Triatomine bugs carry the parasitic protozoa Trypanosoma cruzi, the causal agent of Chagas disease. It is known that both the parasite and entomopathogenic fungi can decrease bug survival, but the combined effect of both pathogens is not known, which is relevant for biological control purposes. Herein, the survival of the triatomine Meccus pallidipennis (Stal, 1872) was compared when it was coinfected with the fungus Metarhizium anisopliae (Metschnikoff) and T. cruzi, and when both pathogens acted separately. The immune response of the insect was also studied, using phenoloxidase activity in the bug gut and hemolymph, to understand our survival results. Contrary to expectations, triatomine survival was higher in multiple than in single challenges, even though the immune response was lower in cases of multiple infection. We postulate that T. cruzi exerts a protective effect and/or that the insect reduced the resources allocated to defend itself against both pathogens. Based on the present results, the use of M. anisopliae as a control agent should be re-considered.

中文翻译：

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克氏锥虫和真菌病原体的共同感染增加了恰加斯虫的存活率：反对真菌控制策略的建议

Triatomine bug 携带寄生原生动物克氏锥虫，恰加斯病的病原体。众所周知，寄生虫和昆虫病原真菌都会降低虫子的存活率，但两种病原体的综合作用尚不清楚，这与生物防治目的有关。在这里，triatomine的生存苍白麦(Stal, 1872) 与真菌同时感染时进行了比较绿僵菌（梅奇尼科夫）和T. cruzi，并且当两种病原体分别作用时。还使用昆虫肠道和血淋巴中的酚氧化酶活性研究了昆虫的免疫反应，以了解我们的生存结果。与预期相反，尽管多重感染的免疫反应较低，但多次感染的 triatomine 存活率高于单次攻击。我们假设T. cruzi发挥保护作用和/或昆虫减少了分配用于防御两种病原体的资源。根据目前的结果，使用M. anisopliae作为控制剂应重新考虑。