Crabronidae Research Articles

First report of Trypoxylon clavicerum (Crabronidae: Hymenoptera) from the Indian subcontinent: its nesting behaviour and prey preference

Abstract A study was conducted to document the nesting behaviour and prey composition of a crabronid wasp, Trypoxylon sp. The wasp was molecularly characterised as T. clavicerum (NCBI Accession No. OQ913679.1). Nest acceptance rate was significantly higher in the reeds of Ipomea carnea (79.20%) and bamboo (84.80%). The mean number of brood cells (4.40 ± 0.89 cells/nest) and vestibular cells (1.06 cells/nest) built by the wasp was significantly higher in the reeds of I. carnea. Brood parasitisation by the nest parasite Amobia sp. was significantly higher in nests built by the wasp in paper straws (58.57%) compared to the nests built in the reeds of bamboo (23.33%). The mean durations of the egg, larval and pupal stages of T. clavicerum were 2.60 ± 0.55, 6.01 ± 0.71 and 4.80 ± 0.84 days. The number of nests recovered was observed to be the highest during the months of August (3.66 ± 1.53 nests), September (5.00 ± 4.36 nests), October (8.67 ± 2.89 nests) and November (6.00 ± 2.10 nests). The major species of spider from the occupied nests belonged to two families, viz. Salticidae (81%) and Oxyopidae (19%). During the nesting period the adult wasp provisioned a greater number of spiderlings (3.25 to 3.60 spiderlings/cell) than adult spiders (1.20 to 1.60 adult spiders/cell) to her brood. The time taken to complete a single nest provisioned with adult spiders and spiderlings (13.20 ± 6.83 hr/single nest) was significantly less than for the nests provisioned with adult spiders (46.80 ± 14.80 hr/single nest) only. This study is the first ever report of nesting behaviour and prey composition of the spider-hunting wasp T. clavicerum from India.

Commonly used triazole fungicides accelerate the metamorphosis of digger wasps (Hymenoptera: Spheciformes).

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.

The first crabronid wasps (Hymenoptera, Apoidea) from the Crato Formation (Northeastern Brazil) and implications for the evolution of apoid wasps and bees during the Early Cretaceous

In the present study, we describe a new extinct lineage of the hymenopteran family Crabronidae from the Crato Formation of northeastern Brazil. The new taxon represents the oldest crabronid and extends the occurrence of the lineage about 20 million years into the Early Cretaceous. We describe a new species in a new crabronid genus, †Exallopterus spectabilis gen. et sp. nov. Despite the similarities with living members of the subfamily Crabroninae, the new taxon cannot be placed in any of the existing subfamilies or tribes, and therefore we propose a new tribe, †Exallopterini trib. nov. and leave it as incertae sedis in Crabronidae. The discovery of crabronid wasps in the Crato formation sheds light on the understanding of the paleoenvironment and biogeography of apoid wasps and bees during the Early Cretaceous of Gondwana. Apparently, during their early evolution, crabronids occupied a much wider range of environments and exhibited a broader paleobiogeographic distribution compared to bees.

Solierella turneri Dutt, 1917 (Hymenoptera: Crabronidae: Crabroninae) from India: description of female and new distribution records

The crabronid wasp, Solierella turneri Dutt, 1917 (Hymenoptera: Crabronidae) is newly recorded from various regions of India and female is described. Hitherto, the S. turneri Dutt has been only reported from northern India (Pusa of Bihar), the current record extends its range to southern India (Kerala, Tamil Nadu and Karnataka).

Life in extreme habitats: the number of prepupae per nest of the crabronid wasp Pemphredon fabricii is constant even under pressure from high concentrations of toxic elements.

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.

Behavior notes and prey spectrum of three species of the bee-hunting wasp Trachypus Klug (Hymenoptera: Apoidea)

Trachypus Klug is a Neotropical genus of crabronid wasps comprising 31 ground-nesting species. Its species can be solitary or communal, and two diet ranges are known: they can forage on several bee subfamilies and wasps; or can be specialists on stingless bees. Natural history observations are scarce nowadays but are essential to contextualize ecological and evolutionary studies. Here we report new records and give biological notes for Trachypus elongatus (Fabricius, 1804), Trachypus taschenbergi Rubio-Espina, 1975, and Trachypus varius (Taschenberg, 1875). Observations and samplings were carried out twice a month, during one year in the city of Curitiba, southern Brazil. Besides field observations, circular statistics were used to analyze seasonality. All species nest in sloped soil and are solitary. Trachypus elongatus and T. taschenbergi were active during most of the year with marked seasonality in the late spring and early summer. Both species were observed hunting only stingless bees, with T. elongatus specialized on Trigona spinipes (Fabricius, 1793), and T. taschenbergi specialized on Paratrigona subnuda Moure, 1947 drones. Trachypus varius was observed only in January and one female was recorded foraging on a Paratrigona subnuda worker. Our observations provide additional data for understanding the biology of bee-hunting wasps, and this is the first study to bring information for T. taschenbergi and T. varius. Our data corroborate that some species of the genus Trachypus are specialized on stingless bees.

Contribution to the knowledge of little known Crabronid wasps (Hymenoptera: Crabronini) of India

Two Indian Crabronid wasp species viz., Lestica quadriceps (Bingham, 1897) and Isorhopalum marunum Leclercq, 1963 were redescribed with additional characters of male genitalia along with coloured illustrations. New locality records are also included.

Oxybelus lusitanicus spec. nov., a new Crabronid wasp species from Portugal.

Oxybelus lusitanicus spec. nov., a new European Crabronid wasp species is described and diagnosed. It is currently known only from two regions of Portugal. An amendment to the relevant section of Guichard's (1993) most recent English language key to European Oxybelus Latreille, 1796 is included.

Neonicotinoid insecticides hinder the pupation and metamorphosis into adults in a crabronid wasp

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.

New Record of Crabronidae (Insecta: Hymenoptera) from Turkey

Crabronid wasp Lindenius abditus Kohl, 1898 is recorded for the first time from Turkey. Recorded species are described and taxonomically important morphological characters are photographed.

Necrophagy in Honey Bees (Apis mellifera L.); A Forensic Application of Scent Foraging Behavior

Scent training and field detection trials were conducted to determine if honey bee (Apis mellifera) foraging behavior could be employed as a practical application in the location of vertebrate carrion. Resource recognition and querying trials consisted of two components. Honey bees were trained to associate chemical compounds found in decaying tissues with a high-quality food source via introduction of the compounds into a sugar solution. Randomized scented and non-scented sugar solution choices were subsequently provided to hived bees at varying distances within a rural outdoor study area. Following initial forager recruitment by scouts, twice the number of bees were observed feeding at carrion-scented stations. Additional field trials performed using wildlife carrion reinforced experimental results. Scent trained scout bees showed a marked interest in decomposing wildlife remains by aerially investigating and landing on the carrion. These findings demonstrate honey bee retention of carrion sensory recognition capabilities and support the crabronid wasp hypothesis of honey bee evolutionary origins. Applications for forensic remains detection, wildlife trafficking interdiction, and endangered species conservation are indicated.

Revised checklist of the genus Cerceris (Hymenoptera: Crabronidae) of Iran, with two new records

Revised checklist of the genus Cerceris (Hymenoptera: Crabronidae) of Iran, with two new records

The effects of contact exposure to azole fungicides on insect metamorphosis

External stressors often cause delayed post-exposure effects by affecting the larvae that survive until but not beyond metamorphosis. Despite that, little information is available regarding the effects of anthropogenic external stressors, such as the fungicides, on insect metamorphosis success and timing. We tested the effects of four azole fungicides that are widely used in agriculture (epoxiconazole, flusilazole, thiophanate-methyl, and thiabendazole). We applied the fungicides topically on prepupae of the abundant polyphagous predator of aphids, the crabronid wasp Pemphredon fabricii (M. Müller, 1911) (Hymenoptera: Crabronidae). We recorded the number of prepupae that molted successfully into pupae and adults, the mortality and the time to metamorphosis. We found the pupation to be delayed in prepupae collected from field margins compared to other sampling sites. This delay in pupation was further strengthened by the contact application of any of the four tested azole fungicides. The metamorphosis into adults was prolonged by flusilazole and thiabendazole but only in individuals that were collected from wetlands at field margins. Only flusilazole increased premature mortality during pupation. Because the shared metabolic degradation pathways of azoles, neonicotinoids, and acaricides used in beehives, further research should examine the possible synergistic effects of these compounds on farmland aculeates, including commercially exploited species.

Strategy for sneaking into a host's home: The cuckoo wasp Omalus biaccinctus (Hymenoptera: Chrysididae) inserts its eggs into living aphids that are the prey of its host

Parasitic Hymenoptera usually need to have direct access to their host or its offspring or to be able to enter and place their offspring in a nest of their host, where their progeny develop at the expense of the host. In the case of the cleptoparasitic cuckoo wasps (Chrysididae) their main target is the nest of the host and they have various strategies for locating and entering their host's brood cells for ovipositing. The chrysidid Omalus biaccinctus (Buysson, 1893), a parasitoid of aphid hunting crabronid wasps, was observed ap- parently inserting its eggs into living aphids at the hunting site of their host and the presence of the parasitoid's egg and DNA in aphids after oviposition was confirmed. It is concluded that O. biaccinctus hitch-hikes into a host's brood cell concealed in the aphid prey collected by the host wasp and the adult parasites do not need to enter the nest of their host in order to lay their eggs.

Gene variation and genetic differentiation among populations of the solitary mud dauber wasp Trypoxylon (Trypargilum) albitarse Fabricius 1804 (Hymenoptera, Crabronidae).

Trypoxylon is a genus of solitary crabronid wasps whose population genetics is poorly known. The purpose of the present study was to investigate the genetic variation and differentiation among five populations of Trypoxylon albitarse, a species widely distributed throughout the Neotropics, with records from Panama to northern Argentina. Eight species-specific microsatellite loci were used for genotyping 96 adult wasps (one female per nest) sampled at five sites in Brazil. The analysis of allelic richness and private alleles indicated high genetic diversity in the populations sampled. Pairwise comparisons using the F st and D est indices revealed significant differentiation for all, but one pair of populations. F st, D est, AMOVA and assignment test values pointed to inter-population differentiation. Additionally, the analysis of population structure using Bayesian and PCA methods characterized two alternative genetic groups. The Mantel test indicated no correlation between genetic and geographic distances. Despite evidence of considerable dispersal capacity for T. albitarse, the data indicate low to moderate population structuring in this species.

Nest architecture and colony composition of communally nesting Spilomena socialis sp. n. (Hymenoptera, Crabronidae, Pemphredoninae) from peninsular Malaysia

Communal nesting, rare in the crabronid wasps, has been recorded for various species in the Spilomenina clade of the Pemphredoninae. A new communally nesting species, Spilomena socialis, is described from peninsular Malaysia where it nested on buildings at Bukit Fraser. The nest consists of a group of closely spaced clusters of vertically oriented cells attached to walls, and is constructed of tiny pieces of vegetal and mineral origin, parts of insects, and fungal hyphae bound together by silk secreted from each female wasp’s abdominal gland. Nests contained up to 39 cells (average 10.4 cells, N = 35). Nest entrances were at the upper end of the cells and were protected on one side by a “roof”. Cells constructed side-by-side have their roofs connected to form a tube that allowed access to all the cells. Nests were inhabited by 1–13 females (average 4.3 females per nest, N = 21) and 0–4 males, the overall sex ratio being 0.22. Ovarian development among the females in a nest varied. In 8 of 20 nests with 3 or more females only one female had developed ovaries, but female size (measured as head width) did not correlate with ovarian development. Cells are apparently progressively provisioned with thrips, and are often re-used. Adult females cooperatively defend the nests against intruders.

Overview of the distribution and biogeography of Crabronidae in Turkey (Hymenoptera: Aculeata)

Faunistic and systematic studies on Crabronidae of Turkey are reviewed and the distribution and biogeography of the Turkish Crabronid wasp fauna is analyzed. In this study, 21 species and subspecies of 2 genera of Astatinae, 122 species and subspecies of 19 genera of Bembicinae, 72 species and subspecies of 3 genera of Philanthinae, 61 species and subspecies of 13 genera of Pempherdoninae, 2 species of 1 genus of Mellininae, 1 species of 1 genus of Dinetinae and 238 species and subspecies of 26 genera of Crabroninae are recorded. In total, 502 species and 15 subspecies belonging to 65 genera of Crabronidae are recorded from Turkey. Among them, 44 species and 6 subspecies comprising 9,7% of Turkish crabronids are endemic. Furthermore, the type localities of 69 species and 10 subspecies of Crabronidae are located in Turkey. Species composition, diversity and proportion of endemism varies considerably between the biogeographic subregions of the country.

Buprestidae Collected as Prey by the Solitary, Ground-Nesting Philanthine Wasp Cerceris fumipennis (Hymenoptera: Crabronidae) in North Carolina

ABSTBACT The solitary, ground-nesting crabronid wasp Cerceris fumipennis Say excels at detecting buprestid diversity in a given geographic area, and after the introduction of the invasive pest emerald ash borer (Agrilus planipennis Fairmaire) to the United States in 2002, has been developed as an effective tool for the biosurveillance of pest Buprestidae in eastern North America. Here we report records of Buprestidae collected from foraging C. fumipennis in 13 North Carolina counties over the course of three seasons (2009–2011). Nests of the wasp were located, and beetle prey collected from foraging females in three geographic regions, with a concentration on the western, mountainous area of the state. In total, 909 beetles were collected, comprising 52 buprestid species that included eight native pests and 17 species of Agrilus. Our results emphasize the utility of C. fumipennis in documenting buprestid biodiversity and in detecting forest pests. Eight new state records and five new prey records for the wasp are here recorded.

Key to the Oriental species of Passaloecus Shuckard (Hymenoptera: Crabronidae), with descriptions of four new species from China

A key to the Oriental species of Passaloecus Shuckard (Crabronidae: Pemphredoninae: Pemphredonini) is provided. Four new

Accelerated evolution of mitochondrial but not nuclear genomes of Hymenoptera: new evidence from crabronid wasps.

Mitochondrial genes in animals are especially useful as molecular markers for the reconstruction of phylogenies among closely related taxa, due to the generally high substitution rates. Several insect orders, notably Hymenoptera and Phthiraptera, show exceptionally high rates of mitochondrial molecular evolution, which has been attributed to the parasitic lifestyle of current or ancestral members of these taxa. Parasitism has been hypothesized to entail frequent population bottlenecks that increase rates of molecular evolution by reducing the efficiency of purifying selection. This effect should result in elevated substitution rates of both nuclear and mitochondrial genes, but to date no extensive comparative study has tested this hypothesis in insects. Here we report the mitochondrial genome of a crabronid wasp, the European beewolf (Philanthus triangulum, Hymenoptera, Crabronidae), and we use it to compare evolutionary rates among the four largest holometabolous insect orders (Coleoptera, Diptera, Hymenoptera, Lepidoptera) based on phylogenies reconstructed with whole mitochondrial genomes as well as four single-copy nuclear genes (18S rRNA, arginine kinase, wingless, phosphoenolpyruvate carboxykinase). The mt-genome of P. triangulum is 16,029 bp in size with a mean A+T content of 83.6%, and it encodes the 37 genes typically found in arthropod mt genomes (13 protein-coding, 22 tRNA, and two rRNA genes). Five translocations of tRNA genes were discovered relative to the putative ancestral genome arrangement in insects, and the unusual start codon TTG was predicted for cox2. Phylogenetic analyses revealed significantly longer branches leading to the apocritan Hymenoptera as well as the Orussoidea, to a lesser extent the Cephoidea, and, possibly, the Tenthredinoidea than any of the other holometabolous insect orders for all mitochondrial but none of the four nuclear genes tested. Thus, our results suggest that the ancestral parasitic lifestyle of Apocrita is unlikely to be the major cause for the elevated substitution rates observed in hymenopteran mitochondrial genomes.