Agricultural and Forest Entomology (2004) 6, 311-322

Michael J. Furlong, Zu-hua Shi, Shu-Sheng Liu and Myron P. Zalucki (2004)
Evaluation of the impact of natural enemies on Plutella xylostella L. (Lepidoptera: Yponomeutidae) populations on commercial Brassica farms
Agricultural and Forest Entomology 6 (4), 311-322
Abstract: 1 Accurate assessment of the impact of natural enemies on pest populations is fundamental to the design of robust integrated pest management programmes. In most situations, diseases, predators and parasitoids act contemporaneously on insect pest populations and the impact of individual natural enemies, or specific groups of natural enemies, is difficult to interpret. These problems are exacerbated in agro-ecosystems that are frequently disrupted by the application of insecticides.
2 A combination of life-table and natural enemy exclusion techniques was utilized to develop a method for the assessment of the impact of endemic natural enemies on Plutella xylostella populations on commercial Brassica farms.
3 At two of the experimental sites, natural enemies had no impact on P. xylostella survival, at two other sites, natural enemy impact was low but, at a fifth site, natural enemies drastically reduced the P. xylostella population.
4 The calculation of marginal death rates and associated k-values allowed the comparison of mortality factors between experimental sites, and indicated that larval disappearance was consistently the most important mortality factor, followed by egg disappearance, larval parasitism and pupal parasitism. The appropriateness of the methods and assumptions made to calculate the marginal death rates are discussed.
5 The technique represents a robust and easily repeatable method for the analysis of the activity of natural enemies of P. xylostella, which could be adapted for the study of other phytophagous pests.
(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): Michael J. Furlong, Myron P. Zalucki, Shu-Sheng Liu, Zu-Hua Shi

Research topic(s) for pests/diseases/weeds:
biocontrol - natural enemies
Research topic(s) for beneficials or antagonists:
surveys/distribution/isolation
general biology - morphology - evolution

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Plutella xylostella	Cabbage (Brassica oleracea)