Pereira M H, Penido C M, Martins M S, Diotaiuti L
Unifenas, ICB, Alfenas, MG, Brasil.
Mem Inst Oswaldo Cruz. 1995 Nov-Dec;90(6):765-7. doi: 10.1590/s0074-02761995000600019.
We compared the influence of bug density in the capacity of Triatoma infestans and Panstrongylus megistus in obtaining blood meal in non anaesthetized mice. The regression analysis for increase in body weight (mg) versus density (no. of bugs/mouse) showed that in experiments with anaesthetized mice (AM), no correlation was observed. In experiments with non anaesthetized mice (NAM) the weight increase was inversely proportional to density. The regression slope for blood meal size on density was less steep for T. infestans than for P. megistus (-1.9 and -3.0, respectively). The average weight increase of P. megistus nymphs in experiments with AM was higher than for T. infestans nymphs; however, in experiments with NAM such results were inverted. Mortality of P. megistus was significantly higher than that of T. infestans with NAM. However, in experiments with AM very low mortality was observed. Considering the mortality and the slope of regression line on NAM, T. infestans is more efficient than P. megistus in obtaining blood meal in similar densities, possibly because it caused less irritation of the mice. The better exploitation of blood source of T. infestans when compared with P. megistus in similar densities, favours the maintenance of a better nutritional status in higher densities. This could explain epidemiological findings in which T. infestans not only succeeds in establishing larger colonies but also dislodges P. megistus in human dwellings when it is introduced in areas where the latter species prevails.
我们比较了臭虫密度对骚扰锥蝽（Triatoma infestans）和大臭蝽（Panstrongylus megistus）在未麻醉小鼠身上获取血餐能力的影响。体重增加量（毫克）与密度（每只小鼠的臭虫数量）的回归分析表明，在麻醉小鼠（AM）实验中，未观察到相关性。在未麻醉小鼠（NAM）实验中，体重增加与密度成反比。骚扰锥蝽血餐大小对密度的回归斜率比大臭蝽的斜率更平缓（分别为-1.9和-3.0）。在AM实验中，大臭蝽若虫的平均体重增加高于骚扰锥蝽若虫；然而，在NAM实验中，结果相反。在NAM实验中，大臭蝽的死亡率显著高于骚扰锥蝽。然而，在AM实验中，观察到的死亡率非常低。考虑到死亡率和NAM实验中的回归线斜率，在相似密度下，骚扰锥蝽在获取血餐方面比大臭蝽更有效，这可能是因为它对小鼠造成的刺激较小。与大臭蝽相比，骚扰锥蝽在相似密度下对血源的利用更好，有利于在更高密度下维持更好的营养状态。这可以解释流行病学研究结果，即骚扰锥蝽不仅成功建立了更大的群体，而且当它被引入大臭蝽占优势的地区的人类住所时，还会取代大臭蝽。
