Geographical distribution and host range in Nigeria of the mango mealy bug, Rastrococcus invadens Williams, a serious exotic pest of horticulture and other crops.
Ivbijaro M. F., Udensis N., Ukwela U. M., Anno-Nyako F. V.
Author Affiliation: Department of Agricultural Biology, University of Ibadan, Ibadan, Nigeria.
Insect Science and its Application 13 : 411-416
Abstract : The geographical distribution and host range in Nigeria of Rastrococcus invadens, a serious exotic insect pest of mango and many other crops, are reported. The spread of R. invadens in Nigeria is at present limited to Lagos, Ogun and Oyo States of the humid south-west contiguous with the Republic of Benin, where the incidence of the pest has previously been reported. Infestation has not been observed in any of the 11 states of the north, nor in the Federal Capital Territory, all of which have lower rainfall and relative humidity. R. invadens is highly polyphagous on over 20 species of host plants belonging to 12 different plant families ranging from fruit crops, which constituted 42.8% of the crops attacked, to food crops (14.28%) and to shade trees and ornamentals (42.85%). The severity of attack, which was based on the number and area of foliage, inflorescence and fruits attacked by R. invadens alone or together with sooty mould, was highest in mangoes, Citrus, breadfruits, guavas and ornamentals including oleander [Nerium oleander], frangipani [Plumeria alba] and roses. Hosts with mild infestation include maize, pawpaws and Croton. The frequency with which infested plants were being felled, burnt or sprayed with synthetic chemicals suggested that the presence of R. invadens caused a degree of panic by growers.