Research Article |
Corresponding author: Sonia Maria Lopes ( sonialfraga@gmail.com ) Academic editor: Benjamin Wipfler
© 2015 Leonardo de Oliveira Cardoso da Silva, Sonia Maria Lopes.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Silva LOC, Lopes SM (2015) Two new species of Tribonium Saussure, 1862 (Blattodea, Blaberidae, Zetoborinae), with a key to males of the genus. ZooKeys 502: 117-127. https://doi.org/10.3897/zookeys.502.8591
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This contribution describes and illustrates the male genitalia of two new species of Blaberidae collected in the state of Minas Gerais, Brazil: T. caldensis sp. n. resembles T. neospectrum Lopes, 1978, differing in the coloration, size and genitalia; and T. morroferrensis sp. n., which resembles T. guttulosum (Walker, 1868) but also differs in the size and coloration of specimen and genital pieces morphology. The genital plates were removed after dissection of the posterior part of the abdomen, and were stored in microvials containing glycerin, attached to the respective exemplar in the collection of the Museu Nacional of Rio de Janeiro, Brazil. A key to males of the species of the genus is also presented. Illustrations of T. neospectrum and T. guttulosum are provided to clarify the comparisons with the new species described here.
Blattodea , genitalia, key, new species, taxonomy
The genus Tribonium was described by
In a footnote,
Eight of the 11 presently known species are from Brazil: T. conspersum (Guérin & Percheron), T. conspurcatum (Burmeister), T. delicatum Lopes, T. elegans (Brunner), T. guttulosum (Walker), T. litoris Lopes, T. neospectrum Lopes, and T. spectrum (Eschscholtz).
In this contribution two new species of Tribonium are added, from the state of Minas Gerais, Brazil, and present illustrations of their internal genitalia and a key for the available males of the genus. T. guyanense, T. conspurcatum, and T. elegans are not included in the key because they were described based only on females.
The type species (T. spectrum) was not used in the key because the description by Saussure provides few morphological characters. Unfortunately, we received no response to our request for the loan of the type material, because of the absence of a researcher in the Moscow Museum where it is deposited. Tribonium colombicum was not examined because the Philadelphia Academy of Natural Sciences failed to respond to our request for the loan of the specimen deposited under number 1215. It is necessary to include color characters in the key, because these are essential for the identification of species of Tribonium, as is the shape of the genitalia.
The genital plates were removed after dissection of the posterior part of the abdomen, using traditional dissection techniques as described by
After observation and comparison of specimens of different species of Tribonium under the stereomicroscope, distinguishing characteristics were selected for use in the key.
The holotypes are deposited in the collection of the Department of Entomology at the Museu Nacional of Rio de Janeiro (MNRJ).
Holotype ♂, BRAZIL, Minas Gerais, Poços de Caldas, Morro do Ferro, 07/IX/1967, J. Becker, O. Roppa, O. Leoncini cols.
The species name refers to the city of Poços de Caldas, where the material was collected.
Dimensions (mm): Male holotype, total length 23.2; length of pronotum 4.2; width of pronotum 7.9; length of tegmen 19.8; width of tegmen 6.5.
Male holotype. Coloration yellowish brown with dark brown spots (Fig.
Head. Triangular; vertex slightly exposed; interocular space ample, 1.6 mm, wider than 2/3 distance between antennae. Antenna not reaching apex of tegmen. Palps and antennae tomentose; second segment of maxillary palps small, third segment 0.71 mm in length, fourth segment same size as second, fifth segment clavate, similar in size to third segment.
Thorax. Pronotum convex, transverse, apical surface embossed, with rounded edges and straight basal surface. Tegmina developed, extending beyond apex of cerci; marginal field short and slightly concave; scapular field tapering toward apex, mid-field discoidal, extended apically, slightly angular along veins. Wings with marginal field narrow, subcostal vein reaching basal third of scapular field; cubital vein with numerous complete and few incomplete veins; apical triangle absent. Legs short, robust, inner side of femora with narrow posterior apical projection. Fore, mid and hind femora sparsely ciliate along anteroventral margin. Pulvilli small, present on fourth tarsal segments; claws simple, symmetrical, with concave arolia.
Abdomen. Supranal plate ciliated, with prominent median edges between enclosures and with slight invagination in middle portion; cerci short, ciliated, with 11 segments (Fig.
Tribonium caldensis sp. n. resembles T. neospectrum Lopes, 1978 in the coloration of the head (Figs
Holotype ♂, BRAZIL, Minas Gerais, Poços de Caldas, Morro do Ferro, 07/IX/1967, J. Becker, O. Roppa, O. Leoncini cols.
The species name refers to Morro do Ferro, where the material was collected.
Dimensions (mm): Male holotype, total length 25.3; length of pronotum 4.6; width of pronotum 8.2; length of tegmina 21.6; width of tegmina 7.7.
Male holotype. Coloration yellowish brown with dark brown spots (Fig.
Head. Triangular, vertex slightly exposed, interocular space ample, 1.9 mm, approximately 2/3 distance between antennae. Antenna not reaching apex of tegmen. Palpi and antennae ciliated; second segment of maxillary palpi small, third segment 0.70 mm in length, fourth segment same size as second, fifth segment clavate, similar in size to third segment, conspicuously ciliated.
Thorax. Pronotum convex, transverse, apical surface embossed, with rounded margin and straight basal surface. Tegmina developed, extending beyond apex of cerci; marginal field short and slightly concave; scapular field tapering toward apex, discoidal field extended apically, slightly angular along veins. Wings with marginal field narrow, subcostal vein reaching basal third of scapular field; cubital vein with numerous complete and few incomplete veins; apical triangle absent. Legs short, robust, inner thigh narrow with clear apical projection. Fore, mid and hind femora sparsely ciliated along anteroventral border. Pulvilli small, present on fourth tarsal segments; claws simple, symmetrical, with concave arolia.
Abdomen. Supranal plate ciliated, with prominent median edges between enclosures, with slight median invagination; cerci short, ciliated, with 12 segments (Fig.
Tribonium morroferrensis sp. n. resembles T. guttulosum (Walker, 1868) in general coloration and pronotum (Figs
1 | Total length of specimen 27 mm or more | T. conspersum (Guérin-Méneville & Percheron, 1835) |
– | Total length of specimen less than 27 mm | 2 |
2 | Pronotum with compact, symmetrical dark-brown to black medial spot with no definite shape | 3 |
– | Pronotum without compact medial spot | 4 |
3 | Tegmina without concentration of dark-brown spots at base of discoidal field | T. delicatum Lopes, 1978 |
– | Tegmina with concentration of dark-brown spots or spots scattered throughout its length | 6 |
4 | Supranal with tapered paraprocts, cerci long and tapered | T. litoris Lopes, 1978 |
– | Supranal with well-defined paraprocts, cerci short and wide | 5 |
5 | Apex of the median sclerite arrow-shaped | T. sagittum Lopes & Silva, 2010 |
– | Apex of the median sclerite elongated | T. neospectrum Lopes, 1978 |
6 | Head with vertex dark brown with yellowish-brown ocellar and clypeal areas | T. guttulosum (Walker, 1868) |
– | Head with vertex black with yellowish-brown ocellar and clypeal areas | 7 |
7 | Tegmina with the base of discoidal field with spots less concentrated | T. caldensis sp. n. |
– | Tegmina with the base of discoidal field with more concentrated spot | T. morroferrensis sp. n. |
To Dr. Janet W. Reid for editing the text in English.