EFFECT OF DRY CONIDIA FORMULATIONS OF METARHIZIUM ANISOPLIAE ON SITOPHILUS ZEAMAIS (COLEOPTERA: CURCULIONIDAE) MORTALITY, PROGENY EMMERGENCE AND MAIZE GRAIN DAMAGE

Abstract

The efficacy of dry conidia formulation of Metharhizium anisopliae (PPRC-2) produced
on locally available grains was assessed against Sitophilus zeamais (Coleoptera: Curculionidae) in the
laboratory. Conidial suspension was inoculated into glass jars containing 200 grams of maize, rice,
wheat and sorghum grains sterilized and were incubated at 27°C and 70 ± 5% RH for 21days. Each
grain substrate was air-dried and grounded to powder using a sterile coffee grinder. The powdered
dry conidia were applied to the maize grain infested with S. zeamais. High mortality to the maize
weevil was recorded 7-days after the fungus grown on rice (91%) and maize (84%) substrates were
applied. The number of F1 progeny emerged was 0, 0.5 and 1, for primiphos methyl, rice and maize,
respectively. Percentage grain protection ranged from 41% to 83% for fungal treatments. The
number of grain damaged and percent grain weight loss were reduced in dry conidia treated maize
grain than in the control. Therefore, the use of M. anisopliae holds promising prospect in managing
S. zeamais.