This paper presents the results of out door catches of Culicidae mosquitoes performed in the Ribeira Valley, State of S. Paulo, Brazil, where an outbreak of encephalits occurred in 1976 and 1977. These entomological investigations were made using several techniques for collecting mosquitoes, including human bait. Several places were chosen considering the environmental aspects related to human activities. In regions where high agricultural activities predominate and the primary forest was reduced to remaining spots, large numbers of Aedes serratus, Aedes […]

OBJECTIVE: To evaluate the impact of wind velocity on the behavior of An. marajoara population and its parity. METHODS: Collections were made bimonthly from January 1999 to February 2000 in the municipality of Ilha Comprida, Brazil. Adult mosquitoes were captured with a battery hand aspirator. Mann-Whitney test was applied to verify the wind impact on mosquito behavior. Polovodova technique and Christophers and Mer’s follicular development analysis were used to determine parity. RESULTS: A total of 11,833 mosquitoes were captured, including […]

Results obtained through domiciliary catches of Culicidade mosquitoes in the “Vale do Ribeira” S. Paulo, Brazil are given on a study of the mechanisms of local encephalitis transmission. The same orientation for extra-domiciliary observation was followed. Significant presence of Aedes scapularis and Culex (Melanoconion) sp. in indoor catches suggested their participation in domiciliary transmission. This pattern was more evident in the rural areas than the urban ones. Association of these findings to the occurrence of clinical cases of the disease […]

The results of fortnightly 25-hour catches of Culicidae mosquitoes carried out at ground level with human bait in a residual forest area of the Ribeira Valley, S. Paulo, Brazil, are presented and discussed. Besides this, regular simultaneous catches with Shannon traps were made within and outside the forest environment. Daily biting cycles showed diurnal and nocturnal behaviour patterns which distinguished the nine most frequent species. Even through Ae. scapularis and Ae. serratus show a clear diurnal pattern they sustain moderate […]

First-generation progeny of field-collected Psorophora ferox, Aedes scapularis, and Aedes serratus from the Rocio encephalitis epidemic zone in S.Paulo State, Brazil, were tested for vector competency in the laboratory. Psorophora ferox and Ae. scapularis are susceptible to per os infection with Rocio virus and can transmit the virus by bite following a suitable incubation period. Oral ID50S for the two species (10(4.1) and 10(4.3) Vero cell plaque forming units, respectively) did not differ significantly. Infection rates in Ae. serratus never […]

Monthly 25-hour catches of Culicidae mosquitoes were carried out at ground level with human bait, in two primitive rain forests on plains in the Ribeira Valley, S.Paulo, Brazil. Regular simultaneous catches were made too, with Shannon traps, both within and outside wooded environments, which included quaternary and transitional forests on plains. Results obtained are presented and discussed. The An. cruzii dominance, though present, was not so remarkable as in the highland forest, previously reported on another work (1986). Nevertheless this […]

Results of blood-meal identification for mosquitoes collected in 5 different Ribeira Valley (S.Paulo State, Brazil) environments are presented. Precipitin tests identified the sources of 1444 blood-meals. Aedes mosquitoes fed chiefly on mammals. Ae. scapularis showed a preference for cattle and horses. Ae. serratus also obtained meals from avian hosts. Leaving aside the anthropophilic Cx.quinquefasciatus, the other Culex (Culex) mosquitoes showed feeding pattern directed to avian hosts. On the whole Culex (Melanoconion) showed a largely eclectic pattern including all the host […]

Results of mosquito collections in two Ribeira Valley localities are presented. These places represents environments highly modified by agrarian and cattle raising activities. The collections were made by the aspiration method, in the search for resting mosquitoes, in all the domiciliary and peridomiciliary compounds, in the early morning. The use of the diversity index and similarity quotient on communities such as these that are tropically related gives some insight into resources and their distribution. So they are considered of great […]

The biting activity of a population of Aedes scapularis (Rondani), Haemagogus capricornii Lutz and Hg. leucocelaenus (Dyar and Shannon) in Southern Brazil was studied between March 1980 and April 1983. Data were obtained with 25-hour human bait catches in three areas with patchy residual forests, named “Jacaré-Pepira”, “Lupo” Farm, and “Sta. Helena” Farm, in the highland region of S. Paulo State (Brazil). Data obtained on Ae. scapularis were compared with those formerly gathered in the “Ribeira” Valley lowlands, and were […]

New results on blood-meal identification and the environmental distribution of mosquitoes collected in four different Ribeira Valley (S. Paulo State, Brazil) environments, during the period February to November 1986, are presented. Sources of 651 blood-meals were identified. The preference of Ae. scapularis for large mammals, chiefly cattle, horse and even man, was confirmed. Data suggests that a similar behavioral pattern is presented by Cx. ribeirensis. Both mosquitoes seem to be strongly attracted by peridomiciliar blood sources represented by domestic animals […]