ABSTRACT
This is the first study providing long-term data on the dynamics of bees and wasps and their parasitoids for the evidence-based management of reed beds. Ten years ago, we identified Lipara (Chloropidae) - induced galls on common reed (Phragmites australis, Poaceae) as a critically important resource for specialized bees and wasps (Hymenoptera: Aculeata). We found that they were surprisingly common in relatively newly formed anthropogenic habitats, which elicited questions about the dynamics of bees and wasps and their parasitoids in newly formed reed beds of anthropogenic origin. Therefore, in the winter and spring of 2022/23, we sampled reed galls from the same set of reed beds of anthropogenic and natural origin as those in 2012/13. At 10 sites, the number of sampled galls was similar in both time periods (80-122% of the value from 2012/13); 12 sites experienced a moderate decline (30-79% of the value from 2012/13), and the number of galls at six sampling sites was only 3-23% of their abundance in 2012/13. Spontaneous development was associated with increasing populations. After 10 years of spontaneous development, the populations of bees and wasps (including their parasitoids) bound to Lipara-induced reed galls increased in abundance and species richness or remained at their previous levels, which was dependent on the sampling site. The only identified threat consisted of reclamation efforts. The effects of habitat age were limited, and the assemblages in habitats of near-natural and anthropogenic origin largely overlapped. However, several species were consistently present at lower abundances in the anthropogenic habitats and vice versa. In conclusion, we provided evidence-based support for the establishment of oligotrophic reed beds of anthropogenic origin as management tools providing sustainable habitats for specialized reed gall-associated aculeate hymenopteran inquilines, including the threatened species.
Subject(s)
Ecosystem , Wasps , Animals , Wasps/physiology , Hymenoptera/physiology , Poaceae , Bees/parasitology , Plant Tumors/parasitologyABSTRACT
The study presents DNA barcoding results of five families of Hymenoptera in Germany. DNA barcodes are provided for 24 of the 25 species of Gasteruption occurring in Central Europe, including 18 of the 19 species recorded from Germany. The genetic diversity was higher than expected, with five species exhibiting two or more Barcode Index Number (BINs), whereas BIN sharing occurred in four species. Gasteruptionfoveiceps Semenov, 1892, stat. nov. is removed from synonymy with G.nigrescens Schletterer, 1885 and treated as a distinct species.
ABSTRACT
At a time when nature conservation has become essential to ensure the long-term sustainability of our environment, it is widely acknowledged that conservation actions must be implemented within a solid taxonomic framework. In preparation for the upcoming update of the IUCN Red List, we here update the European checklist of the wild bees (sensu the IUCN geographical framework). The original checklist, published in 2014, was revised for the first time in 2017. In the present revision, we add one genus, four subgenera and 67 species recently described, 40 species newly recorded since the latest revision (including two species that are not native to Europe), 26 species overlooked in the previous European checklists and 63 published synonymies. We provide original records for eight species previously unknown to the continent and, as original taxonomic acts, we provide three new synonyms, we consider two names as nomina nuda, ten names as nomina dubia, three as species inquirenda, synonymize three species and exclude 40 species from the previous checklist. Around a hundred other taxonomic changes and clarifications are also included and discussed. The present work revises the total number of genera for IUCN Europe to 77 and the total number of species to 2,138. In addition to specifying the taxonomic changes necessary to update the forthcoming Red List of European bees, we discuss the sampling and taxonomic biases that characterise research on the European bee fauna and highlight the growing importance of range expansions and species invasions.
Subject(s)
Ctenophora , Hymenoptera , Bees , Animals , EuropeABSTRACT
Azole fungicides have been essential pillars of global food security since the commercialization of triadimefon. However, the potential for fungicides to induce sublethal effects on larval development and emergence from overwintering is underresearched. We hypothesized that contact exposure to field-realistic concentrations of a broad spectrum of triazole fungicides alters the pupation and metamorphosis of crabronid wasps. Therefore, triazole fungicides shape the hymenopteran communities in agrocenoses. We applied field-realistic concentrations of three triazole fungicides, difenoconazole, penconazole, and tebuconazole, to the defecated prepupae of Pemphredon fabricii (Hymenoptera: Crabronidae). We monitored their survival, pupation, and metamorphosis into adults, including the timing of these events. All three tested triazole fungicides altered the time to the metamorphosis into adults of P. fabricii prepupae compared to the vehicle-treated controls. This effect was concentration-independent within the recommended concentration ranges for foliar applications. However, the three triazole fungicides were not associated with any significant declines in overall survival. Thus, the commonly used triazole fungicides affect the synchronization of the metamorphosis into adults with the availability of food and nesting resources of the study species. The study compounds did not affect the survival, which agrees with previous studies of other azole fungicides, which revealed effects on survival only when used in combination with other compounds. Further research should address the multiplicative effects of the triazole fungicides with other agrochemicals on the timing of the metamorphosis of bees and wasps.
Subject(s)
Fungicides, Industrial , Hymenoptera , Wasps , Animals , Azoles/pharmacology , Bees , Fungicides, Industrial/chemistry , Metamorphosis, Biological , Triazoles/chemistry , Triazoles/toxicityABSTRACT
Anthropogenic habitats that are contaminated by toxic elements were recently shown to host abundant and diverse assemblages of bees and wasps (Hymenoptera: Aculeata), including numerous threatened species. However, toxic elements adversely affect insect fitness. We address the effects of toxic elements on aculeate inquilines that occupy Lipara lucens-induced galls on the common reed, Phragmites australis. We hypothesized that contamination of potential nesting and feeding habitats is associated with adverse changes in bee and wasp populations that are attracted in these environments. To address this hypothesis, we analyzed the contents of As, Cd, Cu, Pb, Zn, Fe, and S in site-matched samples of soil, reed galls, and crabronid wasp bodies and correlated them with abundance and species richness of aculeate hymenopterans in reed galls and with the number of larvae in nests of the eudominant hymenopteran, Pemphredon fabricii. The common reed was present at all the examined sites, and L. lucens-induced galls were present at all but one sampling site; the single exception was the sampling site with the highest contents of four of the seven analyzed elements. The alpha diversity of gall-associated aculeate inquilines, abundance of P. fabricii, and number of prepupae per nest of P. fabricii were not correlated with the contents of any of the seven analyzed toxic elements. We found P. fabricii to be abundantly present in habitats with extreme concentrations of toxic elements. Exposed P. fabricii accumulated Cd, Cu, and Pb, while they eliminated Fe and Zn. The obtained data did not support the hypothesis that heavy metal contamination of anthropogenic sites affects P. fabricii and other reed gall-associated aculeates.
Subject(s)
Diptera , Wasps , Animals , Bees , Ecosystem , Insecta , LarvaABSTRACT
Human-induced climate and land-use changes are important factors influencing global insect diversity. Nevertheless, the influence of weather on biodiversity is still relatively rarely studied. Grassland insects may be the taxon that is most affected by changing weather. We focused on the influence of weather and land-use management on butterflies in hayed meadows in the Czech Republic. During two consecutive years (2019-2020), we studied nearly 300 independent meadows. The abundance of butterflies was more influenced by the weather than their species richness. We observed positive and mainly linear effects of increasing vegetation temperatures. One very influential variable was the light intensity, which had a nonlinear effect that promoted butterflies under direct sunlight. The humidity had mainly moderate, nonlinear effects. Surprisingly, the wind had only a small effect. We observed important effects of the flowering intensity and vegetation height on the butterfly species richness and abundance regarding land use. Marginal woody vegetation cover had a positive effect on the butterfly abundance, and management had little effect. We concluded that weather and land use had important effects on butterflies. Based on our research, we recommended the reconsideration of scientific studies and monitoring programs for insects concerning the temperature threshold (≥ 25 °C) and the consideration of light intensity as an important factor. Applying a detailed approach to measuring the flowering intensity is likely unnecessary, while meadow land-use parameters appear to be necessary for insect populations.
Subject(s)
Butterflies , Agriculture , Animals , Biodiversity , Ecosystem , Humans , InsectaABSTRACT
Colletes hederae Schmidt & Westrich, 1993 is a cryptic bee species from the C. succinctus species-group. The previous occurrence and spreading of this species were predominantly in south-western Europe. To determine if the species was spreading in Slovak territory, Hedera helix was monitored from autumn 2015. The ivy-bee was first recorded in Slovakia during autumn 2017. This species is widespread inside and around Bratislava; however, it was not recorded under this study in any sites located eastwards. In the Czech Republic, it was not recorded in the south-east part of the country in 2017-2019. In 2020, the occurrence of this species was confirmed in many localities in the south of the country and strong populations were discovered, especially in the towns Znojmo and Mikulov. The populations likely originated from neighbouring Austria, where this species was discovered in 2006 and the localities are usually less than 100 km away from Czech and Slovak localities. A further survey could map a route of the northwards spread of this species.
ABSTRACT
A recurrent concern in nature conservation is the potential competition for forage plants between wild bees and managed honey bees. Specifically, that the highly sophisticated system of recruitment and large perennial colonies of honey bees quickly exhaust forage resources leading to the local extirpation of wild bees. However, different species of bees show different preferences for forage plants. We here summarize known forage plants for honey bees and wild bee species at national scale in Denmark. Our focus is on floral resources shared by honey bees and wild bees, with an emphasis on both threatened wild bee species and foraging specialist species. Across all 292 known bee species from Denmark, a total of 410 plant genera were recorded as forage plants. These included 294 plant genera visited by honey bees and 292 plant genera visited by different species of wild bees. Honey bees and wild bees share 176 plant genera in Denmark. Comparing the pairwise niche overlap for individual bee species, no significant relationship was found between their overlap and forage specialization or conservation status. Network analysis of the bee-plant interactions placed honey bees aside from most other bee species, specifically the module containing the honey bee had fewer links to any other modules, while the remaining modules were more highly inter-connected. Despite the lack of predictive relationship from the pairwise niche overlap, data for individual species could be summarized. Consequently, we have identified a set of operational parameters that, based on a high foraging overlap (>70%) and unfavorable conservation status (Vulnerable+Endangered+Critically Endangered), can guide both conservation actions and land management decisions in proximity to known or suspected populations of these species.
Subject(s)
Bees , Flowers , Pollen , Pollination , Animals , Conservation of Natural Resources , Denmark , Endangered SpeciesABSTRACT
The genus Gasteruption (Gasteruptiidae) is represented in Europe by more than 30 species. Of these, twenty-one are recorded from the Czech Republic and Slovakia, with six being new records for the Czech Republic and eight for Slovakia. Three species are recorded as new for Bohemia (western part of the Czech Republic). Gasteruption goberti is excluded from the fauna of the Czech Republic because specimens previously identified as G. goberti belong to G. caucasicum. Four species (G. assectator, G. caucasicum, G. jaculator and G. nigritarse) are common and widespread in both countries, G. tournieri is very common but prefers warmer regions. Only G, subtile occurs predominantly in higher altitudes of mountain ranges, while the other species are usually restricted to or are more common in warmer regions. Gasteruption opacum and G. subtile are regionally extinct from the Czech Republic and G. paternum from Slovakia, with the the most recent records of these species are pre-1990. Gasteruption freyi, G. hastator and G. hungaricum are considered very endangered thermophilous species of loess walls and steppe habitats with a marked loss of occurrence records post-1990. Locally common but much rarer than in the past are G. erythrostomum and G. boreale. Due to the fact that recent determination keys are focused on other regions, a determination key for all species recorded in central Europe is presented.
Subject(s)
Hymenoptera , Animals , Czech Republic , Ecosystem , SlovakiaABSTRACT
The first comprehensive information on the bionomics of the digger wasp Oxybelus variegatus Wesmael, 1852 is presented. Females nested in small aggregations in crevices between paving stones of a frequently used pedestrian pathway in lowland agricultural wasteland. Nests were dug in the ground using mandibles, legs and abdomen. The nest consists of a main burrow with one or, rarely, two cells. The mature larva is described for the first time. The egg stage lasts for about two days before the larva hatches. The female provisioned each cell with an average of 11 paralysed male flies of Delia platura (Meigen, 1826) (Diptera: Anthomyiidae). Numerous females of dipteran kleptoparasites were observed in the nesting area of O. variegatus. However, only a few nests were infested by larvae of Senotainia conica (Fallen, 1810).
ABSTRACT
Morocco is a well known hot-spot of biodiversity in the Mediterranean basin. While some taxa like vascular plants are relatively well recorded, important groups of pollinators like bees are still understudied. This article presents an updated checklist of the bee species of Morocco and includes a summary of global and regional distribution of each species. A total of 961 species belonging to six bee families and 68 genera are recorded: Andrenidae (8 genera, 217 species); Apidae (15 genera, 241 species); Colletidae (2 genera, 74 species), Halictidae (12 genera, 144 species), Megachilidae (28 genera, 271 species) and Melittidae (3 genera, 14 species). Among them, 67 species are recorded for the first time in Morocco. Around 70% of the bee fauna of Morocco consists of widespread Palaearctic species. Only 18% of Moroccan species recorded are restricted to North Africa and 8% are Moroccan single-country endemics (81 species). Afrotropical elements in the Moroccan fauna are few, with only 3% of Morocco species co-occuring in that region. This checklist is intended to stimulate new regional research on bees including their taxonomy and biogeography. As many groups of bees have been understudied, discovery of new species for science and new records for the country can be expected. Additional research including inventorying, monitoring, and integrative taxonomic studies are needed to develop a comprehensive strategy for bee conservation in Morocco.
Subject(s)
Bees , Hymenoptera , Animals , Base Sequence , Hymenoptera/genetics , MoroccoABSTRACT
Neonicotinoid insecticides are associated with a decline in the diversity and distribution of bees and wasps (Hymenoptera: Aculeata). The effects of neonicotinoids on the metamorphosis of aculeates have never been addressed in detail; however, recent evidence suggests that neonicotinoids induce wing abnormalities. We hypothesized that the metamorphosis success of bees and wasps differs in response to contact exposure to field-realistic concentrations of neonicotinoid insecticides or in response to combined exposure to neonicotinoid insecticides and benzimidazole fungicides. We treated prepupae of the model crabronid wasp Pemphredon fabricii with field-realistic concentrations of four neonicotinoids, acetamiprid, imidacloprid, thiacloprid and thiamethoxam, and/or with the benzimidazole fungicide thiabendazole. Treatment with acetamiprid or imidacloprid decreased the pupation rates to only 39% and 32%, respectively. Treatment with thiacloprid or thiamethoxam did not affect the pupation rate when applied alone, but the subsequent treatment of thiacloprid- or thiamethoxam-treated prepupae with thiabendazole led to significant decreases in pupation rates. A high concentration of acetamiprid, which severely affected the pupation rates, had moderate effects on metamorphosis into adults, resulting in 53% metamorphosis success (as opposed to 95% metamorphosis success in the water-treated group). However, imidacloprid or thiamethoxam treatment resulted in only 5%-10% metamorphosis success into adults. Overall survival decreased in response to treatment with any of the neonicotinoids or benzimidazoles or their combinations, with extremely low survival (<2%) following combined treatment with imidacloprid and thiabendazole or thiamethoxam and thiabendazole. In conclusion, neonicotinoids alter insect metamorphosis success, which can be further potentiated by their combination with other agrochemicals, such as benzimidazoles.
Subject(s)
Insecticides/pharmacology , Metamorphosis, Biological/drug effects , Neonicotinoids/pharmacology , Wasps/growth & development , Animals , Pupa/growth & developmentABSTRACT
The bee genus Epeolus Latreille (Hymenoptera: Apidae) consists of 109 species, which are known to be exclusively cleptoparasites of polyester (or cellophane) bees of the genus Colletes Latreille (Hymenoptera: Colletidae). Both genera have a nearly cosmopolitan distribution and are represented on all continents except Antarctica and Australia. We present the most comprehensive phylogeny for Epeolus to date, based on combined molecular and morphological data. In total, 59 ingroup taxa (species of Epeolus) and 7 outgroup taxa (other Epeolini) were scored for 99 morphological characters, and sequence data were obtained for seven genes (one mitochondrial and six nuclear, 5399â¯bp in total). Epeolus was found to be monophyletic, with a crown age estimated to be 25.0-13.4â¯Ma (95% HPD) and its origins traced to the Nearctic region. Epeolus was found to contain six major clades, five of which were well supported. The evolutionary history of Epeolus is explored in the context of earth history events and the evolutionary history of its host genus Colletes, for which a molecular phylogeny was constructed based on the same seven genes. A comparison of Epeolus and Colletes phylogenies limited to taxa for which there is evidence of an association suggests there was some cospeciation. However, more cladogenetic events in Epeolus were linked to instances of dispersal/vicariance. It is not yet clear the extent to which allopatric speciation contributed to diversification in Colletes, but the genus' success in having colonized and diversified across much of the globe made it possible for Epeolus to do the same.
Subject(s)
Bees/classification , Host-Parasite Interactions , Hymenoptera/parasitology , Phylogeny , Phylogeography , Animals , Antarctic Regions , Australia , Genetic SpeciationABSTRACT
The structure of forests is an important stabilizing factor regarding ongoing global climate and land use change. Biodiverse mountain forests with natural structure are one of the ecosystems most endangered by these problems. We focused on the mountain forest islands of European beech (Fagus sylvatica) and their role in the natural distribution of organisms. The study area was situated in the oldest Czech national park, Krkonose (385 km2), which is the highest mountain ridge in the country. We studied multi-taxa (lichens, beetles and hymenopterans) responses to three hierarchical spatial levels of the environment: the topography was described by the elevation gradient; the patch structure was described by canopy openness, dead wood amounts, and Norway spruce (Picea abies) cover; and the tree level was described by species of the sampled tree and its diameter. Lichens preferred higher elevations, while insect groups responded conversely. Furthermore, insect groups were mainly influenced by the inner patch structure of beech islands. Lichens may be jeopardized due to the predicted future increase in temperatures, since they would need to shift toward higher altitudes. Insects may be mainly threatened in the future by land use changes (i.e., forest management) - as indicated by an interconnection of canopy openness and the amount of dead wood.
Subject(s)
Biodiversity , Coleoptera/classification , Forests , Hymenoptera/classification , Lichens/classification , Animals , Conservation of Natural Resources , Czech Republic , Spatial AnalysisABSTRACT
Seventeen species of Epeolus Latreille, 1802 and one species of Triepeolus Robertson, 1901 have been recorded from Europe. Members of these genera are cuckoo bees, cleptoparasites that appropriate provisions of other bee genera (Colletes Latreille [hosts of Epeolus] and Tetraloniella Ashmead [hosts of Palaearctic Triepeolus]) for their own offspring. We present an identification key to all European species plus four species known from neighbouring regions (the Middle East and North Africa) that might also occur in Europe. The taxonomy of all species is reviewed, with new synonymies proposed, one subspecies elevated to a species (Epeolus eriwanensis Bischoff, 1930, stat. nov.), and a new species (Epeolus ibericus Bogusch, sp. nov.) described. Five new synonymies are proposed: E. giannelli Gribodo, 1894 syn. nov. and Epeolus speculifer Pérez, 1895 syn. nov. under E. fallax Morawitz, 1872, E. berlandi Benoist, 1943 syn. nov. and E. laevigatus Bischoff, 1930 syn. nov. under E. flavociliatus Friese, 1899, and E. julliani Pérez, 1884 syn. nov. under E. transitorius Eversmann, 1852. The following species are redescribed because their identity is less clear due to type specimens and/or vague original descriptions: Epeolus aureovestitus Dours, 1873, Epeolus cruciger (Panzer, 1799), Epeolus fallax Morawitz, 1872, Epeolus schummeli Schilling, 1849, Epeolus siculus Giordani Soika, 1944, and Epeolus variegatus (Linnaeus, 1758). Males are described for the first time for the following species: Epeolus compar Alfken, 1938, Epeolus eriwanensis Bischoff, 1930, Epeolus intermedius Pérez, 1884, Epeolus laevifrons Bischoff, 1930, and Epeolus subrufescens Saunders, 1908. Distribution maps created using records from the literature and data from private and museum collections are also provided, which show changes in the distributions of epeoline bees before and after 1990. Several species are considered endangered, especially Epeolus fasciatus Friese, 1895, which is nearly extinct, and Epeolus tarsalis Morawitz, 1874, which was recently reported only from the coastal parts of the Netherlands and Belgium. Epeolus variegatus is the only common and widespread species still encountered in most of Europe. Comprehensive information on the ecology of these cuckoo bees is also included.
Subject(s)
Animal Distribution , Hymenoptera , Africa, Northern , Animals , Bees , Belgium , Europe , Male , Middle East , NetherlandsABSTRACT
The ability of aculeate Hymenoptera to utilize wetlands is poorly understood, and descriptions of their nests and developmental stages are largely absent. Here we present results based on our survey of hymenopterans using galls induced by Lipara spp. flies on common reed Phragmites australis in the years 2015-2016. We studied 20,704 galls, of which 9,446 were longitudinally cut and the brood from them reared in the laboratory, while the remaining 11,258 galls reared in rearing bags also in laboratory conditions. We recorded eight species that were previously not known to nest in reed galls: cuckoo wasps Chrysis rutilans and Trichrysis pumilionis, solitary wasps Stenodynerus chevrieranus and Stenodynerus clypeopictus, and bees Pseudoanthidium tenellum, Stelis punctulatissima, Hylaeus communis and Hylaeus confusus. Forty five species of Hymenoptera: Aculeata are known to be associated with reed galls, of which 36 make their nests there, and the other are six parasitoids of the family Chrysididae and three cuckoo bees of the genus Stelis. Of these species, Pemphredon fabricii and in southern Europe also Heriades rubicola are very common in reed galls, followed by Hylaeus pectoralis and two species of the genus Trypoxylon. We also found new host-parasite associations: Chrysis angustula in nests of Pemphredon fabricii, Chrysis rutilans in nests of Stenodynerus clypeopictus, Trichrysis pumilionis in nests of Trypoxylon deceptorium, and Stelis breviuscula in nests of Heriades rubicola. We provide new descriptions of the nests of seven species nesting in reed galls and morphology of mature larvae of eight species nesting in reed galls and two parasitoids and one nest cleptoparasite. The larvae are usually very similar to those of related species but possess characteristics that make them easy to distinguish from related species. Our results show that common reeds are not only expansive and harmful, but very important for many insect species associated with habitats dominated by this plant species.
Subject(s)
Host-Parasite Interactions , Plant Tumors/parasitology , Wasps/growth & development , Animals , Biodiversity , Diptera/pathogenicity , Life Cycle Stages , Nesting Behavior , Plant Tumors/etiology , Wasps/classification , Wasps/pathogenicityABSTRACT
Last instar larva and pupa of Metadonus vuillefroyanus (Capiomont, 1868) (Curculionidae: Hyperini) are described and compared with known larvae of the other 43 hyperine taxa. The thorn-like setae located on distinct black protuberances on the larval body are characteristic features of the genus Metadonus and the subgenus Eririnomorphus of the genus Hypera. The biological singularity of this species was studied and described. The variable colouration of larvae has been confirmed in association with the variability of the host plant's colouration at the studied localities. This species' reported inability to spin cocoons has been disproven. A different type of cocoon with two layers, where the inner layer consists of proteins from Malpighian tubules while the outer layer contains soil particles, is described. This type of cocoon is unique compared with those known from other hyperines, which usually pupate on or above the ground and do not use substrate particles in building their cocoons.
ABSTRACT
Open interior sands represent a highly threatened habitat in Europe. In recent times, their associated organisms have often found secondary refuges outside their natural habitats, mainly in sand pits. We investigated the effects of different restoration approaches, i.e. spontaneous succession without additional disturbances, spontaneous succession with additional disturbances caused by recreational activities, and forestry reclamation, on the diversity and conservation values of spiders, beetles, flies, bees and wasps, orthopterans and vascular plants in a large sand pit in the Czech Republic, Central Europe. Out of 406 species recorded in total, 112 were classified as open sand specialists and 71 as threatened. The sites restored through spontaneous succession with additional disturbances hosted the largest proportion of open sand specialists and threatened species. The forestry reclamations, in contrast, hosted few such species. The sites with spontaneous succession without disturbances represent a transition between these two approaches. While restoration through spontaneous succession favours biodiversity in contrast to forestry reclamation, additional disturbances are necessary to maintain early successional habitats essential for threatened species and open sand specialists. Therefore, recreational activities seem to be an economically efficient restoration tool that will also benefit biodiversity in sand pits.
Subject(s)
Biodiversity , Conservation of Natural Resources/methods , Forestry , Mining , Animals , Arthropods , Czech Republic , Plants , Time FactorsABSTRACT
Monotypic stands of common reed and the reed-gall-associated insect assemblages are distributed worldwide. However, fungi associated with these assemblages have not been characterized in detail. Here we examined 5200 individuals (12 species) of immature aculeate hymenopterans or their parasitoids collected at 34 sampling sites in Central Europe. We noticed fungal outgrowth on exoskeletons of 83 (1.60%) larvae and pupae. The most common host was eudominant Pemphredon fabricii. However, the less abundant aculeate hymenopteran reed gall inquilines were infected at higher prevalence, these included Trypoxylon deceptorium, Trypoxylon minus, Hoplitis leucomelana and Hylaeus moricei (all considered new host records). We identified three fungal species, Penicillium buchwaldii (72% of cases), Aspergillus pseudoglaucus (22%) and Penicillium quebecense (6%). When multibrooded nests were affected, only a part of individuals was infected in 62% of cases. The sampling site-specific infection rate reached up to 13%, thus fungal infections should be considered an important variable driving the abundance of gall inquilines. Infections of generalist host species were more frequent than those of reed gall specialists, suggesting that suboptimal conditions decreased the immunocompetence of non-specialized species, which only occasionally nest in reed galls and feed in reed beds.
Subject(s)
Aspergillus/physiology , Hymenoptera/microbiology , Penicillium/physiology , Plant Tumors/microbiology , Animals , Aspergillus/cytology , Aspergillus/genetics , DNA, Fungal/chemistry , Host-Pathogen Interactions , Hymenoptera/classification , Larva/microbiology , Likelihood Functions , Penicillium/cytology , Penicillium/genetics , Phylogeny , Pupa/microbiologyABSTRACT
Wetland species of aculeate Hymenoptera are poorly known, even though many of them may serve as diagnostic or flagship species in nature conservation. Here we examined 6,018 galls induced ≥1 year prior their collection by the chloropid flies Lipara spp. The galls were collected at 34 sites in Central Europe. We examined 1,389 nests (4,513 individuals) of nine species, part of which were parasitized by one dipteran and two chrysidid parasitoid species. We describe the nests of seven dominant species and larvae of four species (Pemphredon fabricii, Trypoxylon deceptorium, Hoplitis leucomelana and Hylaeus pectoralis) and two parasitoids (Trichrysis cyanea and Thyridanthrax fenestratus, both in nests of Pemphredon fabricii and Trypoxylon deceptorium). All the species, but H. pectoralis, preferred robust galls at very thin stalks (induced typically by Lipara lucens) over the narrow galls on thick stalks. The larvae of P. fabricii and T. deceptorium resembled strongly their sibling species (Pemphredon lethifer and Trypoxylon attenuatum sensu lato, respectively). The larvae of T. fenestratus showed features different from those previously described. By hatching set of another 10,583 galls induced by Lipara spp. ≥1 year prior their collection, we obtained 4,469 individuals of 14 nesting hymenopteran species, two cleptoparasites, three chrysidid and one dipteran parasitoid. Of these species, four new nesting species have been recorded for the first time in galls induced by Lipara spp.: Chelostoma campanularum, Heriades rubicola, Pseudoanthidium lituratum and Hylaeus incongruus. We also provide first records of their nest cleptoparasites Stelis breviuscula and Stelis ornatula, and the parasitoid Holopyga fastuosa generosa. Thyridanthrax fenestratus formed strong populations in nests of Pemphredon fabricii and Trypoxylon deceptorium, which are both newly recorded hosts for T. fenestratus. The descriptions provided here allow for the first time to identify the larvae of the most widespread central European aculeate hymenopteran reed gall specialists.