Tropical and subtropical agroecosystems
On-line version ISSN 1870-0462
OCHILO, Willis N. and NYAMASYO, Gideon H. Pest status of bean stem maggot (Ophiomyia spp.) and black bean aphid (Aphis fabae) in Taita District, Kenya. Trop. subtrop. agroecosyt [online]. 2011, vol.13, n.1, pp. 91-97. ISSN 1870-0462.
On-station and on-farm studies were carried out in Taita district, Kenya, to assess the effect of various soil fertility regimens on bean stem maggot (BSM) (Ophiomyia spp.) and black bean aphid (BBA) (Aphis fabae) incidence. These studies aimed at gathering information useful in the development of an IPM programme for the project on conservation and sustainable management of below-ground biodiversity (CSM-BGBD). Field survey of bean stem maggot and black bean aphid was conducted in both the on-station and on-farm plots four weeks after bean emergence. From each plot forty bean plants were sampled. The parameter assessed included stems, leaves and flowers and the percent numbers of plants having bean stem maggot and black bean aphid were expressed as the percentage incidence for that particular plot. The incidence of bean stem maggot and black bean aphid were significantly higher in the on-farm plots than in the on-station plots. On the other hand, influences of integrated soil fertility management (ISFM) interventions and location on bean stem maggot and black bean aphid incidence were minimal. These findings point to the fact that, soil fertility management interventions alone are not effective in mitigating the challenge of insect pest. Instead, there is a strong need to adopt a holistic management approach that incorporates both pest management (IPM) and soil fertility management (ISFM).
Keywords : Black bean aphid (Aphis fabae); Bean stem maggot (Ophiomyia spp); Soil fertility management practices.