Ecosystem services and drivers of change in Nyando floodplain wetland, Kenya

Papyrus wetlands in East Africa play a vital role in supporting livelihoods of people living around them. Although, subject to natural fluctuations and threats by anthropogenic activities, little is known about historical changes in wetland functions and services, or their present status. We focused on Nyando wetland on the eastern shores of Lake Victoria, Kenya. Three sites in the wetland were identified for assessment of history and current status. Changes during the past fifty years were assessed through participatory exercises with local communities and a review of published work. To establish the current status, we used field surveys and transect walks. Results showed that the wetland is important for hydrological and also ecological functions, which depend on the connectivity of the wetland with river and lake. The major direct drivers of change were hydrological regimes and livelihood activities. The main indirect driver of change was population growth, which leads to more pressure on wetland resources. Provisioning services are important in Nyando wetland but are generated at the expense of regulating services. Hydrology and livelihoods are strongly interlinked as flooding limits access to the wetland. Understanding the historical changes in wetland functions and services is important for rural communities, policy makers and for wetland managers in guiding, planning and wetland management.Key words: Papyrus wetland, wetland ecosystem services, drivers of change, community perception, Nyando wetland

Annual cycle of the legume pod borer Maruca vitrata Fabricius (Lepidoptera: Crambidae) in southwestern Burkina Faso

Maruca vitrata is an economically significant insect pest of cowpea in sub-Saharan Africa. Understanding the seasonal population patterns of M. vitrata is essential for the establishment of effective pest management strategies. M. vitrata larval populations on cultivated cowpea and adult flying activities were monitored in addition to scouting for host plants and parasitoids during 2 consecutive years in 2010 and 2011 in southwestern Burkina Faso. Our data suggest that M. vitrata populations overlapped on cultivated cowpea and alternate host plants during the rainy season. During the cowpea off-season, M. vitrata maintained a permanent population on the wild host plants Mucuna poggei and Daniella oliveri. The parasitoid fauna include three species, Phanerotoma leucobasis Kri., Braunsia kriegeri End. and Bracon sp. Implications of these finding for pest management strategies are discussed

An assessment of the risk of Bt-cowpea to non-target organisms in West Africa

Cowpea (Vigna unguiculata Walp.) is the most economically important legume crop in arid regions of sub-Saharan Africa. Cowpea is grown primarily by subsistence farmers who consume the leaves, pods and grain on farm or sell grain in local markets. Processed cowpea foods such as akara (a deep-fat fried fritter) are popular in the rapidly expanding urban areas. Demand far exceeds production due, in part, to a variety of insect pests including, in particular, the lepidopteran legume pod borer (LPB) Maruca vitrata. Genetically engineered Bt-cowpea, based on cry1Ab (Event 709) and cry2Ab transgenes, is being developed for use in sub-Saharan Africa to address losses from the LBP. Before environmental release of transgenic cowpeas, the Bt Cry proteins they express need to be assessed for potential effects on non-target organisms, particularly arthropods. Presented here is an assessment of the potential effects of those Cry proteins expressed in cowpea for control of LPB. Based on the history of safe use of Bt proteins, as well as the fauna associated with cultivated and wild cowpea in sub-Saharan Africa results indicate negligible effects on non-target organisms

Host plant resistance to insect pests of cowpea (Vigna unguiculata L. Walp.): achievements and future prospects

Published online: 06 Oct 2017Cowpea (Vigna unguiculata L. Walp.) is an important cash, food and nutritional security grain legume crop in the semi-arid regions of sub-Saharan Africa. However, its productivity is hampered by several biotic stress factors including numerous insect pests that infest and damage the crop at all its development stages in the field as well as during storage. Host plant resistance is an environmental friendly, cost-effective and sustainable pest management option for minimizing the pests’ incidence and severity. This review article aims at describing the major insect pests in cowpea and highlight key past and recent research findings in cowpea resistance to insect pests. It also provides in-depth knowledge in the host-plant resistance mechanisms in cowpea i.e. biophysical, biochemical and physiological factors that regulate the defense systems in the plant. Furthermore, the paper discusses the need for advanced investigation on the genetic basis of the plant defense systems and its application to the crop breeding program for developing new improved materials. The review would support the cowpea breeding program with the overall expectations of developing insect-resistant lines, reducing the input costs of insecticides while also enhancing cowpea productivity in sub-Saharan Africa