Response of larvae of Cirina forda Westwood (Lepidoptera: Saturniidae) to spatio-temporal variation in the nutritional content of foliage of Vitellaria paradoxa Gaertn. f. (Sapotaceae)

Cirina forda, an economically important edible folivore of Vitellaria paradoxa in the moist and dry woodland savanna ecosystems of Nigeria, has become ecologically restricted to the upper dry woodland savanna ecozone. The larvae of this insect are good source of protein for human and livestock consumption and income. However, little information is available on the bioecology of the insect to facilitate mass production. The study investigated, therefore, the emergence pattern and the physiological responses of the larval stages of the pest to spatial and temporal variations in the nutritional quality of foliage of the host tree, and their role in ecological adaptation of this pest. Field studies showed that the emergence pattern of C. forda is entrained to coincide with the period of abundant leaves of V. paradoxa at the beginning of the rainy season in the dry woodland savanna. Occurrence of C. forda in Nigeria has become restricted to the northernly dry woodland savanna ecosystem principally due to variation in the nutritional quality of leaf diet, and this is directly related to foliage age and geographical location of the host, V. paradoxa. Older leaves contained significantly higher (P < 0.05) micronutrients than immature leaves of the same plant, and larvae developed faster with access to foliage of different ages significantly (P < 0.05) than those fed on exclusive diets. Variation in micronutrient content and, probably, phytosterols in the leaves of different ages were suspected to be major reasons for non-survival to adult on exclusive diets. The knowledge would aid laboratory culture and management of this pest

The Pricing of Audit Services in Nigeria Commercial Banks

This  study investigates the determinants of audit fees in commercial banks in Nigeria.  Data were collected from a sample of banks mostly quoted on Nigerian Stock Exchange.  Consistent with previous studies, the result of our data analysis showed that bank size,  degree of bank complexity and transaction and saving accounts to total deposit ratio are positively related and statistically significant to audit fees charged by the auditors.  Even though , non performing loan  is positively related to audit fees , it is statistically insignificant.  While, the risk weighted capital adequacy ratio is negatively related and statistically insignificant to audit fees. Keywords: Audit fees, commercial banks, firm size, subsidiaries, auditor

Effect of Tree Height and Girth on Gum Yield of Acacia senegal L. in Savanna Woodland of Nigeria

<p>Parameters influencing gum yield such as tapping techniques and soil mineral elements had earlierbeen investigated while there is dearth of information on effect of morphological characteristics on gumyield. This study investigated effects of height and girth on yield of Acacia senegal L. in the naturalforests. Three heights and girth classes were purposely selected. Trees which heights and girth fell withinthose classes were selected randomly and tapped at constant height classes with varying girth classes.Exudates were collected, weighed and recorded according to height and girth class respectively.Descriptive and ANOVA results showed that when total tree height was lower than 2.0 m, gum yieldincreased as tree girth goes higher from 35 - 54cm (163.6 - 209.7g). Tree girth significantly affected gumyield (p≤0.05) and trees which total heights were lower than 2.0m (maximum of 1.95m) and girth higherthan 54cm (maximum of 65cm) produced the highest mean gum yield. Silvicultural practices that couldbring about increase in girth such as early pruning and re-spacing which is applicable to plantation treescould also be carried out on the natural forest trees to increase gum yield.</p><p>Key words: Savanna woodland, Acacia senegal, Gum yield.</p

Farmer's participation in social forestry in the semi-arid zone of Nigeria

In July 1996, a structured questionnaire was used to interview 475 people in 38 farm-family groups to elicit information on their participation in social forestry in the semi-arid zone of Nigeria. States covered included Bauchi; Borno; Jigawa, Kano; Katsina; Kebbi; Plateau; Sokoto and Yobe. Forty seven percent of farmers interviewed own private nurseries to supplement the government nurseries. About 68% owned woodlots, 47.4% orchards while only 3% were involved in apiculture. No farmer was involved in amenity planting but 40% of them had home gardens; 23.6% were engaged in borderline (boundary) planting. All the farmers interviewed participated in tree planting, even though management of trees (weeding, tending, pruning) in these various technologies was poor. NGO participation is high in one state Katsina) while a lot of Community Based Organizations (CBOs) were present in all the states and some of them participated in tree planting. Farmers interviewed appear confident with high self-worth. They are satisfied with the forestry projects. [JEXT Vol.2(1) 2001: 71-80

Thermal and physico-mechanical stability of recycled high density polyethylene reinforced with oil palm fibres

The impressive physical and mechanical properties achievable with organic fillers make them a good choice for polymer composite reinforcement. In this study, oil palm fibres (OPF), often hardly thought of as having any reasonable economic value in developing economy was used as reinforcing fillers in recycled high density polyethylene (rHDPE). Thermal behaviour, physical and mechanical stability of rHDPE filled with OPF have been studied. Fourier Transform Infrared Spectroscopy (FTIR) results present band spectra characteristic of OH stretching vibration in the cellulose of the fibre material. The absorption bands of the spectra are attributed to the presence of stretching vibration of CO group mostly found in the form of hemicelluloses and lignin structure in the fibre. Upon examination of the test specimens produced through compression moulding technique, it was found that the addition of OPF (filler) into rHDPE (matrix) increased the composites’ water absorption rate linearly for the first 16 days of exposure to the water environment. Stability was achieved for all the materials after this period. Thermal studies of the various compositions (OPF/rHDPE: 5/95, 10/90, 15/85, 20/80 and 25/75) using derivative thermogravimetric analysis (DTGA) showed two main degradation peaks at 490 °C and 380 °C. The mechanical study revealed that the composite with 20 wt% filler contents was the most eco-friendly and had the best mechanical properties while that with 25 wt% was the most thermally stable. This material was thermally stable up to approximately 330 °C. Microstructure examination of the different components of the composites further explains the reason for good physical and mechanical strength of the sample with 20 wt% filler. It can, therefore, be inferred from the results of the various analyses conducted that OPF is a good reinforcing phase for rHDPE and a potential material for construction and automotive industries