Gürtler Ricardo E, Fernández María Del Pilar, Cecere María Carla, Cohen Joel E
Laboratorio de Eco-Epidemiología, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina.
Instituto de Ecología, Genética y Evolución de Buenos Aires, Consejo Nacional de Investigaciones Científicas y Técnicas, Buenos Aires, Argentina.
PLoS Negl Trop Dis. 2017 Dec 6;11(12):e0006097. doi: 10.1371/journal.pntd.0006097. eCollection 2017 Dec.
Human sleeping quarters (domiciles) and chicken coops are key source habitats of Triatoma infestans-the principal vector of the infection that causes Chagas disease-in rural communities in northern Argentina. Here we investigated the links among individual bug bloodmeal contents (BMC, mg), female fecundity, body length (L, mm), host blood sources and habitats. We tested whether L, habitat and host blood conferred relative fitness advantages using generalized linear mixed-effects models and a multimodel inference approach with model averaging. The data analyzed include 769 late-stage triatomines collected in 120 sites from six habitats in 87 houses in Figueroa, Santiago del Estero, during austral spring. L correlated positively with other body-size surrogates and was modified by habitat type, bug stage and recent feeding. Bugs from chicken coops were significantly larger than pig-corral and kitchen bugs. The best-fitting model of log BMC included habitat, a recent feeding, bug stage, log Lc (mean-centered log L) and all two-way interactions including log Lc. Human- and chicken-fed bugs had significantly larger BMC than bugs fed on other hosts whereas goat-fed bugs ranked last, in consistency with average blood-feeding rates. Fecundity was maximal in chicken-fed bugs from chicken coops, submaximal in human- and pig-fed bugs, and minimal in goat-fed bugs. This study is the first to reveal the allometric effects of body-size surrogates on BMC and female fecundity in a large set of triatomine populations occupying multiple habitats, and discloses the links between body size, microsite temperatures and various fitness components that affect the risks of transmission of Trypanosoma cruzi.
在阿根廷北部的农村社区，人类居住场所（住所）和鸡舍是致倦库蚊的主要源栖息地，致倦库蚊是导致恰加斯病感染的主要传播媒介。在这里，我们研究了个体臭虫血餐含量（BMC，毫克）、雌虫繁殖力、体长（L，毫米）、宿主血源和栖息地之间的联系。我们使用广义线性混合效应模型和带有模型平均的多模型推断方法，测试了体长、栖息地和宿主血液是否赋予相对适合度优势。分析的数据包括在南半球春季期间，从圣地亚哥 - 德尔埃斯特罗省菲格罗亚市87所房屋的6种栖息地的120个地点收集的769只晚期锥蝽。体长与其他体型替代指标呈正相关，并受到栖息地类型、虫态和近期取食情况的影响。来自鸡舍的臭虫明显大于猪圈和厨房中的臭虫。对数BMC的最佳拟合模型包括栖息地、近期取食情况、虫态、对数Lc（平均中心化的对数L）以及包括对数Lc在内的所有双向相互作用。以人类和鸡为食的臭虫的BMC明显大于以其他宿主为食的臭虫，而以山羊为食的臭虫排名最后，这与平均吸血率一致。繁殖力在来自鸡舍且以鸡为食的臭虫中最高，在以人类和猪为食的臭虫中次高，在以山羊为食的臭虫中最低。本研究首次揭示了在占据多个栖息地的大量锥蝽种群中，体型替代指标对BMC和雌虫繁殖力的异速生长效应，并揭示了体型、微生境温度与影响克氏锥虫传播风险的各种适合度成分之间的联系。
