Main Article Content
Variation in biological parameters of cypermethrin resistant and susceptible strains of Helicoverpa armigera from Benin Republic, West Africa
Abstract
The aim of this survey was to assess the costs of cypermethrin resistance in Helicoverpa armigera strains by using variation in their biological parameters such as fecundity, number of larval slough, development time, weight and survival at each stage of insect development in comparison with susceptible strains. AGB01 and AGB03 are the resistant strains compared respectively with BK77 and OKP01 as susceptible strains. Fecundity, fertility and survival from egg to adult emergence of AGB03 strain were significantly (P < 0.001) lower than those observed in OKP01 strain. No difference (P > 0.05) was observed with time of pre-adult development, survival at each stage of insect development, fecundity and number of larval slough in comparison with AGB01 and BK77 strains. Larvae of AGB01 strain took significantly (P < 0.01) longer time to develop and were significantly (P < 0.01) lighter than BK77 at the same age, but the slower development of larvae of AGB01 strain was counteracted by the shorter times of egg and pupae stages. The lower fecundity, fertility and survival from egg to adult emergence should represent the main costs for the AGB03 strain resistant to cypermethrin.
Keywords: Cypermethrin resistance, resistance cost, fecundity, fertility, development time