From early March 1981 to late May 1982, the aphid population trend on 2-year-old Raphia hookeri palm plantation in Nigerian Institute for Oil Palm Research Benin, was studied in relation to ambient weather conditions. The population, taken from the central ‘spear’ and leaflets of Raphia, where it is most abundant, was high from March to April 1981. This declined to a low level in July and August 1981 following a heavy rainfall. Another peak was observed in September, but this however declined gradually to a very low level at the end of March 1982. However, in mid-April, there was an incipient peak which was quickly lowered again in early May by larvae of the ladybird, Platynaspis sp. The number of adult alatae correlated positively with the total aphid population on spear and leaflets (r = 0.68). There was no direct relationship between the measured environmental factors and the aphid population fluctuation.
