Major insect pests attacking okra; Abelmoscus esculentos (L) Moench, in Sebele

Abstract

Abelmoscus esculentus (L) Moench (Okra) is an important crop in many African countries, but its production is constrained by insect pests. Species that cause yield losses on the crop in Botswana have not been identified. This study identified major pests of okra found in surveys conducted during three seasons from 2006 to 2009 at the Botswana College of Agriculture farm, Sebele in Gaborone. Yield losses caused by pod damaging species were estimated on three cultivars: Clemson spineless, Asontem and Legon 6. The most important pests were Earias biplaga, Pachnoda rubrocincta, Mylabris sp., Dysdercus sp. and Aphis gossypii. Pod damage caused by P. rubrocincta was similar (P < 0.05) on the three cultivars and about 23% per plant. Earias biplaga caused 0.0, 2.0 and 16.7% damage on Legon 6, Asontem and Clemson spineless, respectively. Dysdercus sp. and Aphis gossypii damaged okra throughout the growing period. Dysdercus sp. was most abundant during late podding period of plants, 100 days after plant emergence, while A. gossypii was most abundant 78 days after plant emergence. Application of control measures against the pod damaging species and those that occur throughout the growth of the plants should be made before podding begins to prevent yield losses.