The horse guard wasp (''Stictia carolina'') is a type of

sand wasp A sand wasp is a wasp of one of the following groups: * '' Ammophila'', a narrow-waisted genus of hunting wasps that often nests in sandy soil * Bembicini The Bembicini, or sand wasps, are a large tribe of bembicid wasps, comprising 20 genera. ...

(Bembicini) from the eastern

United States The United States of America (USA), also known as the United States (U.S.) or America, is a country primarily located in North America. It is a federal republic of 50 U.S. state, states and a federal capital district, Washington, D.C. The 48 ...

which preys primarily upon

horse-flies Horse flies and deer flies are true flies in the family Tabanidae in the insect order Diptera. The adults are often large and agile in flight. Only females bite land vertebrates, including humans, to obtain blood. They prefer to fly in sunli ...

(Tabanidae). It is a large, colorful, fast-flying wasp, one of 28 species in the genus ''

Stictia ''Stictia'' is a largely neotropical genus of large, often brightly colored predatory sand wasps, consisting of about 30 species. List of species (selected) * '' Stictia andrei'' (Handlirsch, 1890) * '' Stictia antiopa'' (Handlirsch, 1890) ...

'' (which occur throughout

North North is one of the four compass points or cardinal directions. It is the opposite of south and is perpendicular to east and west. ''North'' is a noun, adjective, or adverb indicating Direction (geometry), direction or geography. Etymology T ...

and

South America South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a considerably smaller portion in the Northern Hemisphere. It can also be described as the southern Subregion#Americas, subregion o ...

), all of which have similar biology.

Biology

A female wasp of this species may take anywhere from 30 to 60 flies as food to provision each one of her nests; she makes a new nest for every egg she lays. Nests are simple

burrow file:Chipmunk-burrow (exits).jpg, An eastern chipmunk at the entrance of its burrow A burrow is a hole or tunnel excavated into the ground by an animal to construct a space suitable for habitation or temporary refuge, or as a byproduct of Animal lo ...

s some 15 cm deep, with a single enlarged chamber at the bottom. An egg is laid in the empty chamber, and the female wasp brings back

paralyzed Paralysis (: paralyses; also known as plegia) is a loss of motor function in one or more muscles. Paralysis can also be accompanied by a loss of feeling (sensory loss) in the affected area if there is sensory damage. In the United States, r ...

flies and sometimes silver-spotted skipper larvae until the chamber is full (

mass provisioning Mass provisioning is a form of parental investment in which an adult insect, most commonly a hymenopteran such as a bee or wasp, stocks all the food for each of her offspring in a small chamber (a "cell") before she lays the egg. This behavior is ...

), at which point she closes the nest and begins another. Numerous females often excavate nests within a small area where the soil is suitable, creating large and sometimes very dense nesting aggregations. Nearly all the prey are biting female horse-flies; exceptionally, other flies such as ''Odontomyia'' and the screw-worm fly ''Cochliomyia'' are taken. Horses and cattle are not disturbed by the presence of the horse guard wasp, despite its rapid flight and loud buzzing; the same animals may however respond strongly to horse-flies or

bot flies Botflies, also known as warble flies, heel flies, and gadflies, are flies of the family Oestridae. Their larvae are internal parasites of mammals, some species growing in the host's flesh and others within the gut. ''Dermatobia hominis'' is t ...

. Nonetheless, these beneficial wasps are sometimes eliminated by horse owners unfamiliar with them, thus exacerbating their problems with horse-flies. The horse guard wasp acts as a natural biological control, helping to keep horse fly populations down. This makes it important to the economies of those areas where horses are reared; in the words of Bohart and Menke, it "fully lives up to its name". The generic name "Stictia" may be related to Ancient Greek "stictis" which means "spotted"; the specific name "carolina" is a reference to the eastern American state to which this species is native. It occurs from the 100th meridian eastwards, and as far north as Pennsylvania.

References

{{Taxonbar, from=Q5905609 Bembicidae Biological pest control wasps Hymenoptera of North America Insects described in 1793