Wasp, line drawing.
- Andrew Howells
- © Australian Museum
Wasps belong to the Order Hymenoptera. They are a diverse group of insects: in Australia alone there are over 12,000 species, ranging from the tiny diapriid wasps, which are barely visible to the naked eye, to the spider wasps and cicada-killer wasps, capable of taking large prey. Most wasps have carnivorous larvae that feed on other insects and spiders. The adults provide food for them by capturing prey or by laying the egg on or near the food source, which might be an egg, larva or pupa of another insect.
What do wasps look like?
- 0.15 mm - 120 mm in length.
- Elongate or stout.
- Constricted at 'waist' appears to be pinched or like a leaf stalk.
- Appears hard.
- Short or long.
- Thread-like or club-like.
- Often distinctly elbowed.
- Segment closest to body longer than the others.
- Large and well separated.
- For chewing or munching.
- Held downward at rest.
- Two pairs if present.
- Both pairs are membranous and clear; with few veins and if cross-veins present form few cells. Veins never reach wing margin.
- Hindwing always shorter and narrower than forewing.
- Fore- and hindwing coupled tightly by a row of minute hooks (hamuli) along adjacent edges.
- At rest, wings are held flat over body, parallel or overlapping or they are held upright but not touching.
- Six legs.
- Generally thin, though thigh region of hindlegs often enlarged.
- With long spike (ovipositor/sting) sometimes visible but often folded below body, or retracted within the abdomen.
Where are wasps found?
- Almost everywhere.
- In soil, amongst plant debris and on vegetation especially flowers.
- On the ground.
- In galls created by them or others.
- Inside fruit especially figs.
- In the air.
- In the nests or burrows of other insects or even other species of wasps.
- Holes in the ground, or pre-existing cavities in rocks and wood.
- In mud or paper nests. Wasps that make these nests are often found hovering around water collecting moisture necessary for nest construction.
- Around the house.
What do wasps do?
- Most wasps are solitary nesters. Some nest together in groups occupying the nest much like the way humans occupy an apartment block.
- A few are truly social, that is, they form colonies where individuals share the responsibility of providing care for the young. Social wasps have a queen, reproductive males and sterile workers and soldiers.
- When disturbed run or fly away; may bite, sting or even swarm (rare) if threatened.
- They tend to hold their antennae out in front at rest and in motion.
- When searching they may rapidly flicker their antennae or wings. As they move they may also hop or stutter walk.
- They are generally strong fliers capable of long and rapid flights as well as hovering. Some may also just simply drift on air currents.
- Adults mostly feed on nectar. Some consume fluids from prey provided to young.
- They provide food for their young. Most are parasitoids laying eggs inside, on or near a host for offspring to devour as they grow. In this circumstance they may attack and paralyse prey before returning it back to the nest. A fewcapture prey, and chop it up for their offspring.
- Some look, smell or behave like other invertebrates. This mimicry lets them get close to intended prey or potential food stores.
- They are active during the day or night. Some are only active during twilight periods.
What looks similar?
- Bees are closely related to wasps and share many features. In general the following features distinguish bees from wasps: legs and body hairy with forked hairs; hindlegs enlarged to form baskets of hairs to carry pollen; wings have cells; movement generally restricted to interaction with flowers and returning to nests.
- Ants are closely related to wasps and share many features. To further complicate matters some wasps look and behave remarkably like certain ant species. In general the following features distinguish ants: constricted 'waist' with one or two knobs; antennal segment closest to body very long (five times as long at least) to any of the remaining segments; presence of certain glands (microscope and taxonomic expertise required). Wasps never have all of these features.
- Sawflies are closely related to wasps and share many features. Sawflies can be distinguished by a lack of constriction at the 'waist' and more complete wing venation. The wings have more veins and cross-veins that form cells, with at least one vein extending to wing margin. They are nearly always plant feeders (one or two are parasites of wood-boring beetles), and females have a saw-like ovipositor folded into a groove when not in use.
- Some moth families are wasp-like in appearance. Some species of case moths (Family Psychidae), cup moths (Family Limacodidae), clearwing moths (Family Sesiidae), forester moths (Family Zygaenidae), and hawk moths (Family Sphingidae) have adults which have clear membranes on their wings, with scaling restricted to veins and the body of the moth. This can sometimes give a wasp-like appearance (eg. Family Sesiidae), and may result in incorrect identifications. The scales on the body should still identify these insects as moths.