Palm bract breeding sites and their exploitation by Toxorhynchites (Lynchiella) haemorrhoidalis haemorrhoidalis (Diptera: Culicidae) in an upland forest of the central Amazon.

Abstract

Considering the potential importance of Toxorhynchites (Lynchiella) haemorrhoidalis haemorrhoidalis (F.) as a biological control agent of other mosquitoes, this species was studied in an upland forest of the Central Amazon. Palm bracts, the natural breeding sites, were sampled monthly in two different study areas for a period of 1 yr to detect the presence of immature stages and to determine their capacity to recolonize new or empty bracts. The ability of these breeding sites (bracts) to retain water was greater on a plateau where there is less humidity than in a valley. The availability of breeding sites may be related to the number of existing palms and the low precipitation. Tx. h. haemorrhoidalis is multivoltine, and the greatest abundance of larvae occurred in natural breeding sites in the valley. The population fluctuations of the larvae of this species may be influenced by the availability of natural breeding sites and by low precipitation which occurs during the dry season.