Dufour's gland is an abdominal gland of certain insects, part of the anatomy of the ovipositor or sting apparatus in female members of Apocrita. The diversification of Hymenoptera took place in the Cretaceous and the gland may have developed at about this time (200 million years ago) as it is present in all three groups of Apocrita, the wasps, bees and ants. [1]
Dufour’s gland was first described by Léon Jean Marie Dufour in 1841. Along with the spermatheca and the poison gland, it develops as an invagination of valves of the sternum. It empties at the base of the ovipositor in ants but into the dorsal vaginal wall in bees and wasps. The gland is lined by a single layer of epithelial cells which secrete substances into the hollow interior. Muscles round the opening of the duct may help control the outflow. [1]
The purpose of Dufour’s gland is to secrete chemicals, but the nature of the secretions and their function differs in various hymenopteran groups. The secretion is often used in communication to mark members of the colony, to mark hosts (parasitic wasps), during slave raids (ants), for territory marking (ants), to signal fertility, to attract a member of the opposite sex, to give an alarm warning (ants) or to mark a trail (ants). This use of scent marking pheromones secreted by Dufour's gland is observed in the carpenter bee Xylocopa pubescens to mark flowers and nests. [2] Other functions include lubricating the valves of the ovipositor during egg-laying, serving as a component of material used to build the nest, serving as a food for the developing larvae and being mixed with pollen and nectar to provision the brood cell before egg-laying. For instance, the well developed Dufour's gland is one of the main physical characteristics of a social wasp Parischnogaster mellyi , and the abundant abdominal secretion from the gland has been found to play an important role in egg development and oviposition. [3] The gland is well-developed in various solitary mining bees where it is used to waterproof and make the lining of the brood cells fungus-resistant. [1] [4]
Furthermore, the Dufour's gland of the parasitic Vespula austriaca wasp releases substances that prevent oogenesis in workers to suppress reproduction in host workers. [5]
Hymenoptera is a large order of insects, comprising the sawflies, wasps, bees, and ants. Over 150,000 living species of Hymenoptera have been described, in addition to over 2,000 extinct ones. Many of the species are parasitic. Females typically have a special ovipositor for inserting eggs into hosts or places that are otherwise inaccessible. This ovipositor is often modified into a stinger. The young develop through holometabolism —that is, they have a wormlike larval stage and an inactive pupal stage before they mature.
The ovipositor is a tube-like organ used by some animals, especially insects, for the laying of eggs. In insects, an ovipositor consists of a maximum of three pairs of appendages. The details and morphology of the ovipositor vary, but typically its form is adapted to functions such as preparing a place for the egg, transmitting the egg, and then placing it properly. For most insects, the organ is used merely to attach the egg to some surface, but for many parasitic species, it is a piercing organ as well.
Trophallaxis is the transfer of food or other fluids among members of a community through mouth-to-mouth (stomodeal) or anus-to-mouth (proctodeal) feeding. Along with nutrients, trophallaxis can involve the transfer of molecules such as pheromones, organisms such as symbionts, and information to serve as a form of communication. Trophallaxis is used by some birds, gray wolves, vampire bats, and is most highly developed in eusocial insects such as ants, wasps, bees, and termites.
Paper wasps are vespid wasps and typically refers to members of the vespid subfamily Polistinae, though it often colloquially includes members of the subfamilies Vespinae and Stenogastrinae, discussed elsewhere, which also make nests out of paper. Paper wasp nests are characterized by open combs with down pointing cells. Some types of paper wasps are also sometimes called umbrella wasps, due to the distinctive design of their nests.
Apocrita is a suborder of insects in the order Hymenoptera. It includes wasps, bees, and ants, and consists of many families. It contains the most advanced hymenopterans and is distinguished from Symphyta by the narrow "waist" (petiole) formed between the first two segments of the actual abdomen; the first abdominal segment is fused to the thorax, and is called the propodeum. Therefore, it is general practice, when discussing the body of an apocritan in a technical sense, to refer to the mesosoma and metasoma rather than the "thorax" and "abdomen", respectively. The evolution of a constricted waist was an important adaption for the parasitoid lifestyle of the ancestral apocritan, allowing more maneuverability of the female's ovipositor. The ovipositor either extends freely or is retracted, and may be developed into a stinger for both defense and paralyzing prey. Larvae are legless and blind, and either feed inside a host or in a nest cell provisioned by their mothers.
Vespula vulgaris, known as the Common wasp, is a species found in regions that include the United Kingdom, Ireland, Germany, India, China, New Zealand and Australia. It is sometimes known in English as the European wasp, but the same name is used for the species Vespula germanica or German wasp. In 2010, the ostensible Vespula vulgaris wasps in North America were found to be a different species, Vespula alascensis.
The European beewolf, also known as the bee-killer wasp or the bee-eating philanthus, is a solitary wasp that lives in the Western Palearctic and Afrotropics. Although the adults of the species are herbivores, the species derives its name from the behaviour of the inseminated females, who hunt Western honey bees. The female places several of its paralysed prey together with an egg in a small underground chamber, to serve as food for the wasp larvae. All members of the genus Philanthus hunt various species of bees, but P. triangulum is apparently the only one that specialises in Western honey bees.
Xylocopa virginica, sometimes referred to as the eastern carpenter bee, extends through the eastern United States and into Canada. They are sympatric with Xylocopa micans in much of southeastern United States. They nest in various types of wood and eat pollen and nectar. In X. virginica, dominant females do not focus solely on egg-laying, as in other bee species considered to have "queens". Instead, dominant X. virginica females are responsible for a full gamut of activities including reproduction, foraging, and nest construction, whereas subordinate bees may engage in little activity outside of guarding the nest.
The Stenogastrinae are a subfamily of social wasps included in the family Vespidae. They are sometimes called hover wasps owing to the particular hovering flight of some species. Their morphology and biology present interesting peculiarities.
A wasp is any insect of the narrow-waisted suborder Apocrita of the order Hymenoptera which is neither a bee nor an ant; this excludes the broad-waisted sawflies (Symphyta), which look somewhat like wasps, but are in a separate suborder. The wasps do not constitute a clade, a complete natural group with a single ancestor, as bees and ants are deeply nested within the wasps, having evolved from wasp ancestors. Wasps that are members of the clade Aculeata can sting their prey.
Dolichovespula adulterina is a species of parasitic social wasp found in the Palearctic region. D. adulterina feeds on a variety of foods, including insects, spiders, arthropods, meat, molluscs, fruit, nectar, and larval secretions. D. adulterina was formerly considered to be synonymous with D. arctica from the Holarctic region, but more recent research indicates that D. arctica is a separate species.
Vespula austriaca is an obligate parasitic wasp, parasitizing the nests of other species in the genus Vespula in the Old World. Its common host species include V. rufa in Europe, Japan, and East Siberia.V. austriaca wasps pollinate orchids.
Parischnogaster mellyi is a medium-sized species of a hover wasp in the family Vespidae. It is found in Southeast Asia and is widely spread in Thailand and Malaysia. Its nests feature flexible and dynamic qualities, and they are commonly seen under roofs of houses and huts in rural areas. Hovering and patrolling behaviors are the species’ main defining behavioral features, and such activities are closely linked to its mating patterns.
Chrysis ignita is a species of cuckoo wasp. It is one of a group of species which are difficult to separate and which may be referred to as ruby-tailed wasps.
Parischnogaster striatula is a species of social hover wasps found in Southeast Asia. Their nests are uniquely shaped, mimic their surroundings and, like the other Stenogastrinae social wasps, lack a nest pedicel. They are also unique in their use of glandular secretion when laying eggs. P. striatula is also different than typical wasps because the queens are not the only ones who possess reproductive capabilities; other females also have developed ovaries. This wasp is also known for fiercely protecting its nest against enemies, such as ants or other hornets.
Parischnogaster jacobsoni is a species of social wasp within Parischnogaster, the largest and least known genus of Stenogastrinae. It is distinguished mainly by its tendency to construct ant guards on its nests. Natural selection has led this wasp to have a thick substance emitted from its abdominal glands that allows it to protect its nest from invasions. Parischnogaster as a genus has been relatively unstudied; P. jacobsoni is one of the few investigated species because it has sufficient durability to live near human populations and it has demonstrated unusual resilience to pollution. While P. jacobsoni is a more complex organism than other wasps in Parischnogaster, the genus overall is relatively primitive with respect to social wasps as a whole.
Xylocopa sulcatipes is a large Arabian carpenter bee. These multivoltine bees take part in social nesting and cooperative nesting. They are metasocial carpenter bees that nest in thin dead branches. One or more cooperating females build many brood cells. They have been extensively studied in Saudi Arabia and Israel.
Xylocopa pubescens is a species of large carpenter bee. Females form nests by excavation with their mandibles, often in dead or soft wood. X. pubescens is commonly found in areas extending from India to Northeast and West Africa. It must reside in these warm climates because it requires a minimum ambient temperature of 18 °C (64 °F) in order to forage.
Xylocopa micans, also known as the southern carpenter bee, is a species of bee within Xylocopa, the genus of carpenter bees. The southern carpenter bee can be found mainly in the coastal and gulf regions of the southeastern United States, as well as Mexico and Guatemala. Like all Xylocopa bees, X. micans bees excavate nests in woody plant material. However, unlike its sympatric species Xylocopa virginica, X. micans has not been found to construct nest galleries in structural timbers of building, making it less of an economic nuisance to humans. Carpenter bees have a wide range of mating strategies between different species. The southern carpenter bee exhibits a polymorphic mating strategy, with its preferred method of mating changing as the season progresses from early spring to mid summer. Like most bees in its genus, the southern carpenter bee is considered a solitary bee because it does not live in colonies.
Vespula infernalis is an obligate parasitic wasp, parasitizing the nests of other species in the genus Vespula. Its common host species is V. acadica in North America. It is sometimes called the cuckoo yellowjacket wasp due to its inquiline lifestyle. They differ from other parasitic wasps in their intensely aggressive behaviour during invasion and occupation of the host colony. Several morphological adaptations such as bigger body parts and highly curved stingers are present in these wasps to aid their aggressive parasitic behaviour.