Olgia helena, copyright Centre for Biodiversity Genomics.

Belongs within: Apoidea.
Contains: Alyssontini, Nyssonini, Heliocausina, Ammatomus, Stizini, Bembicina, SpheciusClitemnestra, Ochleroptera, Argogorytes, Gorytina.

The Bembicidae are a diverse group of apoid wasps whose members commonly possess an oblique carina near the rear corners of the scutum and/or two spurs on the mid tibiae (Bohart & Menke 1976).

Wasps in the sand
Published 14 October 2014
Sand wasp Bembix oculata with prey (a bombyliid, I think), copyright Carlos Enrique Hermosilla.

The sand wasps of the tribe Bembicini are a diverse group of about 500 species of wasp that get their name because, obviously, of their habit of constructing burrows in sand-banks. Like other members of the wasp family Crabronidae, sand wasps provision these burrows with food for their larvae in the form of other insects. The adults themselves feed on nectar. Some of the Bembicini are among the larger members of the Crabronidae, and most of them are strikingly marked in black and yellow, white or red. Other characteristics of the group include an elongate labrum above the mouth, and the reduction of the ocelli, often to simple scars.

Bembicins are divided between a reasonable number of genera (Bohart & Menke, 1976, listed fifteen, but subsequent authors have recognised more) but the greater number of species are included in just one of these, the cosmopolitan Bembix with over 300 species (some older sources spell this name ‘Bembex‘, but Bembix seems to be correct). Bembix is also the only genus found outside the Americas. Bohart & Menke (1976) suggested three main lineages within the Bembicini: one containing the relatively plesiomorphic genera Microbembex and Bicyrtes, a group of four genera including Stictiella and Glenostictia in which the ocelli are sunken into pits, and a large group containing genera related to Bembix with a raised welt at the front of the scutum on the thorax.

Sand Wasp—Bembix americana from Dick Walton on Vimeo.

While other wasps will lay their egg(s) on a paralysed insect in a brood chamber and then fly off never to return, many bembicins continue to bring fresh food items to the burrow throughout their larvae’s development (take a look at the video above, by Dick Walton). The majority of bembecins provide their larvae with flies as food, which they paralyse with their sting and then carry back to the burrow between their mid-legs. Only a small number of genera regularly use other prey, though notably these genera include both Bicyrtes and Microbembex (so predation on flies is possibly ancestral for a clade excluding these two genera rather than for the tribe as a whole). Bicyrtes species stock their burrows with bugs (Heteroptera), most commonly nymphs. Microbembex species are the gourmands of the tribe, taking prey ranging from mayflies to midges. They are also somewhat unusual in that they stock their burrows with dead as well as paralysed insects (because they are providing food continuously, freshness over an extended period is less important than it is for other wasps). Females may compete for dead insects: in the words of J. Parker (as quoted by Bohart & Menke, 1976): “The struggles at the mouth of the burrow for the possession of a dead insect are frequent and furious, the contestants grappling and rolling over and over on the sand. Frequently it happens that the prey is dropped in the struggle, and while the pair of contestants are rolling on the sand a third wasp comes along and settles the quarrel by quietly carrying off the coveted treasure”. Of the other bembecin genera, species of the genera Stictiella and Editha are predators of Lepidoptera. Editha species are found in southern South America, and include the largest of the bembecins. Xerostictia longilabris, a member of the Stictiella-group from southern North America that gets its own genus, has been recorded stocking its burrow with ant-lions and flatid bugs (Evans 2002). Members of other genera may also stock their burrows with prey other than flies, though in the majority of cases they do not do so exclusively (Evans 2002).

Sand wasp, possibly Microbembex monodonta, burying the entrance to her burrow, copyright Tim Lethbridge.

Many bembecins (most notably in the genera Microbembex and Bembix) nest gregariously, and may form sizable colonies. Species of Bembix will maintain the same colony from year to year. In some species, such as B. pallidipicta, the females may dig accessory burrows near the main burrow without laying eggs in them; these have been presumed to act as decoys to discourage parasitoids or kleptoparasites. Males perform prolonged ‘sun dances’ above the colony in which they fly in circles or figures-of-eight, looking out for attractive females (O’Neill 2001). Males of many species have a serrated mid-femur that they use to hold down the female’s wings while mating; in species without these leg serrations, mating may involve more of a struggle (Bohart & Menke 1976). The male produces a loud chirping during mating, presumably just to add atmosphere.

Systematics of Bembicidae

Characters (from Bohart & Menke 1976, as Nyssoninae excluding Mellinus): Eyes with inner margins essentially parallel or converging below, if converging above then at least hindocelli somewhat distorted and scar-like. Mandible not notched nor toothed externoventrally, inner subteeth, when present, associated with apical tooth; mandible socket open; palpal formub usually 6-4. Scutum without complete notauli; an oblique scutal carina often present. Episternal sulcus present or absent, sometimes forming a continuous arc with scrobal sulcus (episternal-scrobal sulcus); omaulus usually present. Midtibia with two apical spurs (sometimes one or none), claws simple, midcoxae usually essentially contiguous, plantulae present or absent. Propodeal sternite absent. Forewing with two or three submarginal cells of which II usually receives at least one recurrent vein, three discoidal cells present. Hindwing media diverging before, at or beyond cu-a; jugal lobe usually small, rarely absent, at most half as long as anal area. Gaster usually sessile but peduncle, when present, made up of both tergum and sternum; male gaster with six or seven exposed terga; sternum VIII often modified and largely or entirely concealed; male genitalia usually with volsella differentiated into cuspis and digitus.

<==Bembicidae [Bembecides, Bembiciles, Bembicinae, Gorytini, Spheciina]
| i. s.: Kohlia Handlirsch 1895 [incl. Stizobembex Gussakovskij 1952]BM76
| |--*K. cephalotes Handlirsch 1895BM76
| |--K. coxalis Morice 1897BM76
| `--K. pavlovskii (Gussakovskij 1952) [=*Stizobembix pavlovskii]BM76
| `--NyssoniniPK17
| `--Tanyoprymnus Cameron 1905SN18, BM76 [incl. Ceratostizus Rohwer 1921BM76]
| `--T. moneduloides (Packard 1867)BM76 (see below for synonymy)
| `--BembicinaBM76
| |--Handlirschia Kohl 1896BM76
| | |--*H. aethiops (Handlirsch 1889) [=Sphecius aethiops]BM76
| | |--H. scoliaeformis (Arnold 1929)NP09
| | `--H. tricolor Gess 1973BM76
| `--Pterygorytes Bohart 1967NP09
| |--*P. valens (Fox 1897) [=Gorytes valens]BM76
| `--P. triangularis (Smith 1873) [=Gorytes triangularis]BM76
`--+--Trichogorytes Rohwer 1912 [Trichogorytina]NP09
| |--*T. argenteopilosus Rohwer 1912BM76
| `--T. cockerelli (Ashmead 1899) [=Harpactus cockerelli]BM76
| `--+--OchleropteraE66
| `--Olgia Radoszkowski 1877NP09, BM76 [incl. Kaufmannia Radoszkowski 1877BM76]
| |--*O. modesta Radoszkowski 1877BM76
| |--O. bensoni (Beaumont 1950) [=Gorytes bensoni]BM76
| |--O. helena Beaumont 1953BM76
| |--O. maracandica (Radoszkowski 1877) [=*Kaufmannia maracandica]BM76
| `--O. spinulosa de Beaumont 1953NP09
`--+--Exeirus Shuckard 1838BM76 [=Exirus Schulz 1906BM76; ExeirinaNP09]
| `--*E. lateritius Shuckard 1838C85 [incl. Sphecius lanio Stal 1857C85, E. lanioBM76]
| |--+--ArgogorytesNP09
| | `--Neogorytes Bohart in Bohart & Menke 1976NP09
| | |--*N. ecuadorae Bohart in Bohart & Menke 1976BM76
| | `--N. hansoni Bohart 2000NP09
| `--Paraphilanthus Vardy 1995NP09
| `--P. costaricae Vardy 1995NP09

Tanyoprymnus moneduloides (Packard 1867)BM76 [=Gorytes moneduloidesBM76, Ammatomus moneduloidesE66, *Ceratostizus moneduloidesBM76; incl. G. belfragei Cresson 1872BM76, *Tanyoprymnus longitarsis Cameron 1905BM76]

*Type species of generic name indicated


[BM76] Bohart, R. M., & A. S. Menke. 1976. Sphecid Wasps of the World. University of California Press: Berkeley.

[C85] Cardale, J. C. 1985. Vespoidea and Sphecoidea. In: Walton, D. W. (ed.) Zoological Catalogue of Australia vol. 2. Hymenoptera: Formicoidea, Vespoidea and Sphecoidea pp. 150–303. Australian Government Publishing Service: Canberra.

[E66] Evans, H. E. 1966. The Comparative Ethology and Evolution of the Sand Wasps. Harvard University Press: Cambridge (Massachusetts).

Evans, H. E. 2002. A review of prey choice in bembicine sand wasps (Hymenoptera: Sphecidae). Neotropical Entomology 31 (1): 1–11.

[NP09] Nemkov, P. G., & W. J. Pulawski. 2009. A cladistic analysis of Gorytina (Hymenoptera: Crabronidae: Bembicini), with a reclassification of the subtribe. Zootaxa 2069: 1–17.

O’Neill, K. M. 2001. Solitary Wasps: behavior and natural history. Cornell University Press.

[PK17] Peters, R. S., L. Krogmann, C. Mayer, A. Donath, S. Gunkel, K. Meusemann, A. Kozlov, L. Podsiadlowski, M. Petersen, R. Lanfear, P. A. Diez, J. Heraty, K. M. Kjer, S. Klopfstein, R. Meier, C. Polidori, T. Schmitt, S. Liu, X. Zhou, T. Wappler, J. Rust, B. Misof & O. Niehuis. 2017. Evolutionary history of the Hymenoptera. Current Biology 27 (7): 1013–1018.

[SN18] Sann, M., O. Niehuis, R. S. Peters, C. Mayer, A. Kozlov, L. Podsiadlowski, S. Bank, K. Meusemann, B. Misof, C. Bleidorn & M. Ohl. 2018. Phylogenomic analysis of Apoidea sheds new light on the sister group of bees. BMC Evolutionary Biology 18: 71.

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