Preliminary observations on a field population of the oil palm-pollinating weevil Elaeidobius kamerunicus in Benin City, Nigeria

Abstract

Anthesizing male inflorescences of oil palms were randomly sampled for the oil palm-pollinating weevil Elaeidobius kamerunicus at the Nigerian Institute for Oil Palm Research (NIFOR) (field 56) in Benin City, Nigeria from March to September 2002. The weevils were counted and later examined for nematodes. There were no significant differences in the mean number of adult weevils sampled from various positions on the inflorescences, but there were significant differences in their mean numbers sampled on the various dates ( P =0.001). Microscopic examination of adult weevils indicated that nematodes are associated with the weevils and the spikelets. This preliminary survey indicates that E. kamerunicus is a major insect pollinator of the oil palm in NIFOR oil palm plantations. Its association with parasitic nematodes may have a bearing on the weevil's pollination efficiency. These findings will help in understanding further the factors that govern pollination efficiency, percent fruit set and the occurrence of seasonal peaks in yields of fresh fruit from Nigerian oil palms.