IntroductionFor the first time we provide the description of the melanic (dark) morphotype of Rhodnius nasutus and determine the pattern of genetic inheritance for this characteristic.MethodsDark morph R. nasutus specimens were crossbred with standard (typically patterned) R. nasutus.ResultsWe present the first occurrence of the melanic morphotype in the genus Rhodnius. The crossbreeding results demonstrate that the inheritance pattern of this characteristic follows Mendel's simple laws of segregation and an independent assortment of alleles.ConclusionsPhenotypic variation of R. nasutus reinforces the heterogeneity found in the Triatominae. Descriptions of new species in this subfamily require rigorous validation criteria.

Phimophorus spissicornis, el enigmático representante exclusivamente neotropical de Phimophorinae (Heteroptera: Reduviidae), se registra por primera vez para Colombia. Seis especimenes adultos y una ninfa fueron recolectados en los municipios de Vegachí y San Carlos, departamento de Antioquia. En ambas localidades P. spissicornis fue recolectado en palmas (Arecaceae) en asociación con Rhodnius pallescens (Reduviidae: Triatominae). Phimophorus spissicornis se encontró en las brácteas de las palmas Attalea butyracea y Oenocarpus bataua. Se presentan imágenes del hábito en vista dorsal para macho, hembra y último instar de P. spissicornis

Phimophorus spissicornis, the enigmatic and exclusively Neotropical representative of the Phimophorinae (Heteroptera: Reduviidae), is recorded for the first time from Colombia. Six adult specimens and one nymph were collected in the municipalities of Vegachí and San Carlos, department of Antioquia. In both localities P. spissicornis was collected from palms (Arecaceae) in associatión with Rhodnius pallescens (Reduviidae: Triatominae). Phimophorus spissicornis was found on the axils of palm fronds of Attalea butyracea and Oenocarpus bataua. Dorsal habitus illustrations of the male, female, and late instar nymph of P. spissicornis are provided.

The most important vectors of human Plasmodium in the neotropics belong to the subgenus Nyssorhynchus. These species are generally sympatric in terms of their geographical distributions. Some are difficult to identify based solely on examination of adult females using the available morphological keys, in these cases examination of immature stages and male genitalia is required to make correct determinations. However, in epidemiological studies it is necessary to identify the species of adult females which are found near humans, i.e. in studies of malaria transmission or evaluation of control measures. The purpose of the present study was to evaluate the discrimination of adult females of different species of Nyssorhynchus isolated mainly from Southern Colombia (department of Putumayo), using morphometric analysis. Adult females were obtained after rearing larvae collected in natural breeding places and from the progeny of females collected on humans. The morphological characteristics of the immature stages allowed the identification of four species of the subgroup Oswaldoi from Southern Colombia: Anopheles rangeli Gabaldon, Cova Garcia & Lopez, An. oswaldoi (Peryassu), An. benarrochi Gabaldon, Cova Garcia & Lopez and An. triannulatus (Neiva & Pinto). The species An. nuneztovari (Gabaldon) from the Northwest of Colombia was included for comparison. Morphometric analysis allowed differentiation of the females of all species to a confidence level approaching 90% using principal components analysis of 10 wing and leg variables, followed by canonical variate analysis of the first four principal components. We conclude that morphometrics may represent a useful taxonomic tool for this group and that its use should be further studied.

The finding of Panstrongylus geniculatus nymphs inside a house in northeastern Antioquia, Colombia, and the reports related to their increasing presence in homes suggest the need for surveillance methods for monitoring the invasion processes. We analyzed the morphological differences between a wild population and its laboratory descendants, using the techniques of geometric morphometry, with the idea that such differences might parallel those between sylvatic and synanthropic populations. The analyses over five generations showed differences in size but not in shape. Head size and wing size were both reduced from sylvatic to laboratory populations, but the decrease in head size occurred only up to the second generation while the decrease in wing size proceeded up to the fifth generation. In contrast, although a decrease in sexual size dimorphism has been proposed as a marker of colonization in human dwellings, we did not detect any significant loss of dimorphism between sexes of P. geniculatus over the five generations studied. We conclude that size changes may have a physiological origin in response to a change of ecotopes, but more than five generations may be required for the expression of permanent morphological markers of human dwellings colonization.