Preliminary Studies on Inherited Sterility for Field Management of Diamondback Moth (Plutella xylostella) (Lepidoptera: Plutellidae) on Crucifers in Ghana

The diamondback moth (DBM), Plutella xylostella (L.) (Lepidoptera: Plutellidae) is the most destructive insect pest of crucifers in Ghana and the world over. It is estimated to cost about USD 1 billion to control annually worldwide. Reliance on chemicals as the sole control measure for diamondback moth has resulted in the development of a myriad ofproblems including resistance, high residue levels on produce, destruction of natural enemies and pest resurgence among others. Inherited sterility in Lepidoptera insects has a potential for suppressing DBM populations. We conducted this study to evaluate the use of the technique to manage the diamond back moth in Ghana. When 3 – 4 day old pupae were treated with 130 Gy and 150 Gy of gamma radiation, 47% and 46% respectively of the male pupae developed as normal adults whiles 40% and 17% respectively of the female pupae developed as normal adults. However, radiation-induced reductions in fecundity and egg viability were expressed in the parental and first filial (F ) generations. Sterility exceeded 1 66% in the treated parental male and 92% in the treated parentalfemale in both treatments as compared with 78% and 95% in treated F male and female, respectively. The sex ratio was 1 skewed in favour of males in the parental progeny. These results indicate the possibility of using inherited sterility for DBM control.Keywords: Diamondback moth Plutella xylostella, irradiation, inherited sterility, F 1 sterility

Relationship between land use and groundwater quality in six districts in the eastern region of Ghana

The chemical quality of groundwater in six district of the eastern region beneath the different types of land use areas of Ghana was examined to evaluate the effects of human activities on groundwater. Analyses indicate that groundwater in the studied area is fresh and generally suitable for most uses. The groundwater is generally characterised by a chemical facies of Ca-HCO3−, Na-Cl and mixed Na–Ca-HCO3 types and is weakly mineralised. Anthropogenic disturbances have had and continue to have an impact on the aquatic ecosystem of Ghana. High concentration of Cl− and TDS were found in wells in high residential areas while the highest levels of Na, Ca, SO42− and NO3− were found in agricultural and high density residential areas. About 50% of boreholes sampled have elevated level of NO3−-N emanating from agricultural runoff

Geochemistry of Pegmatites associated with the cape coast granite complex in the Egyaa and Akim Oda areas of southern Ghana

The Cape Coast granite complex, which is associated with  metasedimentary rocks of the Birirmian in Ghana, is characterised by various minor intrusions that include pegmatites. The pegmatites, which are feldspar-rich, occur within, and at the margins of the granite batholiths and the surrounding schists. The major and trace element compositions of the pegmatites sampled from Egyaa and Akim Oda areas have been determined. The data indicates that the pegmatites from these areas have granitic compositions. The rocks are medium-K to high-K, calc-alkaline, S-type granitoids that are peraluminous and magnesian. Lower values of molar CaO/ (MgO + FeO <sub>tot</tot>) coupled with higher values of molar Al<sub>2</sub>O<sub>3</sub>/(MgO + FeO<sub>tot</sup>) suggest their derivation from partial melting from metapelitic sources, with the Birimian metasedimentary rocks being the likely source material. The rocks are depleted in Rb, Ba, Nb, Ce and Ti but rich in U, K, La, Hf and Y relative to primitive mantle. The data suggest that the pegmatites from these areas are late orogenic, and were emplaced at upper to middle crustal levels in a volcanic arc geotectonic environment

Trace and heavy metals analysis of Phyllanthus amarus and Phyllanthus fraternus in Ghana

Ethno-pharmacological uses and information about Phyllanthus species have prompted this work. The aim was to investigate the presence and levels of aluminum (Al), magnesium (Mg), iron (Fe), manganese (Mn) lead (Pb), cadmium (Cd), copper (Cu), zinc (Zn), chromium (Cr) and nickel (Ni) in Phyllanthus amarus (PA) and Phyllanthus fraternus (PF) in Ghana. Three different extracts (hot aqueous, hot ethanol and cold ethanol) were prepared from dried powdered samples of these plants. These extracts, including the dried samples of the plants were analyzed for the presence and levels of Al, Mg, Fe, Mn, Pb, Cd, Cu, Zn, Cr, and Ni using Atomic Absorption Spectrophotometry (AAS). The levels of Ni (0.43±0.24 ppm), Cr (0.35±0.04 ppm) and Cd (0.18±0.10 ppm) in both plant species were found to be very low in the dried samples plants and below the FAO/WHO maximum limits for vegetables, but were below the detectable limits of our AAS in the extract. Pb was not detected in the dried plant samples and in the extracts of the PA and PF; hence the plants may not pose serious health threat to consumers. PA and PF contain appreciable amounts of trace metals though they were all below the FAO/WHO maximum permissible limits in vegetables. The level of Fe in PA and PF (145.11±11.69 ppm and 179.94±14.60 ppm respectively) was found be to relatively high compared to the other elements analyzed. This finding makes the two plants suitable candidates for use in formulating effective remedies against iron deficiency diseases besides conferring some nutritive value to the patients.Keywords: Ethno-pharmacological, phytoextration, concentration, medicinal valu

Detection of a reduced susceptibility to chlorfenapyr in the malaria vector Anopheles gambiae contrasts with full susceptibility in Anopheles funestus across Africa

New insecticides have recently been produced to help control pyrethroid-resistant malaria vectors including the pyrrole, chlorfenapyr. Monitoring the susceptibility of mosquito populations against this new product and potential cross-resistance with current insecticides is vital for better resistance management. In this study, we assessed the resistance status of the major malaria vectors Anopheles gambiae and Anopheles funestus to chlorfenapyr across Africa and explored potential cross-resistance with known pyrethroid resistance markers. Efficacy of chlorfenapyr 100 µg/ml against An. gambiae and An. funestus from five Cameroonian locations, the Democratic Republic of Congo, Ghana, Uganda, and Malawi was assessed using CDC bottle assays. Synergist assays were performed with PBO (4%), DEM (8%) and DEF (0.25%) and several pyrethroid-resistant markers were genotyped in both species to assess potential cross-resistance between pyrethroids and chlorfenapyr. Resistance to chlorfenapyr was detected in An. gambiae populations from DRC (Kinshasa) (mortality rate: 64.3 ± 7.1%) Ghana (Obuasi) (65.9 ± 7.4%), Cameroon (Mangoum; 75.2 ± 7.7% and Nkolondom; 86.1 ± 7.4). In contrast, all An. funestus populations were fully susceptible. A negative association was observed between the L1014F-kdr mutation and chlorfenapyr resistance with a greater frequency of homozygote resistant mosquitoes among the dead mosquitoes after exposure compared to alive (OR 0.5; P = 0.02) whereas no association was found between GSTe2 (I114T in An. gambiae; L119F in An. funestus) and resistance to chlorfenapyr. A significant increase of mortality to chlorfenapyr 10 µg/ml was observed in An. funestus after to PBO, DEM and DEF whereas a trend for a decreased mortality was observed in An. gambiae after PBO pre-exposure. This study reveals a greater risk of chlorfenapyr resistance in An. gambiae populations than in An. funestus. However, the higher susceptibility in kdr-resistant mosquitoes points to higher efficacy of chlorfenapyr against the widespread kdr-based pyrethroid resistance

Use of environmental isotopes to assess the sustainability of intensively exploited aquifer systems (2012‐2015)

Intensive exploitation of groundwater over longer period has led, in many important aquifers, to marked lowering of water tables, increasing exploitation costs, and often, to a progressive deterioration of water quality. Concentrated pumping may also alter flow patterns permanently with the risk of migration of pollutants into aquifers from the surrounding aquifers or surface water bodies due to lack of physical protection to prevent them. Isotope hydrology tools have proven to be very useful in assessing groundwater hydrology, addressing aspects related to recharge processes, delineation of flow patterns, water quality issues and interactions with other water bodies; this unique information can be further used to evaluate long term aquifer sustainability. The objective of the Coordinated Research Project F33019 is to develop and review approaches and methodologies, mostly based on the combined use of conventional hydrogeological techniques and environmental isotopes, to assess the response of groundwater systems to intensive exploitation and groundwater availability. Access to new dating tools and approaches for groundwater dating covering different time scales offers the possibility to evaluate changes in groundwater dynamics and flow patterns, providing key data to predict the evolution of aquifers and their sustainability as major sources of water. The CRP aims to assess the performance of these new tools and approaches and the possible adoption of these methods by water management experts

Determination of Trace Elements in the Sakumo Wetland Sediments

Abstract: The objective of this research was to determine the current pollution status of the Sakumo wetland with the aim of identifying factors affecting the long-term integrity of the wetland ecosystem. Sediment samples from the Sakumo wetland were analysed for Cd, Co, Cr, Cu, Fe, Ni, Mn and Zn using Instrumental Neutron Activation Analysis (INAA) coupled with the conventional counting system. The sediment materials exhibited higher concentrations of trace elements Cd (maximum; 0.041 mg/kg), Co (maximum; 0.64 mg/kg), Cr (maximum; 30.73 mg/kg), Cu (maximum; 22.89 mg/kg), Ni (maximum; 11.69 mg/kg) and Zn (maximum; 6.52 mg/kg). In some of the lagoon sediments compared with their levels in world average soils, the average concentrations of the trace elements in general are below or within levels in world average soils/uncontaminated soils. Concentrations of Ni showed positive correlation with Cr whilst Co correlated positively with Cr and Zn. However, lack of correlation between Fe and Cd, suggests that the influence of these parameters on the distribution of trace metals is not important

Leachate Characterization and Assessment of Unsaturated Zone Pollution near Municipal Solid Waste Landfill Site at Oblogo, Accra-Ghana

Abstract: Leachate and unsaturated zone water samples were collected from landfill-site and its adjacent area at Oblogo, Accra-Ghana to study the possible impact of leachate percolation on unsaturated zone water quality. Concentration of various physico-chemical parameters including heavy metal (Cd, Cr, Cu, Fe, Mn, As, V, and Zn) were determined in unsaturated zone water and leachate samples. The moderately high concentrations of ClG, NO 3 G, SO 4 2 G, Fe, Zn, Cd, Cr, Cu, Fe, Mn, and BOD in unsaturated zone water, likely indicate that water quality in the unsaturated zone is being significantly affected by leachate percolation. This suggests that leachate percolation is having an impact the unsaturated zone water which indicates the originality of the groundwater in the area is threatened

Target rocks, impact glasses, and melt rocks from the Lonar impact crater, India: Petrography and geochemistry

The Lonar crater, India, is the only well-preserved simple crater on Earth in continental flood basalts; it is excavated in the Deccan trap basalts of Cretaceous-Tertiary age. A representative set of target basalts, including the basalt flows excavated by the crater, and a variety of impact breccias and impact glasses, were analyzed for their major and trace element compositions. Impact glasses and breccias were found inside and outside the crater rim in a variety of morphological forms and shapes. Comparable geochemical patterns of immobile elements (e.g., REEs) for glass, melt rock and basalt indicates minimal fractionation between the target rocks and the impactites. We found only little indication of post-impact hydrothermal alteration in terms of volatile trace element changes. No clear indication of an extraterrestrial component was found in any of our breccias and impact glasses, indicating either a low level of contamination, or a non-chondritic or otherwise iridium-poor impactor.The Meteoritics & Planetary Science archives are made available by the Meteoritical Society and the University of Arizona Libraries. Contact [email protected] for further information.Migrated from OJS platform February 202

Geochemical and isotopic studies of groundwater conditions in the Densu River Basin of Ghana.

The Densu River Basin (DRB) is an important agricultural area in Ghana and has a high population density. Water shortages have occurred in the basin due to drying out of surface water, heavy pollution and low yield in most of the production wells, which are crucial factors restricting sustainable socioeconomic development. This study was carried out to investigate the geochemical characteristics and evolution, as well as recharge processes in the DRB system with regard to the tectonics, geomorphology, lithology and flow system. It mainly used hydrochemistry, environmental isotopes and a series of comprehensive data interpretation, e.g., statistics, ionic ratios and Piper diagram to obtain a better understanding of the functioning of the system. The following hydrochemical processes were identified as the main factors controlling the water quality of the groundwater system: weathering of silicate minerals, dissolution, ion exchange and, to a lesser extent, evaporation, which seems to be more pronounced downgradient of the flow system. As groundwater flows from the recharge to discharge areas, chemical patterns evolve in the order of Ca2+-HCO3 (-), Ca2+/Mg2+-HCO3 (-) to Ca2+/Na+-Cl-, Ca2+-Na+-HCO3 (-) and Na+-Cl- according to lithology. The environmental isotope (delta O-18, delta H-2, H-3) measurements further revealed that groundwater in the DRB was a relatively well-mixed system as evidenced by the encoded narrow range of values. However, deviation from the rainwater signature indicates combined local processes such as direct percolation through preferential channels, evaporation, and probable surface water and anthropogenic contribution to the system