African Plant Protection (2006) 12, 111-115

M. Obopile (2006)
Economic threshold and injury levels for control of cowpea aphid, Aphis craccivora Linnaeus (Homoptera : Aphididae), on cowpea
African Plant Protection 12 (1), 111-115
Abstract: A two-year study was conducted to establish the economic injury level for cowpea aphid, Aphis craccivora, on cowpea, Vigna unguiculata, in Botswana during the 2000/01 and 2001/02 cropping seasons. Cowpea plants were exposed to natural infestation by aphids for durations of 0 (no exposure), 1, 2, 3, 4, 5 and 6 weeks and complete exposure (control). The corresponding treatments were 7, 6, 5, 4, 3, 2, 1 and 0 sprays with demeton-S-methyl. Allowing aphids to feed on cowpea plants beyond three weeks resulted in more than 50 % yield loss. The highest benefit-to-cost ratio was obtained at three-weeks of exposure when initiation of insecticide application was most economical. Determination of an economic injury level of cowpea aphid is considered a prerequisite for developing an integrated pest management programme to control the pest in Botswana.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Database assignments for author(s): Motshwari Obopile

Research topic(s) for pests/diseases/weeds:
damage/losses/economics
control - general

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Aphis craccivora	Cowpea and relatives (Vigna)	Botswana