Revision of the emBelostoma triangulum/em group (Insecta: Heteroptera: Belostomatidae).

The genus Belostoma comprises about 70 species classified in sixteen species groups. Here, the remarkable Belostoma triangulum group sensu Lauck, 1964, is revised. Belostoma bicavum Lauck, 1964 is proposed as a junior synonym of B. bachmanni De Carlo, 1957, which is added to this group. Thus, the rearranged group is now composed of two species: Belostoma bachmanni and B. triangulum Lauck, 1964. Redescriptions of these species are presented including a discussion about comparative morphology with other species of the genus. The geographic distributions of the species in the B. triangulum group are also updated.

Revision of the Belostoma dentatum group sensu Nieser (Insecta, Heteroptera, Belostomatidae).

Species of Belostoma in the dentatum and subspinosum groups are large and closely related, and have been combined by some authors into a single group, the dentatum group, comprising 15 species. This group is recognized by the scutellum reaching the nodal line and the ventral diverticulum of the phallus with distinct dorsal caudal and ventroapical protuberances. Previously, each group included five and 10 species, respectively; members of the dentatum group ranged in length from 38.0 to 52.0 mm, whereas those of the subspinosum group ranged from 26.0 to 40.0 mm. The following species of the dentatum group, now reformulated, include: Belostoma anurum (Herrich-Schäffer), B. asiaticum (Mayr), B. bordoni De Carlo, B. cummingsi De Carlo, B. columbiae Lauck, B. dallasi De Carlo, B. dentatum (Mayr), B. elongatum Montandon, B. ellipticum Latreille, B. foveolatum (Mayr), B. guianae Lauck, B. harrisi Lauck, B. malkini Lauck, B. porteri De Carlo, B. pseudoguianae Roback & Nieser, B. subspinosum Palisot de Beauvois, and B. venezuelae Lauck. Belostoma bordoni is herein included in the dentatum group based on male genitalic morphology, and the subspecies B. subspinosum subpinosum (Palisot de Beauvois) and B. subspinosum cupreomicans (Stål) are synonymized as a single valid species, B. subspinosum. Belostoma peruvianum De Carlo is synonymized with B. dentatum. Based on the study of male genitalic characteristics, B. cachoeirinhensis Lanzer-de-Souza appears to be conspecific with B. cummingsi; however, because we could not borrow types of B. cachoeirinhensis, we do not synonymize it. Sketches of specimens identified either as B. boscii (Le Peletier de Saint-Fargeau & Serville) or B. anurum by A.L. Montandon from Muséum National d'Histoire Naturelle are provided with comments in order to show the variation of male genitalia through the B. subspinosum complex. Our findings suggest that the dorsal arms of the phallotheca curved apically to be diagnostic of this complex. No firm conclusion is possible because of the great variation in the male genitalia; however, the general aspect of the ventroapical protuberance together with the dorsal arms provide some definition of B. subspinosum. A key to these species is also given, deeply modified after D.R. Lauck and N. Nieser.

The small species of Belostoma (Heteroptera: Belostomatidae): revision of plebejum group

Nieser gathered the water bug species included by Lauck in the groups Belostoma pygmeum and Belostoma plebejum in a single group, Belostoma plebejum. We follow this criterion and use the terminology used by EstCvez and Polhemus for species descriptions. The Belostoma plebejum group includes seven small species with the ventral diverticulum of male genitalia recurved ventrad: Belostoma lariversi De Carlo, 1969; B. micantulum (Stål, 1858); B. plebejum (Stål, 1858); B. pygmeum (Dufour, 1863); B. minusculum (Uhler, 1884). B. parvum sp. nov. from Venezuela, Colombia, Guyana, Suriname and Brazil, and B. nicaeum sp. nov. from Manaus, Brazil. The two new species are described and illustrated, and new synonymies are proposed.

The small species of Belostoma (Heteroptera: Belostomatidae): revision of plebejum group.

Nieser gathered the water bug species included by Lauck in the groups Belostoma pygmeum and Belostoma plebejum in a single group, Belostoma plebejum. We follow this criterion and use the terminology used by EstCvez and Polhemus for species descriptions. The Belostoma plebejum group includes seven small species with the ventral diverticulum of male genitalia recurved ventrad: Belostoma lariversi De Carlo, 1969; B. micantulum (Stål, 1858); B. plebejum (Stål, 1858); B. pygmeum (Dufour, 1863); B. minusculum (Uhler, 1884). B. parvum sp. nov. from Venezuela, Colombia, Guyana, Suriname and Brazil, and B. nicaeum sp. nov. from Manaus, Brazil. The two new species are described and illustrated, and new synonymies are proposed.

Separación de subfamilias en la familia de chinches Gelastocoridae (Hemiptera) / Subfamily separation in the hemipteran family Gelastocoridae (Hemiptera)

Gelastocoridae (Kirkaldy, 1897) has over 70 species in two subfamilies: Nerthrinae (Kirkaldy, 1898), genus Nerthra (Say, 1832) and Gelastocorinae (Champion, 1901), genus Gelastocoris (Kirkaldy, 1897). The position of the cephalic gland openings, presence and shape of the gular bridge and the number and position of abdominal spiracles, are presented as new morphologic diagnostic characteristics that support the argument used by Todd for the segregation of the subfamilies. The characteristics are described and illustrated on the basis of specimens from Laguna Iberá, Corrientes, Argentina.

Se describen nuevos caracteres morfológicos diagnósticos que apoyan los argumentos utilizados por Todd, para separar las subfamilias Nerthrinae y Gelastocorinae (Gelastocoridae). Se describen e ilustran las glándulas cefálicas, la placa maxilar y la ubicación de los espiráculos abdominales.

Successful hatching from eggs carried by females and naturally removed from incubant males in Belostoma spp. water bugs (Heteroptera: Belostomatidae)

Within Belostomatinae water bug species (Heteroptera, Belostomatidae) it has been hitherto believed that the completion of embryonic development is successful only if eggs are incubated on male hemelytra. Nevertheless, we found egg successful hatching from a back-brooding Belostoma elegans (Mayr) and B. micantulum (Stål) females, as well as from fertilized eggs kicked off from four back-brooder B. elegans males. One "encumbered" B. elongatum Montandon female was also recorded, but eggs did not hatch after she removed them.

Se considera que el desarrollo embrionario y la emergencia de las ninfas de las especies de Belostomatinae (Heteroptera, Belostomatidae) se cumplen con éxito si los huevos son incubados sobre el espacio dorsal de machos adultos. No obstante, hemos registrado eclosiones exitosas a partir de dos hembras grávidas portando huevos sobre su dorso; una de ellas de la especie Belostoma elegans (Mayr), la otra de B. micantulum (Stål). Se registra la eclosión de huevos, previamente removidos del área de postura por los propios machos incubantes de B. elegans (N=4) y la presencia de una hembra de B. elongatum Montandon, portando huevos sobre sus hemiélitros, los cuales no eclosionaron después de haber sido removidos por la propia hembra.

Successful hatching from eggs carried by females and naturally removed from incubant males in Belostoma spp. water bugs (Heteroptera: Belostomatidae).

Within Belostomatinae water bug species (Heteroptera, Belostomatidae) it has been hitherto believed that the completion of embryonic development is successful only if eggs are incubated on male hemelytra. Nevertheless, we found egg successful hatching from a back-brooding Belostoma elegans (Mayr) and B. micantulum (Stål) females, as well as from fertilized eggs kicked off from four back-brooder B. elegans males. One "encumbered" B. elongatum Montandon female was also recorded, but eggs did not hatch after she removed them.

[Subfamily separation in the hemipteran family Gelastocoridae (Hemiptera)]. / Separación de subfamilias en la familia de chinches Gelastocoridae (Hemiptera).

Gelastocoridae (Kirkaldy, 1897) has over 70 species in two subfamilies: Nerthrinae (Kirkaldy, 1898), genus Nerthra (Say, 1832) and Gelastocorinae (Champion, 1901), genus Gelastocoris (Kirkaldy, 1897). The position of the cephalic gland openings, presence and shape of the gular bridge and the number and position of abdominal spiracles, are presented as new morphologic diagnostic characteristics that support the argument used by Todd for the segregation of the subfamilies. The characteristics are described and illustrated on the basis of specimens from Laguna Iberá, Corrientes, Argentina.