Defining the Order. This vast assemblage of insects is second only to Coleoptera (Beetles) in the number of described species. Of the 6,000–7,000 new species of insects described annually, Hymenoptera is a large component, especially in the parasitic wasp groups. Nearly all commonly encountered Hymenoptera can be recognized by a narrow "waist." When winged, the wings form two membranous pairs that can be hooked together. Ovipositors of Hymenopteta are usually well developed and modified into a stinger in the higher forms of the order. Because the "stinger" of such forms has developed from the ovipositor of females, male wasps are not able to sting. Many species of Hymenoptera are extremely small and are thus difficult to identify even to family. A publication by Edward Mockford in 1997 recorded discovery of a new species of tiny wasp that is now known as the tiniest existing insect.
Benefits to mankind. This order of insects is considered to be the most beneficial to humankind of all the insects. The strongest benefit performed by most Hymenoptera is active pollination of plants, ensuring the proper development of many fruit and vegetable crops. Many kinds of Hymenoptera are also helpful in their actions of parasitism and predation on pest species of insects.
Ants. These are familiar insects, and are most numerous in tropical forests, where surveys of tree species of insects have consistently shown that individuals of ants compose some 50 percent of the entomofauna. Some species of ants squirt formic acid into wounds. There are more than 8,000 species of ants in the world. Ants are often confused with termites, but have a slender waist and elbowed antennae. In some cases, ants can by pests, especially in such species as the Carpenter Ant, which invades houses near wooded areas. Fire Ants, of course, are a major concern in the Southern United States. Army Ants are perhaps the most fascinating species of ant, capable of preying upon insects, small reptiles, birds, and even small mammals.
Wasps. This group of Hymenoptera includes some familiar types, such as Hornets, Spider Wasps, and Hunting Wasps. Sawflies are also a group of wasps, composed of several families, and noteworthy because they have no "waist" that is present in all other Hymenoptera. Tiny parasitic wasps are one of the most beneficial groups of insects, reducing populations of pest species. The Family Ichneumonidae includes vast numbers of parasites also, and is considered one of the largest families of insects.
Bees. The most familiar bee, of course, is the Honeybee, a social insect that was imported from Europe for honey production. Most bees are not social and do not build large nests like the Honeybee. The most colorful of bees are a group of Tropical American insects called Orchid Bees, which have brilliant iridescent colors of green, blue and red. The males visit orchid flowers. Africanized Bees, or Killer Bees, are a major health threat to the population of the Southern United States, and are slowly expanding their geographic range. Entomologists are attempting to find ways to alleviate the invasion of this aggressive strain of bees.
Selected References:
Evans, H. E. & Ebarhard, J. W. 1970. The Wasps. University of Michigan Press, Ann Arbor.
Holldober, B. & Wilson, E. 0. 1990. The Ants. The Belknap Press of Harvard University Press, Cambridge.
Krombein, K. V., Hurd, P. D. Jr., & Smith, D. R. 1979. Catalog of Hymenoptera in America North of Mexico. Volumes 1-3. Smithsonian Press, Washington, D. C.
Michener, C. D. 1974. The Social Behavior of Bees. A Comparative Study. Belknap Press of Harvard University Press.
Michener, C. D., McGinley, R. J. & Danforth, B. N. 1994. The Bee genera of North and Central America (Hymenoptera: Apoidea). Smithsonian Institution Press, Washington and London.
Mitchell, T. B. 1960-1962. "Bees of Eastern United States." Volume 1, Technical Bulletin141, North Carolina Agricultural Experiment Station.
Prepared by the Department of Systematic Biology, Entomology Section,
National Museum of Natural History, in cooperation with Public Inquiry Services,
Smithsonian Institution
Information Sheet Number 184, May 1999
