Mischocyttarus mixtus Richards 1978

Silveira, Orlando Tobias, 2019, Taxonomic notes on social wasps of the groups of Mischocyttarus wagneri (Buysson 1908) and M. barbatus Richards 1945 (Hymenoptera, Vespidae, Polistinae), Revista Brasileira de Entomologia 63 (1), pp. 53-72 : 68-69

Mischocyttarus mixtus Richards 1978

( Figs. 6; 9; 11; 13 ; 31; 32 )

Mischocyttarus mixtus Richards 1978: 319 , Holotype: female, Panama, Bugaba 800–1500 ft., Champion col. (NHM); [examined]. Mischocyttarus mixtus : Silveira (2008: 540).

Female

Length of fore wing 9–10 mm; clypeus wider than high, H/WCLP about 0.87 (min–max: 0.85–0.91), apex narrowly truncate, clypeus not so extensively in contact with eye, free upper part of lateral margin relatively long, more than 0.3 times the clypeus height at middle; malar space narrow; tentorial pit a little closer to eye margin than to antennal socket; distance between posterior ocelli distinctly larger than between one of these and the anterior median ocellus, in a proportion of ca 1.6; occiput rounded, carina absent; gena distinctly narrower than the upper lobe of the eye; pronotum with lateral fovea, central part of the anterior margin of pronotum with the lamella wide and poorly raised not at all reflexed, region immediately behind produced into a secondary margin which is very low and obtuse, and does not even come close to projecting itself over the lamella; humeral angle poorly developed and not projecting laterally, total humeral width about equal that of mesoscutum, sides of the pronotum as seen from above distinctly converging; pronotal carina completely absent at center, and very low at sides scarcely having a translucent lamellar portion, mesoscutum slightly wider than long, L/WMS mean 0.97 (min–max: 0.95–1.00), lateral margin adjacent to tegula poorly demarcated, less prominent; fore wing relatively short (mean LSI/HMP 2.16; min–max: 2.03–2.26); basal inner (posterior side) margin of fore coxa raised but comparatively less reflexed; inner claw of hind tarsus with the apex definitely acute; propodeal dorsal cavity considerably deep and wide, more round than triangular in shape; propodeal valve variable moderately expanded in an uniform way so that it has a roughly round shape; first segment of metasoma well elongate, its length a little more than 1.3× height of mesopleuron (LSI/HMP about 1.36, min–max: 1.31–1.41), distinctly slender but variably wide at apex, from 1.93–2.27× wider than at base, spiracles moderate to strongly prominent.

Sculpture: head and mesosoma with moderately course sculpture; clypeus with minute dense punctation (diameter ca. 0.015 mm), with moderately shining interstices measuring about one puncture diameter, and also with shallow sparser larger punctures (diameter 0.030 –0.037 mm), apical central area very finely reticulate, appearing almost smooth, shining, with a few interspersed large shallow punctures (diameter 0.037–0.44 mm); frons with a stronger pattern of slightly larger and deeper punctures (diameter 0.015 –0.022 mm) separated by interstices of 0.5–1 puncture diameter; humeral area of pronotum with slightly larger punctures, diameter mostly 0.022 mm, rarely 0.030 mm; mesoscutum with quite similar pattern, slightly less dense; mesopleuron also with such a patter of 0.022 mm punctures, but also presenting more or less regularly spaced sparser larger 0.030 mm punctures; propodeum presenting higher proportion of the larger punctures, the pattern being less dense than mesoscutum.

Vestiture: eyes bare; clypeus covered by fine appressed shining (silvery) pubescence, not so dense to the point of obscuring the pattern of micropunctures underneath; clypeus with sparser erect longer setae especially near apical margin (length ca. equal to one median ocellus diameter; mod), most of head at sides and behind and mesosoma covered by very long fine hairs, length on mesoscutum ca. 1.3 mod, on mesopleuron ca. 1.6 mod, on propodeum still longer, ca. 2.0 mod; hairs on metasomal sterna 2–6 not noticeably long and outstanding.

Color (see Figs. 31; 32 ): Black; mandible anteriorly and basally mostly yellow gradually turning to reddish brown at apex; antennal articles 9–12 yellowish to light reddish beneath; apical area of clypeus reddish yellow to light reddish brown (in north of Mexico specimens, the ventral half of clypeus and a dorsal spot are yellow, separated by a blackish area); inner orbits to about center of ocular sinus, genal stripe (outer orbit), yellow to reddish yellow, sometimes interrupted or blurred below; small mark on pronotum ventral corner (sometimes reddish, or entirely absent), tubercle (sometimes reddish, or entirely absent), carina (sometimes discontinuously), and hind margin of pronotum (sometimes indistinct or reddish), front margin of metanotum narrowly (sometimes absent), propodeal valves (sometimes dark), and paired propodeal posterior dorsal spots (sometimes only small dots, or fading reddish, or entirely absent), one dorsolateral stripe on mid coxa (sometimes just a dot, or absent), one outer dorsal stripe on hind coxae (sometimes absent), none inner stripe on hind coxa; small apical mark on all femora; distal lateral marks on metasomal sternum 1 (sometimes absent), narrow distal bands on metasomal terga l-2 (or -4, somewhat indistinctly, or without any tergal bands) and sterna 2 (or -4, somewhat indistinctly, or without any sternal bands), yellow; axillar spot and most of disc of scutellum light reddish brown; other red suffused areas on lateral (sometimes hind margin) of pronotum, mesepisternum and upper and lower metapleural plate; posterior margin of meso and metasternum extending laterally to border of coxal articulation (sometimes indistinct), anterior ventral face of fore and mid coxae (hind coxae only distally very narrowly), and all trochanters, elongate marks on anterior face of all femora (interrupted on fore femur) and tibiae, light reddish brown to yellowish brown; hind tibia with distal pad concolorous with adjacent area; all tarsi dark brown to black, paler below; tegula brown; wings hyaline, venation brown.

Male Unknown

Variation

There is relatively small variation in size and color, especially regarding specimens from the north of Mexico which are a little larger and darker.

Nest Unknown

Distribution Mexico and Central America: Costa Rica; Panamá ( Fig. 46 )

Remarks

Richards (1978) described M. mixtus based only on the holotype female from Panamá, and apparently did not see any further specimens (e.g. O. W. Richards, unpublished manuscript prepared as a supplement to his 1978 book). Thus, all the material cited here is new, and the range of the species is greatly expanded northward up to Puebla and Vera Cruz states, in Mexico. Two northernmost Mexican specimens are a little larger and darker, otherwise matching every character of this species, including the typical reddish-brown scutellum. Unfortunately, the male and nest remain unknown .

Examined material: México: Chiapas, 1 female, Lagunas de Montebello , 20/iv/1993, Ayala, R . & Noguera, F.A. (Chamela); Puebla, 1 female, Huehuetlan, Clemente, M.; Vera Cruz, 1 female, Xalapa, Clemente, M. ( MPEG); Costa Rica: Puntarenas, 2 females, P.N. Amistad, Est. Las Melizas, Fca. Cafrosa, 1300 m, iv/1989, Ramirez, M. & Mora, G. ( INBIO) .

Figures

Figs. 5–18. 5–7: frontal–dorsal view of anterior face of pronotum showing secondary margin (arrow) in M. barbatus (5), M.mixtus (6), M. wagneri (7); 8–10: same structures and species in dorsal view; 11–12: mesial view of fore coxa showing raised basal margin (arrow) in M. mixtus (11), M wagneri (12); 13–14: inner (larger) hind tarsal claw (arrow) in M. mixtus (13, lateral) and M. barbatus (14, ventral); 15: hind tarsus of M. wagneri (a), M. mourei (b), M. proximus (c), M. camanducaia sp. nov. (d), M. declaratus (e); 16–18: nests of M. proximus (16), M. wagneri (17), M. barbatus (18); all scales = 0.50mm, except in Fig.18 (= 10 mm); groups of figs. (5–7), (8–10), (11–12), (13–14) share the same scale.

Figs. 27–34. General dorsal and lateral body views (females). 27–28: M. mourei (Brazil, PR, Curitiba, paralectotype, IOC); 29–30: M. barbatus (Colombia: Antioquia, MPEG); 31–32:M.mixtus (Mexico:Chiapas, EBCC); 33–34:M.imeldai (33 dorsal – holotype, Peru, IOC) (34 lateral – Bolivia,NHM); all scales =1.0 mm; scales in figs. (27–28), (33–34) are estimates.

Fig. 46. Partial truncated map for Central and South America with species distributions for the M. barbatus group, and with the pooled distribution of the group of M.wagneri (see next figure for detailed representation of distributions of species of this group).