Biosystematics of Old World Triatominae

Trypanosoma cruzi -- the vector-parasite paradox

“…In Africa, the niche occupation of Cimicidae is very similar to that of the Triatominae in the Americas, suggesting that both have followed a similar evolutionary route. But the complete absence of Triatominae from Africa [except for T. rubrofasciata exported in sailing ships to some African ports (see Gorla et al 1997)] tempts the idea that evolution of blood-sucking reduviids in Africa was inhibited by prior evolution of those blood-sucking anthocorids, now known as Cimicids, that had already occupied the niches available for that type of evolutionary progression. The high degree of morphological specialisation of the Cimicidae suggests that they evolved earlier than the Triatominae, so that it would appear that the Triatominae evolved independently in the Americas, after separation of the Atlantic divide, rather than having arisen also in Africa but subsequently becoming locally extinct.…”

“…Bloodsucking reduviids have also evolved independently in the Indian subcontinent (a biogeographic island for most of its existence) to give the aberrant triatomine genus Linshcosteus. However, neither Cimicidae nor Triatominae appear to have arisen elsewhere in Asia, which may relate to the proliferation of the Polyctenidae in the Asia-Pacific region (Table II) and may also explain why T. rubrofasciata was able to differentiate quite rapidly on arrival in east Asia during the 17-18th centuries (Gorla et al 1997). …”

Triatominae as a model of morphological plasticity under ecological pressure

“…This latter idea is not new: it was formulated by Usinger et al (1966) as the conclusion of many interfertility experiments. It was contained also in the conclusion of Gorla et al (1997) suggesting a New World origin of the Old World Triatoma. According to these authors, the New World members of the genus Triatoma would have T. rubrofasciata as unique ancestor.…”

“…According to these authors, the New World members of the genus Triatoma would have T. rubrofasciata as unique ancestor. This species seems to have been spread from the Americas a few centuries ago, and subsequently specialised into the seven recognised species of Triatoma found in the Asian region (Gorla et al 1997). This iconoclastic idea relies on the assumption of relatively rapid morphological changes.…”

Phylogenetic approach to the study of Triatomines (Triatominae, Heteroptera)

“…For instance, the bite of P. geniculatus in pigs and humans in the Amazon leaves painful lesions and, in the case of T. rubrofasciata, there has been at least one report of human death (Schofield, 2000). Gorla et al (1997) consider that triatomines are polyphyletic in origin and they believe that hematophagy have appeared recently, associated with the evolution of vertebrate nests. The polyphyletic hypothesis suggests that the adaptative steps from free life predators to hematophagous feeding might have occurred several times, not only among different groups of Reduviidae, but also among other Hemiptera groups.…”