Symptoms of iridovirus disease in a mosquito / Carlos Félix Marina Fernández

Tesis Maestría en Ciencias en Recursos Naturales y Desarrollo Rural El Colegio de la Frontera Sur 1998

Bibliografía: páginas 19-22

Acceso en línea sin restricciones

Recognition is currently, growing as to the importance of debilitating effects of insect virus diseases. At the individual level, commonly observed effects of sublethal infection include extended development times, reduced pupal and adult weight and lowered fecundity. At the population level, such effects may translate into changes in the periodicity and amplitude of population cycles and a lowering of the mean population density. However, for the most part, sublethal infections are assumed to be present in survivors of an inoculum challenge, rather than demonstrated to be present by microscopy or molecular techniques. Invertebrate iridescent viruses are dsDNA viruses capable of causing patent, lethal disease and covert, non-lethal infection. In the present study, replication of invertebrate iridescent virus 6 in Aedes aegypti larvae was demonstrated in the absence of patent disease. A sensitive insect bioassay (using Galleria mellonella) allowed the detection of covert infections which were more common than patent infections. A concentration-response relationship was detected for the incidence of patent infections, whereas the frequency of covert infections was not dependent on the inoculum concentration. Exposure to virus inoculum resulted in extended juvenile development times. A reduction in the mean and an increase in the variability of fecundity and adult progeny production was observed in females exposed to an inoculum challenge, although formal analysis was not possible. Males appeared capable of passing virus to uninfected females during the mating process. Covertly infected females were smaller and had shorter lifespans than control or virus-challenged females. A conservative estimate for the reduction in R0 of such insects was calculated at slightly more than 20% relative to controls. eng

Agroecología y Manejo de Plagas