CW-Department of Zoological Sciences

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    Ecological management of cereal stem borers in Ethiopia. Integrated Approaches to Higher Maize Productivity in the New Millennium.
    (2002) Kairu, E. W.; Degaga, E. G.; Overholt, W. A.
    Three lepidopterous stem borers were reported on maize in Ethiopia. Although complete crop loss is evident in some areas, the average yield loss of maize caused by cereal stem borers in Ethiopia can be estimated between 20 and 50%. A resource-poorfarmers produce over 87% of aize, inexpensive, ecologically sound and effective cereal stem borer control methods are indispensable. To this end, surveys and field experiments were conducted in 1999 and 2000. Surveys were conducted in major maize growingareas of eastern, western, southern and northern thiopia. In the surveys, four stel1 borers, 20 species of parasitoids, 14 species of predators and seven entomopathogens were investigated. These natural enemies gave about 18% re<1:uction of cereal stem borers. Of these natural enemies Cotesia flavipes Cameron (Hymenoptera raconidae) alone gave 13% reduction. Intercropping of maize with beans significantly (P
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    Effect of larval food plants and seasons on the quality of the African wild silkmoth, gonometa postica walker (lepidoptera: lasiocampidae) cocoons
    (Kenyatta University, 2009) Fening, K. O.; Kioko, E. N.; Raina, S. K.; Mueke, J. M.
    Wild silkmoth farming offers an economic incentive for forest-adjacent communities to fully participate in forest conservation initiatives. Gonometa postica Walker is known to produce high-quality silk. It is being utilised for commercial wild silk production by the forest-adjacent communities in Mwingi District in Kenya. The developmental time of G. postica larvae and cocoons quality were studied in the Imba and Mumoni woodlands of Mwingi during the long and short rainy seasons of 2006 and 2007. Acacia elatior Brenan, Acacia tortilis (Forssk.) and Acacia nilotica (L.) Del were used as larval host plants. Larvae were reared in semi-captivity by using net sleeves attached to the branches of the host plants. Also, cocoons from the wild population were sampled from the host plants to evaluate their quality. The weight and size of cocoons were used as the determinant of their quality. Larval developmental period and cocoons quality differed according to host plants, seasons and sites, for those reared in semi-captivity. However, cocoons quality from the wild habitat varied with seasons and sites but not with host plants. Larvae reared on A. elatior had the shortest developmental period and highest cocoons quality than those raised on A. tortilis and A. nilotica. Thus, A. elatior is recommended as the most suitable host plant for the semi-captive rearing of G. postica larvae. This will help augment the natural population of the silkmoth and to ensure the sustainable harvesting of the cocoons.
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    Effect of bacillus thuringiensis (bt)–cotton protein endotoxins (cryiac and cry2ab2) on below ground fauna diversity with reference to entomopathogenic nematodes
    (2010) Mbugi, J.P.; Njinju, S.M.; Waturu, C.N.
    This study was conducted with the aim of determining the impact of genetically modified (GM) cotton on the diversity of below ground fauna. The entomopathogenic nematode, Steinernema karii infectivity to the larvae of the wax moth was also used to determine the effect of Bacillus thuringensis-cotton protein endotoxin on below ground biodiversity. Soils from theconfined field trial area had a diverse fauna that included Hemiptera, Hymenoptera, Coleoptera, spiders, wireworms and chaffer grabs. Cotton containing Bt series, non Bt cotton and kenaf were grown in pots under confined conditions and uprooted at flowering stage. Soils from the rhizosphere (soils that adhered to the roots) were tested for the presence of Bt endotoxin using the Quick Stix Comb strip method and were found to be positive for the endotoxin even within non Bt treatments. Those soils werethen inoculated with S.karii and fifth instar larvae of the wax moth, Galleria mellonella in the laboratory. Cadavers of Galleria larvae were recovered from the soils over a period of 10 days and dissected to confirm the cause of mortality. Data was transformed using SQRX + 1, subjected to Analysis Of Variance (ANOVA) and means separated using LSD. Results from the study showed that there were no significant differences between treatments. Galleria larva mortality due to S. karii infections were 64%, 63%, 61% and 50% for HART89M, sterilized soil, Bt cotton and Isoline treatments respectively. A number of false positives were recorded during the experiment for the Bt toxin implying that further refinement of the Quick Stix comb strip technique is required.
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    Current State of Handling, Processing and Quality of Omena (Rastrionebola argentea) in Mfangano and Rusinga Islands, Kenya
    (2010-12) Jumbe, J; Kibas, P.; Kakongoro, D.; Tumwebaze, R.
    The livelihood of many Small Scale Fishers in Lake Victoria is based on the Omena Rastrionebola argentea fishery. The processing and trading in Omena in Kenya is dominated by women (80%) who derive their livelihood from the sale of the fish species. Their operations and practice in handling, processing and packaging of the fish is characterized by poor methods and low quality of the fish product due to current wide, traditional practice of drying the fish on the ground or on old fishing nets. This drying method results in fish products which are contaminated by microorganisms and debris. As a result Omena products on the market are of low quality, value and demand. The objective of this research was to determine the current status and practice in the handling, processing and quality of Omena in Suba District and appropriate technological interventions needed to improve the quality and add value to Omena products for a better sale price and to reduce post harvest losses especially during the rainy season. The second objective was to determine gender disparities among the small scale processors and the effects on fish quality and practice. Results indicate that there is no difference in the fish handling and processing practice among the genders. The quality of the Small Scale Fish processors’ fish products was low as fish samples tested were contaminated with debris and had a high bacterial load which included faecal coliforms. The experimental solar tent and rack dried fish samples were of high quality such as low bacterial count and free from faecal coliforms. Solar tent and rack drying technology if adopted by the Small Scale Fish processors can improve the Omena quality, raise the market value and increase income for poverty alleviation.
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    Nutritional Characteristics of Brachiaria ruziziensis (Germain & Evrard) Subjected t d) Subjected to Different Doses of Gamma Ra ent Doses of Gamma Rays
    (International Grassland Congress, 2021) Hoka, A. I.; Gicheru, M; Otieno, S.
    Appropriate methods of mutation induction are of high importance in pastures for increased genetic variability and improved forage performance. The objective of this research was to improve agronomic and nutritive performance of mutant lines through induced mutagenesis to seeds of a local landrace Brachiaria ruziziensis. The seeds were irradiated with 0, 10, 20, 30, and 40Gy doses of gamma radiation from Cobalt 60 (60Co). Treatments were; KE 0Gy, KE 10Gy, KE 20Gy, KE 30Gy, and KE 40Gy resulting into M1 seeds. The seeds were planted in the greenhouse in germination pots then transplanted to the field. Seeds of M6 plants (M7 seeds) were used to establish field experiment in a completely randomized block design, with three replications. Parameters measured included; tillering, leaf-stem ratio, dry matter, mineralogy, digestibility, and crude protein. Data collected was analyzed using Genstat version 18 software. Growth parameters that were affected by radiation included tillering and days to 50% flowering. Radiation increased neutral detergent fiber (NDF), acid detergent fiber (ADF), and crude protein (CP). NDF had high positive correlation with ADF, CP had high positive correlation with leaf length. Results from agronomic performance, nutrient profiles indicated that the mutant lines differed from their parents. The mutant lines could be selected, multiplied and used in feeding trials to determine reproductive performance of dairy cattle fed on the mutant lines. Future studies should focus on total mixed ration formulation using the mutant lines, designed feeding trials, fractionation of amino and fatty acids from the lines for incorporation in poor forages and national performance trials of mutant lines with an aim of forage variety release. Application of nuclear technology to other grasses would lead to increased biomass and improved nutrition for increased animal productivity leading to food and nutrition security