Studies Of Pigeonpea Insect Pests And Their Management In Kenya, Malawi, Tanzania And Uganda

African Crop Science Journal, Vol. 7 No. 1 1999 pp. 59-69 Studies Of Pigeonpea Insect Pests And Their Management In Kenya, Malawi, Tanzania And Uganda E.M. Minja, T.G. Shanower, J.M. Songa, J.M. Ong ' aro,W.T. Kawonga, P. J. Mviha, F.A. Myaka, S. Slumpa, H. Okurut-Akol and C. Opiyo Code Number: CS99006 ABSTRACT Systematic surveys were conducted in farmers ' fields in Kenya, Malawi, Tanzania, and Uganda to determine the incidence, distribution and damage levels due to insect pests of pigeonpea seeds. Three surveys were conducted in eastern Kenya, one in 1992 and two in 1995. Two surveys, one per country per year - were conducted in Malawi, Tanzania, and Uganda in 1995 and 1996. Key insect pests were pod sucking bugs (dominated by Clavigralla tomentosicollis Stål), pod and seed boring Lepidoptera (Helicoverpa armigera Hübner, Maruca vitrata (= testulalis) Geyer, Etiella zinkenella Treitschke), and pod fly (Melanagromyza chalcosoma Spencer). Seed damage due to insect pests were 22, 15, 14, and 16% in Kenya, Malawi, Tanzania, and Uganda, respectively. Damage levels indicated that pod sucking bugs were more damaging in Malawi (caused 69% of total seed damage) and Kenya (43%), while pod borers caused more damage in Tanzania (50%) and Uganda (54%). Pod fly caused more damage in Kenya than in the other countries. Pod borer damage was high in early maturing crops and pod fly in late maturing crops, while pod sucking bugs damage was high regardless of crop maturity period. Greater variations in seed damage were observed between locations in Kenya, Malawi, and Tanzania than in Uganda. Warm and dry locations had less seed damage than warm and humid, cool and dry, or cool and humid locations in Kenya, Malawi and Tanzania. None of the farmers visited in Malawi, Tanzania, and Uganda used conventional pesticides on pigeonpea in the field. Over 80% of these farmers used traditional methods in storage pest management. In contrast, 35 and 53% of farmers in Kenya had used conventional pesticides on long-duration pigeonpea genotypes in their fields. Key Words: Distribution, Lepidoptera, pod fly, pod sucking bugs RÉSUMÉ On a conduit une série d ' enquêtes en champs paysans au Kenya, au Malawi, en Tanzanie, et en Ouganda afin de déterminer l ' incidence et la répartition des ravageurs de pois d ' Angole ainsi que les taux de dégâts aux grains dus à ces ravageurs. Trois enquêtes ont été menées dans l'est du Kenya, une en 1992 et deux en 1995. Chacun des trois pays - Malawi, Tanzanie et Ouganda - ont fait l ' objet d'enquêtes une fois en 1995 et une autre fois en 1996. Les ravageurs importants ont compris des punaises suceuses de gousse (surtout Clavigralla tomentosicollis Stal), des foreurs des gousses et des grains (Helicoverpa armigera Hubner, Maruca vitrata (= testulalis) Geyer, Etiella zinkenella Treitschke), ainsi que des mouches des gousses (Melanagromyza chalcosoma Spencer). En milieu réel, les dégâts aux grains dus aux ravageurs ont été 22% au Kenya, 15% au Malawi, 14% en Tanzanie, et 16% en Ouganda. Les taux de dégâts ont indiqué que les punaises suceuses de gousse ont été les plus graves au Malawi (69% des dégâts totaux aux grains) et au Kenya (43%), tandis que les foreurs des gousses ont occasioné plus d Mots Clés: Distribution, Lepidoptera, foreurs de gousses, punaises suceuses Copyright 1999, African Crop Science Societ