Wasps – Hymenoptera

Identification & Descriptions
Wasp, common name applied to most species of hymenopteran insects (see Hymenoptera), except bees and ants. Insects known as wasps include the sawflies, the parasitic wasps, and the stinging wasps, which are the best known. About 75,000 species of wasps are known, most of them parasitic (see Chalcid; Ichneumon). wasp is any insect of the order Hymenoptera and suborder Apocrita that is not a bee, sawfly, or an ant. Less familiar, the suborder Symphyta includes the sawflies and wood wasps, which differ from the Apocrita by having a broad connection between the thorax and abdomen. Also, Symphyta larvae are mostly herbivorous and “caterpillarlike”, whereas those of Apocrita are largely predatory or parasitic.

Most familiar wasps belong to the Aculeata, a division of the Apocrita, whose ovipositors are modified into a venomous stinger. Aculeata also contains ants and bees. In this sense, the species called “velvet ants” (Mutillidae) are actually wasps.
A narrower meaning of the term wasp is any member of the Aculeate family Vespidae. This includes the yellowjackets (Vespula, Dolichovespula spp.) and hornets (Vespa spp.).

The following characteristics are present in most wasps:
• Two pairs of wings (exception: female Mutillidae)
• A stinger (only present in females because it derives from the ovipositor)
• Few or no hairs (in contrast to bees); exception: Mutillidae
• Predators or parasitoids, mostly on other insects; some species of Pompilidae, such as the tarantula hawk, specialize in using spiders as a host

Wasps are critically important in natural biocontrol. Almost every pest insect species has a wasp species that is predator or parasite upon it. Wasps are also increasingly used in agricultural pest control.

Wasps are characterized by two pairs of membranous wings and an ovipositor (tube for laying eggs) that may be modified in various ways. In some species one sex may be wingless. In the vegetarian sawflies, the abdomen is broadly attached to the thorax and the ovipositor is rigid; in the higher wasps, the abdomen is flexibly attached to the thorax and the ovipositor is movable. The larvae of parasitic wasps consume the bodies of other insects or, in a few cases, consume plant tissue. Most stinging wasps are predators or scavengers; their ovipositors may be modified to inject venom used for killing prey or for defense.

Unlike social wasps, sawflies and parasitic wasps are free-living-that is, they do not build nests. After depositing their eggs on a host plant or animal, the adult wasps fly off in search of food for themselves or more hosts for their larvae. The eggs are left to develop and hatch on their own. However, some stinging wasps live in societies that are more complex than those of social bees and ants.

Most wasps typically ignore people. For example, social insects that live in colonies will readily sting when they perceive their nest or territory is threatened while solitary insects only sting in self-defense when mishandled. In addition, only female wasps can sting. In any case, it is best to regard any wasp with care before attempting to control it, since stings can be very painful. The best and easiest way to tell wasps apart is to look at the relative size of the wasp, and the pattern on the abdomen.

Small wasps include yellow jackets and white grub parasites. Yellow jackets are social insects. Fertilized queens overwinter,then start a colony in the spring and provision the first brood of young. Once the first brood has matured, they will take over the provisioning duties, care for the queen and the following broods throughout the summer. In late summer, reproductive males and females will be produced, which consequently mate and then the females overwinter (colonies always die out at the end of the year). In order to eliminate yellow jacket wasps that are indirect competition with humans, the entire colony or nest must be eliminated. Football-shaped nests may be either in the ground or above ground, and will be paperlike.

White grub parasites, usually of the genus Scolia, are solitary wasps. They fly low over lawns in mid- to late summer. They will insert their eggs inside white grubs, which are pests of lawns. The wasp larvae will feed on the grubs as they develop. These wasps are in far less competition with humans. However, they will sting if disturbed.

Large wasps (up to 2″) include European hornets, baldfaced hornets and cicada killers. Cicada killers are solitary wasps, with the female provisioning larvae with cicadas in burrows in the soil during mid- to late summer. The larvae overwinter in their burrows. These wasps generally want nothing to do with humans and will rarely sting, even when bothered. European and baldfaced hornets, on the other hand, are colonial insects like yellow jackets. There is a reproductive queen, and many workers who tend the queen and the developing larvae. Nests are football-shaped and may be found in trees, shrubbery, or under eaves. These wasps are present well into the fall, but do not survive the winter. In order to control hornets, the nest of large, angry wasps must be eliminated. Proceed with extreme caution.

Finally, a medium-sized wasp named the velvet ant may also be present in lawns or pastures. These solitary wasps, as the name implies, are densely covered with hair. Males have wings, but females are wingless, and are sometimes confused with ants. Ants, however, have elbowed antennae, and a “hump” in the constriction between the thorax and abdomen. Velvet ants are either shades of brown or red and black, and females will sting if encountered.

• Chrysididae – cuckoo wasps
• Crabronidae
• Mutillidae – velvet ants
• Orussidae, and Syntexidae
• Pompilidae – spider wasps
• Rhopalosomatidae – rhopalosomatid wasps
• Sapygidae – club-horned wasps
• Scoliidae – scoliid wasps
• Sierolomorphidae – sierolomorphid wasps
• Sphecidae – digger wasps, e.g. the Cicada killer wasp
• Tiphiidae – flower wasps
• Vespidae – yellowjackets, hornets, paper wasps.
• Xiphydriidae

The stinging wasps rely on a nest from which they conduct many of their activities, especially rearing young. Wasp nests may be as simple as a straight burrow in the ground, like those made by the females of many digger wasps. Some wasp nests, such as those of mud daubers and potter wasps, are above ground, constructed of mud cavities attached to twigs, rocks, or human structures. The simplest mud nests contain only one or a few larval cells and are not used by the adults. Other mud nests contain many cells arranged side by side. Among the most intricate nests are those made of paper fibers collected from dry wood and bark and mixed with the wasps’ saliva. The vespoid wasps (yellow jackets, hornets, and paper wasps) build nests of this type. In each paper-fiber nest there are one or more combs, or densely packed arrays of larval cells. The adults may congregate on the combs, and some nests have an outer cover, forming a protective refuge for the whole colony. This is the familiar “hornet’s nest” that may house hundreds or thousands of individuals.

Wasp Facts
All worker wasps die out during the winter; the only wasps that survive are the queen wasps. Queen wasps hibernate during the winter inside the old nest or construct a small “golf ball” sized hibernation cell.

During April and until early June, the queen wasp will leave the old nest or hibernation cell and begin the construction of a brand new nest in a new location. The old nest or hibernation cells are never used again.

Nests are mostly made out of a mixture of chewed wood and wasp saliva. Queen wasps will often start to build their nests in roof voids, wall cavities or in outbuildings.

By the time September arrives the nest can be as large as a small armchair with up to 10,000 wasps using it.
During June and July you are unlikely to get wasp stings, as wasps are too busy chasing insects and bringing up the larval wasps. However as autumn arrives these activities stop and the wasps start to feed on fermenting, over ripe fruit. These “drunken wasps” are now at their most dangerous and can become very aggressive, with a wasp sting more likely to happen.

The question we are most asked is “How can I tell if I have a wasp nest?” and “How do I destroy a wasp nest?” I hope the following information will be useful:
The first thing to do is to look in your attic or look up into the top of your garage, shed or other outbuildings. During June and July the nest will only be the size of a tennis ball or football. It will be straw in colour and have “swirl shapes” all over it. From August to October it may become much bigger and a darker straw colour will lots of swirl patterns all over it. If you can’t see the nest then take a very slow walk around you property looking for wasps going in and out of a single entrance hole every 2-4 seconds. This will indicate a nest 4-6 inches behind this hole.

If you do discover a wasp nest or a wasp nest entrance hole, we recommend that the best way to kill the wasps nest is with our wasp nest destroyer kit.

If you cannot find the nest or entrance hole but are still plagued with wasps, then the best way to get rid of them will be to buy one of our wasp trap packs or electronic flying insect and wasp killers. These will kill wasps, significantly reducing numbers.