Influence of the host-plant on the development and reproduction of the whitefly Aleurodicus dispersus Russell in the Republic of the Congo.

摘要

A study of the behaviour of the whitefly Aleurodicus dispersus on different host plants was undertaken in the Republic of the Congo where this pest is not very well known. Experimental rearings were maintained at 26.7deg C and 74.9% relative humidity on 5- to 6-month-old seedlings of four different fruit trees (Citrus paradisi (grapefruits), Persea americana, Mangifera indica (mangoes), Dacryodes edulis) and a shade species (Hura crepitans). Data on development stages (egg to adult), mortality stages,and fecundity were daily determined under a binocular magnifying glass. Host plant type was shown to have a distinct influence on whitefly behaviour. According to the plant species, the preimaginal development stage lasted from 30.2 d to 38.3 d; the rate of mortality of immature stages (L1) varied from 40% to 82%; fecundity varied from 4.3 to 34.2 eggs laid/female. H. crepitans was the most suitable for pest development and C. paradisi was the least suitable. The adverse effects of the less suitable host plants were shown to limit the density of the A. dispersus population rather than to extend the time needed for development of the surviving individuals.