantitative and national data are included with bibliographic references to almost all records published in 2011 and earlier. The catalogue is followed by two checklists, firstly one of the Chalcidoidea with numbers of each species recorded from each type of host gall (galls of the sexual and asexual generations of the host gall wasps are listed separately), and secondly one of Inquiline Cynipidae with host galls. Compared to non-oak gall wasps, the Cynipini support a much larger parasitoid and especially Inquiline fauna, and this fauna is very largely restricted at the species level to Cynipini galls. About one hundred chalcidoid species are recorded from galls of Cynipini, distributed over six families: Pteromalidae and Eulophidae (29 species each), Torymi-dae (21 species), Eurytomidae (10 species), Eupelmidae (8 species) and Ormyridae (at least 2 species). Polyphagy is usual in the chalcidoid parasitoids, most species having a broad host gall range, but quantitatively the fauna of each type of oak gall is rather characteristic and is strongly influenced by gall morphology, situation on the tree, season of growth and host tree species. These and other extrinsic factors restrict the full exploitation of the chalcidoids’ potential host gall range.
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Western Palaearctic phylogeography of an Inquiline oak gall wasp, Synergus umbraculus
Biological Journal of the Linnean Society, 2011Co-Authors: Péter Bihari, Graham N Stone, George Melika, Botond Sipos, Balázs Fehér, Kálmán Somogyi, Zsolt PénzesAbstract:Insect-induced galls on plants comprise species-rich but self-contained communities of herbivores and natural enemies. In the present study, we focus on galls induced by cynipid gall wasps on oaks, and on the least-known trophic level that these galls contain: Inquilines. These insects, also cynipids, feed on gall tissue and are an abundant but taxonomically poorly understood part of an otherwise well-studied system. We used DNA sequence data to examine spatial patterns in the genetic diversity of Synergus umbraculus Olivier 1791 (Hymenoptera: Cynipidae: Synergini), a widespread species attacking many host galls across the Western Palaearctic. Analysis of 239 cytochrome b sequences revealed eight haplogroups showing significant phylogeographic pattern across the Western Palaearctic, corresponding to putative glacial refugia in Iberia, Central Europe, Turkey, and Iran. There were significant genetic discontinuities across the Pyrenees and the Anatolian diagonal but no impact of the Alps, suggesting that significant discontinuities have biotic rather than physical causes. Detailed analysis of sites in the Carpathian Basin reveal a high diversity and low spatial structure, and identify Central Europe as the source of colonists for Quaternary colonization of Germany, France, and Britain. We found no evidence for host-associated differentiation of S. umbraculus lineages associated with the most common cynipid host galls, suggesting frequent shifts within the host gall assemblage by Inquiline lineages. © 2011 The Linnean Society of London, Biological Journal of the Linnean Society, 2011, 102, 750–764.
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The incidence and diversity of Wolbachia in gallwasps (Hymenoptera; Cynipidae) on oak.
Molecular Ecology, 2002Co-Authors: Antonis Rokas, Rachel J. Atkinson, José Luis Nieves-aldrey, Stuart A West, Graham N StoneAbstract:Wolbachia bacteria infect ≈ 20% of all insect species, and cause a range of alterations to host reproduction, including imposition of thelytoky. The incidence and phenotypic impact of Wolbachia remains to be established in many insect taxa, and considerable research effort is currently focused on its association with particular reproductive modes and the relative importance of the various pathways via which infection occurs. Gallwasps represent an attractive system for addressing these issues for two reasons. First, they show a diversity of reproductive modes (including arrhenotoky, thelytoky and cyclical parthenogenesis) in which the impact of Wolbachia infection can be examined. Second, they occupy two intimately linked trophic niches (gall-inducers and Inquilines) between which there is potential for the horizontal exchange of Wolbachia infection. In the arrhenotokous gallwasp lineages screened to date (the herb-galling ‘Aylacini’ and the rose-galling Diplolepidini), Wolbachia infection always induces thelytoky. The impact of Wolbachia in other arrhenotokous clades, and in the cyclically parthenogenetic clades remains unknown. Here we use polymerase chain reaction (PCR) screening and sequence data for two Wolbachia genes ( wsp and ftsZ ) to examine the prevalence and incidence of Wolbachia infection in 64 species (a total of 609 individuals) in two further tribes: the arrhenotokous Inquilines (tribe Synergini), and the cyclically parthenogenetic oak gallwasps (tribe Cynipini). We ask: (i) whether Wolbachia infection has any apparent impact on host reproduction in the two tribes and (ii) whether there is any correlation between Wolbachia infection and the apparent lack of an arrhenotokous generation in many oak gallwasp life cycles. We show: (i) that Wolbachia infection is rare in the Cynipini. Infected species show no deviation from cyclical parthenogenesis, and infection is no more common in species known only from a thelytokous generation; (ii) that there is a higher incidence of infection within the arrhenotokous Inquilines, and generally in gallwasp tribes without cyclical parthenogensis; (iii) all Wolbachia -positive Inquiline species are known to possess males, implying either that Wolbachia infection does not result in loss of sex in this tribe or, more probably, that (as for some rose gallwasps) Wolbachia infection leads to loss of sex in specific populations; and (iv) although we find some Inquilines and gall inducers to be infected with Wolbachia having the same wsp sequence, these hosts are not members of the same gall communities, arguing against frequent horizontal transmission between these two trophic groups. We suggest that exchange may be mediated by the generalist parasitoids common in oak galls.
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alien herbivores and native parasitoids rapid developments and structure of the parasitoid and Inquiline complex in an invading gall wasp andricus quercuscalicis hymenoptera cynipidae
Ecological Entomology, 1996Co-Authors: Karsten Schönrogge, Graham N Stone, Michael J. CrawleyAbstract:. 1 Rapid and substantial changes have occurred in the parasitoid and Inquiline community associated with the agamic galls of Andricus quercuscalicis since it invaded Britain in the late 1950s. The number of parasitoid and Inquiline species has risen from one to thirteen over a 15-year period. Although the number of species has been relatively consistent over the last 8 years, the species composition has changed considerably and in a highly characteristic way during this period. 2 The parasitoid complex can be divided into two broadly distinct sets of parasitoid species; one set attacks only the gall former whereas the other set concentrates on the Inquilines living in the wall of the gall. 3 The most dramatic change, however, is in the abundance of Inquilines which were reported to be virtually absent in earlier studies on this community in Britain. Over a period of only 5 years, between 1988 and 1993, Inquiline attack rose from less than 0.01 to an average of 0.26 Inquilines per gall. The intensity of Inquiline attack is geographically heterogenous, with high Inquiline numbers restricted to south-east England. Because of the relatively high specificity of the parasitoids, high Inquiline abundance is positively correlated with parasitoid species richness in knopper galls. 4 Parasitism rates, particularly on the gall former, were generally low (<10%). Over the last 5 years, however, seven parasitoid species have been consistently recorded and the mortality caused by these species has increased continuously. The species composition of the community associated with this alien gall wasp in Britain has quickly converged to the community known from its native range in continental Europe. Parasitoid species known to attack the galls of A.quercuscalisis on the continent have been recorded from it in Britain for the first time mainly in areas where Inquilines have recently become abundant. 5 Since rates of parasitism of the gall former are still low, parasitoids are unlikely to play a major role in the population dynamics of this invading gall wasp at present, but the rapidly increasing Inquiline and parasitoid attack could be a source of increased mortality for native cynipid species which are the alternative hosts of those parasitoid species.
Michael J. Crawley - One of the best experts on this subject based on the ideXlab platform.
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Parasitoid and Inquiline attack in the galls of four alien, cynipid gall wasps: host switches and the effect on parasitoid sex ratios.
Ecological Entomology, 2000Co-Authors: Karsten Schönrogge, P. Walker, Michael J. CrawleyAbstract:Summary 1. Four alien cynipid gall wasps of the genus Andricus are established and still spreading in the British Isles. The order, according to the northerliness of their distribution boundary, is: A. corruptrixA. quercuscalicisA. lignicolaA. kollari. All four aliens have a sexual generation in spring on Quercus cerris (introduced to Britain) and an agamic generation in autumn on native oak species. 2. For 2 years 1994 and 1995, galls of both generations of the four alien species were sampled at eight sites from the south of England to the north of Scotland to determine the parasitoid and Inquiline species that attack the new galls. The spring generations of the invading species shared a parasitoid complex of four pteromalid species. Five species of Inquilines and 11 species of parasitoids emerged from the autumn galls. 3. Two colonisation events were recorded for A. lignicola and A. corruptrix. On both occasions, the spring generations were found first at the new sites, indicating that the agamic generation provides the colonisers for these invading species. After colonisation, the galls of both species were attacked by parasitoids in their first season. 4. In spring, the invading species were among the most abundant cynipids at all eight sites. By sampling the whole local community of cynipid galls, it was found that the parasitoid species attacking the spring galls of the invaders seemed to have shifted their attack to the new hosts. 5. The secondary sex ratios of the parasitoid species emerging from the sexual galls of A. quercuscalicis (the smallest of the four) showed a strong and significant male bias at all sites and in both years. Parasitoid emergence from the galls of the sexual generations of the other three species (all about equal in size) was between 60 and 70% male, and variable among sites and between years.
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alien herbivores and native parasitoids rapid developments and structure of the parasitoid and Inquiline complex in an invading gall wasp andricus quercuscalicis hymenoptera cynipidae
Ecological Entomology, 1996Co-Authors: Karsten Schönrogge, Graham N Stone, Michael J. CrawleyAbstract:. 1 Rapid and substantial changes have occurred in the parasitoid and Inquiline community associated with the agamic galls of Andricus quercuscalicis since it invaded Britain in the late 1950s. The number of parasitoid and Inquiline species has risen from one to thirteen over a 15-year period. Although the number of species has been relatively consistent over the last 8 years, the species composition has changed considerably and in a highly characteristic way during this period. 2 The parasitoid complex can be divided into two broadly distinct sets of parasitoid species; one set attacks only the gall former whereas the other set concentrates on the Inquilines living in the wall of the gall. 3 The most dramatic change, however, is in the abundance of Inquilines which were reported to be virtually absent in earlier studies on this community in Britain. Over a period of only 5 years, between 1988 and 1993, Inquiline attack rose from less than 0.01 to an average of 0.26 Inquilines per gall. The intensity of Inquiline attack is geographically heterogenous, with high Inquiline numbers restricted to south-east England. Because of the relatively high specificity of the parasitoids, high Inquiline abundance is positively correlated with parasitoid species richness in knopper galls. 4 Parasitism rates, particularly on the gall former, were generally low (<10%). Over the last 5 years, however, seven parasitoid species have been consistently recorded and the mortality caused by these species has increased continuously. The species composition of the community associated with this alien gall wasp in Britain has quickly converged to the community known from its native range in continental Europe. Parasitoid species known to attack the galls of A.quercuscalisis on the continent have been recorded from it in Britain for the first time mainly in areas where Inquilines have recently become abundant. 5 Since rates of parasitism of the gall former are still low, parasitoids are unlikely to play a major role in the population dynamics of this invading gall wasp at present, but the rapidly increasing Inquiline and parasitoid attack could be a source of increased mortality for native cynipid species which are the alternative hosts of those parasitoid species.
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Alien herbivores and native parasitoids: rapid developments and structure of the parasitoid and Inquiline complex in an invading gall wasp Andricus quercuscalicis (Hymenoptera: Cynipidae)
Ecological Entomology, 1996Co-Authors: Karsten Schönrogge, Graham N Stone, Michael J. CrawleyAbstract:. 1 Rapid and substantial changes have occurred in the parasitoid and Inquiline community associated with the agamic galls of Andricus quercuscalicis since it invaded Britain in the late 1950s. The number of parasitoid and Inquiline species has risen from one to thirteen over a 15-year period. Although the number of species has been relatively consistent over the last 8 years, the species composition has changed considerably and in a highly characteristic way during this period. 2 The parasitoid complex can be divided into two broadly distinct sets of parasitoid species; one set attacks only the gall former whereas the other set concentrates on the Inquilines living in the wall of the gall. 3 The most dramatic change, however, is in the abundance of Inquilines which were reported to be virtually absent in earlier studies on this community in Britain. Over a period of only 5 years, between 1988 and 1993, Inquiline attack rose from less than 0.01 to an average of 0.26 Inquilines per gall. The intensity of Inquiline attack is geographically heterogenous, with high Inquiline numbers restricted to south-east England. Because of the relatively high specificity of the parasitoids, high Inquiline abundance is positively correlated with parasitoid species richness in knopper galls. 4 Parasitism rates, particularly on the gall former, were generally low (
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Abundance patterns and species richness of the parasitoids and Inquilines of the alien gall-former Andricus quercuscalicis (Hymenoptera: Cynipidae)
Oikos, 1996Co-Authors: Karsten Schönrogge, Graham N Stone, Michael J. CrawleyAbstract:1) Four parasitoid species attack the gall-maker in the agamic galls of the invading cynipid Andricus quercuscalicis and further two parasitoid species attack Inquiline larvae developing in the parenchymatic wall of the gall. The abundance of the parasitoids and Inquilines are correlated with: 1) gall morphology; 2) the geographical location within Europe where the samples were collected; and 3) the abundance of other members of the species complex. 2) The invading gall wasp has been present for different periods of time at different sites, and this is likely to affect the geographic distribution of attack by parasitoid and Inquiline species. One of the parasitoid species was restricted to the native range in south-eastern Europe (Aulogymnus trilineatus), while another species (Cecidostiba hilaris), a parasitoid of the Inquilines, was present throughout continental Europe but is not yet recorded from the British Isles. Species richness of the parasitoid complex associated with the galls of A. quercuscalicis declined with increasing distance away from the native range. Within the native range, however, species richness was negatively correlated with the total number of cynipid species (alternative hosts for the parasitoid species) recorded at the same sample site. 3) The size of mature knopper galls declined westwards and northwards away from the native range of the gall wasp. Inquiline abundance was higher in larger galls, and so was the occurrence of one of the parasitoid species, Megastigmus stigmatizans. The occurrence of two other parasitoid species was negatively correlated with gall size while one species, Mesopolobus jucundus, was not affected by gall size. 4) Neither the abundance of Inquilines nor of parasitoids attacking the Inquilines show any significant geographical trend associated with the invasion history of the gall-maker. Attack rates by C. hilaris, the dominant parasitoid species in continental Europe, showed a slight positive density dependence to the number of Inquilines per gall, while those by M. jucundus, the dominant parasitoid of Inquiline in Britain, showed no such trend.
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Spatial and temporal variation in guild structure: parasitoids and Inquilines of Andricus quercuscalicis (Hymenoptera: Cynipidae) in its native and alien ranges.
Oikos, 1995Co-Authors: Karsten Schönrogge, Graham N Stone, Michael J. CrawleyAbstract:The communities associated with the invading gall wasp Andricus quercuscalicis vary considerably in species richness and species composition throughout its native and invaded ranges. Seventeen species of Inquilines and parasitoids were identified as coinhabitants of the agamic galls of Andricus quercuscalicis throughout Europe. The life-histories of the parasitoid species are described; one is a solitary endoparasitoid, one a gregarious endoparasitoid and the remainder are solitary ectoparasitoids. A tortricid moth which develops as an Inquiline in the agamic galls of A. quercuscalicis kills the gall causer; this is the first description of such an interaction between moths and cynipids. While some parasitoid species appear to be restricted in their attack to the native range of A. quercuscalicis, others were found throughout the range. Geographic variation in the species composition and the possible role of the invasion history of the host are discussed. Food web parameter calculated for the community from the native range and six regions across the invaded range appear to be correlated with the residence time of the invading host, in accordance with studies of successional communities. However, it might be impossible to separate effects of time from those of species richness
Karsten Schönrogge - One of the best experts on this subject based on the ideXlab platform.
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Catalogue of parasitoids and Inquilines in cynipid oak galls in the West Palaearctic
Zootaxa, 2013Co-Authors: R. R. Askew, Graham N Stone, Karsten Schönrogge, George Melika, Juli Pujade-villar, José Luis Nieves-aldreyAbstract:A quantitative catalogue of the parasitoids (almost exclusively Chalcidoidea) and Inquiline Cynipidae recorded in the western Palaearctic from galls induced on Quercus by Cynipidae (Cynipini) is presented. Quantitative and national data are included with bibliographic references to almost all records published in 2011 and earlier. The catalogue is followed by two checklists, firstly one of the Chalcidoidea with numbers of each species recorded from each type of host gall (galls of the sexual and asexual generations of the host gall wasps are listed separately), and secondly one of Inquiline Cynipidae with host galls. Compared to non-oak gall wasps, the Cynipini support a much larger parasitoid and especially Inquiline fauna, and this fauna is very largely restricted at the species level to Cynipini galls. About one hundred chalcidoid species are recorded from galls of Cynipini, distributed over six families: Pteromalidae and Eulophidae (29 species each), Torymi-dae (21 species), Eurytomidae (10 species), Eupelmidae (8 species) and Ormyridae (at least 2 species). Polyphagy is usual in the chalcidoid parasitoids, most species having a broad host gall range, but quantitatively the fauna of each type of oak gall is rather characteristic and is strongly influenced by gall morphology, situation on the tree, season of growth and host tree species. These and other extrinsic factors restrict the full exploitation of the chalcidoids’ potential host gall range.
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Parasitoid and Inquiline attack in the galls of four alien, cynipid gall wasps: host switches and the effect on parasitoid sex ratios.
Ecological Entomology, 2000Co-Authors: Karsten Schönrogge, P. Walker, Michael J. CrawleyAbstract:Summary 1. Four alien cynipid gall wasps of the genus Andricus are established and still spreading in the British Isles. The order, according to the northerliness of their distribution boundary, is: A. corruptrixA. quercuscalicisA. lignicolaA. kollari. All four aliens have a sexual generation in spring on Quercus cerris (introduced to Britain) and an agamic generation in autumn on native oak species. 2. For 2 years 1994 and 1995, galls of both generations of the four alien species were sampled at eight sites from the south of England to the north of Scotland to determine the parasitoid and Inquiline species that attack the new galls. The spring generations of the invading species shared a parasitoid complex of four pteromalid species. Five species of Inquilines and 11 species of parasitoids emerged from the autumn galls. 3. Two colonisation events were recorded for A. lignicola and A. corruptrix. On both occasions, the spring generations were found first at the new sites, indicating that the agamic generation provides the colonisers for these invading species. After colonisation, the galls of both species were attacked by parasitoids in their first season. 4. In spring, the invading species were among the most abundant cynipids at all eight sites. By sampling the whole local community of cynipid galls, it was found that the parasitoid species attacking the spring galls of the invaders seemed to have shifted their attack to the new hosts. 5. The secondary sex ratios of the parasitoid species emerging from the sexual galls of A. quercuscalicis (the smallest of the four) showed a strong and significant male bias at all sites and in both years. Parasitoid emergence from the galls of the sexual generations of the other three species (all about equal in size) was between 60 and 70% male, and variable among sites and between years.
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alien herbivores and native parasitoids rapid developments and structure of the parasitoid and Inquiline complex in an invading gall wasp andricus quercuscalicis hymenoptera cynipidae
Ecological Entomology, 1996Co-Authors: Karsten Schönrogge, Graham N Stone, Michael J. CrawleyAbstract:. 1 Rapid and substantial changes have occurred in the parasitoid and Inquiline community associated with the agamic galls of Andricus quercuscalicis since it invaded Britain in the late 1950s. The number of parasitoid and Inquiline species has risen from one to thirteen over a 15-year period. Although the number of species has been relatively consistent over the last 8 years, the species composition has changed considerably and in a highly characteristic way during this period. 2 The parasitoid complex can be divided into two broadly distinct sets of parasitoid species; one set attacks only the gall former whereas the other set concentrates on the Inquilines living in the wall of the gall. 3 The most dramatic change, however, is in the abundance of Inquilines which were reported to be virtually absent in earlier studies on this community in Britain. Over a period of only 5 years, between 1988 and 1993, Inquiline attack rose from less than 0.01 to an average of 0.26 Inquilines per gall. The intensity of Inquiline attack is geographically heterogenous, with high Inquiline numbers restricted to south-east England. Because of the relatively high specificity of the parasitoids, high Inquiline abundance is positively correlated with parasitoid species richness in knopper galls. 4 Parasitism rates, particularly on the gall former, were generally low (<10%). Over the last 5 years, however, seven parasitoid species have been consistently recorded and the mortality caused by these species has increased continuously. The species composition of the community associated with this alien gall wasp in Britain has quickly converged to the community known from its native range in continental Europe. Parasitoid species known to attack the galls of A.quercuscalisis on the continent have been recorded from it in Britain for the first time mainly in areas where Inquilines have recently become abundant. 5 Since rates of parasitism of the gall former are still low, parasitoids are unlikely to play a major role in the population dynamics of this invading gall wasp at present, but the rapidly increasing Inquiline and parasitoid attack could be a source of increased mortality for native cynipid species which are the alternative hosts of those parasitoid species.
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Alien herbivores and native parasitoids: rapid developments and structure of the parasitoid and Inquiline complex in an invading gall wasp Andricus quercuscalicis (Hymenoptera: Cynipidae)
Ecological Entomology, 1996Co-Authors: Karsten Schönrogge, Graham N Stone, Michael J. CrawleyAbstract:. 1 Rapid and substantial changes have occurred in the parasitoid and Inquiline community associated with the agamic galls of Andricus quercuscalicis since it invaded Britain in the late 1950s. The number of parasitoid and Inquiline species has risen from one to thirteen over a 15-year period. Although the number of species has been relatively consistent over the last 8 years, the species composition has changed considerably and in a highly characteristic way during this period. 2 The parasitoid complex can be divided into two broadly distinct sets of parasitoid species; one set attacks only the gall former whereas the other set concentrates on the Inquilines living in the wall of the gall. 3 The most dramatic change, however, is in the abundance of Inquilines which were reported to be virtually absent in earlier studies on this community in Britain. Over a period of only 5 years, between 1988 and 1993, Inquiline attack rose from less than 0.01 to an average of 0.26 Inquilines per gall. The intensity of Inquiline attack is geographically heterogenous, with high Inquiline numbers restricted to south-east England. Because of the relatively high specificity of the parasitoids, high Inquiline abundance is positively correlated with parasitoid species richness in knopper galls. 4 Parasitism rates, particularly on the gall former, were generally low (
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Abundance patterns and species richness of the parasitoids and Inquilines of the alien gall-former Andricus quercuscalicis (Hymenoptera: Cynipidae)
Oikos, 1996Co-Authors: Karsten Schönrogge, Graham N Stone, Michael J. CrawleyAbstract:1) Four parasitoid species attack the gall-maker in the agamic galls of the invading cynipid Andricus quercuscalicis and further two parasitoid species attack Inquiline larvae developing in the parenchymatic wall of the gall. The abundance of the parasitoids and Inquilines are correlated with: 1) gall morphology; 2) the geographical location within Europe where the samples were collected; and 3) the abundance of other members of the species complex. 2) The invading gall wasp has been present for different periods of time at different sites, and this is likely to affect the geographic distribution of attack by parasitoid and Inquiline species. One of the parasitoid species was restricted to the native range in south-eastern Europe (Aulogymnus trilineatus), while another species (Cecidostiba hilaris), a parasitoid of the Inquilines, was present throughout continental Europe but is not yet recorded from the British Isles. Species richness of the parasitoid complex associated with the galls of A. quercuscalicis declined with increasing distance away from the native range. Within the native range, however, species richness was negatively correlated with the total number of cynipid species (alternative hosts for the parasitoid species) recorded at the same sample site. 3) The size of mature knopper galls declined westwards and northwards away from the native range of the gall wasp. Inquiline abundance was higher in larger galls, and so was the occurrence of one of the parasitoid species, Megastigmus stigmatizans. The occurrence of two other parasitoid species was negatively correlated with gall size while one species, Mesopolobus jucundus, was not affected by gall size. 4) Neither the abundance of Inquilines nor of parasitoids attacking the Inquilines show any significant geographical trend associated with the invasion history of the gall-maker. Attack rates by C. hilaris, the dominant parasitoid species in continental Europe, showed a slight positive density dependence to the number of Inquilines per gall, while those by M. jucundus, the dominant parasitoid of Inquiline in Britain, showed no such trend.
Og Desouza - One of the best experts on this subject based on the ideXlab platform.
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Unexpected termite Inquilines in nests of Constrictotermes cyphergaster (Silvestri, 1901) (Blattodea: Isoptera)
2019Co-Authors: Diogo Andrade Costa, Alessandra Marins, Og DesouzaAbstract:Abstract The heterospecific termite-termite cohabitation in a single termitarium, so called in-quilinism, is a common event whose basal mechanisms remain hypothetical. While some termite hosts have plenty of Inquilines, others house only a few. Among these, Constrictotermes cyphergaster are frequently found cohabiting with a single obligate Inquiline species but have been unknown to house any facultative Inquilines. Here we present the first record of facultative Inquilines (Embiratermes festivellus, Nasutitermes kemneri, Obitusitermes bacchanalis and Subulitermes) to this host, evidencing that this was unlikely to have happened fortuitously. In an attempt to pose hypotheses on the mechanisms behind such invasions, we explored likely connections between the settlement of obligate and facultative Inquilines and nest wall’s physical traits. We found that nests bearing atypical external walls (moist, eroded, and partially covered by mosses) held higher richness of facultative Inquilines than nests presenting walls void of such traits (χ2 = 8.3965, 1 df, n = 17, P = 0.0038). The presence of healthy host colonies in all nests, including the atypical ones, reinforces the hypothesis that the settlement of these facultative Inquilines depends less on host colonies biotic status and more on abiotic features associated to the nest. In addition, the presence of obligate Inquilines was not affected by the nest wall status (χ2 = 8.3965, 1 df, n = 17, P = 0.0038), implying that invasion by facultative and obligate Inquilines in these nests would obey distinct restrictions. While warning that these hypotheses require further testing, we suggest that their understanding could shed light on the determinants of cohabitation not only in C. cyphergaster but in termites in general. cohabitation interspecific interaction nest invasion barriers
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heterospecific detection of host alarm cues by an Inquiline termite species blattodea isoptera termitidae
Animal Behaviour, 2016Co-Authors: Ana Paula Albano Araújo, Paulo F Cristaldo, Vinicius B Rodrigues, Simon L Elliot, Og DesouzaAbstract:Termite Inquilines specialize on living in and feeding on a host termite nest. However, the mechanisms allowing survival of two mutually hostile populations confined to a single nest are not understood. Here we report on Inquiline termites that respond to their host's alarm cues. Upon detecting these cues, the Inquilines do not join in with the host's nest defence, but use this information for their own benefit, to escape danger. Using behavioural bioassays under laboratory conditions, we show that the obligatory Inquiline Inquilinitermes microcerus (Termitidae: Termitinae) responds both to its own alarm signal and to alarm cues from its host, Constrictotermes cyphergaster (Termitidae: Nasutitermitinae). Conversely, this host responded only to its own alarm signal. Despite perceiving their host's alarm cues, Inquilines were never observed sharing nest defence with their host in experimentally damaged nests in the field. We argue that this allows Inquilines not only to minimize encounters and hence conflict with their hosts, but also to use their host alarm information to escape the host's enemies, which are also likely to be enemies of the Inquilines. Our results show a new benefit that Inquilines gain from the host, and we discuss the Inquiline way-of-life from an evolutionary perspective, as the outcome of constraints and benefits imposed by living in host nests.
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Heterospecific detection of host alarm cues by an Inquiline termite species (Blattodea: Isoptera: Termitidae)
Animal Behaviour, 2016Co-Authors: Cristaldo, Paulo F., Rodrigues, Vinícius B., Elliot, Simon L., Araújo, Ana P. A., Og DesouzaAbstract:Artigo da EntomologiaTermite Inquilines specialize on living in and feeding on a host termite nest. However, the mechanisms allowing survival of two mutually hostile populations confined to a single nest are not understood. Here we report on Inquiline termites that respond to their host's alarm cues. Upon detecting these cues, the Inquilines do not join in with the host's nest defence, but use this information for their own benefit, to escape danger. Using behavioural bioassays under laboratory conditions, we show that the obligatory Inquiline Inquilinitermes microcerus (Termitidae: Termitinae) responds both to its own alarm signal and to alarm cues from its host, Constrictotermes cyphergaster (Termitidae: Nasutitermitinae). Conversely, this host responded only to its own alarm signal. Despite perceiving their host's alarm cues, Inquilines were never observed sharing nest defence with their host in experimentally damaged nests in the field. We argue that this allows Inquilines not only to minimize encounters and hence conflict with their hosts, but also to use their host alarm information to escape the host's enemies, which are also likely to be enemies of the Inquilines. Our results show a new benefit that Inquilines gain from the host, and we discuss the Inquiline way-of-life from an evolutionary perspective, as the outcome of constraints and benefits imposed by living in host nests
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Allometric Scaling of Patrolling Rate and Nest Volume in Constrictotermes cyphergaster Termites: Hints on the Settlement of Inquilines.
PloS one, 2016Co-Authors: Og Desouza, Ana Paula Albano Araújo, Vinicius B Rodrigues, Daniela Faria Florencio, Cassiano Sousa Rosa, Alessandra Marins, Diogo Andrade Costa, Paulo F CristaldoAbstract:Structural and functional traits of organisms are known to be related to the size of individuals and to the size of their colonies when they belong to one. Among such traits, propensity to inquilinism in termites is known to relate positively to colony size. Larger termitaria hold larger diversity of facultative Inquilines than smaller nests, whereas obligate Inquilines seem unable to settle in nests smaller than a threshold volume. Respective underlying mechanisms, however, remain hypothetical. Here we test one of such hypotheses, namely, that nest defence correlates negatively to nest volume in Constrictotermes cyphergaster termites (Termitidae: Nasutitermitinae). As a surrogate to defence, we used ‘patrolling rate’, i.e., the number of termite individuals attending per unit time an experimentally damaged spot on the outer wall of their termitaria. We found that patrolling rate decayed allometrically with increasing nest size. Conspicuously higher patrolling rates occurred in smaller nests, while conspicuously lower rates occurred in larger nests presenting volumes in the vicinity of the threshold value for the establishment of inquilinism. This could be proven adaptive for the host and guest. At younger nest age, host colonies are smaller and presumably more vulnerable and unstable. Enhanced defence rates may, hence, prevent eventual risks to hosts from inquilinism at the same time that it prevents Inquilines to settle in a still unstable nest. Conversely, when colonies grow and maturate enough to stand threats, they would invest in priorities other than active defence, opening an opportunity for Inquilines to settle in nests which are more suitable or less risky. Under this two-fold process, cohabitation between host and Inquiline could readily stabilize.
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Diet Segregation between Cohabiting Builder and Inquiline Termite Species
2016Co-Authors: Daniela Faria Florencio, Paulo Fellipe Cristaldo, Ra Marins, Cassiano Sousa Rosa, Paula Albano Araújo, Ivo Ribeiro Silva, Og DesouzaAbstract:How do termite Inquilines manage to cohabit termitaria along with the termite builder species? With this in mind, we analysed one of the several strategies that Inquilines could use to circumvent conflicts with their hosts, namely, the use of distinct diets. We inspected overlapping patterns for the diets of several cohabiting Neotropical termite species, as inferred from carbon and nitrogen isotopic signatures for termite individuals. Cohabitant communities from distinct termitaria presented overlapping diet spaces, indicating that they exploited similar diets at the regional scale. When such communities were split into their components, full diet segregation could be observed between builders and Inquilines, at regional (environment-wide) and local (termitarium) scales. Additionally, diet segregation among Inquilines themselves was also observed in the vast majority of inspected termitaria. Inquiline species distribution among termitaria was not random. Environmental-wide diet similarity, coupled with local diet segregation and deterministic Inquiline distribution, could denounce interactions for feeding resources. However, Inquilines and builders not sharing the same termitarium, and thus not subject to potential conflicts, still exhibited distinct diets. Moreover, the areas of the builder’s diet space and that of its Inquilines did not correlate negatively. Accordingly, the diet areas of builders which hosted Inquilines were in average a
Douglass R. Miller - One of the best experts on this subject based on the ideXlab platform.
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First incidence of inquilinism in gall‐forming psyllids, with a description of the new Inquiline species (Insecta, Hemiptera, Psylloidea, Psyllidae, Spondyliaspidinae)
Zoologica Scripta, 2001Co-Authors: Man-miao Yang, Charles Mitter, Douglass R. MillerAbstract:The two largest lineages of holometabolous gall-forming insects, cynipid wasps and cecidomyiid flies, have given rise to numerous obligate Inquilines, species which are unable to form galls themselves and survive by inhabiting galls formed by other species. In contrast, only a single obligate Inquiline, an aphid, is known in the sternorrhynchous Hemiptera, the hemimetabolan lineage in which gall-forming is best developed. We describe the first known gall Inquiline in psyllids (Sternorrhyncha, Psylloidea), Pachypsylla cohabitans Yang & Riemann sp. n. All other members of this genus produce closed galls on hackberries, Celtis spp. (Ulmaceae). Newly hatched nymphs of P. cohabitans feed next to nymphs of several species of leaf gall-makers, becoming incorporated into the gall as the stationary nymphs are gradually enveloped by leaf tissue. In the mature gall, the Inquilines occupy separate, lateral cells surrounding a central cell containing a single gall-maker. Pachypsylla cohabitans is similar in morphology to leaf-gallers, but differs in nymphal and adult colour, allozyme frequency, especially in the malic enzyme, and in adult phenology. Laboratory-reared progeny of side-cell females, when caged alone, never form galls, while progeny of centre-cell individuals alone only form galls comprising single individuals. Multiple-cell galls are formed only when adults of side-cell and centre-cell individuals are caged together. Experimental removal of centre-cell nymphs in early stages of gall initiation leads to smaller galls or death of side-cell individuals. We conclude that the side-cell individual is an obligate Inquiline that is incapable of forming a gall on its own but is derived from a leaf-galling ancestor. We speculate on selective forces that might favour this evolutionary transition.
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first incidence of inquilinism in gall forming psyllids with a description of the new Inquiline species insecta hemiptera psylloidea psyllidae spondyliaspidinae
Zoologica Scripta, 2001Co-Authors: Man-miao Yang, Charles Mitter, Douglass R. MillerAbstract:The two largest lineages of holometabolous gall-forming insects, cynipid wasps and cecidomyiid flies, have given rise to numerous obligate Inquilines, species which are unable to form galls themselves and survive by inhabiting galls formed by other species. In contrast, only a single obligate Inquiline, an aphid, is known in the sternorrhynchous Hemiptera, the hemimetabolan lineage in which gall-forming is best developed. We describe the first known gall Inquiline in psyllids (Sternorrhyncha, Psylloidea), Pachypsylla cohabitans Yang & Riemann sp. n. All other members of this genus produce closed galls on hackberries, Celtis spp. (Ulmaceae). Newly hatched nymphs of P. cohabitans feed next to nymphs of several species of leaf gall-makers, becoming incorporated into the gall as the stationary nymphs are gradually enveloped by leaf tissue. In the mature gall, the Inquilines occupy separate, lateral cells surrounding a central cell containing a single gall-maker. Pachypsylla cohabitans is similar in morphology to leaf-gallers, but differs in nymphal and adult colour, allozyme frequency, especially in the malic enzyme, and in adult phenology. Laboratory-reared progeny of side-cell females, when caged alone, never form galls, while progeny of centre-cell individuals alone only form galls comprising single individuals. Multiple-cell galls are formed only when adults of side-cell and centre-cell individuals are caged together. Experimental removal of centre-cell nymphs in early stages of gall initiation leads to smaller galls or death of side-cell individuals. We conclude that the side-cell individual is an obligate Inquiline that is incapable of forming a gall on its own but is derived from a leaf-galling ancestor. We speculate on selective forces that might favour this evolutionary transition.