ARS | Publication request: NOVEL BACULOVIRUSES: IMPLICATIONS FOR MOSQUITO VECTOR CONTROL

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: November 11, 2004
Publication Date: November 11, 2004
Citation: Shapiro, A.M., Becnel, J.J., White, S.E. 2004. Novel baculoviruses: implications for mosquito vector control. Meeting Abstract.

Technical Abstract: Baculoviruses that are pathogenic for insects have been intensively investigated due to their potential as biological control agents and because of their importance as gene expression vectors in invertebrate and vertebrate cells. Dipteran (mosquito) baculoviruses, unlike those from Lepidoptera, have been difficult if not impossible to transmit to the mosquito host and therefore basic biological studies have been greatly hindered. We have discovered a highly pathogenic, baculovirus (designated CuniNPV) that caused repeated and extended epizootics in field populations of the mosquitoes Culex nigripalpus and Culex quinquefasciatus. These mosquito species are important vectors of West Nile Virus, St. Louis and Eastern equine encephalitis in the United States. Our initial attempts to transmit CuniNPV to larval mosquitoes in the laboratory were unsuccessful. A salt mixture similar to that found in water supporting infection in the field was used in laboratory bioassays and indicated that certain salts were crucial to transmission. Further investigations revealed conclusively that transmission is mediated by divalent cations: magnesium is essential, whereas calcium inhibits transmission. CuniNPV infect and kills only Culex spp. mosquitoes. Recent studies with a baculovirus from Ochlerotatus sollicitans (OcsoNPV) have shown that transmission is also mediated by divalent cations. OcsoNPV infects only species of Aedes (including Ae. aegypti) and Ochlerotatus. Transmission of a third baculovirus isolated from Uranotaenia sapphirina (UrsaNPV) is also mediated by divalent cations. This common requirement for transmission of mosquito baculoviruses should enhance their use for vector control and assist with the isolation of new baculoviruses from mosquitoes, especially important Anopheles spp.