Response of Males of Maruca vitrata Fabricius(Lepidoptera: Pyralidae) to Synthetic Lures in Mauritius

Abstract

Maruca vitrata Fabricius (Lepidoptera: Pyralidae) is a key pest of bean in Mauritius. Their larvae feed within flowers and pods and are thus well protected from insecticidal sprays. To achieve effective control, farmers spray their bean fields on a prophylactic basis. This has consequently led to undesirable problems that threaten safe bean production, sustainability, health and the environment. Action threshold based on pheromone-baited trap catches have been developed to rationalize insecticide use against M. vitrata in cowpea fields in Benin and Ghana. The study aimed at testing the attractiveness of four promising pheromone lures to males of M. vitrata in Mauritius. The lures were formulated by Natural Resources Institute (NRI) and consisted of a major component (EE 10,12-16:Ald) alone or in combination with one or both of two minor components (EE 10,12-16:OH and E 10-16:Ald). Two of these lures are reported to be effective in Africa (one in Benin and Ghana and the other in Burkina Faso). The four lures were tested in three types of traps in treated and untreated bean plots in Mauritius. Males of M. vitrata did not respond to any of the four NRI lures but were attracted to caged virgin females. This leads to postulate that the pheromone released by virgin females were not similar to any of the synthetic lures. Results tend to indicate that the M. vitrata in Mauritius can represent another geographically distinct population from those in Benin, Ghana and Burkina Faso.