Phenology, life tables, and reproductive biology of Tetraleurodes perseae (Hemiptera: Aleyrodidae) on California avocados

Abstract

Tetraleurodes perseae Nakahara (Hemiptera: Aleyrodidae) is an exotic whitefly in California that is a minor pest of avocados, Persea americana Miller (Lauraceae). Field monitoring over a 4.5-yr period (1997-2002) 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 February-April each year ranged from 30 to 100%. Partial life tables constructed from cohorts of T. perseae in the field indicated that survivorship from settled first and second instars to emerged adult whiteflies ranged from 34 to 37%. There were no significant differences in marginal mortality rates by life stage for whitefly cohorts enclosed in sealed mesh bags, open mesh bags, or on unenclosed avocado leaves. Survivorship curves constructed from field 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 ≈43-46 d is needed by T. 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. © 2006 Entomological Society of America.