Microvelia (Kirkaldya) nessimiani Moreira & Rúdio, 2011

Rúdio, Jéssika Ana & Moreira, Felipe Ferraz Figueiredo, 2011, A new species of Microvelia (Insecta: Hemiptera: Heteroptera: Gerromorpha) from coastal Espírito Santo State, with a key to the species of the genus recorded from southeastern Brazil, Zootaxa 3004, pp. 63-68 : 65-67

Microvelia (Kirkaldya) nessimiani Moreira & Rúdio , n. sp.

( Figs. 2–3 )

Apterous male. BL 1.35–1.46, ANT I 0.19–0.22, ANT II 0.10–0.12, ANT III 0.19–0.23, ANT IV 0.31–0.36, INT 0.18–0.20, PL 0.17–0.24, PW 0.42–0.48.

Body color pale yellow to yellow, lighter on venter. Antennomeres I–II yellow with darker apices; III dark yellow; IV brown, darker on distal 3/4. Eyes red. Rostrum with article I yellow, II–III pale yellow, IV dark brown. Punctuations of thorax marked by brown. Pronotum may bear irregular brown marks. Acetabula, coxae, trochanters, and base of femora pale yellow. Remaining of femora yellow, darker towards apex. Tibiae yellow; fore and mid ones brown on apex. Fore tarsus basally yellow, turning brown distally; mid tarsus dark yellow; hind tarsus dark yellow on proximal 1/3, distally brown. Abdominal tergite IV may bear a pair of brownish maculae on sides of midline. Abdominal connectives darker on anterior half. Genital segments pale to yellow. Body dorsally covered by sparse short setae. Antennae covered by sparse short setae, more numerous on antennomere IV. Antennomeres I–III cylindrical, IV fusiform; I slightly thicker than others, bowed outside on base; II–IV with almost same width. Rostrum slightly surpassing posterior margin of prosternum. Pronotum relatively long, reaching sublateral pits, but leaving metanotum exposed; pronotum superficially divided into two lobes, with the area between lobes impressed and marked by circular punctuations ( Fig. 4 ). Metanotum with posterior margin centrally straight, curved on sides. Abdomen slightly narrowed on area posterior to segment II, bowed posteriorly. Abdominal connectives without posterior spines. Abdominal tergite VII subquadrate, with posterior margin slightly rounded. Abdominal sternites without tubercles or spines. Legs long and thin, covered by short light setae. Hind femur slightly thicker than others, with two ventral rows of sharp spines ( Fig. 5 ). Hind tibia straight ( Fig. 5 ). Genital segments well exposed; segment I cylindrical, unmodified; proctiger without lateral projections; parameres symmetrical.

Apterous female BL 1.52–1.57, ANT I 0.17–0.18, ANT II 0.11, ANT III 0.18–0.19, ANT IV 0.32–0.33, INT 0.22–0.24, PL 0.19–0.24, PW 0.40–0.47.

Color as in male, with maculae on abdominal tergite IV darker. Body larger and more rounded, wider on region of abdominal tergite I. Sparse dark setae present on abdominal tergite I. Hind femur slightly thicker than others, without spines.

Macropterous female BL 1.62–1.93, ANT I 0.15–0.19, ANT II 0.11–0.12, ANT III 0.18–0.22, ANT IV 0.31– 0.32, INT 0.22–0.23, PL 0.41–0.51, PW 0.66–0.71.

Color darker than in apterous forms. Pronotum brown, with a transversal yellow stripe anteriorly, with width similar to that of base of head, except eyes. Thoracic sternites yellow, marked by brown, dark brown on intersegmental area. Abdominal tergites brown, darker on anterior portion; IV–VII with longitudinal yellow stripe. Venter of abdomen centrally brown, yellow on sides. Forewing brown, with area inside cells and apex whitish. Pronotum long, subpentagonal, divided into anterior and posterior lobes, with weak longitudinal median carina, and humeri slightly elevated. Anterior lobe of pronotum with a transversal row of punctuations adjacent to anterior margin; another row between anterior and posterior lobes. Posterior lobe with several punctuations and posterior angle rounded. Wings slightly passing apex of body.

Type material. Brazil, Espírito Santo, Vitória, Porto de Tubarão, Lagoa 0 7 [-20.256025 / -40.248818], 17.XII.2009, (J. L. Nessimian): 1 apterous male [HOLOTYPE], 2 apterous males, 2 apterous females, 3 macropterous females [PARATYPES] ( UFES).

Etymology. Named in honor of Dr. Jorge Luiz Nessimian, entomologist and friend.

Discussion. Microvelia nessimiani sp. nov. is described as belonging to the subgenus Kirkaldya Torre-Bueno, 1910, based on antennomere I (ANT I) longer than head width between eyes (INT), a feature used in keys of both Andersen (1982: 419) and Nieser and Melo (1997: 97) to separate the subgenera Microvelia s. str. and Microvelia (Kirkaldya) . In the case of Microvelia nessimiani sp. nov., however, only males display ANT I longer than INT, whereas females have ANT I slightly shorter than INT. Such a fact shows that this feature should be reevaluated in a revision of the subgenera of Microvelia from the New World, which is not possible for the authors at the moment because of lack of specimens of several species, especially those from the Nearctic Region.

Another problem for the definition of subgenera or species-groups of New World Microvelia is that several species are known only in the macropterous forms, such as those of the marginata group sensu Nieser & Alkins- Koo (1991). Being macropterous, the pronotum is always well-developed and covers all of the thorax, leaving no room for its use as a diagnostic feature or as a character to be used in a data matrix.

Finally, the interpretation of the dorsal thoracic sclerites of Neotropical Microvelia changed considerably through time. According to Drake and Hussey (1955), the basic apterous thorax of Microvelia would be composed of a pronotum of variable length, a mesonotum divided in two lobes (partially or totally covered by pronotum in some cases), and by lateral metathoracic triangles. The interpretation seen on J.T. Polhemus and Chapman (1979) and followed here, however, is more consistent with other groups of Gerromorpha , and defines a pronotum, which can be more or less extended backwards, a simple mesonotum and a metanotum sided by lateral triangles.

Being so, the apterous pronotum of M. nessimiani sp. nov. is here described as consisting of a relatively long pronotum divided into two superficial lobes, which covers mesonotum, but leaves metanotum fully exposed ( Fig. 4 ). According to Drake and Hussey (1955) interpretation, which was probably used at least on the majority of species descriptions between the decades of 1950 and 1970, the thorax of M. nessimiani sp. nov. would consist of a pronotum that covers about half of the mesonotum only, the actual metanotum corresponding to the posterior lobe of the mesonotum in their view. This arrangement was given on the original descriptions of M. chilena Drake & Hussey, 1955 , M. costaiana Drake & Hussey, 1951 , M. inannana Drake & Hottes, 1952 and M. quieta Drake & Carvalho, 1954 , none of which has spines on male hind femur.

Taking in consideration South American species which display spines on male hind femur, M. nessimiani sp. nov. is similar to M. mimula White, 1879 , M. peruviensis McKinstry, 1937 , and M. trinitatis China, 1943 . Only macropterous and brachypterous specimens of the last species are known, all with a well-developed pronotum, which bears anteriorly a peculiar light band with two broad lobes extending to posterior lobe of pronotum. Moreover, general color of M. trinitatis is cinnamon, whereas specimens of M. nessimiani sp. nov. have almost all body yellow, except for the dark marks on connexives.

Besides the spines on hind femur, males of M. mimula can be identified because of the long horn-like projections on the sides of the proctiger. These projections are not seen in M. nessimiani sp. nov, the proctiger displaying lateral margins only slightly convex. Males of M. mimula also have only one spine row on hind femur, whereas those of M. nessimiani sp. nov. have two. Finally, the new species can be differentiated from M. peruviensis by being smaller (males with body length 1.35–1.46 vs. 1.6 in M. peruviensis ), lighter in coloration (specimens of M. peruviensis are brown with markings of yellow), and for having parameres of same the size (in M. peruviensis the left one is much larger than the right one). Mckinstry (1937) mentions only that the hind femur of M. peruviensis is covered by short sharp spines on the ventral surface, but does not mention in how many rows they might be organized.

Figures

FIGURES 2 – 5. Microvelia nessimiani n. sp. 2. Apterous male, dorsal view. 3. Apterous female, dorsal view. 4. Apterous thorax, male, dorsal view. 5. Hind leg, male. Scale bar = 1.00 mm. [P 1 = anterior superficial lobe of pronotum; P 2 = posterior superficial lobe of pronotum; MT = metanotum; T = lateral triangle]