Biology and Pest Status of Venomous Wasps

Abstract

There are about 15,000 species of aculeate (stinging) wasps in the world (56). However, 95% of these are solitary and nonaggressive species that use their stings primarily for subduing prey. Their venoms are also specialized for this purpose and most cause only a slight and temporary pain to humans. Many are so small that the sting cannot penetrate human skin (33). Therefore, with the exception of infrequent complications resulting from stinging by Mutillidae, Eumenidae, Sphecoidea, Be­ thyloidea, and Scolioidea (30), most wasp stings affecting humans are inflicted by the social Vespidae. These wasps use the sting primarily as a defensive weapon, and the venom contains materials that cause intense pain to vertebrates. In addition, because social vespids live in colonies comprised of 30 to several thousand individu­ als, stings inflicted by disturbance of the colony are usually multiple and therefore more serious. Good data on deaths from Hymenoptera stings are unavailable. Stings from vespids were reported to cause 15-20 deaths per year in the United States, although the actual number is probably much higher. Since most stings serious to humans are inflicted by social wasps, this review is restricted to the Vespidae, with special emphasis on the Vespinae (hornets and yellowjackets ). Nearly all literature references to the Vespidae have used the classification system of Bequaert (13, 14), but Richards (126) divided the Vespidae into three families: Vespidae, Eumenidae, and Masaridae. Under this system the Vespidae is comprised of the Stenogastrinae, the Polistinae, and the Vespinae. These three subfamilies contain about 800 species (142, 164). This classification is followed in this review. The Vespidae include a number of species of extremely diverse habits. Behavior varies from presocial to eusocial in those species that are known, and for many