Infection Rates of Aedes Triseriatus Following Ingestion of La Crosse Virus by the Larvae *

Abstract

Infection rates ranged from 0-2.1% in adults of Aedes triseriaus reared from groups of larvae that had ingested La Crosse (LAC) virus (Clifornia encephalitis group) at dosages of 7.0-8.3 log 10 SMICLD50/ml. Females form orally infected larvae transmitted the virus to suckling mice. Larvae that devoured carcasses of transovarially infected larvae containing 3.0 log 10 SMICLD 50/ml failed to become infected. Ingestion by larvae of infected carcasses appears, therefore, to be unimportant as a method of horizontal amplification of LAC virus.

Utilization of larval and pupal detritus byAedes aegyptiandAedes albopictus

“…Alternatively, it is possible that Aedes larvae have no active recognition for invertebrate detritus and forage on any detritus source they come across while browsing. The rapid consumption of larval carcasses also has epidemiological consequences since it could be a mechanism for the horizontal transmission of pathogens within the larval habitat (Miller et al , Bara et al ).…”

Ecological interactions affecting the role of mosquito larvae on dengue virus transmission.

“…Another potential mechanism for viral amplification within mosquito populations could occur among larvae (Miller et al 1978, Ture11 et al 1990). Susceptibility of Aedes mosquito larvae to arboviruses has been reported for Rift Valley Fever virus, La Crosse virus, Yellow Fever virus, Japanese B encephalitis virus, St. Louis encephalitis virus, and…”

“…West Nile virus when larvae are placed into a viral suspension (Peleg 1965, Miller et al 1978, Ture11 et al 1990). Although an initial study investigating the susceptibility of larval Ae.…”

“…We have found that dead larvae will often be completely consumed by other larvae within 24 hours (data not shown). Though dengue, like other arboviruses, does not remain infectious in the environment between hosts for more than several days, the rapid scavenging of carcasses ensures that larvae will come into contact with dengue when infected mosquitoes die within the larval habitat (Miller et al 1978, Ture11 et al 1990). When infected larvae or adults die in the larval habitat, their carcasses are a potential source of infection to the larvae that consume them.…”

“…This experiment demonstrates for the first time that larval detritus is consumed rapidly within the larval habitat. In addition to potentially influencing the role of larval detritus on mosquito development, the rapid consumption of larval carcasses has epidemiological consequences since it could be a mechanism for the horizontal transmission of pathogens within the larval habitat (Miller et al 1978).…”