Spatial summer–autumn distribution of the diamondback moth, Plutella xylostella (L.) and its parasitoids in cauliflower fields

Gholamhossein Hasanshahi | Habib Abbasipour | Alireza Askarianzadeh | Jaber Karimi | Fatemeh Jahan

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URL :   http://research.shahed.ac.ir/WSR/WebPages/Report/PaperView.aspx?PaperID=43029
Date :  2017/01/17
Publish in :    Zoology and Ecology
DOI :  https://doi.org/10.1080/21658005.2016.1261515
Link :  http://www.tandfonline.com/doi/pdf/10.1080/21658005.2016.1261515?needAccess=true
Keywords :Spatial, distribution, diamondback, Plutella, xylostella, cauliflower, fields

Abstract :

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Agricultural intensification and greater production of Brassica vegetable and oilseed crops over the past two decades have increased the pest status of the diamondback moth (DBM), Plutella xylostella L., and it is now estimated to cost the world economy US4–5 billion annually. Our understanding of some fundamental aspects of DBM biology and ecology, particularly host plant relationships, tritrophic interactions, and migration, has improved considerably but knowledge of other aspects, e.g. their spatial distribution and relative abundance, remains surprisingly limited. In this study, the summer–autumn spatial distribution of the diamondback moth, P. xylostella, and its parasitoids, including Diadegma anurum, Cotesia plutellae and Oomyzus sokolowskii in cauliflower fields south of Tehran were assessed from late May until October 2011. Each plant was presumed as a sampling unit and sampling was carried out every two weeks. The spatial distribution pattern of all life stages of diamondback moth and its parasitoids was determined using regression models (Taylors power law and Iwaos patchiness regression). Results showed that the spatial distribution pattern of all life stages of P. xylostella was aggregated. But based on both models, the spatial distribution pattern of parasitoids of P. xylostella was uniform; the slopes of regression for all life stages of the parasitoids were less than one.