Hymenoptera

(Sawflies, ants, bees, and wasps)

Class Insecta

Order Hymenoptera

Number of families About 84

Evolution and systematics

Hymenoptera is a worldwide order of at least 100,000 described species, more biologically diverse than any other insect order. The order is divided into two suborders— Symphyta (wood wasps and sawflies) and Apocrita (wasps, bees, and ants)—with 22 superfamilies and about 84 families. The fossil record dates from the Triassic (245–210 million years ago). The Hymenoptera may be the sister group of the Antliophora, made up of Diptera (flies), Siphonaptera (fleas), and Mecoptera (scorpionflies and hangingflies); and the Amphiesmenoptera, comprising the Trichoptera (caddisflies) and Lepidoptera (butterflies and moths).

Physical characteristics

Adult hymenopterans range in size from minute to large, at 0.006–4.72 in (0.15–120 mm) and from slender (e.g., many wasps) to robust (e.g., the bumble bees). The head usually is very mobile. The compound eyes often are large and sometimes strongly convergent dorsally. Fine setae occasionally emerge from between facets, and ocelli may be present, reduced, or absent, especially in forms with reduced wings. The antennae are long and multisegmented, and their surfaces are covered with various sense organs. The mouth-parts vary from the generalized biting type to the combined sucking and chewing type (e.g., bees). Mandibles typically are present and are used by the adult to cut its way out of the pupal cell, for defense, for killing and handling prey, and in nest construction.

The first abdominal segment of the Apocrita is attached firmly to the metathorax and usually is separated from the remaining abdominal segments (metasoma) by a narrow waist (petiole). In Apocrita thoracic segments plus the first abdominal segment are called the mesosoma, and the incorporated first abdominal segment is the propodeum, followed by the remainder of abdomen. There are generally two pairs of wings. Venation is most complete in Symphyta and mostly reduced in small Apocrita. The hind wings have rows of hooks (hamuli) along the leading edge that couple with the hind margin of the forewing in flight. The legs frequently are cursorial (adapted for running), sometimes with fossorial (adapted for digging) forelegs; the hind legs are modified to carry pollen.

Sensory structures (sensilla) on the ovipositor enable the female to recognize suitable egg-laying sites. In some ants, bees, and wasps the ovipositor has lost its egg-laying function and is used as a defensive, venomous stinger. Although the smooth stingers of ants and wasps allow for repeated use, the barbed stings of the honeybee can be used only once. As the honeybee struggles to leave the stinger and venom behind, it is disemboweled and soon dies.

Bees have several morphological adaptations associated with pollen collection, including plumose (branched) hairs. Moreover, the hind tibia and basitarsus are enlarged, with long hairs on their outer surfaces. These hairs either form a brush (scopa) or are reduced to a fringe surrounding a bare area or concavity (corbicula, or pollen basket). Leaf cutter bees have a well-developed scopa on the ventral surface of the abdomen.

Distribution

Hymenopterans are found worldwide.

Habitat

Hymenoptera occur in soil and litter or on vegetation. Most are active on bright, sunny days, hunting insects, gathering pollen and nectar, or assembling nest-building materials. Some parasitic species are active at night, when their nocturnal hosts are active.

Behavior

Symphyta lay their eggs on or in leaves, stems, wood, and leaf litter, and females sometimes stand guard over their egg masses. The larvae are almost exclusively phytophagous. Pupation takes place within the plant tissue or in the ground. Most have a single generation a year and overwinter as full-grown larvae. The larvae of many species of Apocrita are parasitoids in the immature stages of other insects (or other invertebrates), while the adults are free living.

Idiobiont parasitoids prevent any further development of the host after initial parasitization. Koinobiont parasitoids allow the host to continue its development and often do not kill and consume the host until the host has reached its maximum size. The development of a secondary parasite, or hyperparasite, at the expense of a primary parasite is more frequent in Hymenoptera. The Apocrita species that have the ovipositor modified into a sting are grouped together into the Aculeata. Female Scoliidae locate and attack large subterranean beetle larvae in their burrows or earthen pupal cells. The sting does not kill the host but only immobilizes it. Then the female lays her eggs and departs, leaving her offspring to develop without further assistance. Aculeate hymenopterans may or may not use their stings to immobilize the host; mutillids bite through the host cell and lay an egg on the mature larvae or pupae of the host.

Somewhat more complex behavior is exhibited by many Pompilidae, in which the female captures and paralyzes her prey and then drags it to a cavity or crevice on the ground. She lays an egg on the host and usually seals the cavity before leaving. Cleptoparasites, such as cuckoo bees of the genus Chrysis (actually a metallic blue or green, thick-bodied wasp), construct no nests of their own and instead rely primarily on the food stores of hosts (Chrysis). In other aculeates (for example, other Pompilidae), the female wasp prepares a nest before locating prey and can relocate her nest when she returns with prey.

Female Eumenes (Vespidae) lay eggs in the empty cell before prey are introduced. The female then provides the cell with prey and seals it before the larva begins to develop. This is called mass provisioning, because the initial food that is amassed must be sufficient to feed the larva during the entire course of its development. Progressive provisioners, such as many Sphecidae and Vespidae, provide additional food at intervals. Large, multicelled nests, in which each cell is stocked with many small prey, are characteristic of many behaviorally advanced species. Bees (Megachile and Xylocopa) are similar to wasps in this respect, except that they provision larval cells with pollen and nectar rather than arthropod prey.

Truly social or eusocial hymenopterans have a division of labor, with a caste system involving sterile individuals that assist the reproducers, cooperation among colony members in tending the young, and overlap of generations capable of contributing to colony functioning. Among hymenopterans exhibiting primitive eusociality are paper wasps. The highly eusocial hymenopterans comprise the ants, some wasps, and many bees. Common construction materials for nest building are mud, leaves, and masticated wood chips that are formed into a paper- or carton-like nest.

Feeding ecology and diet

Adult parasitoids require carbohydrates in the form of honeydew, nectar, or other plant secretions. Many female parasitoids also feed extensively on the body fluids of hosts, to sustain egg production. Most symphytan larvae are phytophagous (plant eaters); larvae of Siricidae are wood borers and utilize cellulases produced by fungi to feed on wood; the enzymes necessary for processing the wood fragments are acquired from the fungus ingested. Apocritan larvae have diverse feeding habits; they may be parasitic or gall forming, or they may be fed with prey or nectar and pollen by their parents or other colony members. Adult hymenopterans mostly feed on nectar, pollen, or honeydew produced by Homoptera; only a few consume other insects. Many wasps feed their young macerated or paralyzed insects and spiders. Most bees feed young pollen and nectar. Many members of the order visit flowers for nectar or pollen. Leaf cutter ants feed on fungi, which they cultivate in the nest. The ants live in an obligate mutualistic association with a fungus. The fungus has lost its capacity for sexual reproduction; dispersal occurs by means of the queen ant carrying fungal hyphae to a new nest site.

Reproductive biology

Males of parasitic species commonly search for females at their emergence sites and occasionally fight for possession of such sites. Some males form female-attracting swarms. Among most hymenopterans the females produce pheromones, chemicals that attract and sexually stimulate males of the same species. Courtship in the Apocrita is common and complex, involving sequences of antennal contact, leg and wing vibrations, and mandibular movements. Sex in most Hymenoptera species is determined by the fertilization of the egg; fertilized eggs develop into females, and unfertilized eggs usually develop into males. Thus, females determine the sex of their offspring and can manipulate the rate of increase of their populations.

The adult female searches for a host by responding to a series of cues in the environment. When she locates a potential host, she examines it often with her antennae or the tip of the ovipositor, to decide whether it is acceptable as a site for egg deposition. Females of some species lay their eggs on a broad range of similar hosts within a particular habitat, whereas others are highly specific to a single host or a few closely related species. Most parasitoid species lay their eggs on or in the body of the host, and many have a long ovipositor to reach hosts in cocoons, burrows, or other protected situations. In some cases only a single egg is laid on a host (solitary parasitism); in others, several to many eggs may be laid on the same host (gregarious parasitism). The larva may be ectoparasitic, that is, developing externally, or endoparasitic, developing within the host. Sometimes early instars are endoparasitic, and later instars are ectoparasitic. Pupation typically occurs within or beside the host remains.

Hymenoptera are holometabolus insects, that is, they have a life cycle progressing from egg to larva to pupa to adult. The eggs are ovoid or sausage-shaped, with a respiratory stalk in some parasitic species and with hooklike or sucker-like attachment devices in some ectoparasites. The outer covering typically is thin and smooth, sometimes with little yolk. Polyembryony, that is, development of several individuals from one egg, occurs in some parasitic species.

In Symphyta the larva is eruciform. The head is well sclerotized, and there are three pairs of thoracic legs and abdominal prolegs (commonly on the second through eighth and the tenth abdominal segments). There are as many as eight larval instars, with females often having one more than males. In Apocrita the larva is vermiform, apodous, grublike, or maggot-like, and the head capsule is weakly sclerotized. Primitively, they probably have five larval instars, but the number is reduced in many endoparasitoids.

Larval heteromorphosis occurs in many parasitic species. In these species, whereas the final instar larva is vermiform, the first or intermediate instars are of diverse forms. Pupae of the exarate type have free appendages that are not glued to the body; they may form in a cocoon in the host or in special cells. The cocoon is spun with silk from the labial glands. Some hymenopterans may spend a very long period in diapause within the cocoon.

Conservation status

The 2002 IUCN Red List includes 152 hymenopteran species. Of these, 3 are listed as Critically Endangered; 142 as Vulnerable; 6 as Lower Risk/Near Threatened; and 1 as Data Deficient.

Hymenopterans are susceptible to the indiscriminate use of insecticides and to habitat destruction. The effects of insecticides include the eradication of nontarget organisms, including such pollinators as bees and wasps. Without the pollinating services of bees and other insects, we would have few vegetables, fruits, and flowers and little or no clover. To achieve preservation of these key aspects of our lives, hymenopteran biotopes must be conserved and utilized in a sustainable fashion.

Significance to humans

Certain hymenopterans were considered deities in such civilizations as Egypt. To the Greeks the bee Melitta was

known as the Goddess Honey Mother. The ant-hunting species of Dinoponera was a symbol of virility for several Amazon tribes and was used in initiation rituals. The Mixe people of Oaxaca (Mexico) believe that they become more powerful through the ingestion of ants; ants thus have come to stand for virility, fortitude, and courage. The bee Melipona beechei in Mexico represented the spiritual world, merriment, and rain. Wasps and bees are represented frequently in literature, music, theater, cinema, and television. The Greek comic playwright Aristophanes, for example, wrote a play called The Wasps, satirizing the Athenians' love of litigation and characterizing jurors as wasps in their harshness. The Russian composer Nikolai Rimski-Korsakov, inspired by the sound that bees produce, composed the "Flight of the Bumblebee," a piece of music for strings set within the opera The Tale of Tsar Saltan, the story of a prince who is turned into a bee. In modern times, several protagonists of the Pokemon cartoons represent hymenopterans.

From the standpoint of human beings, Hymenoptera probably is the most beneficial order of insects; it contains many insects that are of value as parasitoids or predators of other arthropods, including insect pests. They have been employed successfully as pest control agents in several countries. Bees generally are regarded as the most important group of insect pollinators. Apis mellifera is of great commercial value as a producer of honey that is used extensively as food and in the manufacture of many products. Beeswax is used in making candles, sealing wax, polishes, certain types of ink, models of various kinds, and in other products such as face and hand creams, lipsticks, and lip salves.

Nest-building Hymenoptera can be domestic nuisances. Bees and wasps inject venom when they sting. Many people are highly sensitive to bee or wasp stings and may suffer anaphylactic shock leading to death or disability as the result. The sting of the female hymenopteran can seem unprovoked, but it is, in fact, an aggressive defense of the nest.

Hymenopterans are food for humans in some parts of the world. They are edible at all stages of growth. Boiling tends to break down the poison, which is basically protein and, at boiling temperatures, the stinger softens. Pounding them before boiling makes them more edible. Ants (except the fire ant) and ant larvae are edible and tasty. Australian aborigines living in arid regions derive sugar from species of Melophorus and Camponotus, popularly known as honey pot ants. Specialized worker ants (repletes) are fed with nectar by other workers and store it in their huge distended crops. Honey pot ants in the western United States and Mexico belong to the genus Myrmecocystus.

Few species of Hymenoptera are harmful. Sawfly larvae cause damage to forests, orchards, and ornamental trees. Wood-boring larvae, in association with fungi, can cause extensive damage to plantations of conifers. A few ants are pests, for example, the leaf cutter ants or the seed harvesters; others protect sap-sucking insects, which are pests themselves.

Species accounts

List of Species

Honeybee

Apis mellifera

family

Apidae

taxonomy

Apis mellifera Linnaeus, 1758.

other common names

English: Common honeybee, European honeybee.

physical characteristics

Body length of workers is 0.37–0.62 in (9.5–15.8 mm). The male drone is 0.62 in (15.8 mm), and the queen is 0.75 in (19.5 mm) long. Body is golden brown and black, with pale orange/yellow rings on the abdomen. The head, antennae, and legs are almost black; fine hairs cover the thorax and only lightly cover the abdomen. Wings are translucent. Pollen baskets are made of specialized hairs and are located on the outer surface of the tibiae of the hind legs.

distribution

Worldwide distribution. There are many geographical races distributed throughout Europe, Africa, and parts of western Asia as well as the Americas.

habitat

Most colonies live in man-made commercial hives; swarms that escape generally nest in hollow trees. They visit a wide range of native and introduced flowers.

behavior

Eusocial. A colony of honeybees consists of a queen, several thousand workers, and, in certain seasons, a few hundred drones. A queen can lay as many as 2,000 eggs in a single day. In her four to five years of life she produces about two million eggs. More than 80,000 bees can live in a single colony. The primary function of the queen is to lays eggs; the workers are sterile females that supply the colony with food, guard the nest, and build the combs. These females live about four or five weeks. The drones are fertile males who fly out at certain times of the year to mate with new queens. The cells in the nest are arrayed in vertical combs, two cell layers thick. The comb consists of adjoining hexagonal cells made of wax secreted by the workers' wax gland. The bees use these cells to rear their brood and to store their food. Honey is gathered in the upper part of the comb, and beneath it, in descending order, are rows of pollen-storage cells, worker brood cells, and drone brood cells. The groundnut-shaped queen cells normally are built at the lower edge of the comb. Honeybee colonies are perennial, with the queen and workers overwintering in the hive. Bee colonies propagate by swarms. Shortly before one or more queens emerge from the queen cells, the old queen leaves the hive with about half of its population. Honeybees have impressive communication abilities, especially with respect to forage sites (the type of flower and the direction and distance from the hive).

feeding ecology and diet

Adults and larvae eat a mixture of honey (a sweet, viscid material made of the nectar of flowers in the honey sac) and a type of pollen called beebread. The queen's larvae are fed by the

third day with royal jelly (a nutritious secretion of the pharyngeal glands).

reproductive biology

Fertilized eggs develop into females, and unfertilized eggs develop into males. Whether a larval honeybee destined to be a female becomes a worker or queen depends on the sort of food it is fed.

conservation status

Not threatened.

significance to humans

Pollination of plants and production of honey. They are the main bee pollinators worldwide.

Large red-tailed bumblebee

Bombus lapidarius

family

Apidae

taxonomy

Apis lapidaria Linnaeus, 1758.

other common names

English: Red-tailed bumblebee; German: Steinhummel.

physical characteristics

Body length is 0.78–0.98 in (20–25 mm). Color is mainly black with a red tail; the male has a yellow collar band.

distribution

Palearctic region as well as Europe, Asia, and North Africa.

habitat

Occurs in most grassland areas, collecting nectar from species with short corollas that make good landing platforms, such as daisies, dandelions, and thistles.

behavior

Eusocial. The nests are in underground hollows, surrounded by a cover of moss and other materials. The colonies are annual, and only the fertilized queen overwinters. In the spring the queen selects a nest site and begins nest construction; the first brood raised by the queen consists of workers. With the exception of egg laying, the workers take over all duties of the colony, including food gathering and its storage in little sacs resembling honey pots, and care for the larvae. In summer, males and queens are produced, and in the fall all but the queens die.

feeding ecology and diet

Adults feed on nectar and pollen; larvae are reared with a mixture of pollen and nectar, which are carried in large pollen sacs on the back legs and in the stomach, respectively.

reproductive biology

The queen makes pots of wax and pollen, into which the first eggs are laid. When these eggs hatch, she provides them with honey while making storage cells for honey and more cells for future eggs.

conservation status

Not threatened.

significance to humans

Valuable as pollinators.

Large carpenter bee

Xylocopa virginica

family

Apidae

taxonomy

Apis virginica Linnaeus, 1771.

other common names

English: Drone carpenter bee.

physical characteristics

Body length is about 1.28 in (20 mm). The body is mostly black. The antennal scape is completely dark; the thorax has yellow hair both dorsally and laterally. The abdomen is black, with a slight purplish tint, and the legs have dark brown hair. Males have white areas on the head.

distribution

Eastern United States southward to Texas and northern Florida.

habitat

Adults are seen in well-lighted areas.

behavior

These bees make their nests in wood. They nest on wood that is not painted and usually construct the nest in the same areas for generations. Carpenter bee tunnels are about 4–6 in (101.6–152.4 mm) long and 0.5 in (12.7 mm) in diameter. The bees frequently reuse old tunnels for pollen storage and overwintering chambers. They prefer rotten or seasoned wood.

feeding ecology and diet

Adults feed on nectar; larvae on pollen mixed with nectar.

reproductive biology

After excavating the gallery, female bees gather pollen, which is mixed with regurgitated nectar. The pollen mass is put at the end of a gallery, an egg is laid, and the female places a partition or cap over the cell, composed of chewed wood pulp. This process is repeated until a linear complement of six to eight end-to end cells is completed. Bees emerge in the late summer and overwinter as adults, with mating taking place in spring.

conservation status

Not listed by the IUCN.

significance to humans

The most important damage done by carpenter bees is weakening of structural timbres and gallery excavation on wooden water tanks. They are, however, valuable pollinators of wild and domestic fruit blossoms. Females of carpenter bees may sting (rarely), and male bees may hover or dart at humans who venture into the nesting area.

Cuckoo wasp

Chrysis coerulans

family

Chrysididae

taxonomy

Chrysis coerulans Fabritius, 1805.

other common names

Spanish: Avispas cuclillo.

physical characteristics

Body length of 0.47 in (12 mm). Metallic green and blue in color and usually has a coarsely sculptured body. Fairly complete venation of the front wing but no closed cells in hind wing. Abdomen has only three visible segments and is hollowed out ventrally.

distribution

Canada (Yukon and southern Canada) and United States (Colorado).

habitat

Flowers, arid and sandy soils, old wood exposed to sun, and pebbles.

behavior

Cleptoparasite of Eumenes fraternus.

feeding ecology and diet

Adults feed chiefly on flowers for nectar and pollen; larvae feed on larvae of the potter wasp. Eumenes fraternus.

reproductive biology

The female uses her mandibles to penetrate the host nest or to gain access to the host by entering an open cell that is to be provisioned. If the host attacks the female, her concave metasoma allows the female to roll up into an impenetrable ball and play dead. The larva hatches and addresses itself immediately to the consumption of the host egg and the paralyzed caterpillars that were to serve as food for the host larvae.

conservation status

Not listed by the IUCN.

significance to humans

They are more injurious than beneficial to humans because they attack wasps (Eumenes) that are themselves beneficial to humans. However, adult cuckoo wasps do serve as pollinators.

No common name

Apoanagyrus lopezi

family

Encyrtidae

taxonomy

Apoanagyrus lopezi De Santis, 1964, Chacras de Coria, Argentina.

other common names

None known.

physical characteristics

Small wasp, 0.027 in (1.4 mm) long. Black or shiny blue and violet coloring, with light areas.

distribution

Argentina, Brazil, Colombia, and Paraguay. It was introduced and established in Africa (Senegal, Gambia, Guinea Bissau, Guinea Conakry, Sierra Leona, Ivory Coast, Ghana, Togo, Benin, Nigeria, Cameroon, Niger, Central African Republic, Gabon, Democratic Republic of the Congo, Angola, Rwanda, Burundi, Tanzania, Malawi, Mozambique, and the Republic of South Africa).

habitat

Savanna, tropical rainforest, and highlands.

behavior

Parasitoid on the nymphal stages of the cassava mealybug, Phenococcus manihoti (Hemiptera: Pseudoccocidae).

feeding ecology and diet

Adults feed of nectar and pollen; immature insects are parasitoids.

reproductive biology

Females copulate only once, whereas males may do it several times. Parthenogenesis also occurs, in which case all offspring are male. Females deposit about 40 eggs. Females feed on the exudate of wounds inflicted by the ovipositor on nymphal stages of the mealybug that serves as host for the young. The life cycle is complete in 11–25 days: egg, 2 days; larva, 6 days; prepupa, 4 days; pupa, 6 days.

conservation status

Not threatened.

significance to humans

One of the most successful biological control programs used these wasps to eradicate the cassava mealybug, Phenacoccus manihoti. This pest was first reported in the Democratic Republic of the Congo in 1971, and within a few years it had infested nearly all of tropical Africa, devastating the primary sources of nutrition for 200 million people. The introduction of Apoanagyrus lopezi immediately produced spectacular control in field trials in Nigeria; by 1990 these parasitoids had been established successfully in 24 African countries and had spread over more than 1 million mi² (2 million km²). The mealybug is now under complete control throughout the whole of its range in Africa.

Leaf cutter ant

Atta sexdens

family

Formicidae

taxonomy

Formica sexdens Linnaeus, 1758, Paramaribo, Surinam.

other common names

Spanish: Hormigas cortadoras, sepes.

physical characteristics

The dorsum of the thorax bears three pairs of teeth or spines. The body surface is partly tuberculate and reddish. Major workers or soldiers are 0.43–0.47 in (11–12 mm) in length.

distribution

Costa Rica, Panama, Colombia, Venezuela, Guiana, Ecuador, Peru, Bolivia, Brazil (Rondônia, Acre, Amazonas, Pará, Amapá, Maranhao, Piaui, Ceará, Rio Grande do Norte, Paraiba, Pernambuco, Sergipe, Alagoas, Bahia, Minas Gerais, Goias, and Mato Grosso), Paraguay, and Argentina.

habitat

Colonies are found throughout the rainforest floor, tropical deciduous forest, and tropical scrub forest.

behavior

Eusocial insects, living in large colonies. Their nests are in the ground, and they bring cut-up leaves from several kinds of plants into them. These materials are chewed and processed to make a nutrient medium on which a certain species of fungus grows. The colony is formed when a queen has been fertilized. There are two major female castes, the reproductive queen (winged) and the workers (wingless). Males are winged. Distinct subcastes are called, according to their size, minor, media, or major workers or soldiers. They exhibit an elaborate range of behaviors, including foraging, cutting living plant tissues, defense of the nest, and care of broods. The nest of leaf cutters expands into labyrinths of chambers located near the surface, which contains the fungus gardens. Large dipper pits hold detritus and waste. A few of these pits contain more soil than organic matter, which is needed as a cover, especially for pathogenic waste. There are ventilation channels in which hot air rises from the refuse chambers and cools, and oxygen-rich air is drawn into the nest.

feeding ecology and diet

Feeds on fungus.

reproductive biology

The female mates with three to eight males. She stores 206–320 million sperm for ten or more years. A queen can produce up to 150 million daughters, the majority of them workers. The queen establishes the nest and continues to produce eggs for the duration of the nest's existence. At the appropriate time, reproductive males and females make their nuptial flight, mate, and the females attempt to found a new colony.

conservation status

Not threatened.

significance to humans

Because they attack most kinds of vegetation, including crop plants, they are serious economic pests. Leaf cutter ants dominate the ecosystems in which they occur. These ants are a good source of protein for humans, and they are eaten in parts of Mexico. Indians used the jaws of the soldier ant as sutures to hold together the edges of wounds.

No common name

Ibalia leucospoides

family

Ibaliidae

taxonomy

Ichneumon leucospoides Hochenwarth, 1785.

other common names

None known.

physical characteristics

Body length of 0.63–0.67 in (16–17 mm). Body and legs are black. Female abdomen is somewhat elongated; in males, it is pyriform.

distribution

Originally from central Europe, it has been introduced to New Zealand, Australia, Tasmania, and Argentina (Andean Patagonia).

habitat

Adults may be seen on the bark of trees.

behavior

Primary solitary endoparasitoids of hymenopterous, wood-boring larvae (Siricidae).

feeding ecology and diet

Adults feed on nectar and honeydew; larvae feed on sirex larvae.

reproductive biology

The males emerge first, and mating takes place while the female is in the act of laying eggs. When attacking its host in the host's tunnel, the parasitoid female inserts the ovipositor into the tunnel entrance, and the stalked egg is placed either in the egg of the host or in the newly hatched larva. The mature larva emerges from the body of the host and completes its feeding externally.

conservation status

Not threatened.

significance to humans

Their biological control action is complementary to that of Megarhyssa nortoni, which attacks the last instars of sirex larvae.

No common name

Megarhyssa nortoni

family

Ichneumonidae

taxonomy

Rhyssa nortoni Cresson, 1864, Colorado, United States.

other common names

None known.

physical characteristics

Giant wasps, 0.59–1.77 in (15–45 mm) long. The female ovipositor can be twice as long as the body, so the wasp can reach overall lengths in excess of 6.29 in (130 mm). Body is colored black, reddish-brown, and yellow and has a distinctive series of round yellow spots down the side of the abdomen.

distribution

United States. Introduced into New Zealand, Tasmania, and Brazil.

habitat

These wasps are found commonly around pine plantations.

behavior

Primary solitary endoparasitoids of last instar larvae of hymenopterous wood-boring larvae (Siricidae).

feeding ecology and diet

Adults feed on nectar; larvae feed on sirex larvae.

reproductive biology

Female sirex wasps lay their eggs in pine trees and introduce a special wood-digesting fungus at the same time. The sirex larvae then bore through the wood, which is digested with the aid of the fungus. It is the smell of this fungus that attracts the female Megarhyssa to an infected tree. She uses her long ovipositor to bore through the wood until she encounters a sirex larva and then paralyzes it before laying an egg on it. The parasitoid completes development within the host.

conservation status

Not threatened.

significance to humans

Megarhyssa nortoni has been utilized for the biological control of siricid forest pests; its action is complementary to the action of Ibalia leucospoides, which attacks the first instars of sirex. It is harmless to people.

Alfalfa leaf cutter bee

Megachile rotundata

family

Megachilidae

taxonomy

Apis rotundata Fabritius, 1787.

other common names

English: Leaf cutter bee; Spanish: Abeja polinizadora de la alfalfa.

physical characteristics

Moderate size, about 0.31–0.35 in (8–9 mm). A fairly stoutbodied bee. Black with yellow pilosity in the front and at the dorsum of the thorax and whitish pilosity in ventrolateral areas, legs, and mouth. Abdomen has short hairs that are white and yellow along the dorsal ridge. Females have pollen brushes on the ventral side of abdomen.

distribution

Originally from Europe, but it was introduced into North America. It is distributed in the Neartic, particularly in Canada; from Canada it was introduced to Chile.

habitat

Grasslands.

behavior

Solitary. Cuts leaves and petal pieces to line cells for offspring in nests. When they cut leaves, they leave a characteristic oblong or circular cutout on the edge of the leaf or petal. Several oblong leaf pieces line individual cells in the nest.

feeding ecology and diet

Adults feed on nectar; larvae eat pollen and nectar.

reproductive biology

The cells are filled with pollen and nectar. A single egg is laid in each cell, which is capped with round leaf pieces. The bee then starts over, collecting oblong leaf pieces.

conservation status

Not threatened.

significance to humans

Valuable as pollinators of alfalfa crops.

Velvet ant

Mutilla europaea

family

Mutillidae

taxonomy

Mutilla europaea Linnaeus, 1758.

other common names

English: Cow-killer, mule-killer; Spanish: Avispas aterciopeladas.

physical characteristics

Body length of 0.47–0.55 in (12–14 mm). Females are wingless, and males are winged. Both have downy hairs covering the body; they are brownish-red in color, except for the abdomen, which is an iridescent black-blue with white, hairy bands.

distribution

Europe.

habitat

Adults commonly are seen on the ground in open areas, especially in sandy places.

behavior

Females attack larvae and pupae of bumblebees.

feeding ecology and diet

Adults feed on nectar; their grubs eat the food provisions stored in the invaded nest and also the grubs and pupae of the host.

reproductive biology

Velvet ants have an unusual courtship ritual, with mating accomplished in the air. The winged male carries the flightless female while copulating. Females lay the eggs with those of the bumblebee, on which the larvae later feed. The mature larvae knit a cocoon within the cell cocoon, or puparium, of the host.

conservation status

Not threatened.

significance to humans

This family must be regarded as predominantly injurious, inasmuch as the majority of insects that they attack are predaceous or parasitic upon other insects. They also have the habit of attacking such pollinators as honeybees or bumblebees. Females have a sting that is painful to humans.

No common name

Pelecinus polyturator

family

Pelecinidae

taxonomy

Ichneumon polyturator Drury, 1773, type locality not specified.

other common names

None known.

physical characteristics

Body length of 2 in (50.8 mm). Females are shiny black with an extremely long, narrow abdomen. Males have a much

shorter abdomen but are extremely rare and are almost never seen.

distribution

Southern portions of the eastern provinces of Canada, the eastern United States (west to North Dakota, Colorado, and New Mexico) and Mexico south to central Argentina.

habitat

Deciduous woodlands.

behavior

Larvae are endoparasitoids of June beetles (Scarabaeidae). Females are active in late summer and early fall.

feeding ecology and diet

Adults feed of nectar and pollen; immature stages are parasitoids.

reproductive biology

Little is known about the reproductive biology. The species has been reared from larvae of Scarabaeidae (Coleoptera), particularly species of Phyllophaga, and it appears to be a solitary endoparasitic koinobiont. Males are very rarely collected. Tropical populations are bisexual, and temperate populations consist only of females (geographic parthenogenesis).

conservation status

Not listed by the IUCN.

significance to humans

The metasoma of female pelecinids is extremely flexible; when handled, they occasionally are capable of inflicting a sting, but it is a mild sensation, like a pinprick.

Tarantula hawk

Pepsis grossa

family

Pompilidae

taxonomy

Sphex grossa Fabritius, 1798, India (in error).

other common names

English: Spider wasp, spider-hunting wasp; Spanish: San Jorge, avispón, matacaballos, halcón de las arañas.

physical characteristics

Slender, with long, spiny legs. Body length is 0.94–2 in (24–51 mm). Body and legs are black with a mainly blue-green shine, often with a violet or copper tinge. Antennae are black, usually with orange on the tip of the last segment. Wings typically are black with quite strong blue-violet reflections, sometimes diffuse amber or orange, often with a dark border.

distribution

Southern United States and the West Indies south through Mexico to north-central Peru and the Guianas.

habitat

Rainforest to desert.

behavior

Adults typically are found on flowers or on the ground in search of prey. The members of this genus make their nests in burrows in the ground and provision them exclusively with mygalomorph spiders (usually Theraphosidae, or tarantulas).

feeding ecology and diet

Adults feed on nectar; larvae feed on spiders.

reproductive biology

Adults capture and paralyze a spider and then prepare a cell for it in the ground, in rotten wood, or in a suitable crevice in rocks. An egg is laid on the victim; the spider is buried alive with the larva, which hatches within a few days. It pupates after it has consumed the spider.

conservation status

Not listed by the IUCN.

significance to humans

This species of wasp is especially attracted to the flowers of Asclepias species (Asclepiadaceae), and it probably forms the largest group of pollinators. The female wasp's sting can be excruciatingly painful, but they are not known to attack humans without being provoked. It is difficult to assess the economic effect of their predation on spiders, because, in most cases, the economic significance of the spiders themselves is unknown.

No common name

Trissolcus basalis

family

Scelionidae

taxonomy

Telenomus basalis Wollaston, 1858, Madeira Archipelago.

other common names

None known.

physical characteristics

Body length of 0.04–0.05 in (1–1.3 mm). Black with downward-pointing elbow-shaped antennae and a flattened abdomen. Wing veins are reduced.

distribution

United States (Florida, Louisiana, Mississippi, and South Carolina), West Indies, Venezuela (Aragua), Brazil (Minas Gerais, Paraná, and Distrito Federal), Australia (Canberra), Egypt, Ivory Coast, Morocco, Republic of South Africa (Pretoria), Zimbabwe (Harare), Portugal, France, and Italy.

habitat

Occurs in all crops attacked by bugs, including cotton, grains, soybeans and other legumes, tomatoes and other solanaceous crops, sweet corn, sunflowers, cole crops, cucurbits, and fruits and nuts.

behavior

Primarily solitary idiobiont endoparasitoid of pentatomid eggs; completes development from egg to adult within the host egg.

feeding ecology and diet

Adults feed on nectar; larvae eat the eggs of bugs.

reproductive biology

Adults mate immediately after emerging from host eggs. The female inserts her egg into a host egg. After oviposition, females apply an external marker with the ovipositor to avoid superparasitism. There are three larval instars, and most feeding occurs during the last two. Pupation takes place in the host egg.

conservation status

Not threatened.

significance to humans

Scelionids have been used quite successfully in classic biological control programs directed principally against pest hemipterans. The species has been introduced into many different countries to control Nezara viridula (Pentatomidae).

Digger wasp

Scolia dubia

family

Scoliidae

taxonomy

Scolia dubia Say, 1837.

other common names

English: Blue-winged wasp.

physical characteristics

Body length is 0.63 in (16 mm). Hairy and blue-black in color, with two yellow spots (one on each side of the abdomen). Behind the yellow spots, the abdomen is brownish and the hairs on the body more noticeable. The wings are dark blue.

distribution

New England to Florida and west to the Rocky Mountains.

habitat

Adults often are found on flowers. These wasps appear in the early morning and fly low over lawns infested with scarabeid larvae. The flight is characteristic: they fly on a horizontal plane only a few inches above the ground and following a circular or figure eight–shaped course. Males become active somewhat earlier than females, and mating takes place largely on the ground or on low vegetation as soon as females appear.

behavior

The female dig into soil or fallen leaves with her powerful forelegs to locate a host. On finding a grub, she stings and paralyzes it. She may burrow 0.5 in (1.2 cm) deeper to construct a cell around the host. Then she lays an egg on the outside of the grub. She may sting many grubs without laying eggs on them; such grubs usually do not recover. Unmated individuals of both sexes are gregarious (form aggregations); after mating this gregariousness is abandoned.

feeding ecology and diet

Adults feed on nectar derived from the blossoms of various plants; larvae feed on beetle larvae. Green June beetle, May beetle, and Japanese beetle grubs seem to be the primary host.

reproductive biology

Females attract males by spreading their wings so that the brilliantly colored body is revealed. Eggs are attached lightly by the posterior end to the body of the host. When the larva hatches, it finds itself provided with food, which has been preserved alive. There are four larval instars; the mature larva spins a cocoon. During the larval stages the entire contents of the beetle larvae are consumed.

conservation status

Not threatened.

significance to humans

These wasps are natural agents in the control of grubs in the soil. These digger wasps do not sting people unless they are aggravated or captured by hand.

European wood wasp

Sirex noctilio

family

Siricidae

taxonomy

Sirex noctilio Fabricius, 1793.

other common names

English: Wood wasp, sirex; Spanish: Avispa taladradora de la madera.

physical characteristics

Male body length 0.7 in (18 mm); female body length 1.18 in (30 mm). Metallic blue-black with a long ovipositor. Male's abdomen predominantly yellowish-red.

distribution

Originally from Eurasia and northern Africa and now established in New Zealand, Tasmania, Australia, South Africa, Canada, and South America.

habitat

Larvae live in wood galleries of such conifers as Abies, Larix, Picea, Pinus, and Pseudotsuga.

behavior

The males form swarms over trees, and mating takes place in the swarms. With her well-developed ovipositor, the female inserts eggs into the tissues of the host plant. Wood wasps carry Amylostereum fungal spores in invaginated intersegmental sacs connected to the ovipositor. During egg laying, spores and mucus are injected into the sapwood of trees, causing mycelial infection. The infestation produces a locally dry condition around the xylem, which allows for optimal development of the larvae.

feeding ecology and diet

Adults do not feed. Larvae rely on fungal hyphae to break down wood into its digestible components.

reproductive biology

The larvae are wood boring. Pupation occurs in galleries made by the larva. They usually spend winter in the tunnels of the host plant.

conservation status

Not threatened.

significance to humans

Wood-boring larvae, in association with fungi, can cause extensive damage to plantations. It is considered a serious pest of forestry plantations of conifers, notably Pinus species. In Australia and New Zealand the fungal disease can cause death of fire-damaged trees or those stressed by drought conditions. Biological control programs include the use of natural enemies, such as the parasitic wasps Rhyssa, Megarhyssa, and Ibalia and the nematod Deladenus siricidicola.

Mud dauber wasp

Sceliphron caementarium

family

Sphecidae

taxonomy

Sphex caementarium Drury, 1773.

other common names

English: Yellow and black mud dauber.

physical characteristics

Large wasps, with a body length of 0.7–1.1 in (20–30 mm). They are predominately matte black with a few yellow areas on the thorax and first tergum of the abdomen. The legs are partly yellow and the wings deep amber.

distribution

Canada (Alberta, British Columbia, Manitoba, New Brunswick, Nova Scotia, Ontario, Prince Edward Island, and Quebec), the United States (Florida and Michigan), Central America, and the West Indies. Introduced to Australia, the Pacific islands (Hawaii and Japan), French Polynesia, Samoa, Fiji, the Marshall and Mariana Islands, Peru, and Europe.

habitat

Lives in wet areas where mud can be found.

behavior

Solitary. Adults emerge in the spring after overwintering, staying about nine months as larvae or pre-pupae. Females spend a few days exploring and feeding on nectar. Afterward, the female mates and hunts for a source of mud to begin the construction of her nest. Then she takes up the search for spiders, which she paralyzes with her sting and carries back to the cell. After completion of one cell, she begins another, until several have been constructed and provisioned. The cells have a characteristic ridged appearance at this point. The entire assemblage of cells finally is coated with a thin layer of mud and smoothed over.

feeding ecology and diet

Adults feed on nectar; larvae eat spiders.

reproductive biology

The female lays an egg on a spider near the base of the cell, and the cell is capped with a mud plug. The larvae develop on spiders, which the adult female finds on foliage and flowers. Pupation takes place within a cocoon inside the cell. After transforming into an adult wasp, it breaks out of the nest.

conservation status

Not threatened.

significance to humans

Mud daubers generally do not sting unless provoked, because they do not defend their nests. Their nests can be a nuisance in garages, under the eaves of houses, and in other types of buildings.

Pear and cherry slug

Caliroa cerasi

family

Tenthredinidae

taxonomy

Tenthredo cerasi Linnaeus, 1758.

other common names

English: Pear sawfly, cherry sawfly pear slug, pear slugworm, cherry slugworm, pear slug sawfly, slugworm; Spanish: Chape del cerezo, babosita del cerezo, chape del peral, babosita de los perales, babosita de los frutales, babosa del peral; French: cherry slug tenthride du Poirier, celendre noire; Dutch: Zaawesp van kersen en peren.

physical characteristics

Adults are small, with a body length of 0.31 in (8 mm). Wide body, with the abdomen strongly joined to the thorax. Black, smooth, and shiny. Wide and hyaline wings. Females have a sawlike ovipositor.

distribution

Presumed to be of European origin. It has been introduced into the New World (Argentina, Colombia, Uruguay, and Chile), Africa, New Zealand, and Tasmania.

habitat

Usually found on foliage or flowers.

behavior

The larvae are phytophagous, feeding externally and skeletonizing leaves. There is usually a single generation per year; the insect overwinters in a pupal cell or cocoon in the ground or in another protected situation.

feeding ecology and diet

Adults feed on nectar; larvae are external feeders on foliage.

reproductive biology

The female lays her eggs on leaves in the spring. She slits the leaf tissue with her ovipositor to deposit small, oval, flattened eggs, which hatch in about two weeks. The eggs are laid between the parenchyma and cuticle. The olive green to black larvae are slug-like, with a well-developed head capsule, thoracic legs, and abdominal prolegs. They are covered with a greenish slime. In autumn larvae make small earthen cells in the soil in which to spend the winter, before pupating in early spring.

conservation status

Not threatened.

significance to humans

The pear and cherry slug is a cosmopolitan pest in cherry-, plum-, and pear-growing regions of the world.

Potter wasp

Eumenes fraternus

family

Vespidae

taxonomy

Eumenes fraternus Say, 1824.

other common names

English: Mason wasp; Spanish: Avispas alfareras.

physical characteristics

Body length of 0.51–0.66 in (13–17 mm). Black with yellow markings on the thorax and abdomen. Wings are smoky with violet iridescence. The first abdominal segment is narrow and stalklike and is followed by a broad, bell-shaped second segment. Middle tibia has one apical spur.

distribution

Minnesota, Nebraska, Kansas, Oklahoma, Texas, and eastward to the Atlantic coast of the United States.

habitat

Adults are seen on the ground in open areas or at flowers.

behavior

Solitary. These wasps make their nests of mud in the form of miniature ceramic-like pots or jugs. The pots are globular with a narrow neck, which has an expanded rim.

feeding ecology and diet

Adults feed on nectar; larvae eat caterpillars.

reproductive biology

The female lays a single egg suspended from a wall by a slender filament in the empty nest. She then provisions the nest with 1 to 12 caterpillars (which have been paralyzed by her sting) and seals the nest. The hatching wasp maggot consumes the stored prey in the nest. After transforming into an adult, it breaks out of the nest.

conservation status

Not listed by the IUCN.

significance to humans

These wasps are not aggressive and rarely sting people, because they do not defend their nests. It has been reported that potter wasp nests served as models for the clay vessels made by Indians.

Golden paper wasp

Polistes fuscatus

family

Vespidae

taxonomy

Polistes fuscatus Fabritius, 1793.

other common names

English: Northern paper wasp, umbrella wasp.

physical characteristics

Body length of 0.75–1 in (19.5–25.4 mm). Body is dark reddish-brown and yellow, elongated, and slender, with a spindle-shaped abdomen. Wings are amber to reddish-brown. Males have a pale face, and females have a brown face.

distribution

British Columbia to the Canadian Maritime Provinces and south to West Virginia.

habitat

Meadows, fields, and gardens on flowers and near buildings.

behavior

Primitively eusocial hymenopterans. Their nests consist of a single more or less circular horizontal comb of paper cells, suspended from a support by a slender stalk. Mixing masticated wood pulp with adhesive saliva, the female builds an open comb consisting of a single layer of hexagonal cells. These paper cells act as a nesting chamber. The comb is attached to the substrate by a strong stalk.

feeding ecology and diet

Adults feed on nectar and juices from crushed and rotting fruits; larvae feed on insects that have been pre-chewed by adults.

reproductive biology

Female lays an egg in each cell. The cells are open on the lower side while the larvae are growing and are sealed when the larvae pupate. After hanging into an adult wasp, they break out of the nest.

conservation status

Not listed by the IUCN.

significance to humans

Paper wasps are considered beneficial insects owing to their predation on garden pests. Paper wasps will defend their nests if disturbed, and they sting repeatedly.

Yellow jacket

Vespula germanica

family

Vespidae

taxonomy

Vespa germanica Fabricius, 1793.

other common names

English: German wasp; Spanish: Chaqueta amarilla, avispa chaqueta amarilla, avispa carnívora, avispa alemana.

physical characteristics

Body length of 0.41–0.80 in (10.5–20.3 mm). Black antennae and yellow and black body, with black arrowhead-shaped markings pointing backward along the top of the abdomen and black spots on either side.

distribution

Worldwide, including Europe, northern Africa, and temperate Asia. It was introduced into Canada, the United States, New Zealand, Tasmania, Australia, Argentina, and Chile.

habitat

These wasps thrive in urban areas; their liking for fruit, meat, and sweets brings them into contact with people.

behavior

Eusocial. These wasps live in hidden nests, which are either underground or in the wall cavities or ceilings of buildings. A mature nest is the size of a football and is constructed of a papery material. The combs are covered completely with a balloon-like envelope. Adult forms include fertile females (queens), workers (females, usually sterile), and fertile males. In late summer, colonies produce new queens and males. After mating, these new queens go into hibernation. Males and workers do not survive the winter. The following spring the queen emerges from hibernation and searches for a suitable nesting site. She then collects wood or other vegetable fiber from shallow cells. Females cooperate in nesting, exhibiting reproductive division of labor.

feeding ecology and diet

Adults forage for meats, sweets, and fruits. The larvae are fed by the workers with masticated portions of animal matter and, at times, with fruit juices, nectar, and honeydew.

reproductive biology

The queen lays an egg in each cell and then protects the resulting larvae, feeding them daily. After 12–18 days the larvae spin cocoon caps over their cells and transform into pupae. When adults emerge about 12 days later, they serve as the first brood of workers, and the queen resumes egg laying.

conservation status

Not listed by the IUCN.

significance to humans

Because yellow jackets forage for meats, sweets, ripe fruit, and garbage, they pose a threat to humans. They are a particular problem in picnic areas and orchards and around garbage containers. The sting is painful but not usually serious, although some people suffer a bad allergic reaction. Stings inside the throat are potentially fatal and require immediate medical attention.

Resources

Books

Artigas, Jorge N. Entomología Económica: Insectos de Interés Agrícola, Forestal, médico y Veterinario. 2 vols. Concepción, Chile: Ediciones Universidad de Concepción, 1994.

Borror, Donald J., Charles A. Triplehorn, and Norman F. Johnson. An Introduction to the Study of Insects. Philadelphia:W. B. Saunders, 1989.

Clausen, C. P. Entomophagous Insects. New York: Hafner, 1972.

Correa-Ferrêira, B. S. Utilizaçao do Parasitóide de Ovos Trissolcus basalis (Wollaston) no Controle de Percevejos da Soja. Centro Nacional de Pesquisa de Soja, Circular Técnica no. 11. Londrina, Brazil: EMBRAPA Soja, 1993.

Costa-Neto, Eraldo M. Manual de Etnoentomología. Manuales & Tesis Sociedad Entomológica Aragonesa (SEA) 4. Zaragoza, Spain: Sociedad Entomológica Aragonesa, 2002.

CSIRO, eds. The Insects of Australia: A Textbook for Students and Research Workers. Carlton, Australia: Melbourne University Press, 1991.

Danks, H. V., and J. A. Downes, eds. Insects of Yukon: Biological Survey of Canada (Terrestrial Arthropods). Ottawa, Canada: Canadian Museum of Nature, 1997.

De Santis, L., and P. Fidalgo. Catálogo de los Himenópteros Calcidoideos de América al Sur de los Estados Unidos. Serie de la Academia Nacional de Agronomía y Veterinaria no. 13. Buenos Aires, Argentina: Editorial Hemisferio Sur, 1994.

Gullan, P. J., and P. S. Cranston. The Insects: An Outline of Entomology. Oxford and Malden, MA: Blackwell Science, 2000.

Hanson, P. E., and I. D. Gauld. The Hymenoptera of Costa Rica. Oxford: Oxford University Press, 1995.

Hölldobler, Bert, and Edward O. Wilson. The Ants. Cambridge, MA: Harvard University Press, 1990.

Samways, M. J. Insect Conservation Biology. London and New York: Chapman and Hall, 1994.

Johnson, N. F. Catalog of World Species of Proctotrupoidea, Exclusive of Platygstridae (Hymenoptera). Memoirs of the American Entomological Institute no. 51. Gainesville, FL: American Entomological Institute, 1992.

Llorente Bousquets, Jorge, and Juan J. Morrone, eds. Biodiversidad, Taxonomía y Biogeografía de Artrópodos de Mexico: Hacia una Síntesis de su Conocimiento. Mejicana. Vol.3. Mexico: Universidad Autónoma de México, 2002.

Loiácono, M. S., N. B. Diaz, and L. De Santis. Estado Actual del Conocimiento de Microhimenopteros Chalcidoidea, Cynipoidea, y "Proctotrupoidea" en Argentina. Monografías Tercer Milenio, vol. 2. Zaragoza, Spain: Sociedad Entomológica Aragonesa (SEA) & CYTED, 2002.

Vardy, C. R. The New World Tarantula-Hawk Wasp Genus Pepsis Fabricius (Hymenoptera: Pompilidae). 2 parts. Backhuys. Netherlands: Zoologische Verhandelingen, 2000–2002.

Periodicals

De Santis, L. "Catálogo de los Himenópteros calcidoideos de América al Sur de los Estados Unidos." Second supplement. Acta Entomológica Chilena 15 (1989): 9–90.

De Santis, L., and N. P. Ras. "Control Biológico de la Cochinilla Phenacoccus manihoti en África (Insecta)." Academia Nacional de Agronomía y Veterniaria 42, no. 7 (1988): 5–11.

Johnson, N. F. "Systematics of New World Trissolcus (Hymenoptera: Scelionidae): Species Related to T. basalis)."Canadian Entomologist 117, no. 4 (1985): 431–445.

Johnson, N. F., and L. Musetti. "Revision of the Prototrupoid Genus Pelecinus Latreille." Journal of Natural History 33 (1999): 1513–1543.

Kempf, W. W. "Catálogo Abreviado das Formigas da Regiao Neotropical." Studia Entomologica 15 (August 1972): 3–334.

Loiácono, M. S., and C. B. Margaría. "Ceraphronoidea, Playgastroidea, and Proctotrupoidea from Brazil (Hymenoptera)." Neotropical Entomology 31, no. 4 (2002): 551–560.

Other

"Chrysis.net" [May 6, 2003]. <http://chrysis.net>.

"Avispa Taladradora de la Madera. Sirex noticlio Fab." [May 6, 2003]. <http://gaf.utalca.cl/sirex.htm>.

"Apoidea" [May 6, 2003]. <http://www.bionet.nsc.ru/szmn/Hymenop/Apoidea.htm>.

Biblioteca de Atualizaçao. Ciêcias Entendendo a Natureza. "Vespa contra Vespa um Exemplo de Controle Biológico" [May 6, 2003]. <http://www.editorasaraiva.com.br/eddid/ciencias/biblioteca/artigos/megarhyssa.html>.

"Chapter 1: Honeybees of the Genus Apis" [May 6, 2003]. <http://www.fao.org/docrep/X0083e/X0083E02.htm>.

"European Wood Wasp, Sirex noctilio F.—Siricidae" [May 6, 2003]. <http://www.faculty.ucr.edu/legneref/biotact/ch-49.htm>.

The Natural History Museum. "Bombus " [May 6, 2003]. <http://www.nhm.ac.uk/entomology/bombus/ml.html>.

"Wild West Yorkshire Nature Diary: Ducks on the Water" [May 6, 2003]. <http://www.wildyorkshire.co.uk/naturediary/docs/apr00/apr08.html>.

Marta Loiácono, DSc

Cecilia Margaría, Lic