Alejandra C. Valverde

A longitudinal study of two species of Belostoma Latreille (Heteroptera: Belostomatidae): allometry and ontogeny

The multivariate allometric growth patterns from longitudinal data of leg and rostral segments of all instars of Belostoma elegans (Mayr) and B. cummingsi De Carlo are presented for the first time, and the allometric coefficients are compared. The segments of the middle and hind legs present allometric coefficients with opposite polarity to those of forelegs. This discrepancy in the ontogenetic trajectories may be due to the different functions of the legs. The foreleg main function is to capture of the prey, while the middle and hind legs are adapted to swimming. The relative size of rostral segments is an important taxonomic character in Belostoma. In B. cummingsi, the proximal segment is longer than the middle one, while in B. elegans they are subequal. Our purpose is to explain these differences through the analysis of their ontogenetic trajectories in an attempt to illuminate the morphological differences among species from a developmental perspective.

OCCURRENCE OF SEXUAL SIZE DIMORPHISM IN BELOSTOMA ELEGANS (HETEROPTERA: BELOSTOMATIDAE)

ABSTRACT: Sexual size dimorphism (SSD) is detected in Belostoma elegans for the first time in a multivariate framework. Females are usually bigger than males in Heteroptera species; size is frequently associated with reproductive success. Following this general trend we found that maximum width of the head and interocular distance are biased towards females. Components of body size involved in paternal care and mating behavior did not follow that general rule. Therefore, SSD is not detected in total length without head and maximum width, presumably a consequence of the male egg-laying area which offers a proportional major surface for the clutch. SSD biased to males is found in middle and hind leg segments, used during mating and brooding behavior.

Blattaria, new generic and specific records for Argentina

Three genera, four species and the phenotype of Blattella germanica are recorded for the first time from Argentina. The distribution area of 15 species is expanded. The cockroach fauna from Argentina is still poorly known and currently represented by 45 genera and 100 species

Contribution to the knowledge of Lanta Hebard, 1921, with remarks on some male genital characters (Blattaria, Ectobiidae)

The genus Lanta Hebard 1921 includes three species found in the Neotropical region. Two species are known from Argentina, L. peniculiger (province of Santa Fe), and L. scotia (provinces of Córdoba and Santiago del Estero) (see Crespo et al. 2010), and one from Brazil, L. borgesae, (Araras, São Paulo) (Rocha e Silva & Vasconcellos, 1984). All species have been described on the basis of male external characters, such as wing veins, leg spines, hypandrium, shape and position of the styli, in addition to coloration and size. Except for a partial representation of the male genitalia of L. borgesae (Rocha e Silva & Vasconcellos 1984), this structure went untreated in morphological and phylogenetic investigations of the Blattaria (Snodgrass 1937; McKittrick 1964; Grandcolas 1996; Klass 1997; Roth 2003;). Females remain unknown.

A new species of Tribonium Saussure, 1862 from the Province of Misiones, Argentina (Blattaria, Blaberidae, Zetoborinae)

Tribonium rothi sp. n. is described from Argentina, whereas T. neospectrum and T. conspersum are recorded for the first time for that country, and their genitalia is redescribed. Femur and tibial spine armature are given and Tribonium is compared with Schistopeltis. A key to identify species of the genus Tribonium recorded in Argentina is provided.

Tres citas nuevas del género Ischnoptera Burmeister, 1838 (Blattellinae, Blattellidae, Blattaria) para Uruguay

The number of species of the genus Ischnoptera reported from Uruguay is doubled, increasing its number to 6. Ischnoptera argentina Hebard, 1921; I. bilunata Saussure, 1869; and I. litostylata Hebard, 1921 are reported for the first time. The available information on the species distribution is mapped.