Xystromutilla bucki Suarez , 1960

Cambra, Roberto A., Queiros, Caroline Nepomuceno, Deus, Jean P. Alves De, Williams, Kevin A., Bartholomay, Pedro R., Iantas, Jucelia, Nether, Michele C., Nishida, Kenji, Anino, Yostin J., Saavedra, Daisy & Buschini, Maria L. Tunes, 2021, Description of the male of Xystromutilla bucki Suarez, 1960 (Hymenoptera, Mutillidae), including new information on the biology of the genus, ZooKeys 1011, pp. 73-84 : 73

Xystromutilla bucki Suarez, 1960 Figs 1-8

Xystromutilla bucki Suárez, 1960: 453-455, ♀, holotype, Porto Alegre, [Rio Grande do Sul], Brasil, 19.iii.1952, P. Buck ( Colección Suárez; now in Museo Nacional de Ciencias Naturales, Madrid, Spain).

Diagnosis.

Male (Figs 1-6 ). This species can be recognized by its unique coloration, wherein the meso-metathorax, propodeum and first metasomal segment are orange-red; wings subhyaline. The following morphological characters are also useful for diagnosis: head with simple setae; mandible ventrally with a strong basal tooth; sternum 1 without a spine; hypopygium posterior margin with a small denticle medially; paramere almost straight and cuspis finger-shaped. Other described males of Xystromutilla have black integument, fore wings partly or totally fuscous, sternum 1 with a basal spine, hypopygium with medial spine on the apical margin, paramere lyre-shaped and cuspis elongate spoon-shaped. These morphological characters are not present in males of X. bucki . Female (Figs 7 , 8 ). Head, pronotum and metasomal segment 1 orange-red, rest of metasoma black; head with simple setae only; humeral angles of pronotum rounded, not carinate; integument of basal half of tergum 2 without carinae.

Description.

Male (hitherto unknown). (Figs 1 , 2 ). Body length. 10.1 mm.

Body Color. Integument black, except apical half of mandible, meso-metathorax, propodeum and first metasomal segment orange-red; tibial spurs white; wings subhyaline, without infuscated area; head, pronotum, mesoscutum and scutellum with long, semierect simple black setae; meso-metapleura and propodeum mostly with long, semierect simple pale white setae; fore legs mostly with simple black setae, mid and hind legs mostly with simple pale white setae and few black setae; metasomal segments one and two with long semierect simple pale white setae, posterior margin of metasomal segment 2 with dense and decumbent band of plumose white setae; metasomal segments 3 to 7 with long, semierect black setae, posterior margins of metasomal segments 3 and 4 with decumbent plumose black setae mostly hidden by simple setae.

Head. Rectangular in dorsal view, frons, vertex and gena with medium-sized, very close punctures; distance between eye margin and lateral ocellus 2.77 × as long as diameter of ocellus; flagellomere I 1.9 × pedicel length; flagellomere II 2.2 × pedicel length; clypeus bidentate medially on anterior margin; mandible apically obliquely tridentate, ventrally with a strong tooth near base.

Mesosoma. Pronotum, mesoscutum, scutellum and mesopleuron with medium-sized, contiguous punctures, metapleuron impunctate; tegula glabrous, except anterior and inner margins setigerously punctate; propodeum totally reticulate; notaulus incomplete, not reaching anterior margin of mesoscutum; scutellum convex; fore wing (Fig. 3 ) with two submarginal cells; coxae without denticle, tubercle or carina.

Metasoma. First segment petiolate, tergum 1 dorsal face 1.47 × as long as wide; tergum 1-2 and sternum 2 and 7 mostly with medium-sized close punctures; metasomal segments 3-6 with small, close punctures; tergum 7 basal half with small punctures, apical half mostly without punctures; sternum 1 without a spine near base, with two longitudinal carinae diverging posteriorly; hypopygium posterior margin not straight, with a small denticle medially.

Genitalia. Parameres (Figs 4 , 5 ) almost straight, not lyre-shaped; basal half in lateral view broad, distal half gradually narrowing toward apex and slightly curved upwards, ending in a sharp point; dorsal surface with five long setae at end of basal broad half; very short sparse setae elsewhere; digitus and cuspis (Figs 4 , 5 ) finger-shaped, digitus with inconspicuous and sparse setae, cuspis laterally flattened with dense long setae on inner surface; penial valve (Fig. 6 ) with an apical tooth and preapical projection with blunt apex, apical dorsal edge with five long setae and near to base of preapical projection with six long setae.

Material examined.

Brazil: Santa Catarina: Porto União, nest 371 (1) (5 mm hole diameter), 13.i.2012-14.ii.2012, J. Iantas, 1 ♀ (MIUP) (reared from nest of Auplopus subaurarius Dreisbach, 1963). Rio Grande do Sul: Cambara do Sul, Itaimbezinho, 10.iii.2000, col. R. da Cunha, 1 ♀ (MIUP); Guaiba, 116 - km 307, col. F.V. Borges: 15.i.1998, 1 ♂ (MIUP); 30.ix.1999, 1 ♂ (MIUP); São Francisco de Paula, CPCN Pro-Mata, col. B. Harter: 4.viii.1997, 1 ♂ (MIUP); 6.i.1998, 1 ♂ (MIUP). Paraná: Turvo, 25°01'55"S, 51°31'53"W, col. M.C. Nether: 22.xii.2012, 2 ♂ (nest 223) (MIUP); 22.ii.2013, 1 ♂ (nest 552) (MIUP); Guarapuava, 25°21'55"S, 51°27'58"W, 24.i.2013, col M.C. Nether, 1 ♂ (nest 447) (MIUP); Guarapuava, 25°24'09.7"S, 51°24'45.5"W, 11.iii.2019, col. C. Queiros and J. De Deus, 6 ♂, 1 ♀ (nests 353, 460) (UNICENTRO); Guarapuava, 25°39'S, 51°42'W, 10.v.2019, col. C. Queiros and J. De Deus, 1 ♀ (nest 365) (UNICENTRO)

Distribution.

Brazil ( Paraná, Rio Grande do Sul, Santa Catarina).

Biology. This is the first record of Pompilidae as a host of Xystromutilla . In the Araucaria forest fragments, 66 trap-nests of Auplopus subaurarius Dreisbach were examined. Of these nests, X. bucki parasitized three of them, all of which were in bamboo, 1.3 cm in diameter and 18.2 cm in length. One of the nests had nine cells, six of which were parasitized by Xystromutilla (five males and one female emerged) and two by Photocryptus sp. ( Ichneumonidae : Cryptinae ). The other two parasitized nests contained one cell each, from which emerged a male and a female. Therefore, six males and two females emerged in total from the nests. The males were larger bodied with average head width 0.3 mm (n = 6; SD = 0.01 mm) and the females 0.2 mm (n = 2; SD = 0.06 mm).

We found in Xystromutilla bucki that the average time between nest collection and adult wasp emergence, for seven of the eight specimens reared, was 265 days (n = 7; SD = 4.2 days), with immatures exhibiting diapause at the prepupal stage (6 males, 1 female). Only one female (from the one-celled nest) did not enter into diapause, but rather emerged 11 days after nest collection.

Figures

Figures 1 - 8. Xystromutilla bucki 1 - 6 male: 1 dorsal view 2 lateral view 3 right wings 4 genitalia, dorsal view 5 genitalia, ventral view 6 penis valve, lateral view 7, 8 female: 7 dorsal view 8 lateral view.