Submitted to: Journal of Invertebrate Pathology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: April 26, 2004
Publication Date: June 9, 2004
Citation: Shapiro, A.M., Becnel, J.J., White, S.E. 2004. A nucleopolyhedrovirus from uranotaenia sapphirina (diptera: culicidae). Journal of Invertebrate Pathology. 86:96-103. Interpretive Summary: In the United States, West Nile virus is transmitted by several species of mosquitoes. Naturally occurring pathogens that kill mosquitoes and are harmless to the environment are very promising biological control agents. Scientists at the Center for Medical, Agricultural and Veterinary Entomology, USDA, ARS, Gainesville, Florida have presented the data on biology, gross pathology, ultrastructure, transmission and host range of a naturally occurring virus that kills mosquitoes. This virus kills larval mosquitoes quickly and over extended periods of time. This fundamental knowledge contributes to our basic understanding of viral mosquito pathogens and will enable the evaluation and development of viruses as biopesticides for the control of mosquitoes that vector deadly diseases of man and animals.
Technical Abstract: Due to the rarity of mosquito NPV isolations from the field, the difficulty of transmission in the laboratory and the impossibility to maintain colonies of some species, few morphological and transmission studies of mosquito NPVs are available. In this report we present data on biology, gross pathology, ultrastructure, transmission and host range studies of a naturally occurring nucleopolyhedrovirus from the mosquito Uranotaenia sapphirina (UrsaNPV). Development of this virus was restricted to nuclei of epithelial cells in posterior midgut and distal gastric caecae. Occlusion bodies contained numerous single-nucleocapsid rod-shaped virions. Early occlusion bodies were irregularly shaped and seemed to subsequently coalesce to form larger polyhedra. Mature occlusion bodies had a unique dumbbell shape, and lacked the polyhedron envelope and crystalline structure. Developmental and structural features of UrsaNPV were generally similar to other mosquito NPVs, with major differences in occlusion body shape and size. Transmission tests showed that only members of Uranotaenia (Ur. sapphirina and Ur. lowii) were susceptible to this virus. Transmission was facilitated by magnesium. Field collected Ur. sapphirina larvae had a relatively high rate of dual infections with UrsaNPV and UrsaCPV (cytoplasmic polyhedrosis virus).