Taxonomy and phylogenetics
''A. vicina'' is a eusocial, swarming member of the subfamilySperm morphology
By analyzing the ultrastructure of ''A. vicina ''sperm and comparing it to samples from other species within its superfamily, Vespidae, it has been found that ''A. vicina ''may be more closely linked to Apoidea than to Vespidae phylogenetically.Description and identification
Appearance
Queens of the species are characterized by smaller heads and larger abdomens relative to workers.Nest structure
''A. vicina ''are known to create outstandingly large nests. The combs themselves are generally horizontal and fairly even, neither convex nor concave. The cells face downward and comb layers are vertically connected by petioles. The bottom combs resemble stratified layers while the top combs expand concentrically to form a singular huge comb. When there are spatial limitations the top most layer stops concentrically expanding, leaving the final shape of the nest to be ellipsoid. The brood is always concentrated near the center of the nest, while peripheral cells are left empty as a means of enveloping the structure. The nests are built out of foraged plant fibers.Distribution and habitat
''A. vicina ''are nest-dwelling species. Colonies may build their nests in sheltered, half-exposed, or fully exposed areas. Their distribution is essentially limited to the neotropical region. The species is common relative to its genus due to the characteristic rapid growth of its colonies. ''A. vicina'' is found in Southern Brazil and their nests have been studied in the cities ofColony cycle
''A. vicina'' are a swarm-founding species, therefore initiation of a new colony involves a large group of workers and one or more queens. Initial construction of the nest is rapid. However, unlike most swarm-founding species where nest growth is episodic, ''A. vicina ''continuously increases the size of its nest. Growth rates have been observed in which the nest size doubles after six months. ''A. vicina ''are known to have the largest colony size among social wasps, as colonies may exceed one million adults. They also have a very high brood production rate of several thousand individuals per day. In the dry season there is a large population increase soon followed by reproductive swarming, leading to a steep decline in colony size. During the rainy season, decreases in the production of workers are believed to be due to difficulties in obtaining food.Behavior
Recruitment to food
All species of the genus ''Agelaia'', including ''A. vicina'' lack the characteristic of actively recruiting nestmates to discover sources of food. It appears the most effective foraging strategy for the genus is for individuals to scramble for food on their own. The reason behind this is that when foragers work at the individual level, they are able to exploit the resources in that area more quickly and efficiently than if they took time to recruit nest mates to that area or tried to defend the area from non-nestmates. By behaving as opportunistic, solitary foragers they regularly find untouched food patches and exploit them as rapidly as possible until they are driven out by predators. As a corollary, this means that individuals of the species do not maintain specific foraging territories.Interaction with other species
Diet
''A. vicina'' have a broad diet relative to other social wasps. Colonies forage for water, plant tissue, protein and carbohydrates. Protein is acquired through the general predation of land arthropods. ''A. vicina'' are known to prey most heavily on insects of the order Lepidoptera and Coleoptera. Additionally, spiders are a staple of their diet. The species also consumes insects of the order Dermaptera, Hymenoptera, Heteroptera, Mantodea, Diptera, Neuroptera, Blattodae and Homoptera.Predators
Much more work has yet to be done on the subject, but it is known that ''Defense
For the duration of the activity period of the colony, most flights that exit the nest are short and unrelated to foraging. However, with a large collection of individuals making these trips at once, a persisting cloud forms. This cloud surrounds the exposed aspect of the nest. It is hypothesized that one of the main functions of this cloud is to block the approach of predators and parasites.Keystone species
AHuman importance
Stings
''A. vicina ''stings can lead to intense allergy, anaphylactic reactions, and even death in humans.Neurotoxins in ''A. vicina'' venom
Much research has been done in isolating and understanding the effective aspects of ''A. vicina'' venom. A recent study involving Wistar rats involved isolating the neurotoxin AvTx8 and then microinjecting it into the brains of rats to understand its effect on brain activity. It was found that the neurotoxin has effects on GABAergic neurotransmission, increasing the activity of specific inhibitory pathways. By doing so, it reduces defensive behavior in rats by propagating an anti-panic effect. The study suggests that AcTx8, as well as many of the other chemicals found in ''A. vicina'' venom, may be used to study mechanisms of the brain and brainstem networks.References
{{Taxonbar, from=Q14423293 Vespidae Hymenoptera of South America