International Journal of Acarology (2000) 26, 203-214

Mark S. Hoddle, Lindsay Robinson and Judy Virzi (2000)
Biological control of Oligonychus perseae (Acari: Tetranychidae) on avocado: III. Evaluating the efficacy of varying release rates and release frequency of Neoseiulus californicus (Acari: Phytoseiidae)
International Journal of Acarology 26 (3), 203-214
Abstract: Three different release rates and timings of the phytoseiid Neoseiulus californicus (McGregor) were evaluated for Oligonychus perseae Tuttle, Baker, and Abbatiello control on avocado trees in a commercial orchard in southern California, USA. Densities of natural enemies and O. perseae were monitored on trees for 34 weeks that were treated with either one, two, or three releases of 500, 1000, or 2000 N. californicus, or two applications of 5% narrow range (NR) 415 petroleum oil. Predator releases were made when 50% (release one), 75% (release two), or 95% (release three) of sampled leaves were infested with one or more motile O. perseae. Densities of O. perseae on trees treated with N. californicus or petroleum oil were compared to control trees that received no treatments for O. perseae suppression. Release of a minimum of 2000 N. californicus per tree was necessary to significantly reduce O. perseae densities in comparison to control trees. Releasing 1000 N. californicus twice or 2000 N. californicus once provided O. perseae control similar to petroleum oil treatments and to trees treated with cumulative releases totaling more than 2000 predators per tree. This result indicated that releases totaling more than 2000 N. californicus per tree did not substantially improve O. perseae control and the cumulative number of predators released per tree is more important than the number of times N. californicus is released for controlling O. perseae.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Link to article at publishers website
Database assignments for author(s): Mark S. Hoddle

Research topic(s) for pests/diseases/weeds:
biocontrol - natural enemies
control - general
Research topic(s) for beneficials or antagonists:
inundative/inoculative release
application technology

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Oligonychus perseae	Avocado (Persea americana)	U.S.A. (SW)
Neoseiulus californicus (predator)	Oligonychus perseae	Avocado (Persea americana)	U.S.A. (SW)