Landcare Research - Manaaki Whenua

Landcare-Research -Manaaki Whenua

FAQ: Frequently Asked Questions

Wasp sting. Image - R Toft

The most frequently asked questions are:

Other FAQs are:

Answers to your questions

How are wasps different to bees?

Wasps and bees both belong to the order "Hymenoptera" and have many features in common. The most obvious differences are:

  • wasps do not collect pollen, bees do
  • wasps do not store food, bees do
  • wasps do not make honey, bees do
  • wasp nests are made of paper, bees nests are made of wax
  • wasp mouth parts are designed to chew food, bees mouth parts are designed to lap liquid
  • wasps can sting more than once, bees can only sting once

What is the venom that the wasp injects into you?

The principal component of venom is protein — it is the protein that causes allergy reactions in people. Several different proteins have been demonstrated in wasp venom, the total number and relative proportions vary among the different genera. Other components of venom include an acetylcholine-like substance, histamine, serotonin, and kinin. Kinins are peptides that cause slow contractions of isolated smooth muscle, lower arterial blood pressure, and increase capillary permeability.

Can wasps sting you if they are dead?

Yes — the venom sac at the end of a wasp sting keeps pulsing for a short period after a wasp dies, so if you come in contact with the sting you may still be injected with venom.

Why do wasps sting people?

Unprovoked wasp attacks are very rare, a wasp will normally only use its sting to defend itself or to subdue prey. Many wasps stings are the result of people squashing wasps, either deliberately or by accident. Wasps are attracted to food (especially fish sandwiches) and sweet drinks. People have been stung while they are eating because they have not seen the wasp that is also sharing the food. Or, in the case of drinks, they have not seen a wasp enter their drink container and are stung as they take a drink by a wasp who wants to escape being swallowed. Wasps also sting intruders to defend their nest. When a wasp nest is disturbed, wasps will fly out with a wing beat frequency that stimulates other wasps to fly out the nest and attack. They will attack an intruder within 7 metres of the nest and pay special attention to moving targets.

Why are wasps black and yellow?

Bright colours are a sign of danger. Many species that are venomous, like snakes, spiders and wasps, are brightly coloured, and this colouring warns potential predators that they are dangerous. A predator, that attacks a wasp and is stung will link pain associated with a sting with the yellow/ black colouration and avoid animals with this colouration in future.

Different colours are produced by the differential absorption and reflection of light. Absorption of light is due to pigments — the black colouration is produced by the pigment melanin, which occurs in granular form within the cuticle, while the yellow colours are created by the pigment xanthopterin.

How many kinds of wasps are there?

The term ‘wasp’ means different things to different people. There are several thousand species of Vespidae (vespid) wasps, a group which contains all of the social wasps (about 800 species), and many more solitary wasps which do not form colonies.

How long do wasps live for?

In social wasps, workers (sterile females) have an average lifespan of 12-22 days, drones (fertile males) have a slightly longer lifespan than workers, and queens (fertile females) have an average lifespan of 12 months. Check our The Life History of Social Wasps page for more details.

Why are queen wasps bigger than worker wasps?

Queens wasps are bigger because they have to produce and store large quantities of eggs. Being bigger also means that they can store more fat, which is essential if they are to survive winter hibernation — by the time queens leave the colony, fat reserves account for nearly 40% o their total dried weight.

The differences in size result primarily from variations in quantity and quality of food received during the larval stage — queens receive almost twice as much food as workers.

How many wasps can there be in a colony?

An average common or German wasp nest produces between 11 000 and 13 000 workers and from 1000 to 2000 queens a season.

Where do wasps build their nests?

German and common queen wasps usually choose a warm spot, often in a bank with a sunny aspect, but also in attics, house roofs, eaves, or walls in which to build their nests.

What do wasps eat?

Wasps eat a wide range of invertebrates including spiders, caterpillars, ants, bees, and flies. It has also been suggested that wasps may prey on nestling birds. Wasps also collect honeydew. Honeydew is produced by a native scale insect. The insect inserts its mouth-parts into the trunk of the beech tree to siphon the sap. The excess sap, modified by the scale insect, forms a sugary droplet at the end of a waxy anal filament. Wasps reduce the standing crop of honeydew by more than 90% for 5 months of the year and so compete with native species (such as birds and invertebrates) that also consume honeydew.

Do any other animals eat wasps?

Yes. In the countries where wasps originate, a wide range of natural predators have been recorded including invertebrates (dragonflies, robber flies, hornets, centipedes, and spiders), birds (at least 24 species are known to eat wasps, including blackbirds, magpies, starlings) and mammals. In Britain, badgers are the chief predator: they destroy entire colonies to obtain the brood-filled comb. Stoats, weasels and mice also disrupt colonies in the early stages. However, in New Zealand, one reason wasps have so successfully established is that most of their natural predators are not present.

Are wasps good fliers?

Yes, workers can fly many hundreds of metres searching for food. In spring, queens can fly many kilometres when searching for sites to make new colonies.

What are wasps wings made of?

Chitin. Wings are platelike extensions of the integument (outer skeleton), strengthened by a framework of hollow tubes known as veins.

How many times does a wasp beat its wings every second?

Wing beat varies between 117 and 247 beats per second.

How do wasps communicate?

Virtually any contact between two wasps can be considered a form of communication. Visual and audible signs are used to attract the opposite sex for mating, and size and posture displays are used in courtship or aggression.

Exchanges of food and pheromones among the members of a colony are also very important in maintaining the social hierarchy and tasking of the colony members.

Worker wasps have very few enzymes in their guts, so they cannot digest much of the food they gather. They bring the raw food into the nest and pass it to other workers who feed the hungry larvae. In return, the larvae release a creamy blob of predigested "soup" that contains all the sustenance the worker needs. This type of food exchange is called "trophollaxic feeding", and is a key part of the social contact between workers and the developing young.

Queens produce a pheromone (insect-produced chemical substances that release certain specific behaviour patterns) that regulates worker behaviour and inhibits the development of their sexual organs. Wasps also produce an "alarm pheromone" that stimulates a general state of alarm in the colony and releases aggressive behaviour towards an intruder. Rapid wing beats also function as an alarm signal stimulating other wasps to defend the nest.