Abstract: A survey was undertaken to study the distribution and nature of infestation of L. viridissima and O. monoceros in 4 oil palm plantations in Cross River State, Nigeria. The results showed that while O. monoceros was fairly prevalent across the 3 Agro-ecological zones of the state, L. viridissima was low in numbers except at Ibiae and Boki plantations where outbreaks was recorded. The mean number of O. monoceros was 13.8 per block in Ibiae, 16.4 in Boki, 13.4 in Calaro and 15.8 in Nsadop oil palm plantations respectively showing no significant differences (p>0.05) among the plantations. However, there were significant differences (p< 0.05) in the mean number of L. viridissima with 18 per block in Ibiae, 10.8 in Boki, 6 in Calaro and 5.2 in Nsadop. Studies on the growth stages of L. viridissima under laboratory conditions showed that, the entire developmental period from egg to adult was between 86-123 days (mean 98 days).