Sunday, December 9, 2001 - 10:00 AM
0033

Overwintering and comparative sampling of Neoseiulus fallacis on ornamental nursery plants

Paul D. Pratt, USDA/ARS, Invasive Plant Research Laboratory, 3205 College Ave, Fort Lauderdale, FL and Brian A. Croft, Oregon State University, Department of Entomology, 2046 Cordley Hall, Corvallis, OR.

The predatory mite Neoseiulus fallacis (Garman) is an important biological control agent of spider mites in many agroecosystems, including ornamental nurseries. In this study, sampling methods, tendencies to overwinter among a range of plant types and the effect of winter protective practices were assessed for N. fallacis females. Ten spider mite-infested plant species representing a range of 5 plant types (conifer, shade tree, evergreen shrub, deciduous shrub, herbaceous perennial) were inoculated with 100 adult female N. fallacis in late autumn. Early the following spring, N. fallacis was extracted from each plant species by either washing plant parts (leaves, branches, trunks-crowns) in 70% ethanol and filtering contents or placing plant parts into separate Berlese funnels for 5 d. The washing method extracted more N. fallacis than the funnel method. When comparing overwintering among a range of plant types, higher densities of N. fallacis were extracted from conifers> evergreen shrubs> herbaceous perennials=deciduous shrubs=shade trees. With respect to overwintering location of N. fallacis within plants, higher densities of N. fallacis were recovered on leaves than trunks-crowns; branches were intermediate. Densities of N. fallacis were positively correlated with those of their spider mite prey. Higher densities of N. fallacis were collected from plants that were held in a greenhouse versus those left unprotected or under a sheet of polyethylene plastic. Manipulating overwintering sites for the conservation of phytoseiid natural enemies is discussed.

Species 1: Acari Phytoseiidae Neoseiulus fallacis
Keywords: Diapause, Landscape

The ESA 2001 Annual Meeting - 2001: An Entomological Odyssey of ESA