Occurrence and phylogenetic characterization of a baculovirus isolated from Culex quinquefasciatus in São Paulo State, Brazil.

The aim of this study was to assess the occurrence of baculovirus infections in mosquitoes and characterize them by using molecular tools. Fortnightly collections were made of mosquito larvae in the city of Caraguatatuba. Six larvae of Culex quinquefasciatus were isolated that had white cysts (nodules) in epithelia cells of the posterior midgut, indicative of infection by a baculovirus. These larvae were subjected to DNA extraction. DNA was amplified, producing a fragment of around 600 nt of the lef-8 gene and 400 nt of Pif-2 gene. The sequences were aligned, using ClustalX 2.0, with partial sequences of lef-8 genes of baculoviruses isolated from members of other insect orders taken from the GenBank database and edited, and phylogenetic analysis was performed. Phylogenetic analysis performed with the lef-8 and pif-2 genes demonstrated that the baculovirus identified in Culex quinquefasciatus in the Caraguatatuba region is most closely related to the deltabaculovirus Culex nigripalpus nucleopolyhedrovirus.

Evaluation of the impact of Bacillus thuringiensis serovar israelensis and Temephos, used for the control of Simulium (Chirostilbia) pertinax Kollar, 1832 (Diptera, Simuliidae) on the associated entomofauna, Paraty, state of Rio de Janeiro, Brazil.

The study was set up to evaluate the impact of two commercial larvicide formulations, Bacillus thuringiensis serovar israelensis base (Bti) at 15 ppm/1 min and temephos at 0.03 ppm of active ingredient, used to control Simulium pertinax populations, on associated non-target entomofauna occupying the same breeding sites. The experiments were carried out on the Pedra Branca and Muricana rivers, on the slopes of Serra do Mar massif, municipality of Paraty, state of Rio de Janeiro, Brazil. Bti was applied to the river Pedra Branca and temephosto theriver Muricana. On both rivers, treatment and control sections were labeled as such, each one with two observation posts: slow moving water and fast water regions respectively. Artificial substrata was used to evaluate the abundance of associated entomofauna. Attached immature stages of arthropods were removed from both of its surfaces fortnightly. Were collected, from the two rivers, 28 477 specimens of the entomofauna associated with S. pertinax. The families Hydropsychidae, Chironomidae, Bactidae, Simuliidae, Blephariceridae and Megapodagrionidae were represented. These was an impact of temephos on the entomofauna associated with S. pertinax only in Simuliidae and Chironomidae, and to Bti only in Simuliidae. However, the reduction in their numbers was not statistically significant.