FIELD-EVALUATION OF PHEROMONE-BAITED TRAPS FOR CONIESTA-IGNEFUSALIS (LEPIDOPTERA, PYRALIDAE) IN NIGER

Studies were conducted in Niger to compare pheromone-baited trapping s ystems for monitoring adults of the millet stem borer, Coniesta ignefu salis (Hampson), a pest of pearl millet, Pennisetum glaucum (L.) R. Br own. A water-oil trap was effective after optimization of various trap parameters. A trap tray of 32-cm diameter was more effective and easi er to handle than other sizes tested. Optimum trap shade size was 8-21 cm, positioned 25 cm above the tray. Motor oil, soap, or liquid deter gent were more effective than vegetable oil as surfactants. The experi mental trap caught significantly more male moths than four commercial traps. More moths were caught with large, thick polythene vial pheromo ne dispensers than small, thin vials, but the attractiveness of both d eclined significantly within 14 d. Trap catches were not greatly affec ted by the height of the crop or by the height of the trap above groun d level when the traps were placed individually at different sites. Ho wever, when traps were stacked at different heights at one site, more moths were caught in traps at heights of 0.10-0.50 m than at 1.30 and 2.0 m above ground level, regardless of crop height. This system is ap propriate for monitoring of pest populations by subsistence farmers an d national and international agricultural research stations in the Sah elian region of Africa.