Francisco Antonio Crespo

Is parental care behavior in Belostoma species an evolutionary cause for their common sexual size dimorphism pattern

Current evidence suggests that sexual size dimorphism (SSD) reflects the male and female adaptation to their different reproductive roles. Belostoma and Lethocerus species, included in Belostomatidae, present different kinds of paternal care. Females of Belostoma Latreille species lay their eggs on the back of males. Males carry, aerate and protect the clutch until hatching, which is critical for offspring survival. Males of Lethocerus Mayr species exhibit some parental care behavior but do not carry the eggs. The genera are nearly related. We studied and compared the SSD patterns of B. oxyurum (Dufour), B. micantulum (Stål), B. elegans (Mayr), B. bifoveolatum Spinola, B. gestroi Montandon and Lethocerus annulipes (Herrich‐Schäffer) by means of a multivariate approach to distinguish selection targets in different components of size. Morphometric analysis revealed that SSD patterns vary among traits and that the arrangements are similar in Belostoma species, showing a common trend under resembling selective mechanisms. The widespread SSD trend in insects is that all components of body size are biased towards females, generally related to a fecundity advantage, a pattern now also detected in L. annulipes. We found in Belostoma species that the male has relatively longer middle and hind legs. We propose that SSD in hind legs biased towards males is a selective response for paternal care; they denote a brood‐adapted morphology. The middle leg enlargement may be an associated response to maintain effective locomotion.

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.