Discovery and description of a novel mode of oviposition in the mosquito genus Culex.

Abstract

Despite the wide variation in mosquito reproductive strategies and the present lack of behavioral and ecological information for the majority of described mosquito species, the predominant egg-laying behaviors observed in well-studied species have led to sweeping generalizations of oviposition patterns across entire mosquito genera. Mosquitoes in the genus Culex, which contains over 800 species across 28 subgenera, are commonly believed to exclusively lay egg masses ("rafts") that float on the water surface. This oversimplification persists, though we currently know little regarding the reproduction of many Culex species and subgenera. Using field observations, photography, and video recordings, we document the oviposition behavior of a Culex subgenus Micraedes species, Culex antillummagnorum (Dyar), and provide the first evidence, to our knowledge, of a Culex species aerially and skip-ovipositing, rather than laying masses of coniform eggs. Gravid Cx. antillummagnorum females were observed and filmed in the Luquillo Experimental Forest of Puerto Rico for several nights as they performed an elliptic flight pattern while launching single eggs into water-filled bracts of Heliconia caribaea. These findings raise questions regarding the evolution and drivers of such an atypical Culex behavior and indicate that our understanding of Culex ecology and behavior remains incomplete.