Mosquito Flight Paths in Relation to the Environment. 1. Illumination Levels, Orientation, and Resting Areas

Abstract

Suction traps were operated within and adjacent to a wooded swamp and in a field with various patterns of potted shrubs. Vehicle aspirator collections were made of mosquitoes in the daytime resting habitats. Aedes mitchellae (Dyar), A. sollicitans (Walker), Psorophora ciliata (F.), and P. confinnis (Lynch Arribalzaga) were field species, i.e., greatest numbers were taken, both day and night, in open grassy areas, and avoided woodland and the vicinity of shrubs. Many species preferred woodland for daytime resting but moved out nightly to forage in the field. At night this behavior resulted in a buildup of mosquitoes along the outside margin of the swamp or in a trap placed in a gap in a hedge row. The largest numbers of Culiseta melanura (Coquillett) and Culex nigripalpus Theobald remained in woodland throughout the diel. When these species were taken out in the field, the greatest numbers were found in the vicinity of shrubs. It is concluded that in the absence of other attractants or adverse meteorological conditions, physical objects guide mosquito flight paths in 3 ways: (1) by reducing the level of illumination, as beneath a forest canopy or adjacent to a forest edge; (2) by forming a visual image, to which each species responds according to its inherent behavior pattern; and (3) by serving as a physical barrier.