Polistes carnifex

As its range includes only small portions of the English-speaking Americas, P. carnifex has only recently taken on an English vernacular name, but in the mid-2010s the name executioner wasp was proposed, a calque upon the Latin specific name carnifex "executioner, hangman". In Paraguay, it is usually known in Guaraní as kava mainomby "hummingbird wasp", in reference to its great size; less commonly, it is called kava alazán "brown wasp" (more usually used for P. cavapyta), or '''''kava sa'yju''' "yellow wasp" (more usually used for Agelaia multipicta or A. pallipes). In the Mexican state of Guerrero, speakers of Malinaltepec refer to the executioner wasp and the closely related P. instabilis as '''a'ma xtíya cháda''''' "huarache-nest wasp", alluding to the flattened shape of the nests that they build. ==Taxonomy==

In 1768 HMS Endeavour left Plymouth on the first voyage of James Cook, reaching the harbour of Rio de Janeiro a few months later, in November. Here one of the passengers, the wealthy naturalist Joseph Banks, procured a female specimen of giant wasp, which made its way around the world to eventually arrive in England in 1771. Meanwhile, the Dane Johan Christian Fabricius had travelled to Uppsala University in 1762 to study under the celebrated Carolus Linnæus, and upon returning to Denmark two years later began to work on his first publication, the Systema Entomologiæ, in which he attempted to list all known species of insects (which included spiders, crabs and other arthropods at the time) according to the new Linnaean system. By 1770 he had been appointed professor at the University of Copenhagen, and when in 1773 the University of Kiel (now German) had been ceded to Denmark, he was soon appointed professor there. By 1771 Fabricius began making yearly summer trips to London to study the collections that Banks and others had made in foreign lands, where he was able to study Banks' Brazilian specimen of wasp at Banks' London residence. In 1775 the 832 pages of the Systema Entomologiæ were finally published, and in this Polistes carnifex was scientifically described for the first time under the name Vespa carnifex, using Banks' specimen as holotype. This specimen is now stored at the Natural History Museum, London. The authority citation of the species has erroneously been attributed to Henri Louis Frédéric de Saussure, who wrote some of the most important books on the subject of wasps. In 1853 de Saussure recognised that numerous taxa which had been described by others were synonyms of this species, and synonymised P. onerata, P. rufipennis, P. transverso-strigata and P. valida with P. carnifex. He also synonymised P. chlorostoma and P. major to it, It is classified in the Polistinae, the paper wasps. However, by 2018 he no longer followed his own taxonomic interpretation and continued to use Richards' Onerarius. In 1857 de Saussure was the first to attempt to organise the American Polistes species, doing so on the basis of the form of the abdomen -either conical, with the first segment broad, and tapering to a compressed last segment, with a conical and somewhat elongated metathorax; or with the abdomen oval-shaped, the first segment ampulliform (shaped like a flask) and the metathorax more flat and its end less elongated. He placed P. carnifex in a third group with characteristics in between these two, together with P. aurifer and a new species he described from Nuevo México (a Mexican territory which had recently been conquered and annexed by the US and at the time included everything in between modern California to east Texas), P. comanchus. Among the species of Polistes which occur in Pará, Adolpho Ducke groups it with P. canadensis, P. goeldii and P. versicolor, based on the morphology of the mesopleuron. One of the hypothesized phylogenetic trees puts P. carnifex most closely related to P. major and more distantly related to the following species: P. apachus, P. aurifer, P. bellicosus, P. carolina, P. metricus, P. poeyi haitiensis and P. perplexus. Mexico • Polistes carnifex rufipennis (Latreille, 1833) - found in Honduras, Panama Polistes carnifex boliviensis (258471790).jpg|Polistes carnifex boliviensis on a nest in Colombia. Polistes carnifex ssp. carnifex - in situ Mazatlán, Sinaloa, Mexico on 21 November 2018 photographed by Francisco Farriols Sarabia.jpg|Polistes carnifex carnifex feeding in Mazatlán, Sinaloa, Mexico. Polistes carnifex rufipennis (177177733).jpg|Polistes carnifex rufipennis on a nest in Panama The holotype of P. carnifex boliviensis was collected by José Steinbach somewhere in Santa Cruz Department, Bolivia. It and three paratypes from Bolivia and Peru are stored in the Museum of Comparative Zoology, Harvard University. The Latin word carnis, meaning 'meat', combined with the genitive plural suffix -fex, derived from the word facio, and meaning '-maker' (among a number of similar concepts), together give 'flesh-maker'. (Carnifex : Butcher) ==Description==

'' in Belize Polistes carnifex is the largest Neotropical wasp in the genus Polistes The normal size is 24-27mm, with a possible maximum of 33mm. Despite its size, it is a relatively non-aggressive insect. The antennae are yellow with a darkened base. The head is yellow, the crown of the head being black and ending with reddish-brown stripes. The maxillae are reddish-brown, outlined in black. The thorax is yellow, the dorsal part black, but with a quartet of dark reddish-brown spots. The abdomen is yellow, the second segment (tergite) darkened at the base. The wings are reddish-brown, The mandibles of P. carnifex are short. Yet, they are markedly wide at their base, with a length to basal width ratio of approximately 2:1. An external basal area stretches "from the basal margin ... to a point situated about half-way the mandible's length." P. carnifex also have teeth. "A convex distal posterior area ... is continuous with the posterior-most apical tooth and stays adjacent to a distal media area". This area is convex in P. carnifex. In P. carnifex, the third tooth's anterior edge is elongated, compared to in other species. Genitals Like most insects, the genitals of this species are very characteristic. The male wasp has a paramere that is two and a half times as long as wide at the middle, with the parameral spine about 1/6th of the length, and a shallow groove at its side. This spine is covered in very long and dense bristles and pointed apically. The paramere lobe is well developed and rounded, the lower part of the paramere is narrow, about 2/3 the width at the middle part. It has a slender aedeagus, with about 27 teeth distributed from the end to beginning of the expansion in the middle part of the aedeagus. The penis valve is weakly dilated, with a central entrance and a weakly bi-lobed appearance (the valve being a little more than 1/3 of the length of apical part of the aedeagus). The expansion of the middle part of the aedeagus is well developed and has a pointed apex. The lateral apodeme of the aedeagus is directed forward with a weak central projection and shorter than the rounded ventral process (projection), while the inferior (lower) portion of the aedeagus is weakly curved -appearing almost straight from the side. The digitus is slender, with a well-developed apical process which is about one and a half times longer than the base of the digitus and the same width from the base to the end. This end (apex) is pointed. The digitus has a band of obvious punctation around its base, and an anteroventral lobe that is short with a rounded end, and is covered in easily rubbed off (evanescent) bristles. The cuspis is slender, with an apex which is pointed and tapers abruptly, and covered in long and sparse bristles, with more bristles found at the edges of the sides, and with short bristles on the lower part. The punctation on the cuspis is only found on the lateral lobe. Similar species In Paraguay, according to the identification key provided by Bolívar Rafael Garcete-Barrett, the most similar species are P. cavapyta, which has a completely yellow head and is banded with a rusty orange color, P. lanio, which has extensive black coloration on the mesosoma (~thorax) and back of the metasoma (~abdomen), P. canadensis, which has a red metasoma except some black in the sutures between the plates of the exoskeleton. The much smaller P. major is the only species in Paraguay with a similar color pattern. In Nicaragua, according to the key provided by Jean-Michel Maes, it is best distinguished from the most similar species of the region, P. major, by its wide cheek plates, and the male genitals of both species are furthermore very characteristic. In Brazil, Ducke compares it to P. claripennis, which has a similar coloration, but with a more pale yellow. This species is much smaller and lacks the wide cheeks of P. carnifex. According to Joseph Charles Bequaert in 1936, many of the specimens labelled as P. carnifex in collections are P. major, these two species being commonly confused. All published records from Cuba and Hispaniola are P. major. See for example the description by William J. Fox of a specimen collected on San Esteban Island in the Gulf of California, Mexico. ==Distribution==

Polistes carnifex is native to Central and South America; its range extends from Arizona and southern Texas and Paraná. Jalisco, Morelos, Nayarit, Sinaloa, Sonora, Veracruz and Yucatan, as well as Mexico City. In Paraguay it is found in the departments of Alto Paraná, Canindeyú, Paraguarí and San Pedro. Bequaert states the species is not common anywhere. Ducke also states it is infrequently seen in Pará, Brazil. ==Ecology==

Habitat The species is found in coastal, humid, and open areas, such as in evergreen tropical forests. To create a colony, the queen enlarges a cell by introducing a ball of recently macerated pulp on her own. Using her mandibles, the queen loads the ball while holding the sides of the wall being constructed with her foretarsi. While completing this task, the queen moves her antennae in circles about her head, touching the parallel-lying opposite wall. The antennae-wall contact allows the queen to construct straight sides on the inner wall. She lays eggs and feeds the larvae, feeding them nectar and macerated prey. The nests are hanging and open-faced, supported by a single Petiole in the centre which is strengthened by a tough gelatinous material. Territorial behavior In Costa Rica, male Polistes carnifex congregate on the top of ridges where they maintain territories. The males chase away other conspecific males from these territories which consist of groups of trees and shrubs with no nests. It is suggested that females only mate with males occupying such territories. Interactions with other species Nests (hanging from low branches on thorny trees near a swamp) were sometimes found within about a meter of nests of a Polybia species and occasionally in similar close proximity to a Mischocyttarus nest. Polybia and Mischocyttarus are often associated in the same area; however, Polistes carnifex only occasionally was found in proximity. The association of P. carnifex with other species of social wasps has not been reported outside of Costa Rica. These obligate parasites infect the developing wasp larvae in the nest and are present within the abdomens of female wasps when they hatch out. Here they remain until they thrust through the cuticle and pupate (males) or release infective first-instar larvae onto flowers (females). These larvae are transported back to their nests by foraging wasps. ==Conservation==

The IUCN has not evaluated this species' conservation status. It has been recorded as present in the following protected areas: • Shipstern Conservation & Management Area, Belize. ==References==