Biotic and Abiotic factors affecting Leptolegnia chapmanii infection in Aedes aegypti.

PELIZZA SEBASTIAN ALBERTO; LÓPEZ LASTRA C.C; BECNEL J. J.; BISARO VILMA; GARCÍA, J.J.

JOURNAL OF THE AMERICAN MOSQUITO CONTROL ASSOCIATION

American Mosquito Control Association

Año: 2007 vol. 23 p. 177 - 181

8756-971X

ABSTRACT. The effects of water volume, container surface area and the density of hosts and fangal 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 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> 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 cm2), 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. KEYS WORDS Entomopathogen, oomycetes, Leptolegnia chapmanii, mosquitoes, Aedes aegypti.