Further records of social parasitic ants in Europe and review of the Bulgarian species.

Background: Social parasitic ants exploit the colonies of other ant species, either permanently or temporarily. The permanent parasites are amongst the rarest species of ants, although their hosts may be very common. Due to their rarity and often restricted distribution range, most of them are listed as vulnerable. Filling in the gaps in geographical and host ranges will advance our understanding of the social parasitic lifestyle's origin and evolution. New information: This study reports the first records of the slave-makers Myrmoxenusalgerianus (Cagniant, 1968) for Europe (Italy, Sicily) and M.ravouxi (André 1896) for Albania and the inquiline Anergatesatratulus (Schenck, 1852) for Malta (Gozo). We also report new localities of Camponotusuniversitatis Forel, 1890 for Albania and Myrmoxenusgordiagini Ruzsky, 1902, M.kraussei (Emery, 1915) and Anergatesatratulus for Bulgaria. Diversity, type of parasite-host relationships, host range, distribution and conservation of social parasitic ant species in Bulgaria are discussed. Although social parasitic ants are still understudied in Bulgaria, they represent 21% of the regional ant fauna.

Discovery of a new species of Synergus (Hymenoptera, Cynipidae, Synergini) based on morphology and molecular data.

A new species of gall inquiline, Synergusdilatatussp. nov., is described from Hubei Province, China. Morphological descriptions, photographs and biological information are provided. Mitochondrial cytochrome oxidase (COI) sequences of the new species were newly obtained and a molecular species delimitation analysis of 12 species of Synergus performed using the ASAP method recovered 16 molecular operational taxonomic units, providing support for recognition of the new species. The results also highlight a few conflicts between morphological and molecular species delimitations in Synergus.

Kleptoparasites of social spider colonies do not track hosts' subdivided population structure.

Organisms with lower dispersal abilities tend to have more genetically dissimilar populations. The same is true for parasites, whose transmission frequency may depend on the population structure of the host. This should be especially true when hosts and parasites face similar barriers to dispersal. Here, we considered the similarities between host and parasite population structure in a social spider system. In this system, host colonies are typified by rapid growth via internal recruitment followed by budding or fission events when colonies grow too large, with each colony representing a distinct population. Host colonies provide habitat for kleptoparasitic spiders, which steal prey from and may also feed directly on host individuals. We asked whether kleptoparasites exhibit a similar degree of population subdivision as their host. Under the free-mixing hypothesis (i.e., horizontal transmission), kleptoparasites would have well-mixed populations across broader regions than a single host nest, whereas host populations would be strongly genetically structured. Under the host-tracking hypothesis (i.e., vertical transmission), kleptoparasites would have a population structure that parallels that of the host. We conducted a genotype-by-sequencing study to assess the population structure of both hosts and kleptoparasites within three nearby regions in eastern Ecuador. We found strong signatures of population differentiation and bottlenecks in the host species, which is congruent with past studies. However, we found that kleptoparasite populations were well mixed across host nests, with no evidence of recent bottlenecks. These results support our free-mixing hypothesis, suggesting that kleptoparasites follow patterns of horizontal transmission in this social spider system.

Seven Sycoryctine Fig Wasp Species (Chalcidoidea: Pteromalidae) Associated with Dioecious Ficus hirta Inhabiting South China and Southeast Asia.

Even though non-pollinating fig wasps are essential components in tropical and subtropical habitats, yet they are poorly described in the Oriental communities. This study presented seven new sycoryctine fig wasp species associated with Ficus hirta fig trees inhabiting South China and Southeast Asia. These new sycoryctine species belong to the genera Philotrypesis, Sycoryctes, and Sycoscapter. They can be easily distinguished by their adaptive morphologies such as face sculpture, body-color, and ovipositors. An identification key is provided to differentiate between them, and the relationships with their host fig trees are also discussed. The holotypes and paratypes are both deposited in the South China Botanical Garden, Chinese Academy of Sciences, China.

Subtle structures with not-so-subtle functions: A data set of arthropod constructs and their host plants.

The construction of shelters on plants by arthropods might influence other organisms via changes in colonization, community richness, species composition, and functionality. Arthropods, including beetles, caterpillars, sawflies, spiders, and wasps often interact with host plants via the construction of shelters, building a variety of structures such as leaf ties, tents, rolls, and bags; leaf and stem galls, and hollowed out stems. Such constructs might have both an adaptive value in terms of protection (i.e., serve as shelters) but may also exert a strong influence on terrestrial community diversity in the engineered and neighboring hosts via colonization by secondary occupants. Although different traits of the host plant (e.g., physical, chemical, and architectural features) may affect the potential for ecosystem engineering by insects, such effects have been, to a certain degree, overlooked. Further analyses of how plant traits affect the occurrence of shelters may therefore enrich our understanding of the organizing principles of plant-based communities. This data set includes more than 1000 unique records of ecosystem engineering by arthropods, in the form of structures built on plants. All records have been published in the literature, and span both natural structures (91% of the records) and structures artificially created by researchers (9% of the records). The data were gathered between 1932 and 2021, across more than 50 countries and several ecosystems, ranging from polar to tropical zones. In addition to data on host plants and engineers, we aggregated data on the type of constructs and the identity of inquilines using these structures. This data set highlights the importance of these subtle structures for the organization of terrestrial arthropod communities, enabling hypotheses testing in ecological studies addressing ecosystem engineering and facilitation mediated by constructs. There are no copyright restrictions and please cite this paper when using the data in publications.

The Role of Monk Parakeets as Nest-Site Facilitators in Their Native and Invaded Areas.

While most of the knowledge on invasive species focuses on their impacts, little is known about their potential positive effects on other species. Invasive ecosystem engineers can disrupt recipient environments; however, they may also facilitate access to novel resources for native species. The monk parakeet (Myiopsitta monachus) is a worldwide invader and the only parrot that builds its own communal nests, which can be used by other species. However, the ecological effects of these interspecific interactions are barely known. We compared the role of the monk parakeet as a nest-site facilitator in different rural and urban areas, both invaded and native, across three continents and eight breeding seasons. A total of 2690 nests from 42 tenant species, mostly cavity-nesting birds, were recorded in 26% of 2595 monk parakeet nests. Rural and invaded areas showed the highest abundance and richness of tenant species. Multispecies communal nests triggered interspecific aggression between the monk parakeet host and its tenants, but also a cooperative defense against predators. Despite the positive effects for native species, monk parakeets also facilitate nesting opportunities to other non-native species and may also transmit diseases to tenants, highlighting the complexity of biotic interactions in biological invasions.

The genus Synergus Hartig (Hymenoptera: Cynipidae: Synergini) in the New World: a complete taxonomic revision with a key to species.

A complete revision of the genus Synergus Hartig (Hymenoptera: Cynipidae: Synergini) in the New World (Nearctic and Neotropical regions) is conducted for the first time in order to stabilize its taxonomy. A total of 11 new species are described from Mexico: S. ashmeadi Lobato-Vila Pujade-Villar, sp. nov.; S. beutenmulleri Lobato-Vila Pujade-Villar, sp. nov.; S. compressus Lobato-Vila Pujade-Villar, sp. nov.; S. diversicolor Lobato-Vila Pujade-Villar, sp. nov.; S. ebenus Lobato-Vila Pujade-Villar, sp. nov.; S. linnei Lobato-Vila Pujade-Villar, sp. nov.; S. macrackenae Lobato-Vila Pujade-Villar, sp. nov.; S. oaxaquensis Lobato-Vila Pujade-Villar, sp. nov.; S. personatus Lobato-Vila Pujade-Villar, sp. nov.; S. ruficephalus Lobato-Vila Pujade-Villar, sp. nov.; and S. weldi Lobato-Vila Pujade-Villar, sp. nov. Synergus splendidus Fullaway, 1911 is proposed as a syn. nov. of S. dorsalis (Provacher, 1889); S. garryana Gillette, 1893 and S. oneratus coloradensis Gillette, 1896 as syn. nov. of S. oneratus (Harris, 1841); and S. magnificus Weld, 1957 as a syn. nov. of S. reniformis McCracken Egbert, 1922. Redescriptions and illustrations are provided for poorly characterized species. A key to species and a summary table including all valid Synergus from the New World, their biology and distribution, are given. Distribution, morphology, and trophic associations are discussed and compared between New World and Palaearctic species.

Insect galls of the Brazilian Cerrado: associated fauna / Galhas de insetos do Cerrado Brasileiro: fauna associada

Abstract: Insect galls host a rich and diverse fauna of secondary dwellers, which compose the associated fauna. In Brazil, many inventories of insect galls in Cerrado areas have recorded secondary dwellers. These records were scattered in several papers. This study gathered literature data to provide an overview of the arthropod fauna associated with insect galls in the Brazilian Cerrado. We searched for scientific publications in online academic databases and retrieved 16 papers with data on the secondary dwellers. We limited our search to the period from 1988 to 2020. We updated the name of plant species and verified endemism and geographic distribution in Flora do Brasil 2020. We provided plant species uses based on the Tropical Useful Plants 2014. We found 163 gall morphotypes with secondary dwellers (16.8% of the total of gall morphotypes of the Brazilian Cerrado) on 94 plant species in 37 families. Asteraceae, Fabaceae, Myrtaceae, and Malpighiaceae exhibited the greatest number of records. These are the richest families in insect galls in the Brazilian Cerrado. Most arthropod fauna were recorded in galls of Cecidomyiidae (Diptera). Most records were in leaf galls, the predominant galled organ. Parasitoids were more frequent than successors, inquilines, and predators. Eulophidae and Eurytomidae were the most frequent parasitoid families. Inquilines were represented by Coleoptera, Diplopoda, Diptera, Hemiptera, Hymenoptera, Lepidoptera, Psocoptera, and Thysanoptera; successors by Acari, Araneae, Cecidomyiidae (Diptera), Coleoptera, Collembola, and Formicidae (Hymenoptera), whereas predators by Pseudoscorpiones and Diptera. Most records were presented in suprageneric categories, showing that the taxonomic knowledge is very deficient. 29 plant species are endemic to Brazil and totaled 45 gall morphotypes with secondary dwellers; 46 plant species are useful and host secondary dwellers in 62 gall morphotypes. These data add ecological and economic importance to these arthropods.

Resumo: As galhas de insetos abrigam uma fauna rica e diversificada de habitantes secundários que compõem a fauna associada. No Brasil, muitos inventários de galhas de insetos em áreas de Cerrado registram habitantes secundários. Estes registros, dispersos em vários artigos, foram reunidos para fornecer uma visão ampla da fauna de artrópodes associados às galhas de insetos no Cerrado brasileiro. Buscamos publicações científicas nas bases de dados acadêmicas virtuais e encontramos 16 artigos com informações de habitantes secundários. Limitamos nossa busca ao período de 1988 a 2020. Atualizamos o nome das espécies botânicas e verificamos sua distribuição geográfica e endemismos no site Flora do Brasil 2020. Fornecemos os usos das espécies vegetais com base no site Tropical Useful Plants 2014. Encontramos 163 morfotipos de galhas com habitantes secundários (16,8% do total de morfotipos de galhas do Cerrado brasileiro) em 94 espécies de plantas de 37 famílias. Asteraceae, Fabaceae, Myrtaceae e Malpighiaceae exibiram o maior número de registros. Estas são as famílias mais ricas em galhas de insetos no Cerrado brasileiro. A maioria da fauna de artrópodes foi assinalada em galhas de Cecidomyiidae (Diptera). A maioria dos registros foi em galhas foliares, órgão vegetal com maior riqueza de galhas. Os parasitoides foram mais frequentes que os sucessores, inquilinos e predadores. Eulophidae e Eurytomidae foram as famílias de parasitoides mais frequentes. Os inquilinos foram representados por Coleoptera, Diplopoda, Diptera, Hemiptera, Hymenoptera, Lepidoptera, Psocoptera, e Thysanoptera; os sucessores por Acari, Araneae, Cecidomyiidae (Diptera), Coleoptera, Collembola e Formicidae (Hymenoptera); enquanto os predadores por Pseudoscorpiones e Diptera. A maioria dos registros foi apresentada em categorias supragenéricas, mostrando que o conhecimento taxonômico é muito deficiente. Vinte e nove plantas são endêmicas do Brasil e totalizam 45 morfotipos de galhas com habitantes secundários; 46 espécies vegetais são úteis e hospedam habitantes secundários em 62 morfotipos de galhas. Estas informações acrescentam importância ecológica e econômica a estes artrópodes.

Synergus Hartig species group (Hymenoptera: Cynipidae: Synergini) with partially smooth mesopleurae from the New World.

Inquiline oak gall wasps from the genus Synergus Hartig (Hymenoptera: Cynipidae: Synergini) that occur in the New World should be classified into the following morphological groups: i) species with the radial cell of fore wings open; ii) species with the radial cell of fore wings closed and mesopleurae completely sculptured, always with transversal striae covering its surface; iii) species with the radial cell of fore wings closed and mesopleurae partially smooth, with the speculum always shiny and not sculptured. The latter group, which appears to be unique to the New World's fauna, is the focus of this study. An exhaustive taxonomical revision of all the Synergus species within this morphological group is carried out for the first time after the initial treatment by Lobato-Vila Pujade-Villar (2017). Redescriptions, images and new distribution and biological data are provided. A new species from Mexico, Synergus aurofacies Lobato-Vila Pujade-Villar, sp. nov., is here formally described and illustrated. Synergus variegatus McCracken Egbert, 1922 is a junior synonym of S. flavens McCracken Egbert, 1922 syn. nov.; S. profusus McCracken Egbert, 1922 is a junior synonym of S. pacificus McCracken Egbert, 1922 syn. nov.; and S. flavus Kieffer, 1904 and S. varicolor Fullaway, 1911 are junior synonyms of S. pomiformis (Ashmead, 1885) syn. nov. A key to species of this group is provided. The morphological traits of the species with partially smooth mesopleurae are discussed.

Revision of world Ceroptresini (Hymenoptera: Cynipidae) with the description of a new genus and five new species.

A taxonomic revision of the tribe Ceroptresini (Hymenoptera: Cynipidae) is conducted for the first time. Prior to this study, the total number of valid species of Ceroptres, the only genus within Ceroptresini to date, was 23. As a result of this revision, 15 Ceroptres species are retained as valid and one species, Amblynotus ensiger Walsh, 1864, is desynonymized from Ceroptres petiolicola (Osten-Sacken, 1861), being considered here as a valid Ceroptres species: C. ensiger (Walsh, 1864) status verified and comb. nov. An additional five new species are described from Mexico: Ceroptres junquerasi Lobato-Vila Pujade-Villar sp. nov.; C. lenis Lobato-Vila Pujade-Villar sp. nov.; C. mexicanus Lobato-Vila Pujade-Villar sp. nov.; C. nigricrus Lobato-Vila Pujade-Villar sp. nov.; C. quadratifacies Lobato-Vila Pujade-Villar sp. nov., increasing the total number of valid Ceroptres species to 21. Ceroptres masudai Abe, 1997 is synonymized with C. kovalevi Belizin, 1973. Ceroptres niger Fullaway, 1911 is transferred to Andricus (Andricus confusus Lobato-Vila Pujade-Villar comb. nov. and nom. nov.). Five species (Amblynotus inermis Walsh, 1864; Cynips quercusarbos Fitch, 1859; Cynips querficus Fitch, 1859; Cynips quercuspisum Fitch, 1859; and Cynips quercustuber Fitch, 1859) are not considered as valid Ceroptres. The status of Ceroptres quereicola (Shinji, 1938), previously classified as an unplaced species, is commented on. In addition, a Nearctic species from the USA, Ceroptres politus Ashmead, 1896, is here proposed as the type species of a new genus within Ceroptresini: Buffingtonella Lobato-Vila Pujade-Villar gen. nov. Redescriptions, biological and distribution data, illustrations and keys to genera and species within Ceroptresini are provided. The diagnostic morphological traits of Ceroptresini, Ceroptres and the new genus are discussed.

Description of a new Synergus species from China and comments on other inquiline species (Hymenoptera: Cynipidae: Synergini).

A new species, Synergus mongolicus Pujade-Villar & Wang n. sp., is described from galls collected on twigs of Quercus mongolica. The morphological characters useful for differentiating the new species are also discussed. Three inquilines species are recorded from China for the first time: Saphonecrus shirakashii, Synergus belizinellus and S. symbioticus. Saphonecrus tianmushanus is considered a n. syn. of S. shirakashii based on comparison of the types. Saphonecrus taiwanensis Pujade-Villar new name is proposed for Saphonecrus lithocarpii Schwéger & Melika, 2015 by homonymy with S. lithocarpi Pujade-Villar, Guo, Wang & Chen, 2015 and finally Saphonecrus chinensis Tang & Schwéger, 2015 is considered a n. syn. of S. lithocarpi Pujade-Villar, Guo, Wang & Chen, 2015.

Arthropods Associate with their Red Wood ant Host without Matching Nestmate Recognition Cues.

Social insect colonies provide a valuable resource that attracts and offers shelter to a large community of arthropods. Previous research has suggested that many specialist parasites of social insects chemically mimic their host in order to evade aggression. In the present study, we carry out a systematic study to test how common such chemical deception is across a group of 22 arthropods that are associated with red wood ants (Formica rufa group). In contrast to the examples of chemical mimicry documented in some highly specialized parasites in previous studies, we find that most of the rather unspecialized red wood ant associates surveyed did not use mimicry of the cuticular hydrocarbon recognition cues to evade host detection. Instead, we found that myrmecophiles with lower cuticular hydrocarbon concentrations provoked less host aggression. Therefore, some myrmecophiles with low hydrocarbon concentrations appear to evade host detection via a strategy known as chemical insignificance. Others showed no chemical disguise at all and, instead, relied on behavioral adaptations such as particular defense or evasion tactics, in order to evade host aggression. Overall, this study indicates that unspecialized myrmecophiles do not require the matching of host recognition cues and advanced strategies of chemical mimicry, but can integrate in a hostile ant nest via either chemical insignificance or specific behavioral adaptations.

Disturbance-modulated symbioses in termitophily.

Symbiosis, the living-together of unlike organisms, underlies every major transition in evolution and pervades most ecological dynamics. Among examples of symbioses, the simultaneous occupation of a termite nest by its builder termites and intruding invertebrate species (so-called termitophily) provides suitable macroscopic scenarios for the study of species coexistence in confined environments. Current evidence on termitophily abounds for dynamics occurring at the interindividual level within the termitarium, but is insufficient for broader scales such as the community and the landscape. Here, we inspect the effects of abiotic disturbance on termitophile presence and function in termitaria at these broader scales. To do so, we censused the termitophile communities inhabiting 30 termitaria of distinct volumes which had been exposed to increasing degrees of fire-induced disturbance in a savanna-like ecosystem in southeastern Brazil. We provide evidence that such an abiotic disturbance can ease the living-together of termitophiles and termites. Putative processes facilitating these symbioses, however, varied according to the invader. For nonsocial invaders, disturbance seemed to boost coexistence with termites via the habitat amelioration that termitaria provided under wildfire, as suggested by the positive correlation between disturbance degree and termitophile abundance and richness. As for social invaders (ants), disturbance seemed to enhance associational defenses with termites, as suggested by the negative correlation between the presence of ant colonies and the richness and abundance of other termitarium-cohabiting termitophiles. It is then apparent that disturbance-modulated distinct symbioses in these termite nests.

Four-trophic level food webs reveal the cascading impacts of an invasive plant targeted for biocontrol.

Biological invasions are a major threat to biodiversity and as such understanding their impacts is a research priority. Ecological networks provide a valuable tool to explore such impacts at the community level, and can be particularly insightful for planning and monitoring biocontrol programmes, including the potential for their seldom evaluated indirect non-target effects. Acacia longifolia is among the worst invasive species in Portugal, and has been recently targeted for biocontrol by a highly specific gall-wasp. Here we use an ambitious replicated network approach to: (1) identify the mechanisms by which direct and indirect impacts of A. longifolia can cascade from plants to higher trophic levels, including gallers, their parasitoids and inquilines; (2) reveal the structure of the interaction networks between plants, gallers, parasitoids and inquilines before the biocontrol; and (3) explore the potential for indirect interactions among gallers, including those established with the biocontrol agent, via apparent competition. Over a 15-month period, we collected 31,737 galls from native plants and identified all emerging insects, quantifying the interactions between 219 plant-, 49 galler-, 65 parasitoid- and 87 inquiline-species-one of the largest ecological networks to date. No galls were found on any of the 16 alien plant species. Invasion by A. longifolia caused an alarming simplification of plant communities, with cascading effects to higher trophic levels, namely: a decline of overall gall biomass, and on the richness, abundance and biomass of galler insects, their parasitoids, and inquilines. Correspondingly, we detected a significant decline in the richness of interactions between plants and galls. The invasion tended to increase overall interaction evenness by promoting the local extinction of the native plants that sustained more gall species. However, highly idiosyncratic responses hindered the detection of further consistent changes in network topology. Predictions of indirect effects of the biocontrol on native gallers via apparent competition ranged from negligible to highly significant. Such scenarios are incredibly hard to predict, but even if there are risks of indirect effects it is critical to weigh them carefully against the consequences of inaction and invasive species spread.

Arthropods associated with fungal galls: do large galls support more abundant and diverse inhabitants?

Fungus-induced galls can attract spore-feeding arthropods as well as gall-feeding ones, resulting in diverse communities. Do large fungal galls support more abundant and diverse arthropod communities than small fungal galls? To address this question, we investigated the structure of the arthropod community associated with bud galls induced by the fungus Melanopsichium onumae on the tree species Cinnamomum yabunikkei (Lauraceae) in central Japan. Thirteen species of arthropods were associated with M. onumae galls. Dominant arthropod species were represented by the larvae of a salpingid beetle (a spore feeder), a nitidulid beetle (a spore feeder), a cosmopterigid moth (a spore feeder), an unidentified moth (a gall tissue feeder), and a drosophilid species (a gall tissue feeder). Arthropod abundance and species richness were positively correlated with gall diameter. The majority of the most abundant species were more frequently found in large galls than in small ones, indicating that large fungal galls, which have more food and/or space for arthropods, could support a more abundant and diverse arthropod community.

Top-down network analysis characterizes hidden termite-termite interactions.

The analysis of ecological networks is generally bottom-up, where networks are established by observing interactions between individuals. Emergent network properties have been indicated to reflect the dominant mode of interactions in communities that might be mutualistic (e.g., pollination) or antagonistic (e.g., host-parasitoid communities). Many ecological communities, however, comprise species interactions that are difficult to observe directly. Here, we propose that a comparison of the emergent properties from detail-rich reference communities with known modes of interaction can inform our understanding of detail-sparse focal communities. With this top-down approach, we consider patterns of coexistence between termite species that live as guests in mounds built by other host termite species as a case in point. Termite societies are extremely sensitive to perturbations, which precludes determining the nature of their interactions through direct observations. We perform a literature review to construct two networks representing termite mound cohabitation in a Brazilian savanna and in the tropical forest of Cameroon. We contrast the properties of these cohabitation networks with a total of 197 geographically diverse mutualistic plant-pollinator and antagonistic host-parasitoid networks. We analyze network properties for the networks, perform a principal components analysis (PCA), and compute the Mahalanobis distance of the termite networks to the cloud of mutualistic and antagonistic networks to assess the extent to which the termite networks overlap with the properties of the reference networks. Both termite networks overlap more closely with the mutualistic plant-pollinator communities than the antagonistic host-parasitoid communities, although the Brazilian community overlap with mutualistic communities is stronger. The analysis raises the hypothesis that termite-termite cohabitation networks may be overall mutualistic. More broadly, this work provides support for the argument that cryptic communities may be analyzed via comparison to well-characterized communities.