ECOLOGY AND POPULATION BIOLOGY Phenology, Life Tables, and Reproductive Biology of Tetraleurodes perseae (Hemiptera: Aleyrodidae) on California Avocados

Tetraleurodes perseae Nakahara (Hemiptera: Aleyrodidae) is an exotic whiteßy in California that is aminorpest of avocados,Persea americanaMiller (Lauraceae). Fieldmonitoringover a 4.5-yr period (1997Ð2002) in a commercial avocado orchard in southern California indicated that T. perseae is probably univoltine, and adult densities show single distinct peaks each year around August. The only hymenopteran parasitoid found attacking T. perseae in California was an aphelinid, Cales noacki Howard, and parasitism over FebruaryÐApril each year ranged from 30 to 100%. Partial life tables constructed from cohorts of T. perseae in the Þeld indicated that survivorship from settled Þrst and second instars to emerged adult whiteßies ranged from 34 to 37%. There were no signiÞcant differences in marginal mortality rates by life stage for whiteßy cohorts enclosed in sealed mesh bags, open mesh bags, or on unenclosed avocado leaves. Survivorship curves constructed from Þeld phenology data indicated that average egg-to-adult survivorship was around 3.5%, which is substantially lower than that suggested from the life table analyses. Laboratory studies conducted at 25 C on excised avocado leaves indicated that 43Ð46 d is neededbyT. perseae to complete development from egg to adult. Demographic analyses of laboratory data indicate that T. perseae has a high reproductive potential with net reproductive rate and intrinsic rate of increase estimates being 21.15 1.39 and 0.07 0.001, respectively.