Abstract: The biological-control function of field boundaries of Guinea grass, Panicum maximum Jacq. on the spotted stem borer, Chilo partellus Swinhoe was examined as a reservoir for arthropod predators and as a trap plant for the pest. Field border vegetation and predator density were manipulated to determine the effect of the grass border on the abundance of stem borers and their predators in maize fields, and the effect of predators on the stem borer population. The strip of Guinea grass...
Abstract: The spider mite Tetranychus evansi Baker & Pritchard can cause severe damage to tomato crops. The predatory mite Phytoseiulus longipes Evans was recently reported in association with T. evansi in Uruguaiana, Rio Grande do Sul State, Brazil. The objective of the present study was to evaluate the effects of P . longipes on the population of T. evansi on tomatoes under screenhouse condition. The study consisted on four experiments, in each of which 80 potted plantlets were distributed...
Abstract: In Cameroon, the noctuid Busseola fusca is the most important pest of maize. The braconid Cotesia sesamiae, which is the most common larval parasitoid of noctuid stemborers in eastern Africa, was absent on B. fusca attacking maize. Thus, it is planned to introduce several strains of the parasitoid from Kenya. Pre-release surveys were undertaken in major maize growing areas to catalogue stemborer species, and larval and pupal parasitoids on maize and four wild host plant species. On...
Abstract: Field surveys were carried out in four agroecological zones to assess the geographic distribution, host range and perennation of Cotesia sesamiae and Cotesia flavipes in cultivated and natural habitats in Kenya.The distribution of the two Cotesia species in different ecological regions was most affected by the suitability of the local stem borer species for parasitoid development, and temperature, as both species were found in localities dominated by their suitable host(s) where te...
Abstract: Polydnaviruses are rarely studied for their natural variation in immune suppressive abilities. The polydnavirus harboring braconid Cotesia sesamiae, a widespread endoparasitoid of Busseola fusca and Sesamia calamistis in sub-Saharan Africa exists as two biotypes. In Kenya, the western biotype completes development in B. fusca larvae. However, eggs of the coastal C. sesamiae are encapsulated in this host and ultimately, no parasitoids emerge from parasitized B. fusca larvae. Both bi...
Abstract: We evaluated eight Napier grass [Pennisetum purpureum Schumach (Poaceae)] varieties, used in various parts of eastern Africa as fodder, for their potential role as trap plants in the management of the African stemborer, Busseola fusca Füller (Lepidoptera: Noctuidae) through a push–pull strategy. Oviposition preference, larval orientation, settling, arrest and dispersal, feeding, mortality and survival, and development were determined for each of these varieties under laboratory ...
Abstract: The effects of biotic and abiotic factors on stem borer parasitoid diversity, abundance,and parasitism were studied in cultivated and natural habitats in four agroecological zones in Kenya.Comparing habitat types, we found partial support for the “natural enemy”hypothesis, whereby, across all localities, parasitoid diversity was higher in more diverse host plant communities in natural habitats, whereas parasitoid abundance was higher in cultivated habitats. For both habitats, p...
Abstract: The mite Tetranychus evansi Baker & Pritchard (Tetranychidae) probably originated in South America. Because of its importance as a tomato pest in Africa, an extensive project has been conducted to detect potentially effective natural enemies in South America for the classical biological control of the pest in Africa. A search for the natural enemies of T. evansi was conducted in the Province of Tucuma´n, northwestern Argentina, in December 2004, and this report describes the resul...
Abstract: The mealybug Phenacoccus solenopsis Tinsley (Sternorrhyncha: Pseudococcidae) is a highly polyphagous pest of fruits, vegetables, crops and ornamentals in Pakistan. Biological control approach by using Aenasius bambawalei Hayat (Hymenoptera: Encyrtidae) has been developed recently to control this pest. However, the efficiency of this parasitoid is variable according to the locality and the plants on which P. solenopsis is feeding. In this context, this experiment investigated under ...
Abstract: The inoculation methods, the fungal strains, and several other factors are known to influent the success of fungal entomopathogens colonization in plants. The physiological status of the plant could also be another determinant. In the present study, the ability of three strains of Beauveria bassiana and one strain of Metarhizium anisopliae to successfully colonize Citrus limon plants and the influence of seedling age on endophytic colonization success was examined. Three, 4, and 6 ...
Abstract: Campylobacter species have developed resistance to existing antibiotics. The development of alternative therapies is, therefore, a necessity. This study evaluates the susceptibility of Campylobacter strains to selected natural products (NPs) and frontline antibiotics. Two C. jejuni strains (ATCC® 33560TM and MT947450) and two C. coli strains (ATCC® 33559TM and MT947451) were used. The antimicrobial potential of the NPs, including plant extracts, essential oils, and pure phytochem...
Abstract: Utilization of Ruspolia differens Serville as functional food ingredient is rapidly gaining popularity. This study evaluated the nutrient quality, microbial safety and consumers’ acceptability of cereal-based cookies fortified with various processed products of R. differens meals. Cookies fortified with blanched, boiled, and toasted R. differens meals had higher protein, fat and energy levels, respectively, than the control cookies. Enrichment of cookies with differentially proce...
Abstract: Despite the discovery of the tubercle bacillus more than 130 years ago, its physiology and the mechanisms of virulence are still not fully understood. A comprehensive analysis of the proteomes of members of the human-adapted Mycobacterium tuberculosis complex (MTBC) lineages 3, 4, 5, and 7 was conducted to better understand the evolution of virulence and other physiological characteristics. Unique and shared proteomic signatures in these modern, pre-modern and ancient MTBC lineages...
Abstract: Microorganisms and their natural products are potentially important for the biological control of crop diseases without detrimental effects to the environment. In this study, acetonitrile-methanol extracts of 361 actinobacterial isolates obtained from Aberdares, Arabuko Sokoke, Lake Bogoria, Mt Kenya,Kakamega, Ruma, Shimba Hills and Imenti forest national parks in Kenya were screened for antagonism against Fusarium oxysporum, Fusarium spp and Colletotrichum kahawae, which are impor...
Abstract: Millions of smallholder farmers in low-income countries are highly vulnerable to food-supply shocks, and reducing this vulnerability remains challenging in view of climatic changes. Restrictions to limit the spread of the COVID-19 pandemic produced a severe supply-side shock in rural areas of Sub-Saharan Africa, including through frictions in agricultural markets. We use a large-scale field experiment to examine the effects of improved on farm storage on household food security dur...