Mischocyttarus socialis (de Saussure, 1854)

Silveira, Orlando Tobias, 2006, Revision of the subgenus Kappa de Saussure of Mischocyttarus de Saussure (Hym.; Vespidae, Polistinae, Mischocyttarini), Zootaxa 1321 (1), pp. 1-108 : 41-45

Mischocyttarus socialis (de Saussure, 1854)

(Figs. 48–49, 98)

Polybia socialis de Saussure, 1854: 177 (only text, not the mentioned figure); Fox, 1898: 450.

Polybia atra de Saussure, 1854 : pl. XXIV, fig. 5 (not the text on page 181), non Vespa atra Olivier.

Polybia atra (Olivier) : von Ihering, 1904: 190, 191 (misidentification).

Megacanthopus ater (Olivier) : Ducke, 1905b: 689 (in part; misidentification); 1906: 10 (misidentification); 1907a: 139 (in part; misidentification, incorrect synonymy); 1907b: 185, 190 (in part; misidentification).

Mischocyttarus ater (Olivier) : Ducke, 1913: 332; 1918: 351, 369 (in part; misidentification); Fonseca, 1926: 175 (misidentification).

M. socialis (de Saussure) : Bequaert, 1943: 721 (in part); Carpenter, 1999: 22.

M. atramentarius Zikán, 1949: 206 , figs. 140,141, 349, 396, 398, 407, 414; Richards, 1978: 298 (in part). Lectotype: ♀ Brazil, Rio de Janeiro, Itatiaia , 5/xi/1931 (J. F. Zikán) (MZSP), designated by Richards (1978), examined, N. syn.

TYPES: 4 ♀ “Le Brésil ” ( Delalande , Caudichaud, cols.) ( MNHN) , examined.

FEMALE. Length of fore wing 8.5–11 mm; MWH/DLH 2.4, head in frontal view often very low, FHH/intOW varying between 0.91 and 0.96; clypeus little convex, very wide, H/WClp 0.82, median angle little produced below, apex narrowly truncate or rounded ( Fig. 98 ), about as narrow as 1/3 of the height of an antennal socket, lateral margin sinuous or (less often) straight, zone in contact with the eye normally shorter than the upper free margin; malar space short, at most corresponding to 1/3 of the height of an antennal socket; tentorial pit as close to eye as to antennal socket, sometimes closer to the latter; mandible anterior surface without a prominent border; antennal scape very short, L/ Wesc 2.20; occeli normally widely separated, POL more than two diameters, POL/OOL about 2/3 or a little more; occipital region at sides well swollen, not appearing as “narrowing” behind upper lobe of the eye, occiput with margin distinct but nor very salient dorso laterally; gena almost as wide as the upper lobe of the eye in lateral view; foraminal area shaped ventrally as a shelf; hypostomal lamella narrow; pronotum wide and very short, fovea large and deep with acute anterior border, region just below noticeably protuberant, anterior margin of pronotum medially with the lamella moderately wide and reflexed, region just behind continuous not raised into secondary margin; humeral angle only moderately prominent, carina usually well elevated, slightly curved and reflexed at sides, forming a little produced lateral lobe that never projects strongly forward, carina as seen from above essentially straight, total width distinctly larger than that of mesoscutum, this practically as long as wide; fore wing short, LDis/HMpl 2.10; inner claw of hind tarsus with the apex rather round; propodeum oblique and shortened posteriorly, median furrow wide and deep, occupying almost the whole dorsal surface, anterior region adjacent to metanotum protuberant only at sides, valve as a high narrow triangle, usually little visible in lateral view; first segment of metasoma very short, LSI/HMpl 0.81, always very wide and dorsally convex, apical region about 2.3 times wider than the base, petiole hardly defined, spiracles not prominent, basal sternum flattened but its lateral limit with the sternum not strongly marked, lateral edge not noticeably prominent nor shining.

Sculpture: disk of clypeus with moderately dense well marked medium sized punctures, with more sparse larger ones, interstices shining, area close to the ventral margin reticulate and shining, with large punctures; upper interantennal area and frons with very dense comb­like medium to large sized punctures; vertex including area between occeli with small but conspicuous punctures; humeral region and mesoscutum with very dense small to medium sized punctures, never separated by distance equal to or larger than one diameter; mesopleuron with dense well marked medium sized punctures arranged into a rather uniform pattern, even on more ventral parts, and with very sparse larger punctures; lateral region of propodeum with very dense small to medium sized punctures, also with uniform aspect.

Vestiture: clypeus and face with decumbent light brown hairs, outstanding hairs of frons not very long, lateral region of occiput adjacent to carina with a not very distinctive spot of transversely directed hairs originating at a position well behind the upper lobe of the eye; eye with short not very distinct hairs.

Color: black; tegula, legs, dark brown; ventral marginal area of clypeus, mandible, reddish brown; inner orbit to the level of antennal socket, gena adjacent to eye, apex of antenna below, region around fovea and posterior margin of pronotum, reddish orange; lateral part of pronotal carina (sometimes), apex of femora, yellow; most of wings basal membrane and hairs, also including pterostigma, black or blackish; apical part of fore wing from third submarginal cell to the apex with membrane hyaline and hairs white, rarely brown, veins of the apical region light yellowish brown; rarely the apex of the fore wing not pale colored, but with the more usual dark brown hairs and veins.

MALE. Head in frontal view excessively low and wide, FHH/intOW ca. 0.90; clypeus very wide, H/WClp 0.80, median angle scarcely projecting below, apex narrowly rounded; tentorial pit much closer to eye than to antennal socket; antennal scape very short, L/Wesc 2.10, ventral surface of flagellomeres with conspicuous shining tyloids, third antennomere about 2.8 times longer than wide, apex of antenna very short, hook like (Fig. 48), apical antennomeres not flattened, antennomere 12 about 1.3 times longer than wide, 13 very short, a little more than 2 times longer than wide (Fig. 49); humeral region a little more prominent than in the female; anterior face of fore coxa not flattened; clypeus with distinct very fine punctation, with dense shining decumbent pubescence.

Color: similar to female; apex of antenna with the inner aspect yellow.

NEST. Zikán (1949, figs. 396, 398, 407, 414) shows photographs of relatively large nests with more than 50 cells, the combs presenting variable shapes. In all cases one can see patterns of straight sectors, as well as a trend of growth along narrow segments formed by 3 to 4 rows of cells. Descriptions of nests in Richards (1978) indicate that placement of the peduncle is also variable.

Remarks

Mischocyttarus socialis differs from M. imitator and M. deceptus in the narrower clypeal apex (see Figs. 97 and 98 ), and the more swollen occipital region with the hairs associated to the occipital carina being rather undifferentiated. Various aspects of the species’ sociobiology, under the name M. atramentarius are reported by Rapôso­Filho et al. (1994), Silva (1988), Silva and Oliveira (1989), and Silva and Rodrigues (1987).

Four of de Saussure’s specimens presently in the MNHN (confirmed by Carpenter, 1999 as syntypes of Polybia socialis de Saussure ) were examined. The morphology of these types decidedly corresponds to Zikán’s M. atramentarius , described from Rio de Janeiro. Richards (1978) also saw these specimens, but because of bad preservation could not identify them either as M. atramentarius , or as the other form that is common in Brazilian Amazonia. Historical evidence about the collecting localitiy of M. socialis types confirms its synonymy with M. atramentarius Zikán. Delalande collected three of the specimens and the fourth type has in the label the collector name “Caudichaud”. Papavero (1971) says that Delalande came to Brazil with the 1816 expedition of Saint­Hilaire, staying for a short period in Rio de Janeiro and soon returning to France. On the other hand, Papavero also mentions the French naturalist C. Gaudichaud­Beaupré, stating that he had been in Brazil on three times collecting along the coast from the southern state of Santa Catarina northwards to Bahia. Such evidence on provenance of de Saussure’s specimens agrees with distributional data for M. atramentarius Zikán , and corroborates the conclusion here taken on morphological grounds.

Based on similarities in sculpture of thorax and propodeum, and shape of the first metasomal segment, Richards (1978) suggested that forms from Mexico and Central America would be disjunct populations of Zikán’s M. atramentarius . However, such characters are indeed those that M. atramentarius shares with M. deceptus Fox (= M. atrocyaneus Zikán ; see next species). All specimens examined from Mexico and Central America, even the smallest ones could be referred to M. deceptus , which has the clypeal apex wider and more truncate (cf. fig. 97), and the hairs on frons and vertex always of very dark brown color. This species has also a higher head, with malar space more extensive, and the pronotal carina is usually lower. Coincidentally, Richards (1978: 298), uncertain about the identity of Central American specimens, indicated the name M. deceptus (Fox) as possibly available for them. However, because he had not seen Fox’s holotype, Richards could not be aware of the synonymy between deceptus and Zikán’s atrocyaneus (whose holotype he had examined!).

While Richards’ records of M. atramentarius from Mexico and Central America are cases of misidentification, two female specimens with anomalous distribution ( Trinidad, Arima valley, 500–1000', 10/iii/1964, C. & E. Ross; CASC) agree in all aspects with the form normally found in southern Brazil, and Argentina. However, this most probably seems to represent a case of error in labeling since a third female with similar data (date and collectors) was examined from CASC collection, except that it was collected in Rio de Janeiro. Another female of this same species group from Trinidad (Maracas Valley, BWI, 19/iii/1944, Callam; AMNH) corresponds to M. imitator Ducke , this species occurring widely in northern South America (see below). Richards (1945) probably correctly records M. socialis from Paraguay, Alto Paraná, Porto Bertoni (under the name M. ater ).

Distribution SOUTH AMERICA: Brazil (MG, RJ, SC, SP, PR), Paraguay, Argentina.

Examined material

ARGENTINA: Misiones, 2♀ Iguazu Nat. Park , 140m, 8–11/iv/1974 (C. & M. Vardy) ( BMNH) ; BRAZIL: Minas Gerais, 1♀ S. Caraça ( Engenho ) 800m, xi/1961 (Kloss, Lenko, Martins e Silva) ( MZSP) , 1♀ Diamantina, 1923 (W.S. Bristowe) ( BMNH) , 1♀ E nv. de Passa­Quatro, R. das Pedras, 1000m, 1903 (Wagner) ( USNM) , 4♀ Ipanema, Faz. Montes Claros (1945/4150), 2/iii/1993 , 1♀ Viçosa , 13/vi/1991 (G.A. R. Melo) ( UFPR) ; Paraná, 1♀ Alexandra , 6/ii/1974 (Rozen & Thompson) ( AMNH) ; Rio de Janeiro, Itatiaia 1♂ 5/xi/1931, 1♂ 14/ii/1932, 1♀ 3/ii/1933, 1♀ 25/ii/1933, 1♂ 1♀ 17/ii/1933 ( PARALE CTOTYPES of M. atramentarius ) (J.F. Zikán ) ( MZSP) , Itatiaia 1♀ 700m, 1/vi/1916, 3♂ 700m, 14/ii/1932, 1♂ 1♀ 550m, 25/ii/1933, 1♀ 550m, 3/ii/1933, (J.F. Zikán) ( IOC) , Rio de Janeiro 2♀ 11/i/1906 , 2♀ 12/i/1906 (A. Ducke) ( MPEG) , 1♀ Rio de Janeiro, Paineiras , 29/iii/1964 (C. & E. Ross) ( CASC) ; São Paulo, Itatiba 3♀ (18.547) 4/x/?, 2♀ (18.340) 6/x/? (J. Lima), Ipiranga 2♀ 1♂ (1.052, PARALECTOTYPES of M. atramentarius ) (no date) (anonymous), 1♀ Jundiaí , 1900, (M. Becon) , 1♀ (17.086) Jundiaí (no date) (anonymous), 1♀ Ubatuba , 31/iii/1962 (K. Lenko) ( MZSP) , 1♂ Jundiaí, 1900, (M. Becon) ( AMNH) , 1♀ Santos , 3/iii/1912 (G.E. Bryant) ( BMNH) , 1♀ São Paulo (no specific locality) (no date) (anonymous) ( MPEG).

* Dubious : TRINIDAD (?), 2♀ Arima valley, 500–1000', 10/iii/1964 (C. & E. Ross) ( CASC) .

Figures

FIGURES 97–100. (SEM images) M. imitator: 97, apical aspect of the female clypeus; M. socialis: 98, same as anterior; M. injucundus: 99, propodeum (strongly striate) lateral view, 97, propodeum (moderately striate) dorsal view.