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Wasp
Vespula germanica
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hymenoptera
Suborder

Apocrita
See text for explanation.

The term wasp is typically defined as any insect of the order Hymenoptera and suborder Apocrita that is neither a bee nor ant[1]. Almost every pest insect species has at least one wasp species that preys upon it or parasitizes it, making wasps critically important in natural control of their numbers, or natural biocontrol. Parasitic wasps are increasingly used in agricultural pest control as they prey mostly on pest insects and have little impact on crops.

Contents

Taxonomy

Wasp stinger, with droplet of venom

The majority of wasp species (well over 100,000 species) are "parasitic" (technically known as parasitoids), and the ovipositor is used simply to lay eggs, often directly into the body of the host. The most familiar wasps belong to Aculeata, a division of Apocrita, whose ovipositors are adapted into a venomous sting, though a great many aculeate species do not sting. Aculeata also contains ants and bees, and many wasps are commonly mistaken for bees, and vice-versa. In a similar respect, insects called "velvet ants" (the family Mutillidae) are technically wasps.

The suborder Symphyta, known commonly as sawflies, differ from members of Apocrita by lacking a sting, and 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 parasitoids.

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); in many countries outside of the Western Hemisphere, the vernacular usage of wasp is even further restricted to apply strictly to yellowjackets (e.g., the "common wasp").

Categorization

The various species of wasps 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 (below); 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. In the more advanced species, just the wasp queen and male wasps can mate, whilst the majority of the colony is made up of sterile female workers.

Characteristics

Spider Hunting Wasp, heterodotonyx bicolor, and prey
Wings Antenna Thorax Leg Head Stinger Abdomen Female Yellowjacket
The basic morphology of a female Yellowjacket wasp

The following characteristics are present in most wasps:

Wasps are critically important in natural biocontrol. Almost every pest insect species has at least one wasp species that is a predator or parasite upon it. Parasitic wasps are also increasingly used in agricultural pest control. Wasps also constitute an important part of the food chain.

Biology

Genetics

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

Wasp ocelli (simple eyes) and dorsal part of the compound eyes; also showing fine, unbranched hairs

Anatomically, there is a great deal of variation between different types of wasp. Like all insects, wasps have a hard exoskeleton covering their three 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 three sets of two 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 vertex.

It is possible to distinguish between certain wasp species genders based on the number of divisions on their antennae. Male Yellowjacket 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 six. 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 females.

Wasps can be differentiated from bees, which 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.

Diet

Sand wasp (Bembix oculata, family Crabronidae) removing body fluids from a fly after having paralysed it with the sting

Generally wasps are parasites or parasitoids as larvae, and feed only on nectar as adults. Many wasps are predatory, using other insects (often paralyzed) as food for their larvae. A few social wasps are omnivorous, feeding on a variety of fallen fruit, nectar, and carrion. Some of these social wasps, such as yellowjackets, may scavenge for dead insects to provide for their young. In many social species the larvae provide sweet secretions that are fed to the adults.

In parasitic species, the first meals are almost always provided by the animal that 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 yellowjackets, invade honey bee nests and steal honey and/or brood.[citation needed]

Wasp parasitism

With most species, adult parasitic wasps themselves do not take any nutrients from their prey, and, much like bees, butterflies, and moths, those that do feed as adults 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 insert one or more eggs into the host or deposit them upon the host externally. The host remains alive until the parasitoid larvae are mature, usually dying either when the parasitoids pupate, or when they emerge as adults.

Nesting habits

Various wasp nests
Tiphiid wasp, a solitary wasp
Paper pulp type wasp colony on maple tree, photographed near Maple Lake in Cook County, Illinois in October 2008

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 fibers 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, they are constructed from mud.

Solitary wasps

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.

Social wasps

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.

Social wasp reproductive cycle (temperate species only)

A young paper wasp queen founding a new colony

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 are needed the following spring. At a certain time of the 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.

First stage

After emerging from hibernation during early summer, the young queens search for a suitable nesting site. Upon finding an area for their colony, the queen constructs a basic wood fiber nest roughly the size of a walnut into which she will begin to lay eggs.

Second stage

The sperm that was 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.

Third stage

European paper wasp (Polistes dominula) with a regurgitated droplet of water

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, probably because the weak construction of most nests render them uninhabitable after the winter.

Unlike honey bee queens, wasp queens typically live for only one year. Also 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.

Social wasp caste structure

A wasp gathering wood fibers

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 behaviorally, 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 largest volume of eggs while ensuring that her own eggs 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 yellowjackets, and stenogastrines have the smallest colonies of all, rarely with more than a dozen wasps in a mature colony.

Common families

See also

References

  1. ^ Norman F. Johnson, Charles A. Triplehorn. 2004. Borror's Introduction to the Study of Insects. 7th Edition.

External links

Sister projects


Quotes

Up to date as of January 14, 2010
(Redirected to Wasp (novel) article)

From Wikiquote

Wasp (1957) is a science fiction novel by Eric Frank Russell.

  • We first dug out sixteen thousand fluent speakers of the several Sirian dialects. Eliminating the females and children brought the number down to nine thousand. Then, step by step, we cut out the elderly, the infirm, the weak, the untrustworthy, the temperamentally unsuitable. We weeded out those too short, too tall, too fat, too thin, too stupid, too rash, too cautious, and so forth. We weren't left with many among whom to seek for wasps.
  • Listen to me. You were born in Masham, capital city of Diracta – the Sirian home planet. Your father was a trader there at the time. You lived on Diracta until the age of seventeen, when you returned with your parents to Terra.
  • That was the kind of chance that must be taken when one holes up in known and regularly checked haunts. The risk was not enormous, in fact it was small – but it was still there. And when tried, sentenced and waiting for death it is no consolation to know that what came off was a hundred to one chance. To keep going and to maintain the one-man battle the enemy had to be outwitted, if possible, all along the line and all the time.
  • When one is fighting a paper-war one uses paper-war tactics that in the long run can be just as lethal as high explosive. And the tactics are not limited in scope by use of one material. The said material is very variable in form. Paper can convey a private warning, a public threat, secret temptation, open defiance; wall-bills, window-stickers, leaflets dropped by the thousands from the roof-tops, cards left on seats or slipped into pockets and purses... money.
Wikipedia
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1911 encyclopedia

Up to date as of January 14, 2010

From LoveToKnow 1911

WASP (Lat. vespa), the common name for a well-known sort of stinging insect. The order Hymenoptera is divided into two sub-orders, the Symphyta and the Apocrita. The latter is subdivided into several sections, one of which, the Vespoidea, includes all the true wasps; in addition to the ruby wasps and many of the "Fossores" or digging wasps.

The true wasps (forming the old section Diploptera) are in their turn divided into three families - (1) the Vespidae, (2) the Eumenidae, and (3) the Masaridae, which together comprise some 1500 different species. They are characterized by their wings, which are present in both sexes and also in the modified females or workers, being longitudinally folded when at rest, except in the Masaridae. The antennae are usually elbowed, and contain twelve or thirteen joints; in some cases they are clavate. A pair of notched faceted eyes are present, and three ocelli in the top of the head. The mouth-parts are arranged for sucking, but have not reached that degree of perfection found amongst the bees. Hence wasps cannot obtain the sugary secretion from deeply-seated nectaries, and their visits to flowers are confined to such as are shallow or widely opened; they particularly frequent the Umbelliferae. The maxillae are elongated, and compressed, the maxillary palp six-jointed. The labium is prolonged centrally into a "tongue," which is glandular at the tip; the paraglossae are linear. The labial palp has three or four joints. The pro-thorax is oval, and its sides are prolonged backward to the base of the wings. The fore wing has two or three submarginal cells. The legs are not provided with any adaptations for collecting pollen. The abdomen is sometimes pedunculate, its second (apparently first) segment being drawn out into a long stalk, which connects it with the alitrunk, made up of the thorax and the first abdominal segment. The queens and the workers are armed with a powerful sting. The usual colour of these insects is black, relieved to a greater or less degree by spots and patches of yellow or buff.

The Diploptera may be subdivided into two groups in accordance with the habits of life of the insects comprising the section. One of the groups includes the family Vespidae, which is composed of social wasps, and includes the hornet (Vespa crabro) and the common wasp (V. vulgaris). The other group contains two smaller families, the Eumenidae and the Masaridae, the members of which are solitary in their mode of life.

Family I. Vespidae. - In addition to their social habits the members of this family are characterized by certain structural features. The anterior wings have three submarginal cells. The antennae have thirteen joints in the males and twelve in the females; the claws of the tarsi are simple; the anterior four tibiae have two spines at the tip; the abdomen is but rarely pedunculated, and the posterior segments are often very contractile.

The members of this family approximate very closely to bees in their social manner of life. The communities are composed of males, fertile females and workers. The latter are females in which the ovary remains undeveloped; they resemble the perfect female in external appearance, but are slightly smaller. It has been shown by P. Marchal that a clear line of distinction between queen and worker cannot always be drawn. Unlike the hive bees', the wasps' community is annual, existing for one summer only. Most of the members die at the approach of autumn, but a few females which have been fertilized hibernate through the winter, sheltered under stones or in hollow trees. In the spring and with the returning warm weather the female regains her activity and emerges from her hidingplace. She then sets about finding a convenient place for building a nest and establishing a new colony. The common wasp (V. vulgaris) usually selects some burrow or hole in the ground, which, if too small, she may enlarge into a chamber suitable for her purpose. She then begins to build the nest. This is constructed of small fibres of old wood, which the wasp gnaws, and kneads, when mixed with the secretion from the salivary glands, into a sort of papier-mache pulp. Some of this is formed into a hanging pillar attached to the roof of the cavity, and in the lower free end of this three shallow cup-like cells are hung. In each of these an egg is laid. The foundress of the society then continues to add cells to the comb, and as soon as the grubs appear from the first-laid eggs she has in addition to tend and feed them. The development within the egg takes eight days.

The grubs are apodal, thicker in the middle than at either end; the mandibles bear three teeth; the maxillae and labium are represented by fleshy tubercles. The body, exclusive of the head, consists of thirteen segments, which bear lateral tubercles and spiracles. The larva has no anus. The larvae are suspended with the head downwards in the cells, and require a good deal of attention, being fed by their mother upon insects which are well chewed before they are given to the larvae, or upon honey. At the same time the mother is enlarging and deepening the cells in which they live, building new cells, and laying more eggs, which are usually suspended in the same angle of each cell.

After about a fortnight the grubs cease to feed, and, forming a silky cover to their cells, become pupae. This quiescent stage lasts about ten days, at the end of which period they emerge as the imago or perfect insect. The silky covering of the cell is round or convex outwards; and to leave the cell the insect either pushes it out, when it opens like a box lid, or gnaws a round hole through it. As soon as the cell is vacated it is cleaned out and another egg deposited. In this way two or three larvae occupy successively the same cell during the summer. The first wasps that appear in a nest are workers, and these at once set to work to enlarge the comb, and feed the larvae, &c.

The material of the nest, as before stated, is usually dried wood, worked by the mandibles of the wasp, with the addition of its salivary secretion, into a pulp, which can easily be moulded whilst moist; it dries into a substance of a papery appearance, but possessing considerable tenacity. Sometimes paper itself, such as old cartridge cases, is used. The combs are arranged horizontally; each contains a single layer of cells opening downwards. The second comb is suspended from the first by a number of hanging pillars which are built from the point of union of three cells. The space between two combs is just sufficient to allow the wasps to cross each other. The combs are roughly circular in outline, and increase in size for the first four or five layers, after which they begin to decrease; the whole is covered by a roughly made coating consisting of several layers of the same papery substance which composes the combs. This is continued down until it forms a roughly spherical covering for the whole, but not giving any support to the combs, which are independent of it. As the nest increases in size, the covering needs to be repeatedly pulled to pieces and reconstructed, its inner layer being cut away as the combs are enlarged. The covering is pierced by apertures for the passage of the wasps. The cells are hexagonal at their mouths, but above become more rounded in their cross section.

During the first half of the summer workers only are produced, but, as fruit ripens and food becomes more abundant, fully developed females and males appear, the latter often from parthenogenetically developed eggs of the later broods of workers. The males and females are larger than the workers, and require larger cells for their development; these are usually kept apart from one another and from those of the workers. The males may be distinguished by their longer antennae, by the more elongated outline of their body, and by the absence of a sting.

In a favourable season, when the weather is warm and food plentiful, a nest may contain many thousands of cells full of wasps in various stages of development; and, as each cell is occupied two or three times in the course of a summer, those authorities who put the number of the members of the community as high as 30,000 are probably not far wrong.

At the approach of autumn the society begins to break up; the males fertilize the females whilst flying high in the air. They then die, often within a few hours. The workers leave the nest, carrying with them any grubs that remain in the cells, and both soon perish. The nest is entirely deserted. The fertilized females, it has been seen, creep into crevices under stones or trees, or hide amongst moss, and hibernate until the warmth of the following spring induces them to leave their hiding-places and set about founding a new community.

There are altogether seven species of Vespa met with in Britain.

V. vulgaris, the common or ground wasp, V. rufa, the red wasp, distinguished by its reddish-yellow abdomen, and V. germanica, the German wasp, with three black spots upon its first abdominal segment, are classed together as ground wasps. They build their nests in burrows in the ground, but this is not an invariable rule; they may be distinguished from the tree wasps by their shorter cheeks and usually by the first joint in the antennae of the female being black. Vespa austriaca (arborea) is a race of V. FIG. I.- Vespa rufa. rufa, in whose nest it sometimes lives as an inquiline. The tree wasps build stouter nests upon branches of trees; the first joint of the antennae of the females is yellow in front. The tree wasps are V. sylvestris, norvegica and crabro. The hornet, V. crabro, is the largest species occurring in Great Britain. They have a more distinctly red colour than the common wasp, and a row of red spots upon each side of the abdomen. They occur much more rarely than the common wasp, and appear to be almost confined to the southern half of England. Their nests resemble those described above, but are larger; they are found in hollow trees or deserted out-houses. Their communities are smaller in number than those of the other wasps.

The hornet, where it occurs in any number, does a considerable amount of damage to forest trees, by gnawing the bark off the younger branches to obtain material for constructing its nest. It usually selects the ash or alder, but sometimes attacks the lime, birch and willow. Like the wasp, it does much damage to fruit, upon the juices of which it lives. On the other hand, the wasp is useful by keeping down the numbers of flies and other insects. It catches these in large numbers, killing them with its jaws and not with its sting. It then tears off the legs and wings, and bears the body back to its nest as food for the larvae. Wasps also act to some extent as flower fertilizers, but in this respect they cannot compare with bees; they visit fewer flowers, and have no adaptations on their limbs for carrying off the pollen.

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The genus Vespa is very widely spread; it contains over forty species, distributed all over the world. Some of the largest and handsomest come from eastern Asia. V. mandarina of China and Japan, and V. magnifica of the East Indies and Nepal, measure 2 in. across the wings; V. orientalis, found in Greece, Egypt and the East, builds its nest of clay.

The only other genus of Vespidae which is found in Europe is Polistes, which occurs in the countries bordering the Mediterranean. The colonies of this genus are much smaller than those of Vespa. Each nest consists of a single tier of cells in the form of a round plate, supported in the middle by a single stalk. This comb is sometimes vertical, the cells then being horizontal or slightly oblique. Some of the members of this genus store up honey, which in the case of a South American species is poisonous, from the nature of the flowers from which it is gathered. The members of this genus have a slender body; the thorax is more oblong than in the genus Vespa, the palps are stouter and the abdomen is more distinctly pedunculate.

The genus Ischnogaster, from the East Indies, has many structural features in common with the Eumenidae, but the character of its communities, and its nest, which is very small, justify its position amongst the social wasps.

The genus Icaria, common in Australia and the East Indies, builds very small nests, of two or three rows of cells, hanging on one side from a stalk.

Synaeca is a South American genus, which builds large nests, sometimes 3 ft. in length, closely applied to the branch of a tree; they never contain more than one layer of cells, which are horizontally placed. The whole nest is built of coarse material, chiefly small pieces of bark; and there is only one opening, at the lower end.

Another South American genus, Chartergus, makes a tough nest, pendent from boughs of trees, and opening to the exterior below by a median aperture. The combs are arranged, somewhat like funnels, inside one another, but with spaces between. The apex of each comb is pierced by a hole for the wasps to pass from one gallery to another.

The nest of Tatua, which occurs in FIG. 3. - Polistes tepidus and nest.

Mexico and South America, is also pendent, but the combs are horizontal; the opening from the exterior is at the side, and the passage from one gallery to another is also lateral.

The external appearance of the nest of Nectarina, found in Brazil and other parts of South America, resembles that of the common wasp, but is rougher. Internally the combs are arranged concentrically, more or less parallel with the external covering which affords them support.

The members of the two remaining families, the Eumenidae and the Masaridae, resemble one another in their solitary mode of life; only males and normal females exist - no workers being found.

Family 2. Eumenidae. - Solitary species, with three submarginal cells in the fore wing; antennae with thirteen joints in the male, twelve in the female; abdomen sometimes pedunculate, posterior segments contractile. In the foregoing structural features the Eumenidae resemble the Vespidae, but they differ in having bifid claws on their tarsi, and the two anterior tibiae have but one spine at the tip. The mandibles are elongated, and form a kind of rostrum, in this respect approaching the Fossores. Eumenes coarctata is the only British species of this genus. The female is 2 in. long, the male somewhat shorter. The abdomen is connected with the thorax by a long peduncle. The colour is black, relieved by spots of yellow. It constructs small spherical cells of mud, which are found attached to stems of plants, very generally to the heath. At first the cell opens to the exterior by means of a round pore; one egg is deposited in each cell, and a store of honey as food for the larva when hatched; the cell is then closed with mud. The larvae of some species are carnivorous, and then the food-supply stored up in the cell consists of caterpillars and other insect larvae which have been paralysed by the parent wasp FIG. 4. stinging them through the cerebral ganglion; Eumenes smithii. when the larva of the Eumenes emerges from the egg it sets upon these and devours them.

The genus Odynerus contains a very large number of species, found in all parts of the world. The members of this genus are about the size of a fly, and they differ from Eumenes in having a sessile abdomen. Some of the species construct their cells in sandheaps, lining them with agglutinated grains of sand; others live in cavities of trees lined with the same material, whilst others build their nests of mud. Like some of the species of Eumenes, they store up paralysed Lepidopterous and Chrysomeleous larvae as food for their carnivorous grubs.

Family 3. Masaridae. - The members of the third family, the Masaridae, are sharply distinguished by the possession of only two submarginal cells in the fore wing, which folds imperfectly or not at all when at rest. Their antennae are frequently clavate, particularly so in the genus Celonites; they are twelve-jointed, but as the terminal joints are almost fused they appear to be composed of only eight joints. The wings are not so completely folded as in the other two families, and the abdomen is but slightly contractile. The maxillae are short and their palps very small, with but three or four joints.

The number of genera comprised in this family is small; none occur in Britain, but in southern Europe some species are found. They make their nest in cavities in the earth, generally in a bank, and construct an irregular gallery leading down to it.

During hot fine summers wasps cause a good deal of loss to market gardeners and fruit growers. During this time of year they live almost exclusively upon the sweet juices of ripe fruit, occasionally carrying off small particles of the flesh. At the same time they have not entirely lost their carnivorous tastes, for they frequently attack the meat in butcher's shops, but render compensation by killing and carrying off to feed their grubs considerable numbers of blow-flies. Wasps also perform an important service in keeping down the numbers of caterpillars. The larvae are almost exclusively carnivorous, living upon insects captured by their parents and reduced by them to a 'pulp before being given to the young. During the spring the first broods that appear live largely upon honey; and this forms the staple food of the genus Polistes throughout their whole life.

In attempting to rid a district of wasps, unless the nest can be taken, there is little good in killing stray members of the community. On the other hand, the killing of queen-wasps in early spring probably means that the formation of a nest and the production of a society whose members are counted by thousands is in each case prevented.

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The number of wasps is kept down by numerous enemies. The most effective of these live in the nests and devour the larvae; among them are two species of beetle, Rhipiphorus paradoxes and Lebia linearis. Two species of Ichneumon, and a species of Anthomyia, also infest the nests of wasps and prey upon the grubs. The larvae of the syrphid flies V olucella, found in the nests of both wasps and bees, are now believed to be scavengers rather than parasites. In the tropics some species are attacked by fungi, the hyphae of which protrude between FIG. 2. - Nest of Vespa sylvestris. FIG. 5. - Masaris vespiformis. the segments of the abdomen, and give the wasp a very extraordinary appearance.

Bibliography. - In addition to various systematic memoirs enumerated at the end of the article on Hymenoptera, reference may be made to De Saussure (Monographie des guepes sociales, Geneve, 1853-1858), P. Marchal (Arch. Zool. Exp. Gen. (3), iv., 1896), C. Janet (Mem. Soc. Zool. France, viii., 1895) and O. H. Latter (Natural History of Common Animals, ch. v., Cambridge, 1904).

(A. E. S.; G. H. C.)


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Simple English


Wasps are members of the Order Hymenoptera, which also includes ants, bees and sawflies. By far the greater number of species (over 100,000) are the parasitic wasps. Almost every pest insect species has at least one wasp species that preys upon it or parasitizes it, making wasps critically important in natural control of their numbers (biocontrol). Parasitic wasps are increasingly used in agricultural pest control as they prey mostly on pest insects and have little impact on crops. The common or garden wasps, Vespula vulgaris, and hornets (Vespa) are members of the eusocial family Vespidae, with 5000 species.[1]

Contents

Wasps and bees

Many people usually get confused between wasps and bees. It's pretty easy to tell the difference between bees and wasps, because bees look quite hairy and wasps do not. Wasps also have a longer petiole, or wasp waist. Often, the petiole that separates the thorax from the abdomen is very long and thin. Some wasps also have an extensively long ovipositer that looks like a needle. It uses the ovipositor to lay eggs in hard-to-get-at places. The ovipositor is also its sting.

Physical description

Wasps have biting mouthparts and antennae with 12 or 13 segments. They usually have wings and their abdomens are attached to their thorax by a slender petiole, or a “waist.” Females have a sting, which they use for piercing and egg laying. Adult wasps feed mostly on nectar, but their larvae feed on insects or pollen, provided by the mother. There are more than 20,000 known species of wasps. [2]

Social Life

Nests made of paper

Most wasps are social insects, like bees and ants, but there are a few solitary wasps. Social wasps are formed of paper wasps, yellow jackets and hornets. All three make paper nests from tree wood. They create paper cells similar to the combs that bees make with wax. They chew up bits of wood and convert it into a paste which they use to construct their paper nests.

Eggs & larvae

The queen lays an egg in each cell of the nests. When it hatches the grub is fed regurgitated insects by the worker wasps. In one group, the pollen wasps, grubs are fed pollen and nectar only. Adult wasps eat only nectar. Unlike honeybees, the ony one in a social wasp colony that will survive the winter is the queen. She will find a place to hibernate - in the hollows of trees, under bark, or in the walls of buildings. In the spring, she crawls out and starts all over agan, building a few cells, laying a few eggs, and nurturing them until they can become workers who will do all the work while she lays more eggs.

Wasp parasitism

File:Aleiodes indiscretus wasp parasitizing gypsy moth
Aleiodes indiscretus wasp laying eggs in gypsy moth caterpillar
With most species, adult parasitic wasps themselves do not take any nutrients from their prey, and, much like bees, butterflies, and moths, those that do feed as adults 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 insert one or more eggs into the host or deposit them upon the host externally. The host remains alive until the parasitoid larvae are mature, usually dying either when the parasitoids pupate, or when they emerge as adults. Farmers buy these parasitic wasps for insect control in their fields.

Solitary life

The mud dauber is one of the most common solitary wasps. The difference between normal wasps and mud daubers can be seen easily because of its long petiole. The female gathers together mud and puts it in her mouth to use when building her paper nest for her young. She uses her ovipositor to sting and paralyze tiny insects, spiders, caterpillars, and other creatures, which are stuffed into the mud nest. After each cell in the nest is filled and almost overflowing with spiders and insects, the mud dauber lays an egg in each cell, closes the openings, and leaves. Then, when the eggs finally hatch, the larvae, have a perfectly nice feast upon which they will dine until they become adults.

Some solitary wasps make galls, which are abnormal growths on plants. They form directly after the wasp lays its eggs, and the plant develops a growth around the egg, encasing it. The trigger for the gall to form is not known. The gall protects the eggs while they develop. Galls can be found almost everywhere in the late summer, especially on the branches of oak trees, like in this picture.

File:Andricus quercuscalifornicus-Female Gall on Quercus
Example of a gall on an oak-tree branch

Some wasps deposit their eggs in wood so that the young wasp larvae will feed on the tree itself, making circular tunnels through the wood as they feed, until they pupate and crawl out of the tree as adult wasps.

Allergy and stings

Only the female wasps can sting. A few people are allergic and might die if stung by a wasp. They do not usually sting something unless it bothers them first. Allergy to bees is uncommon compared with allergy to wasps. Some people have a very marked local reaction to a wasp sting - this can usually be prevented with good self care such as elevation, cold compress, pain relief tablets and antihistamines (care re drowsiness when driving and check if regular medications will react with antihistamines). This is not the same as an allergy - it is a normal immune response If a person has symptoms at a distance from the sting - e.g. spreading rash or itch, tight chest, wheeze, tight swallowing, swollen lips/face, faintness or nausea, he or she needs to seek medical care as an emergency. Prevention of stings is vital as most people do not know if they are allergic or not. Prevention of stings is fairly easy if people understand how wasps live and try to avoid eating sweet foods in their environment and take care over sweet smells when they are particularly hungry in the autumn. Here are special orders to do if somebody gets a wasp sting:

  • 1- Scrape away the stringer with a knife blade, credit card, or any other thin object.
  • 2- Do not squeeze the sac attached to the stinger. This can push more venom into the skin
  • 2- Ice packs will reduce pain as well as swelling.
  • 3- The person may have a strong pain for a couple of hours.
  • 4- Dull pain can last up to 1 week.

Other pages

References

Look up Hymenoptera in Wikispecies, a directory of species
  1. Johnson, Norman F. and Triplehorn, Charles A. 2004. Borror's introduction to the study of insects. 7th Edition.
  2. "wasp (insect) -- Britannica Online Encyclopedia". britannica.com. http://www.britannica.com/EBchecked/topic/636580/wasp. Retrieved 6 April 2010. 

Other websites

Information on Wasps and sting prevention








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