Browsing by Author "Sundufu, Abu James"

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    Effect of Artificial and Corn Leaves Diets on Development, Survival and Reproduction of Spodoptera frugiperda (Lepidoptera: Noctuidae) in Sierra Leone
    (Scientific Research Publishing, 2023) Sundufu, Abu James
    The use of artificial diets to mass reared insect stock under laboratory conditions, promotes knowledge about the biology, behavior, and nutritional requirements of insects; with such information being fundamental for the formulation of efficient integrated pest management programs (IPM) strategies. However, the artificial diets used for rearing Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae) in the laboratory in this study, do not contain wheat germ, used for routine laboratory rearing. The aim of this study was to compare food preference and consumption by S. frugiperda larvae, as well as evaluate insect developmental parameters in the standard diet and the bean-based diets under laboratory conditions. Four artificial diets were used: a standard diet based on broad beans (Phaseolus vulgaris L.) used to rear S. frugiperda (D1), a diet with the substitution of two types of beans, cowpea (Vigna unguiculata L.) (D2) and pigeon pea (Cajanus cajan L) (D3); and a diet of fresh corn leaves (D4), the host plant of the pest species. Using a multiple-choice test, we observed that the larvae preferred diets D4 followed by D1. The relative consumption rate (RCR), relative growth rate (RGR), relative metabolic rate (RMR), approximate digestibility (AD), efficiency of conversion of ingested food (ECI), efficiency of conversion of digested food (ECD), and the metabolic cost (CM) for S. frugiperda fifth instar larvae varied among diets. The diet D4 resulted in better ingestion, digestion, assimilation, and conversion of food, but with a metabolic cost to assimilate the food. The different bean varieties present in the diet influenced larval length, larval periods, larval survival, pupal periods, sex ratio, pupal weight, and pupal survival; but fecundity and longevity of adults were not affected. The different bean-based diets did positively influence population growth, with the most outstanding being D4. From the results of this study, the most adequate diet for rearing S. frugiperda in the laboratory is D4.
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    Electrophysiology and Behavioural Feedback of Diamondback moth,Plutella xylostella(L.) (Lep., Plutellidae) to Volatiles from a non-Host Plant,Lantana camaraL. (Verbenaceae var.aculeate)
    (Taylor & Francis, 2006) Sundufu, Abu James
    Electroantennograms (EAGs) were recorded from laboratory-reared male and female Plutella xylostella (Lepidoptera: Plutellidae) adults in response to the essential oil and its selected components belonging to oxy-and hydrocarbon monoterpenoids as well as a sesquiterpenoid from the non-host plant, Lantana camara L. (Verbenaceae var. aculeate). Measurable EAG responses were elicited to all compounds tested; and, mean, pooled EAGs to the sesquiterpene were larger in magnitude than those in response to oxy- and hydrocarbon monoterpenoids. Females were found to be more responsive than males. However, their responses to hydrocarbon monoterpenoids are smaller than those of male moths. Subsequent behavioural analyses in a four-armed olfactometer revealed R-(+)-limonene and (-) germacrene-D to be attractive to female moths. In laboratory cages, these two volatiles also stimulated oviposition and had little repulsive effect on third instar-larvae of the test insect.
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    Habitat Preferences of Butterflies in the Bumbuna Forest, Northern Sierra Leone
    (Oxford University Press, 2008-10-01) Sundufu, Abu James
    The habitat preferences of the butterfly fauna were studied in the Bumbuna Forest Reserve in northern Sierra Leone. The intact forest reserve and a secondary forest regrowth, disturbed as a result of slash-and-burn agriculture, were compared to savanna habitats. Of the 290 specimens collected, 195 butterfly species were included, of which significant proportion were Nymphalidae. Of the 147 forest species, 111 (75.5%) showed preferences for the forest habitats, while 70 (47.6%) and 34 (23.1%) preferred disturbed and savannah habitats, respectively. Numerically, a comparable proportion of savannah species were recorded in the 18 disturbed (73.9%) and 16 savannah habitats (63.2%). Accumulated species richness and diversity indices were lower in the disturbed habitats compared to the forest reserve, but lowest in the savanna habitats. However, a large proportion of forest species, especially those with either a more restricted geographic range or species for which no information on geographic distribution was available, were exclusively captured in the forest patches. The survey indicated the presence of a rich butterfly fauna, which should be systematically collected for further research and study in order to build a good taxonomic database for Sierra Leone.
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    The prevalence of type 2 diabetes in urban Bo, Sierra Leone, and in the 16 countries of the West Africa region
    (Wiley, 2017-04-26) Sundufu, Abu James
    BACKGROUND: The goal of this study was to measure the prevalence of diabetes among adults in urban Bo, Sierra Leone, and to compare the new results to the diabetes prevalence rates reported from studies across West Africa. METHODS: A total of 694 outpatients ages 18 and older at Bo Government Hospital were tested for diabetes between January 2012 and December 2014. Diabetes was defined as a fasting blood sugar level of ≥126 mg/dL (≥7.0 mmol/L). RESULTS: The overall prevalence of diabetes was 6.2% (43/694). Diabetes prevalence increased from 0.8% (2/256) among patients ages 18 to 29 years to 3.9% (8/204) among patients ages 30 to 39, 8.4% (11/131) among patients ages 40 to 49, 19.0% (12/63) among patients ages 50 to 59, and 25.0% (10/40) among patients ages 60 and older. The prevalence of diabetes was 5.2% among females and 7.4% among males. After adjusting the study population to the age and sex distribution of the national population, the standardized prevalence of diabetes was 7.0%. The only previously published study of diabetes in Sierra Leone found a much lower 2.4% prevalence rate in 1997. A comprehensive literature search identified studies from across West Africa (including Benin, Burkina Faso, Cabo Verde, Côte d'Ivoire, the Gambia, Ghana, Guinea, Guinea-Bissau, Liberia, Mali, Mauritania, Niger, Nigeria, Senegal, Sierra Leone, and Togo) that illustrate an increasing rate of diabetes and impaired glucose tolerance in the region. CONCLUSIONS: It is important for hospitals and clinics across West Africa to increase their ability to diagnose, monitor, and treat type 2 diabetes in urban and rural areas.