TRANSMISSION OF A MOSQUITO IRIDESCENT VIRUS INAEDES TAENIORHYNCHUS .I. LABORATORY EXPERIMENTS

Laboratory studies on the transmission of a mosquito iridescent virus (MIV) in Aedes taeniorhynchus are described. The virus can be effectively transmitted to the larvae per os; transovarial transmission occurs from an infected female to her eggs, and evidence was obtained that all, or a very high proportion, of the eggs are infected. Larvae infected per os in their early instars may develop signs and symptoms of disease, and die before pupation. Exposure to infection progressively later in their development results in later development of signs and symptoms, and a reduction in the total number of larvae that show disease before pupation. Death always occurs in the fourth instar no matter what the time of infection. Exposure of young larvae to increasing quantities of virus increases the number that show evidence of disease, but only to a certain level, suggesting that the disease can develop in only a proportion of the larvae. Rearing larvae under different conditions of temperature, diet, and crowding produced no detectable differences in infection rates among either groups of larvae exposed from the time of hatching to the same dosage of virus, or groups of larvae hatched from a large batch of eggs in which a proportion carrying infection had been homogeneously distributed. © 1969.