Reduviidae - Triatoma recurva
Size: 26 mm
Group Guild Status
Trogloxene Parasite Uncommon
This species is a haematophagous (bloodsucking) parasite of vertebrates. Several species of Triatoma in the southwestern U.S. are primarily or exclusively associated with species of wood rats (Neotoma spp.), and while T. recurva is recorded feeding on the white-throated wood rat (N. albigula; Ibarra-Cerdeña et al. 2009), according to Lent and Wygodzinsky (1979), it is more commonly a parasite of the rock squirrel (Spermophilus variegatus). We observed a single rock squirrel inside the cave just inside the Blowhole Gate on April 17, 2010.
T. recurva commonly bites humans, and is a known vector of the protozoan trypanosome parasite Trypanosoma cruzi, which is common in the new world tropics and afflicts a wide variety of mammals including man (Kettle 1995). T. cruzi is the infective agent of Chaga’s disease. Three closely related species of Triatoma are common in southern Arizona (including T. recurva), all of which are known to carry the T. cruzi parasite. It has recently been found that greater than 40 percent of the animals in the Tucson area (and probably all of southern Arizona) are carriers of this disease (Reisenman et al. 2010). The apparent reason the disease is not readily transmitted in this region is that these species of triatomines do not eliminate (urinate and defecate) until after they have left the host, whereas tropical species commonly defecate while feeding, allowing the parasites in their feces to come in contact with the open bite wound (Klotz et al. 2009; Nogueda-Torres et al. 2000).
T. recurva was observed in the cave on only three occasions during the recent study, but we suspect it is likely more common that our data indicates. Information is sparse on vertebrate hosts for many species of Triatoma, including T. recurva (Ibarra-Cerdeña et al. 2009). Potential hosts for T. recurva in the cave include S. variegatus, N. albigula, and the rigntail (Basariscus astutus). We could find only a single record of T. cruzi infecting the ringtail, where blood serum testing of a wild ringtail from Arizona produced antibodies to T. cruzi, indicating prior infection and an association with some species of Triatoma (Brown 2008). T. recurva was not recorded during the initial study.
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