The insect pest complex of the edible roselle, Hibiscus sabdariffa var. sabdariffa L. and the damage they cause in southwestern Nigeria

Abstract

A four-year survey of the insect pest complex of the edible roselle, Hibiscus sabdariffa var. sabdariffa, and the damage they cause in some parts of southwestern Nigeria showed that the vegetable has many potentially destructive pests. The major seedling and foliage pests are Podagrica sjostedti, Podagrica uniforma, Lagria villosa, Chrysolagria cuprina, Chrysolagria nairobana and Syagrus calcaratus. The major pests of the edible calyces and seeds are Baris sp, Apion sp and Earias spp. whose larvae feed inside and destroy the calyces and the developing seeds. Others are Oxycarenus gossypinus and Oxycarenus hyalinipennis which feed mainly on the seeds. The percentage damage by Baris and Apion to fruit s ranged from 10 to 210,10in fruits harvested in mid-December and from 48 to 84% ill late harvests in mid-January. the percentage germination of insect-infested and uninfested seeds were 10 and 83% respectively. The foliage pests were effectively controlled with two sprays of carbaryl at the rates of 0.5 and 1.0kg a.i./ha applied at intervals of two weeks. Fruit yield and seed viability were significantly higher in treated plots than in the control.