Intra-population plasticity of Anopheles darlingi's (Diptera, Culicidae) biting activity patterns in the state of Amapá, Brazil

Abstract

OBJECTIVE: To assess the variation in Anopheles darlingi's biting activity compared to An. marajoara in the same locality and to biting activity data from other regions. METHODS: Using human bait, eight observations of the biting activity of An. darlingi and An. marajoara were carried out during 1999 and 2000 in the municipality of São Raimundo do Pirativa, state of Amapá, Brazil. Each observation consisted of three consecutive 13-hour collections, close to full moon. There were shifts of collectors in the observation points and nocturnal periods. RESULTS: An. darlingi revealed considerable plasticity of biting activity in contrast to An. marajoara, which showed well-defined crepuscular biting peaks. No significant correlation between density and biting activity was found, but a significant correlation existed between time and proportional crepuscular activity, indicating underlying ecological processes not yet understood. Two of the four available data sets having multiple observations at one locality showed considerable plasticity of this species' biting patterns as well. CONCLUSION: Intra-population variation of biting activity can be as significant as inter-population variation. Some implications in malaria vector control and specific studies are also discussed.

The importance of Anopheles albitarsis E and An. darlingi in human malaria transmission in Boa Vista, state of Roraima, Brazil

“…An. darlingi is known for its geographically variable patterns of biting activity (reviewed in Rosa-Freitas et al 1992, Voorham 2002, resulting from either environmental variables, genetic differentiation, or possibly both. Interestingly, An.…”

Anopheles darlingi bionomics and transmission of Plasmodium falciparum, Plasmodium vivax and Plasmodium malariae in Amerindian villages of the Upper-Maroni Amazonian forest, French Guiana

“…darlingi was the most represented anopheline species in human landing collections at night around the houses. All these results must be compared with caution because population density causes variations, and differences also exist in habitat typology, location and the period of collection (Elliott 1972, Roberts et al 1987, Voorham 2002. Variations in biting times will affect the efficiency of personal protection measures, and consequently, the biting rhythms must be documented in every situation in order to define efficient tools for vector control strategies.…”

Composition, abundance and aspects of temporal variation in the distribution of Anopheles species in an area of Eastern Amazonia

“…In addition, the number of malaria cases caused by Plasmodium falciparum has increased 5 . This increase is a cause for concern because the main malaria vector, Anopheles darlingi, is widely distributed in the state of Amapá 1,[6][7][8][9] and has been captured at high densities in some localities 1,4,10,11 . This framework justifi es further studies in this state to improve knowledge of the diversity and behavior of this species, thus facilitating monitoring and vector control efforts.…”