Bionomics of the Bromeliad-Inhabiting Mosquito Wyeomyia Vanduzeei and its Nursery Plant Tillandsia Utriculata

Abstract

Aquatic stages of the mosquito Wyeomyia vanduzeei Dyar & Knab inhabit leaf axils of the epiphytic bromeliad Tillandsia utriculata L. in southern Florida. Rough-barked trees provide a substrate for T. utriculata and a habitat for W. vanduzeei. The volumetric capacity of T. utriculata leaf axils can be estimated from length of longest leaf (volumetric capacity in ml = 0.003251 x leaf length in cm^2^.^7^7^9^9). In each plant, older, larger axils provide most of the volumetric capacity, but the outermost axils lose their ability to retain water. Water entering bromeliad axils is throughfall, i.e. rainfall reduced in volume but enriched with nutrients as it penetrates the tree canopy (throughfall mm = -0.2715 + (0.8825 x rainfall mm) in a high marsh study area). Organic debris from the tree canopy (estimated annual mean 2.4 g/m^2/day in a high marsh study area), trapped and decomposed in the bromeliad axils, also provides nutrients for aquatic organisms and for the bromeliad. The perennial bromeliad provides a stable habitat for mosquito larvae. The number of mosquito eggs laid in axils is influenced by the size, water content, senescence and flower production of the bromeliad; as many are laid in the smaller, inner axils as in the larger, outer axils. At 27@*C, most floating eggs hatched within 48 and 96 h. Eggs stranded out of water suffered loss in numbers and in viability, with combined loss at 10 days of 49%, at 20 days of 77%, and at 30 days of 95%