Pelizza Sebastian A, López Lastra Claudia C, Becnel James J, Bisaro Vilma, García Juan J
Centro de Estudios Parasitológicos y de Vectores-CEPAVE (UNLP-CONICET), 2 No. 584, 1900 La Plata, Argentina.
J Am Mosq Control Assoc. 2007 Jun;23(2):177-81. doi: 10.2987/8756-971X(2007)23[177:BAAFAL]2.0.CO;2.
The effects of water volume, container surface area and the density of hosts and fungal zoospores on the infectivity of the oomycete fungus Leptolegnia chapmanii to Aedes aegypti were investigated in the laboratory. Late 3rd or early 4th instars from a laboratory colony were used as hosts in all assays. Fourth instars infected with L. chapmanii for 48 h (6.1 +/- 0.2 x 10(4) zoospores/larva) were used as inoculum. Mortality rates were >90% in containers with 20 or fewer larvae when exposed to 1 infected larva, but they decreased to 37% in containers with 60 larvae. Mortality rates varied from 82% to 92% when healthy 4th instars were exposed to 1 and 2 infected larvae, respectively, whereas 100% mortality was obtained with > or =3 infected larvae. Infection and mortality rates in containers with volumes that varied from 300 to 5,000 ml but that had similar water surface area (397 cm2) varied from 89 to 92%, respectively. When water volume was held constant at 250 ml in containers with variable surface areas (14.5-875 cm(2)), larval mortality varied from 96% to 25%, respectively. The ability of L. chapmanii to infect mosquito larvae is dose dependent and influenced by larval density and surface area.
在实验室中研究了水量、容器表面积以及宿主和真菌游动孢子密度对卵菌纲真菌查普曼细囊霉感染埃及伊蚊的影响。在所有试验中，均使用实验室种群的末龄3龄或初龄4龄幼虫作为宿主。将感染查普曼细囊霉48小时（6.1±0.2×10⁴个游动孢子/幼虫）的4龄幼虫用作接种物。当暴露于1只感染幼虫时，在装有20只或更少幼虫的容器中死亡率>90%，但在装有60只幼虫的容器中死亡率降至37%。当健康的4龄幼虫分别暴露于1只和2只感染幼虫时，死亡率分别为82%至92%，而当暴露于≥3只感染幼虫时死亡率为100%。在体积从300至5000毫升但水面面积相似（397平方厘米）的容器中，感染率和死亡率分别为89%至92%。当在表面积可变（14.5 - 875平方厘米）的容器中将水量保持在250毫升时，幼虫死亡率分别从96%至25%不等。查普曼细囊霉感染蚊虫幼虫的能力是剂量依赖性的，并受幼虫密度和表面积的影响。
