Influence of the plant species or variety on the olfactory preferences in Epidinocarsis lopezi (Hym.: Encyrtidae), parasitoid of the cassava mealybug, Phenacoccus manihoti (Hem.: Pseudococcidae)

Epidinocarsis lopezi (Hym.: Encyrtidae) is the principal agent of biologica l control against the cassava mealybug Phenacoccus manihoti (Hem. : Pseudoc occidae) in Africa. The influence of the plant species or variety on the ol factory preferences in Epidinocarsis lopezi was studied in a Y-tube olfacto meter. Dual-choice tests demonstrated that E. lopezi females distinguished between plant species and varieties at the uninfested and the infested stat e. They preferred the cassava variety MM79 to the hybrid Faux-caoutchouc or Talinum. The females of E. lopezi discriminated also between the three pop ulations of P. manihoti reared distinctly on the three plants and preferred that fed on MM79 than on Talinum.