Miscophus littoreus

Face of Miscophus littoreus, from Andrade (1960).

For this post's semi-random subject, I drew the crabronid wasp species Miscophus littoreus. This small, mostly black wasp (about five millimetres in length) was described from Morocco by Nuno Freire de Andrade in 1960, with the original description seeming to still be the only source for information about it. Miscophus is a cosmopolitan genus, found on all continents except Australia and Antarctica (though its presence in South America seems marginal). They are characterised by wings with the outer veins reduced or lost so they have at most two submarginal and two discoidal cells, with the second submarginal cell (if present) triangular and petiolate, and mid-coxae that are very closely placed or touching each other along the midline. Miscophus littoreus is one of a group of closely related species within this genus found between north Africa and central Asia with the fuller complement of wing cells, and the features distinguishing it from other species in this group are rather fine: a slightly longer clypeus, a shinier and less punctate mesosoma. The wings are darker shaded towards the ends, and females have a tarsal comb (a series of longer spines along the front edge of the fore tarsus).

Another species of Miscophus, M. ater, from here.

There don't seem to have been any natural history observations made for M. littoreus itself but we can infer that it is probably similar in behaviour to other species of Miscophus. North American Miscophus species dig nests as short burrows in sandy soil, only a few centimetres in length (Bohart & Menke 1976); this is why the females have the tarsal comb. Nests have at most only a few cells each, often only one. The cells are stocked with small spiders, often juveniles (though I suspect the preference for juvenile spiders has more to do with size preference than anything else. The tendency in many Miscophus species to show a reduction in the wing venation is related to a broader tendency in the genus to not be enthusiastic fliers. Most Miscophus females run along the ground rather than fly when hunting prey, and they do the same when carrying prey back to the nest. At most, they may make only short hopping flights. Miscophus individuals on the ground may be mistaken for ants, which they often hang around while foraging, hoping to avoid attention while they search for unsuspecting spiders.

REFERENCES

Andrade, N. F. de. 1960. Palaearctic Miscophus: bicolor group and isolated species (Hymenoptera, Sphecidae). Memórias e Estudos do Museu Zoológico da Universidade de Coimbra 262: 3–136.

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