Behavioral Ecology Symposium--'85: Bromeliads as Ovipositional Sites for Wyeomyia Mosquitoes: Form and Color Influence Behavior

Abstract

Bromeliad models in cages containing adult Wyeomyia vanduzeei or W. mitchellii (Diptera: Culicidae) allowed quantification of ovipositional response to paired contrasts of form, color, or contained fluid of the models. In 13 of 15 contrasts, mosquitoes of both species showed the same direction of preference, but in each of these 13 contrasts W. mitchellii showed an equal or stronger response. If strength of response indicates degree of specialization, then W. mitchellii is visually more a bromeliad-specialist. In 2 contrasts, W. vanduzeei showed a greater preference for lighter, less saturated yellowish green (and for green), and W. mitchellii showed a greater preference for a darker, more saturated yellowish green (and for yellow). These preferences may be related to level of shade of the habitat occupied by each species. Model bromeliads showing distinct leaflike form were greatly preferred by both species to models lacking such form, and visual perception of fluid in the cup of the model greatly increased its acceptability as an oviposition site. A simulated bromeliad flower spike increased ovipositional response to the model, which was unexpected because previous work had shown reduced oviposition in real bromeliads with flower spikes. It remains unclear if or how the mosquitoes responded to the chemical odor of leaves of the bromeliad Tillandsia utriculata.