Activity spectrum of spinosad and indoxacarb : rationale for an innovative pyrethroid resistance management strategy in West Africa

To face pyrethroid resistance in the cotton ballworm Helicoverpa armigera (Hübner), endosulfan (700 g/ha) has been used in a resistance management strategy for four years in Côte d'Ivoire, West Africa. Lately the recommendation is being questioned with regard to its acute mammalian toxicity and environmental issues. Earlier works revealed that insecticides such as spinosad (48 g/ ha) and indoxacarb (25 g/ha) proved as effective as endosulfan in controlling H. armigera. In contrast to endosulfan, the activity spectrum of these non-pyrethroids insecticides appears to be restricted to a few bollworm and leaf-feeding pests. The present study pointed out the strength and weakness of these new insecticides with respect to major insect pests and beneficial species. On the basis of their activity spectrum and in the light of cotton crop and main pest pheriology, new IRM was designed. Indoxacarb is more appropriate in the fruiting stage (101 - 115 DAE (Days After Emergence)) as it appeared very effective against the cotton stainer Dysdercus voëlkeri (Schmidt) while showing lower performance against Earias spp. and the mite Polyphagotarsonemus latus (Bank). In contrast, spinosad is preferred at the vegetative stage (45-66 DAE) as it proved safer to coccinellids, more effective against Earias spp., while its lower effectiveness against D. voëlkeri suggests avoiding its positioning at the later stages of cotton growth. Various benefits related to these new insecticides strongly advise their use as alternatives to pyrethroids. However, to be more attractive, their activity needs to be reinforced by other insecticides in such a way as to control the whole arthropod pest complex.

Bibliographic Details

Main Authors:	Ochou, Ochou G., Martin, Thibaud
Format:	conference_item biblioteca
Language:	eng
Published:	ARC-IIC
Subjects:	H10 - Ravageurs des plantes, Helicoverpa armigera, résistance aux pesticides, pyréthrine de syntèse, lutte antiravageur, insecticide, http://aims.fao.org/aos/agrovoc/c_30255, http://aims.fao.org/aos/agrovoc/c_25427, http://aims.fao.org/aos/agrovoc/c_7575, http://aims.fao.org/aos/agrovoc/c_5726, http://aims.fao.org/aos/agrovoc/c_3887, http://aims.fao.org/aos/agrovoc/c_4027,
Online Access:	http://agritrop.cirad.fr/520552/ http://agritrop.cirad.fr/520552/1/ID520552.pdf
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