Morphometric changes of Triatoma flavida Neiva, 1911 (Hemiptera:Triatominae) in the transition from sylvatic to laboratory conditions

Abstract

SUMMARYThe one-generational metric changes occurring in Triatoma flavida (Hemiptera: Triatominae) when carried from its wild habitat (caves) to laboratory, were examined using traditional morphometric techniques. As for other species of Triatoma, Rhodnius or Panstrongylus studied in similar conditions, a significant reduction of head, thorax and wing size was observed. Sexual dimorphism of the wings, while present in the wild sample, was not detected anymore in the laboratory individuals. Biological significance and epidemiological importance are discussed.

Changes related to gender, geographic population and habitat in the antennal phenotype of Triatoma patagonica Del Ponte, 1929 (Hemiptera: Reduviidae)

“…The highest number of TK on both antennal flagella in T. patagonica females, observed also in T. sordida (Catalá, 1997) and Triatoma brasiliensis Neiva, 1911 (Carbajal de la Fuente andCatalá, 2002), would be related to specific reproductive activities, such as search of refuge and/or oviposition sites, since TK would be associated with perception of contact pheromones (Bernard, 1974) or with detection of molecules, primary in liquid phase (Catalá, 1997;Gracco and Catalá, 2000). Abundance of TH on the three antennal segments of T. patagonica males was also reported for other species, such as T. infestans (Catalá and Dujardin, 2001), T. sordida (Catalá, 1997), T. pseudomaculata (Carbajal de la Fuente and Catalá, 2002), M. spinolai Porter, 1934and M. gajardoi Frias, Henry & Gonzalez, 1998(Moreno et al, 2005, T. dimidiata (Arroyo et al, 2007), Triatoma flavida (Neiva, 1911), andTriatoma bruneri (Usinger, 1944) (Rodríguez Rodríguez et al, 2009). The high number of this chemoreceptor would be associated with sexual behavior, through perception of chemical signals produced by metasternal glands of females (Crespo and Manrique, 2007), which promote copulation and male aggregation around pairs (Catalá and Schofield, 1994;Catalá and Dujardin, 2001;Carbajal de la Fuente and Catalá, 2002;Moreno et al, 2005), and with host-seeking and refuge searching abilities and of particles released by the sweat and respiration of the host (Mayer, 1968;Bernard, 1974;Abrahan et al, 2008).…”

“…Sexual dimorphism at the level of the antennal phenotype has been reported for several Triatomini species (Catalá and Dujardin, 2001;Carbajal de la Fuente and Catalá, 2002;Catalá et al, 2005;Moreno et al, 2005;Arroyo et al, 2007;Carbajal de la Fuente et al, 2008;Rodríguez Rodríguez et al, 2009). The principal sexual variations are related to the number and distribution of chemoreceptors involved in the reception of stimuli and associated with sexual behavior and active dispersal (Carbajal de la Fuente and Catalá, 2002).…”

“…Considering that the laboratory is a novel habitat for triatomines, which can induce phenotypic changes in the populations, several authors have reported a reduction in some morphological characters (Zeledón, 1981;Dujardin et al, 1997Dujardin et al, , 1998Dujardin et al, , 1999Jaramillo et al, 2002;Borges et al, 2005;Rodríguez Rodríguez et al, 2007). Regarding the antennal phenotype, Catalá et al (2004) suggested that modifications in the sensilla pattern can occur in the laboratory because of the particular characteristics of this habitat.…”