Agelaia multipicta

Agelaia multipicta is a swarm-founding, highly eusocial wasp that lives in Mexico, Argentina, Trinidad and southern Brazil. It nests in natural cavities such as hollow trees and aggressively defends the nest from ants, who are brood predators. The workers and queens are morphologically distinguished by ovarian development as well as external features such as a larger petiole and gaster in the queen. Like other carrion-eating (necrophagous) wasp species, A. multipicta plays a scavenging role in the ecosystem. Agelaia multipicta was described by the Irish entomologist Alexander Henry Haliday in 1836. James Carpenter's taxonomic key describes characteristic features of this species such as that the 'hind-wing with jugal lobe normal, not reduced,' and that the head has an occipital carina present. Additionally, in A. multipicta Carpenter notes the 'pronotum without sinuous carina' and the 'body without pale maculations, cuticle partly to entirely bluish metallic or yellowish with some bluish highlights; head in lateral view with tempera as wide or wider than eye at ocular sinus' The queen and worker castes differ significantly in appearance and ovarian development, reflecting their distinct biological functions. The non-reproductive workers have reduced ovaries and brown coloration of the middle tibia and face between the antennal insertions. Queens have a larger and hairier petiole and gaster and yellow mid tibia and face. A. multipicta is found in Mexico, Argentina, Trinidad and Southern Brazil. Usually, their nests are observed in forest and rural habitats. This may be related to the tendency of A. multipicta to use natural cavities as nest building sites which may be less prevalent in urban areas. A. multipicta is the most abundant wasp species in Matão, in the state of São Paulo, Brazil, a well-preserved area which has little variety of wasp species. The area is surrounded by citrus crops. In a study regarding forest fragmentation there were no strong tendency in A. multipicta habitation regarding habitat type, this is probably due to their generalist nature. Like other wasps in the Epiponini tribe, A. multipicta builds an exposed, single-comb nest, attached with a broad pedicel to its substrate. A. multipicta's nests are exposed in a sense that they are not surrounded by an envelope. However, the nest usually occurs in spaces that are naturally enclosed, such as hollow trees and cavities in the ground. These natural structures may be filling the protective role usually fulfilled by an envelope. The combs can be irregular, not always parallel, and the cells in some findings are 3.0 mm wide and 9.0 mm deep. The variety of nest architecture and location observed in A. multipicta is thought to reflect their adaptability to the variations in cavity-like spaces present in the natural environment. Behavior of A. multipicta seems to be physically as opposed to chemically influenced. Individuals of A. multipicta display aggression towards some, but not all conspecifics encountered on a food source, possibly indicating the ability to recognize nestmates. This species uses aggressive behaviors to combat ants attempting to prey on their brood. Swarm founding wasps, including A. multipicta, evolved a different defense strategy against ants from species with independent founders, which use chemical repellents. Swarm founders rely on the vigilance of workers on the surface of the nest to prevent ants from reaching the brood. Workers immediately remove ants from the nest by directing blasts through wing buzzing. If this fails to knock the ant off, the worker then throws the ant from the nest with their mandibles. A. multipicta retains a 6th sternal gland, which secretes ant repellent chemical in independent founding species. It is unknown whether the chemical function of the gland is retained in A. multipicta. In addition, there has been no observed use of chemical or any other form of communication between wasps of this species while foraging on carrion. Foragers from different colonies have been observed at the same feeding site, suggesting that colony foraging territories overlap. Scramble competition seems to be the main foraging strategy used by this species. A. multipicta is a major egg predator of the harvestman Acutisoma proximum, despite the maternal guarding attempts by this species. These wasps feed on vertebrate carrion itself as well as the larval flies growing on it. This makes A. multipicta both a predator and a necrophage, but the wasps favor fresh carcasses with more meat as opposed to more decomposed carcasses with more flies, suggesting that predation may not be their primary mode of obtaining food resources.