Studies of pigeonpea insect pests and their management in Kenya, Malawi, Tanzania and Uganda

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 Stal), 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

Insect pest incidence in seed pods of pigeonpea genotypes in on-farm trials in southern Malawi

In 1999, pod pest surveys were conducted within the Blantyre Shire Highlands Rural Development Project (RDP) Area, at on-farm trial sites in Nansadi and Mangunda sections of Matapwata Extension Planning Area (EPA) and Lirangwe section of Chiradzulu North (Mombezi) EPA. This article reports results of the surveys in Mangunda section. At crop maturity, pigeon pea (Cajanus cajan) pods as well as pods from Crotalaria ochroleuca, Tephrosia vogelii, Dolichos and other plant hosts were collected and examined for infestation. The results from medium duration genotypes indicated that pod-sucking bugs are a major problem for all genotypes. There were some indications that Chilinga and ICEAP 00073 showed less damage to borers compared to ICEAP 00068 and ICP 6927. Results from long duration genotypes showed that pod-sucking bugs are also a major constraint later in the season. ICP 9145 showed less pest damage in intercrops compared to sole crops, but the differences were not significant. With respect to overall damage and damage by pod-sucking bugs, the ICEAP genotypes performed slightly worse than ICP 9145. The odds of damage were significantly different between the locations, with higher values for the humid and cool sites (Matapwata) compared to the warm and semi-humid sites (Mombezi). The pests were identified as the noctuid Pardasena virgulana that was occasionally parasitized by Cotesia sp. and the tortricid Leguminivora ptychora. L. ptychora and Etiella zinckenella were also collected from Tephrosia pods. Within pods of both pigeon pea and Crotalaria a large chalcidoid wasp (Eurytoma sp.) was abundant. Parasitism of Lampides boeticus by Neotypus intermedius (Ichneumonidae) was high, particularly on Crotalaria. Maruca vitrata parasitization by Braunsia sp. (Braconidae) was also greater on Crotalaria than on pigeon pea

Screening wild Arachis for resistance to groundnut plant hopper Hilda patruelis in Malawi

Plants of Arachis villosulicarpa, A. erecta, A. arasterio, A. monticola and two unidentified Arachis species were grown in single rows with 7 A. hypogaea cultivars as checks during 1999. Seed germination was poor particularly for A. arasterio where only 1 seed per row germinated and survived to harvest. These preliminary observations indicated that Hilda infested all test genotypes. In an off-season crop planted in June 2000, seed germination was >95% and there was no termite or rosette incidence. Hilda infestation was noted on all plants at the late podding stage. All (100%) of A. arasterio plants were green and healthy at the time of the assessment as were the other wild species (86-95%)

Pigeonpea Seed Damage from Insect Pests on Farmers' Fields in Kenya, Malawi, Tanzania, and Uganda

In on-farm field studies in in 1995 in Kenya, Malawi, Tanzania and Uganda, Helicoverpa armigera, Maruca testulalis [M. vitrata], Clavigralla sp. and Melanagromyza chalcosoma were identified as the major pests of pigeon peas. M. vitrata was not found in Malawi

Studies of pigeonpea insect pests and their management in farmers' fields in Kenya, Malawi, Tanzania, and Uganda

(African Crop Science Journal 1999 7(1): 59-70