Digger Wasp Research Articles

Venom and Dufour's glands of the emerald cockroach wasp Ampulex compressa (Insecta, Hymenoptera, Sphecidae): Structural and biochemical aspects

The digger wasp species Ampulex compressa produces its venom in two branched gland tubules. They terminate in a short common duct, which is bifurcated at its proximal end. One leg is linked with the venom reservoir, the other one extends to the ductus venatus. Each venom gland tubule possesses, over its entire length, a cuticle-lined central duct. Around this duct densely packed class 3 gland units each composed of a secretory cell and a canal cell are arranged. The position of their nuclei was demonstrated by DAPI staining. The brush border of the secretory cells surrounds the coiled end-apparatus. Venom is stored in a bladder like reservoir, which is surrounded by a thin reticulated layer of muscle fibres. The reservoir as a whole is lined with class 3 gland units. The tubiform Dufour's gland has a length of about 350 μm (∅ 125 μm) only and is surrounded by a network of pronounced striated muscle fibres. The glandular epithelium is mono-layered belonging to the class 1 type of insect epidermal glands. The gland cells are characterized by conspicuous lipid vesicles. Secretion of material via the gland cuticle into the gland lumen is apparent. Analysis of the polypeptide composition demonstrated that the free gland tubules and the venom reservoir contain numerous proteins ranging from 3.4 to 200 kDa. The polypeptide composition of the Dufour's gland is completely different and contains no lectin-binding glycoproteins, whereas a dominant component of the venom droplets is a glycoprotein of about 80 kDa. Comparison of the venom reservoir contents with the polypeptide pattern of venom droplets revealed that all of the major proteinaceous constituents are secreted. The secreted venom contains exclusively proteins present in the soluble contents of the venom gland. The most abundant compound class in the Dufour's gland consisted of n-alkanes followed by monomethyl-branched alkanes and alkadienes. Heptacosane was the most abundant n-alkane. Furthermore, a single volatile compound, 2-methylpentan-3-one, was identified in various concentrations in the lipid extract of the Dufour's gland.

New and little known digger wasps of the genus Ammophila W. Kirby, 1798 (Hymenoptera: Apoidea: Sphecidae) from Central Asia

Five species of Ammophila are treated. The lectotype of Ammophila separanda F. Morawitz, 1891 is designated and illustrated. The holotype of Ammophila cellularis Gussakovskij, 1930 is redescribed and illustrated. Two new species, Ammophila barkalovi sp. nov. (Kazakhstan) and A. pevtsovi sp. nov. (China), are described and illustrated. The hitherto unknown female of A. vetuberosa Li & Yang, 1994 is described.

The digger wasps of the genus Didineis Wesmael (Hymenoptera: Crabronidae: Bembicinae) of Russia and adjacent territories, with a key to species and new synonymies.

Ten species of Didineis Wesmael 1852 are recorded from Russia and adjacent territories. The new synonymy (valid name listed first) is established for Didineis bactriana Gussakovskij 1937 = D. ogloblini Gussakovskij 1937, D. clavimana Gussakovskij 1937 = D. turanica Gussakovskij 1937, and D. lunicornis (Fabricius 1798) = Didineis ruthenica Gussakovskij 1937. The number of valid species-group taxa in the genus Didineis is reduced to 25. The lectotypes are designated for four species: Didineis bactriana Gussakovskij 1937, D. botsharnikovi Gussakovskij 1937, D. clavimana Gussakovskij 1937, D. ruthenica Gussakovskij 1937. An original key to the species is provided.

Sexual behavior of the digger wasp Sphex ingens Smith (Hymenoptera, Sphecidae)

A species’ mating system depends on its spatial distribution and temporal availability of mating opportunities, as well as on the resources that create these opportunities. In addition, for many species, courtship is driven by specific behaviors that precede and follow copulation. Although Sphex ingens is a taxonomically well known species of digger wasp, its ecology and behavior remain poorly known. Hence, we analyzed patterns and trends of sexual behavior, in order to understand whether courtship can persist in a polygamous mating system. We monitored by video wasp populations in Ilha Grande, southeastern Brazil. Based on the observed behaviors, we calculated stochastic probabilities with a Markov chain to infer on behavioral trends. We recorded four behavioral phases based on 19,196 behavioral acts observed in 224 copulation attempts. There were no significant differences in common behavioral acts between males and females. The copulation patterns, conflicts, and trends observed in S. ingens clearly show the influence of sexual selection in its promiscuous mating system.

A faunistic study on digger wasps (Hymenoptera: Crabronidae, Sphecidae) of Iran

The present paper deals with the fauna of digger wasps of the families Crabronidae and Sphecidae from various regions of Iran. Totally 16 species of 13 genera (Crabronidae: 11 species of 9 genera and Sphecidae: 5 species of 4 genera) were collected and identified.

Cultivation reveals physiological diversity among defensive 'Streptomyces philanthi' symbionts of beewolf digger wasps (Hymenoptera, Crabronidae).

Background‘Candidatus Streptomyces philanthi’ is a monophyletic clade of formerly uncultured bacterial symbionts in solitary digger wasps of the genera Philanthus, Philanthinus and Trachypus (Hymenoptera, Crabronidae). These bacteria grow in female-specific antennal reservoirs and – after transmission to the cocoon – produce antibiotics protecting the host larvae from fungal infection. However, the symbionts’ refractoriness to cultivation has thus far hampered detailed in vitro studies on their physiology and on the evolutionary changes in metabolic versatility in response to the host environment.ResultsHere we isolated in axenic culture 22 ‘Streptomyces philanthi’ biovars from different host species. Sequencing of gyrB revealed no heterogeneity among isolates within host individuals, suggesting low levels of (micro)diversity or even clonality of the symbionts in individual beewolf antennae. Surprisingly, however, isolates from different host species differed strongly in their physiology. All biovars from the Eurasian/African Philanthus and the South American Trachypus host species had high nutritional demands and were susceptible to most antibiotics tested, suggesting a tight association with the hosts. By contrast, biovars isolated from the genus Philanthinus and the monophyletic North American Philanthus clade were metabolically versatile and showed broad antibiotic resistance. Concordantly, recent horizontal symbiont transfer events – reflected in different symbiont strains infecting the same host species – have been described only among North American Philanthus species, altogether indicative of facultative symbionts potentially capable of a free-living lifestyle. Phylogenetic analyses reveal a strong correlation between symbiont metabolic versatility and host phylogeny, suggesting that the host environment differentially affects the symbionts’ evolutionary fate. Although opportunistic bacteria were occasionally isolated from the antennae of different host species, only filamentous Actinobacteria (genera Streptomyces, Amycolatopsis and Nocardia) could replace ‘S. philanthi’ in the antennal gland reservoirs.ConclusionOur results indicate that closely related bacteria from a monophyletic clade of symbionts can experience very different evolutionary trajectories in response to the symbiotic lifestyle, which is reflected in different degrees of metabolic versatility and host-dependency. We propose that the host-provided environment could be an important factor in shaping the degenerative metabolic evolution in the symbionts and deciding whether they evolve into obligate symbionts or remain facultative and capable of a host-independent lifestyle.

The digger wasps of the genus Alysson Panzer (Hymenoptera: Crabronidae: Bembicinae) of Russia and adjacent territories, with a key to species and new synonymies.

Nine species of Alysson Panzer 1806 are recorded from Russia and adjacent territories. The new synonymy is proposed for Alysson pertheesi Gorski 1852 =A. fuscatus var. jaroslavensis Kokujev 1906, =A. harbinensis Tsuneki 1967; Pompilus spinosus (Panzer 1801) =Alysson katkovi Kokujev 1906. The number of valid species-group taxa in the genus Alysson is reduced to 39 species. An original key to the species is provided.

Complex-to-predict generational shift between nested and clustered organization of individual prey networks in digger wasps.

Although diet has traditionally been considered to be a property of the species or populations as a whole, there is nowadays extensive knowledge that individual specialization is widespread among animal populations. Nevertheless, the factors determining the shape of interactions within food webs remain largely undiscovered, especially in predatory insects. We used an aggregation of the digger wasp Bembix merceti to 1) analyse patterns of individual prey use across three flying seasons in a network–based context; and 2) test the effect of four potential factors that might explain network topologies (wasp mass, nest spatial distribution, simultaneous nest-provisioning, prey availability). Inter-individual diet variation was found in all three years, under different predator-prey network topologies: Individuals arranged in dietary clusters and displayed a checkerboard pattern in 2009, but showed nestedness in 2008 and 2010. Network topologies were not fully explained by the tested factors. Larger females consumed a higher proportion of the total number of prey species captured by the population as a whole, in such a way that nested patterns may arise from mass-dependent prey spectrum width. Conversely, individuals with similar body mass didn’t form clusters. Nested patterns seemed to be associated with a greater availability of the main prey species (a proxy for reduced intra-specific competition). Thus, according with theory, clusters seemed to appear when competition increased. On the other hand, the nests of the individuals belonging to a given cluster were not more closely located, and neither did individuals within a cluster provision their nests simultaneously. Thus, a female-female copying behaviour during foraging was unlikely. In conclusion, wasp populations can maintain a considerable individual variation across years under different food web organizations. The tested factors only partially accounted for the shift in network properties, and new analyses should be carried out to elucidate how diet network topologies arise in wasp populations.

A Chemical Lure for Stink Bugs (Hemiptera: Pentatomidae) is used as a Kairomone byAstata occidentalis(Hymenoptera: Sphecidae)

Abstract We tested lures in Washington and Georgia containing methyl (E,E,Z)-2,4,6-decatrienoate and/or methyl (E,Z)-2,4-decadienoate for capturing stink bug species (Hemiptera: Pentatomidae). In both states, we consistently captured adult females of the digger wasp Astata occidentalis Cresson (Hymenoptera: Sphecidae) in traps with lures that contained methyl (E,E,Z)-2,4,6-decatrienoate but not in traps with lures that contained only methyl (E,Z)-2,4-decadienoate. Astata occidentalis is a predator of pentatomid stink bugs (Hemiptera) and apparently uses methyl (E,E,Z)-2,4,6-decatrienoate as a host-finding kairomone. Methyl (E,E,Z)-2,4,6-decatrienoate is an aggregation pheromone of Plauti stali Scott (Hemiptera: Pentatomidae) that is also attractive to, and used for monitoring, the exotic brown marmorated stink bug, Halyomorpha halys Stal (Hemiptera: Pentatomidae). Wasps were captured from Jul through Sep with peak response in Aug in Washington. In Georgia, wasp capture was highest as soon as traps were de...

Spatial Nest‐Settlement Decisions in Digger Wasps: Conspecifics Matter more than Heterospecifics and Previous Experience

AbstractResearch into the driving forces behind spatial arrangement of wasp nests has considered abiotic environmental factors, but seldom investigated attraction or repulsion towards conspecifics or heterospecifics. Solitary female digger wasps (Hymenoptera) often nest in dense aggregations, making these insects good models to study this topic. Here, we analysed the nesting patterns in an area shared by three species of the genusBembix, in a novel study to discover whether female wasps are attracted to or repulsed by conspecific nests, heterospecific nests or their own previously established nests when choosing nest‐digging locations. Early in the season, each species showed a clumping pattern of nests, but later in the season, a random distribution of nests was more common, suggesting an early conspecific attraction. Such behaviour was confirmed by the fact that females started building their nests more frequently where other females of their species were simultaneously digging. The distances between subsequent nests dug by individual females were shorter than those obtained by random simulations. However, this pattern seemed to depend on the tendency to dig close to conspecifics rather than remain in the vicinity of previous nests, suggesting that females' experience matters to future decisions only on a large scale. Nesting patches within nest aggregations largely overlapped between species, but the nests of each species were generally not closer to heterospecific nests than expected by chance, suggesting that females are neither repulsed by, nor attracted to, congenerics within nest aggregations. A role of the spatial distribution of natural enemies on the observed nesting patterns seemed unlikely.Bembixdigger wasp nest aggregations seem thus to be primarily the result of female–female attraction during nest‐settlement decisions, in accordance with the ‘copying’ mechanisms suggested for nesting vertebrates.

Subunit-Dependent Inhibition of Neuronal Nicotinic Acetylcholine Receptors by Philanthotoxins

Philanthotoxin-433 (PhTX-433) is the active component of the Egyptian solitary digger wasp, Philanthus triangulum, venom which non-selectively inhibits several excitatory ion channels. To improve selectivity two synthetic analogues, Philanthotoxin-343 (PhTX-343) and Philanthotoxin-12 (PhTX-12), were developed. Previous work showed a 22-fold selectivity for PhTX-12 on embryonic muscle-type nicotinic acetylcholine receptors (M-nAChR) naturally expressed in the TE671 cell line in comparison to PhTX-343. In this study, we investigated the pharmacological action of both analogues on different mammalian hetero-oligomeric neuronal nicotinic acetylcholine receptor (N-nAChR) subunit combinations expressed in Xenopus oocytes. Whole-cell currents in response to application of acetylcholine alone or co-applied with PhTX-analogue were studied electrophysiologically using two-electrode voltage-clamp at three different membrane holding potentials (VH = −60 mV, −80 mV and −100 mV). Concentration-inhibition curves were constructed and IC50 values estimated for each holding potential. The IC50 values for PhTX-343 inhibition of α3β4, α3β2, α4β2 and α4β4 peak currents at −100 mV were 0.077 µM (n=9), 3.20 µM (n=8), 0.170 µM (n=7) and 0.28 µM (n=6) respectively; for PhTX-12 they were 2.03 µM (n=8), 36.0 µM (n=10), 0.430 µM (n=7) and 1.82 µM (n=9) respectively; i.e. in contrast to M-nAChR, PhTX-343 was more potent than PhTX-12 in all cases. The potency of PhTX-343 was strongly augmented by holding the cell at more negative VH while this was not the case for PhTX-12 where weak voltage-dependence was observed. The variation in potency is most likely due to a single amino acid change in the β2/4 subunit pore lining region. Therefore, we conclude that PhTX-343 works as a potent open channel blocker of the mammalian heteromeric N-nAChR and has binding site deep in the channel while the PhTX-12 site is near to the outside of channel.

Evaluating buprestid preference and sampling efficiency of the digger wasp, Cerceris fumipennis, using morphometric predictors.

In-ground colonies of the native digger wasp, Cerceris fumipennis Say (Hymenoptera: Crabronidae), were sampled over two years in four New York State counties to characterize prey range, primarily their preying on beetles in the metallic wood-boring family, Buprestidae. These records were also used to evaluate beetle sampling efficiency by comparing collected beetles to historic county records and to identify limitations of wasp-mediated sampling in study areas. Overall, 1,530 beetles representing three families and 44 beetle species were collected from C. fumipennis . Five of these species ( Agrilus cuprescens (Ménétriés) (Coleoptera: Buprestidae), A. pensus Horn , Buprestis nutalli Kirby , Chrysobothris scabripennis Gory and Laporte , Dicerca pugionata (Germar)) were new prey records for C. fumipennis . The wasps exhibited a strong preference for larger beetle genera (e.g., Dicerca, Buprestis ), which accounted for 68% of beetles caught. Agrilus and Chrysobothris were the next dominant genera, accounting for 16% and 11%, respectively. A 4–19 mm prey size range is proposed, as all beetles collected were within this range despite the availability of prey outside of this range. Cerceris fumipennis caught 43% of the 42 buprestids species present in museum records from the four census counties as well as an additional 23 buprestid species that were not represented in museum records. Of the 22 buprestid species identified in museum collections that were not caught by C. fumipennis in the census counties, only one was within the proposed size range and active during the C. fumipennis flight season (late June through August). Overall, sampling C. fumipennis colonies over two summers at five sites resulted in 32% of the recorded buprestid species in New York State being caught, indicating that monitoring colonies is an efficient and viable means of quantifying buprestid assemblages.

Morphology, Chemistry and Function of the Postpharyngeal Gland in the South American Digger Wasps Trachypus boharti and Trachypus elongatus

Microbes pose severe threats to animals as competitors or pathogens and strongly affect the evolution of life history traits like parental care. Females of the European beewolf Philanthus triangulum, a solitary digger wasp, provision their offspring with paralyzed honeybees and embalm them with the secretion from large postpharyngeal glands (PPG) that contain mainly unsaturated hydrocarbons. This coating changes the physico-chemical properties of the prey surface, causes a reduction of water condensation and retards growth of mold fungi. Here we examined the closely related South American genus Trachypus, which shows a life-history similar to Philanthus. We investigated whether Trachypus spp. also possess PPGs and embalm larval provisions. Using histological methods and 3D reconstructions we show that Trachypus boharti and T. elongatus possess PPGs that are similar to P. triangulum but somewhat smaller. The ultrastructure of the gland epithelium suggests that the gland content is at least partly sequestered from the hemolymph. Chemical analyses using gas chromatography / mass spectrometry revealed that both the cuticle and PPGs of Trachypus contain mainly unsaturated long-chain hydrocarbons. The gland of T. boharti additionally contains long-chain ketones. The hydrocarbons from the PPG of T. elongatus occurred on prey bees excavated from nests in the field but not on conspecific control bees. While the embalming only slightly elevated the amount of hydrocarbons on prey bees, the proportion of unsaturated hydrocarbons, which is crucial for the antifungal effect, was significantly increased. The Trachypus species under study possess PPGs that are very similar to the PPG of P. triangulum with regard to morphology, ultrastructure and chemistry. Moreover, we provide clear evidence that T. elongatus females embalm their prey, presumably as a means of prey preservation. The observed differences among Trachypus and Philanthus in gland size and prey embalming may have evolved in response to divergent ecological conditions.

The Sphex story: How the cognitive sciences kept repeating an old and questionable anecdote

The Sphex story is an anecdote about a female digger wasp that at first sight seems to act quite intelligently, but subsequently is shown to be a mere automaton that can be made to repeat herself endlessly. Dennett and Hofstadter made this story well known and widely influential within the cognitive sciences, where it is regularly used as evidence that insect behavior is highly rigid. The present paper discusses the origin and subsequent empirical investigation of the repetition reported in the Sphex story. The repetition was first observed by Henri Fabre in 1879, and the last empirical study I found was published in 1985. In contrast to the story's clear message, the actual results have always been equivocal: the endless repetition is not standard. In addition, this repetition itself has become a minor aside in the literature on digger wasps when put in the perspective of many other examples of adaptiveness and flexibility. Nevertheless, the story and its message have to this day persevered within the cognitive sciences. For some reason, the counterevidence has been neglected time and again. The paper closes by presenting two different but compatible hypotheses that could explain why humans keep repeating this particular anecdote.

Diversity of digger wasps in Kasnak Oak Forest Nature Reserve, Isparta, Turkey, with records of eight species new to Turkey (Hymenoptera: Sphecidae, Crabronidae and Ampulicidae)

Three stations selected for altitude and habitat types within the Kasnak Oak Forest Nature Reserve (Isparta, Turkey) were studied comparatively for species composition, richness and abundance of the Hymenoptera families Ampulicidae, Crabronidae, and Sphecidae. A total of 56 species was recorded, 1 from the family Ampulicidae, 43 from the family Crabronidae and 12 from the family Sphecidae. 8 species are new records for Turkey.

A cladistic analysis and classification of the subfamily Bembicinae (Hymenoptera: Crabronidae), with a key to the genera.

A cladistic analysis of the digger wasp subfamily Bembicinae based on morphological characters is presented. The underlying data matrix comprises 83 terminal taxa (coded on genus-level) and 64 morphological characters. The resulting strict consensus tree was used as the basis for a revised tribal and subtribal classification of the Bembicinae. Based on a previously published classification, we herewith propose a change: the tribe Heliocausini Handlirsch 1925, stat. resurr. (composed of Acanthocausus Fritz & Toro 1977, Heliocausus Kohl 1892, and Tiguipa Fritz & Toro 1976) is separated from Bembicini Latreille 1802. Four tribes are recognized within the subfamily Bembicinae and seven subtribes within the tribe Gorytini and two subtribes in the tribe Nyssonini, based on the present cladistic analysis.The subtribe Nurseina Nemkov & Lelej, subtrib. nov. (comprising of Nippononysson Yasumatsu & Maidl 1936 and Nursea Cameron 1902) is separated from other genera in the tribe Nyssonini Latreille 1804. An new identification key to the genera of the Bembicinae is provided.

First detection of Agrilus planipennis in Connecticut made by monitoring Cerceris fumipennis (Crabronidae) colonies

Smoky winged beetle bandits, Cerceris fumipennis Say, digger wasps in the family Hymenoptera: Crabronidae: Cercerini, provision their underground nests with adult metallic wood-boring beetles (Coleoptera: Buprestidae). Researchers, as well as engaged community volunteers, in several states have monitored female wasps returning to their nests as a means to detect invasive buprestid species. In this paper, we report the first detection of emerald ash borer (Agrilus planipennis Fairemore), an invasive beetle responsible for killing millions of ash trees in North America, in Connecticut by C. fumipennis and discuss its relationship to A. planipennis survey efforts by other modalities in the state. We also report detections of A. planipennis by C. fumipennis in Illinois, New York and Ontario; all of which were made after it was known the beetle was in the area. These findings support the use of C. fumipennis as a biomonitoring tool and bolster the use of engaged volunteers.

Defensive microbial symbionts in Hymenoptera

Summary In all stages of their life cycle, insects are threatened by a multitude of predators, parasites, parasitoids and pathogens. The lifestyles and feeding ecologies of some hymenopteran taxa render them especially vulnerable to pathogen infestation. Specifically, development in sub‐terranean brood cells, mass provisioning of resources for the offspring and the life of social insects in large communities can enhance the risk of pathogen infestation and/or the spread of disease among conspecifics. To counteract these threats, insects have evolved mechanical, chemical and behavioural defences as well as a complex immune system. In addition to the host's own defences, some Hymenoptera are associated with protective symbionts. Leaf‐cutting ants, solitary digger wasps, bees and bumblebees engage in symbiotic interactions with bacteria that protect the adult host, the developing offspring or the food resources against microbial infections. In the well‐studied cases of ants and wasps, the protective activity is mediated by the production of antimicrobial secondary metabolites. In other symbiotic interactions, however, competitive exclusion and immune priming may also play an important role in enhancing protection. Phylogenetic studies indicate that the defensive associations in Hymenoptera are generally more dynamic than the intimate nutritional mutualisms, with horizontal transfer or de novo uptake of the symbionts from the environment occurring frequently. Mutualistic micro‐organisms can also significantly influence the outcome of host‐parasitoid interactions. Some insects are protected by symbiont‐produced toxins against parasitic wasps. Ichneumonid and braconid parasitoids, on the other hand, are associated with symbiotic viruses that are injected into the caterpillar host during oviposition and suppress its immune system to the advantage of the parasitoid. The increasing affordability of next‐generation sequencing technologies will greatly facilitate the analysis of insect‐associated microbial communities and undoubtedly uncover a plethora of as yet unknown protective symbioses. However, a detailed understanding of the host's natural history is indispensable for elucidating the fitness benefits of the symbionts and the molecular basis of symbiont‐conferred protection.

Dynamics of symbiont-mediated antibiotic production reveal efficient long-term protection for beewolf offspring

BackgroundInsects have evolved a wide range of mechanisms to defend themselves and their offspring against antagonists. One of these strategies involves the utilization of antimicrobial compounds provided by symbiotic bacteria to protect the host or its nutritional resources from pathogens and parasites. In the symbiosis of the solitary digger wasp, Philanthus triangulum (Hymenoptera, Crabronidae), the bacterial symbiont ‘Candidatus Streptomyces philanthi’ defends the developing larvae against pathogens by producing a mixture of at least nine antimicrobial substances on the cocoon surface. This antibiotic cocktail inhibits the growth of a broad range of detrimental fungi and bacteria, thereby significantly enhancing the offspring’s survival probability.ResultsHere we show that the production of antimicrobial compounds by the beewolf symbionts is confined to the first two weeks after cocoon spinning, leading to a high concentration of piericidins and streptochlorin on the cocoon surface. Expression profiling of housekeeping, sporulation, and antibiotic biosynthesis genes indicates that antibiotic production coincides with morphological differentiation that enables the symbionts to survive the nutrient-limited conditions on the beewolf cocoon. The antibiotic substances remain stable on the cocoon surface for the entire duration of the beewolf’s hibernation period, demonstrating that the compounds are resistant against environmental influences.ConclusionsThe antibiotic production by the beewolf symbionts serves as a reliable protection for the wasp offspring against pathogenic microorganisms during the long and unpredictable developmental phase in the subterranean brood cells. Thus, the beewolf-Streptomyces symbiosis provides one of the rare examples of antibiotics serving as an efficient defense in the natural environment and may aid in devising new strategies for the utilization of antibiotic combination therapies in human medicine against increasingly resistant bacterial and fungal pathogens.

Psenulus meridionalis Beaumont, 1937, a digger wasp species new to the fauna of Poland (Hymenoptera, Crabronidae)

The paper presents Psenulus meridionalis Beaumont, 1937 – the digger wasp new to Polish fauna. Three specimens were collected in the Podlasie region (Biebrza National Park) and another two in the Wielkopolska-Kujawy Lowland. The newly revealed localities define now the northern limit of the species range in Europe. Currently, sixspecies representing the genus are known from Poland.