Response of the Predatory Mite Phytoseiulus Macropilis (Acari: Phytoseiidae) to Pesticides and Kairomones of Three Spider Mite Species (Acari: Tetranychidae), And Non-Prey Food (Report‪)‬

The economic losses caused by phytophagous mites (Acari: Tetranychidae) in various agricultural crops in most areas of the world is well documented (Huffaker et al. 1970). The genera Tetranychus, Oligonychus, Eotetranychus and Panonychus are some of the world's most important pests of agricultural crops (Jeppson et al. 1975). Tetranychid mites, including the two-spotted spider mite Tetranychus urticae Koch, the southern red spider mite Oligonychus ilicis (McGreger), and the spruce spider mite O. ununguis (Jacobi), are important pests of ornamental nursery crops in the southern United States, with T. urticae being the predominant pest species. Nursery and landscape plants have an "aesthetic" economic threshold with low tolerance for pest damage. Therefore, nurseries frequently use pesticides to combat pest outbreaks (Mizell & Schiffhauer 1991). Nursery production requires intensive labor and high volumes of water, both subject to high risk of pesticide exposure. Rapidly increasing pesticide costs, social clamor against hazardous effects of chemicals, legal regulations regarding worker safety, and the risk of pesticide resistance development among pest species indicate a need to develop alternate integrated pest management strategies that reduce or eliminate pesticide use and its side effects in nurseries. Integration of natural enemies with selective pesticides could be a viable strategy for some pest situations in nurseries. Although natural enemies of phytophagous mites have been reported from several acarine families (Lord 1949; Knavel & Salheime 1967), the majority of the well known predatory mites belong to the family Phytoseiidae. Phytoseiids as biological control agents of phytophagous mites are effective in many agricultural systems (Flaherty & Huffaker 1970; Pickett & Gilstrap 1986; Hamlen & Lindquist 1981; Mizell & Schiffhauer 1991). Phytoseiids locate their prey through chemical cues known as "herbivore induced plant volatiles" (van Wijk et al. 2008) emitted from host plants as a result of spider mite feeding activity (Dicke et al. 1990; Takabayashi & Dicke 1992; Takabayashi et al. 1994; van Wijk et al. 2008). The perception of kairomones increases the probability of prey finding by phytoseiids (Hislop & Prokopy 1981; Dicke et al. 1990; Takabayashi et al. 1994; van Wijk et al. 2008). Rosen & Huffaker (1982) regard searching ability as the most important attribute of an effective predator. Some phytoseiids also feed on non-prey foods, such as pollen, honeydew, and plant juices (McMurtry 1982), which may help to sustain the predators through periods when prey are at low densities (Huffaker & Flaherty 1966).