A wasp is any insect of the order Hymenoptera and suborder Apocrita
that is not a bee or ant. The suborder Symphyta includes the sawflies and
wood wasps, which differ from members of Apocrita by having a broader
connection between the mesosoma and metasoma. In addition to this, Symphyta
larvae are mostly herbivorous and "caterpillarlike", whereas those of
Apocrita are largely predatory or "parasitic" (technically known as
Does Anything Eat Wasps?: And 101 Other Questions
addition to the one about the wasps (great answers), favourite questions
included how long you could survive on beer alone, how fat you’d need to be to
be bullet proof, how to get bubbles evenly distributed in Aero bars and this
musing: “What would be the effect on the Earth if an alien spaceship came along
and dragged the moon away?”"
The most familiar wasps belong to Aculeata, a division
of Apocrita, whose ovipositors are adapted into a venomous stinger. Aculeata
also contains ants and bees. In this respect, insects called "velvet ants"
(the family Mutillidae) are technically wasps.
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A much narrower and simpler but popular definition of the term wasp is
any member of the Aculeate family Vespidae, which includes (among others)
the genera known in North America as yellowjackets (Vespula and
Dolichovespula) and hornets (Vespa).
The various species of wasp fall into one of two main categories:
solitary wasps and social wasps. Adult solitary wasps generally live and
operate alone, and most do not construct nests; all adult solitary wasps are
fertile. By contrast, social wasps exist in colonies numbering up to several
thousand strong and build nests—but in some cases not all of the colony can
reproduce. Generally, just the queen and male wasps can mate, whilst the
majority of the colonies are made up of sterile female workers.
The following characteristics are present in most wasps:
- two pairs of wings (except wingless or brachypterous forms in all
female Mutillidae, Bradynobaenidae, many male Agaonidae, many female
Ichneumonidae, Braconidae, Tiphiidae, Scelionidae, Rhopalosomatidae,
Eupelmidae, and various other families).
- An ovipositor, or stinger (which is only present in females because
it derives from the ovipositor, a female sex organ).
- Few or no hairs (in contrast to bees); except Mutillidae,
- Nearly all wasps are terrestrial; only a few specialized parasitic
groups are aquatic.
- Predators or parasitoids, mostly on other terrestrial insects; some
species of Pompilidae, such as the tarantula hawk, specialize in using
spiders as prey, and various parasitic wasps use spiders or other
arachnids as reproductive hosts.
Wasps are critically important in natural bio control. Almost every pest
insect species has a wasp species that is a predator or parasite upon it.
Parasitic wasps are also increasingly used in agricultural pest control as
they have little impact on crops. Wasps also constitute an important part of
the food chain.
Sterile Female Worker Wasp Morphology for the
article on wasps. It can be identified as a female by both the number of
divisions on its antenna and by its sting. This particular wasp is very close in
likeness to a yellowjacket found commonly all around the world.
In wasps, as in other Hymenoptera, sexes are significantly genetically
different. Females have a diploid (2n) number of chromosomes and come about
from fertilized eggs. Males, in contrast, have a haploid (n) number of
chromosomes and develop from an unfertilized egg. Wasps store sperm inside
their body and control its release for each individual egg as it is laid; if
a female wishes to produce a male egg, she simply lays the egg without
fertilizing it. Therefore, under most conditions in most species, wasps have
complete voluntary control over the sex of their offspring.
Anatomy and gender
Anatomically, there is a great deal of variation between different
species of wasp. Like all insects, wasps have a hard exoskeleton covering
their 3 main body parts. These parts are known as the head, metasoma and
mesosoma. Wasps also have a constricted region joining the first and second
segments of the abdomen (the first segment is part of the mesosoma, the
second is part of the metasoma) known as the petiole. Like all insects,
wasps have 3 sets of 2 legs. In addition to their compound eyes, wasps also
have several simple eyes known as ocelli. These are typically arranged in a
triangular formation just forward of an area of the head known as the
It is possible to distinguish between certain wasp species genders based
on the number of divisions on their antennae. Male Yellow jacket wasps for
example have 13 divisions per antenna, while females have 12. Males can in
some cases be differentiated from females by virtue of the fact that the
upper region of the male's mesosoma(called the tergum) consists of an
additional terga. The total number of terga is typically 6. The difference
between sterile female worker wasps and queens also varies between species
but generally the queen is noticeably larger than both males and other
Wasps can be differentiated from bees as bees have a flattened hind
basitarsus. Unlike bees, wasps generally lack plumose hairs. They vary in
the number and size of hairs they have between species.
Generally wasps are parasites as larvae, and feed only on nectar as
adults. Some wasps are omnivorous but this is relatively uncommon, they feed
on a variety of fallen fruit, nectar and carrion. Many wasps are predatory,
preying on other insects. Certain social wasp species, such as yellowjackets,
scavenge for dead insects to provide for their young. In turn the brood
provides sweet secretions for the adults.
In parasitic species the first meals are almost always provided from the
animal the adult wasp used as a host for its young. Adult male wasps
sometimes visit flowers to obtain nectar to feed on in much the same manner
as honey bees. Occasionally, some species, such as yellow jackets, invade
honeybee nests and steal honey and/or brood.
Wasp stinger, with droplet of venom
With most species, adult parasitic wasps themselves do not take any
nutrients from their prey, and, much like bees, butterflies, and moths they
typically derive all of their nutrition from nectar. Parasitic wasps are
typically parasitoids, and extremely diverse in habits, many laying their
eggs in inert stages of their host (egg or pupa), or sometimes paralyzing
their prey by injecting it with venom through their ovipositor. They then
inject the host with eggs or deposit them upon the host externally. When the
eggs hatch, the larvae eat the prey, which provides them with a first meal.
After this point most wasps must obtain their own food and fend for
Social wasp reproductive cycle (temperate
Wasps do not reproduce via mating flights like bees. Instead social wasps
reproduce between a fertile queen and male wasp, in some cases queens may be
fertilized by the sperm of several males. After successfully mating, the
male's sperm cells are stored in a tightly packed ball inside the queen. The
sperm cells are kept stored in a dormant state until they're needed the
following spring. At a certain time of year (often around autumn) the bulk
of the wasp colony dies away, leaving only the young mated queens alive.
During this time they leave the nest and find a suitable area to hibernate
for the winter.
Wasp Nest size of a football
After emerging from hibernation during early spring, the young queens
search for a suitable nesting site. Upon finding an area for their future
colony, the queen constructs a basic paper fibre nest roughly the size of a
walnut into which she will begin to lay eggs.
The sperm that were stored earlier and kept dormant over winter is now
used to fertilize the eggs being laid. The storage of sperm inside the
female queen allows her to lay a considerable number of fertilized eggs
without the need for repeated mating with a male wasp. For this reason a
single female queen is capable of building an entire colony from only
herself. The queen initially raises the first several sets of wasp eggs
until enough sterile female workers exist to maintain the offspring without
her assistance. All of the eggs produced at this time are sterile female
workers who will begin to construct a more elaborate nest around their queen
as they grow in number.
By this time the nest size has expanded considerably and now numbers
between several hundred and several thousand wasps. Towards the end of the
summer, the queen begins to run out of stored sperm to fertilize more eggs.
These eggs develop into fertile males and fertile female queens. The male
drones then fly out of the nest and find a mate thus perpetuating the wasp
reproductive cycle. In most species of social wasp the young queens mate in
the vicinity of their home nest and do not travel like their male
counterparts do. The young queens will then leave the colony to hibernate
for the winter once the other worker wasps and founder queen have started to
die off. After successfully mating with a young queen, the male drones die
off as well. Generally, young queens and drones from the same nest do not
mate with each other; this ensures more genetic variation within wasp
populations, especially considering that all members of the colony are
theoretically the direct genetic descendants of the founder queen and a
single male drone. In practice, however, colonies can sometimes consist of
the offspring of several male drones. Wasp queens generally (but not always)
create new nests each year, this is probably because the weak construction
of most nests render them uninhabitable after the winter.
Unlike most honey bee queens, wasp queens typically only live for one
year (although exceptions are possible). Also, contrary to popular belief
queen wasps do not organize their colony or have any raised status and
hierarchical power within the social structure. They are more simply the
reproductive element of the colony and the initial builder of the nest in
those species which construct nests.
Wasp caste structure
Not all social wasps have castes that are physically different in size
and structure. In many polistine paper wasps and stenogastrines, for
example, the castes of females are determined behaviourally, through
dominance interactions, rather than having caste predetermined. All female
wasps are potentially capable of becoming a colony's queen and this
process is often determined by which female successfully lays eggs first and
begins construction of the nest. Evidence suggests that females compete
amongst each other by eating the eggs of other rival females. The queen may,
in some cases, simply be the female that can eat the most other eggs while
ensuring that her own survive (often achieved by laying the most). This
process theoretically determines the strongest and most reproductively
capable female and selects her as the queen. Once the first eggs have
hatched the subordinate females stop laying eggs and instead forage for the
new queen and feed the young; that is, the competition largely ends, with
the losers becoming workers, though if the dominant female dies, a new
hierarchy may be established with a former "worker" acting as the
replacement queen. Polistine nests are considerably smaller than many other
social wasp nests, typically housing only around 250 wasps, compared to the
several thousand common with yellow jackets, and stenogastrines have the
smallest colonies of all, rarely with more than a dozen wasps in a mature
Polistes dominulus building nest
The type of nest produced by wasps can depend on the species and
location. Many social wasps produce paper pulp nests on trees, in attics,
holes in the ground or other such sheltered areas with access to the
outdoors. By contrast solitary wasps are generally parasitic or predatory
and only the latter build nests at all. Unlike honey bees, wasps have no wax
producing glands. Many instead create a paper-like substance primarily from
wood pulp. Wood fibres are gathered locally from weathered wood, softened by
chewing and mixing with saliva. The pulp is then used to make combs with
cells for brood rearing. More commonly, nests are simply burrows excavated
in a substrate (usually the soil, but also plant stems), or - if constructed
- constructed out of mud.
The nesting habits of solitary wasps are more diverse than those of
social wasps. Mud daubers and pollen wasps construct mud cells in sheltered
places typically on the side of walls. Potter wasps similarly build
vase-like nests from mud, often with multiple cells, attached to the twigs
of trees or against walls. Most other predatory wasps burrow into soil or
into plant stems, and a few do not build nests at all and prefer naturally
occurring cavities, such as small holes in wood. A single egg is laid in
each cell, which is sealed thereafter, so there is no interaction between
the larvae and the adults, unlike in social wasps. In some species, male
eggs are selectively placed on smaller prey, leading to males being
generally smaller than females.
The nests of some social wasps, such as hornets, are first constructed by
the queen and reach about the size of a walnut before sterile female workers
take over construction. The queen initially starts the nest by making a
single layer or canopy and working outwards until she reaches the edges of
the cavity. Beneath the canopy she constructs a stalk to which she can
attach several cells; these cells are where the first eggs will be laid. The
queen then continues to work outwards to the edges of the cavity after which
she adds another tier. This process is repeated, each time adding a new tier
until eventually enough female workers have been born and matured to take
over construction of the nest leaving the queen to focus on reproduction.
For this reason, the size of a nest is generally a good indicator of
approximately how many female workers there are in the colony. Social wasp
colonies often have populations exceeding several thousand female workers
and at least one queen. Polistes and some related types of paper wasp
do not construct their nests in tiers but rather in flat single combs.
- Agaonidae - fig wasps
- Chrysididae - cuckoo wasps
- Crabronidae - sand wasps and relatives, e.g. the Cicada killer wasp
- Cynipidae - gall wasps
- Ichneumonidae, and Braconidae
- Mutillidae - velvet ants
- Mymaridae - fairyflies
- Pompilidae - spider wasps
- Scoliidae - scoliid wasps
- Sphecidae - digger wasps
- Tiphiidae - flower wasps
- Vespidae - yellowjackets, hornets, paper wasps (umbrella), potter
wasps, pollen wasps
Black and yellow Mud Dauber Wasp