Does the spillage of petroleum products in Anopheles breeding sites have an impact on the pyrethroid resistance?

<p>Abstract</p> <p>Background</p> <p>The emergence of <it>Anopheles </it>populations capable of withstanding lethal doses of insecticides has weakened the efficacy of most insecticide based strategies of vector control and, has highlighted the need for further studies on the mechanisms of insecticide resistance and the various factors selecting resistant populations of mosquitoes. This research targeted the analysis of breeding sites and the oviposition behaviour of susceptible and resistant populations of <it>Anopheles </it>in localities of spilled petroleum products. The aim was to establish the possible contribution of oil spillage in the selection of pyrethroid resistance in malaria vectors.</p> <p>Methods</p> <p><it>Anopheles </it>breeding sites were identified and the insecticide susceptibility of the <it>Anopheles gambiae </it>populations mapped in 15 localities of South Western Nigeria. The presence of oil particles as well as the turbidity, the dissolved oxygen and the pH of each identified breeding site was recorded. Data were cross-analysed to correlate the habitat types and the insecticide susceptibility status of emerging mosquitoes. The second phase of this study was basically a laboratory model to provide more information on the implication of the spillage of petroleum on the selection of pyrethroid resistance in <it>An. gambiae</it>.</p> <p>Results</p> <p>Moderate levels of resistance following exposure to permethrin-impregnated papers were recorded with the majority of <it>An. gambiae </it>samples collected in the South Western Nigeria. Data from this study established a link between the constituency of the breeding sites and the resistance status of the emerging <it>Anopheles</it>.</p> <p>Conclusion</p> <p>This study has revealed the segregational occupation of breeding habitats by pyrethroid resistant and susceptible strains of <it>An. gambiae </it>in south-western Nigeria. Compiled results from field and laboratory research point out clear relationships between oil spillage and pyrethroid resistance in malaria vectors. The identification of this factor of resistance could serve as strong information in the management of insecticide resistance in some West African settings.</p

Chemical and non-chemical control of Meloidogyne incognita infecting cowpea under field conditions

Field studies were conducted in 1998 and 1999 to investigate the effects of air-dried milled neem leaves, Siam weed leaves and roots each at 30kg/ha and 50kg/ha and carbofuran at 1.5kg a.i./ha and 2.5 kg a.i/ha on Meloidogyne incognita infecting cowpea cv. IT 86D- 715. Carbofuran-treated plants had the highest grain yield (1.7 t/ha), and the least root galling (0.6) at harvest while carbofuran – treated soil had the least nematode population after harvest and population of Pratylenchus spp was reduced by 83.2%, Helicotylenchus spp. by 86.5%, Xiphinema spp by 89.1% and Meloidogyne incognita by 94.8%. This was followed by the grain yield in neem leaf-treated plants (1.35 t/ha) with a root galling of 1.4, while nematode population in neem leaf-treated soil was reduced as follows: Pratylenchus spp., 67.6%, Helicotylenchus spp., 64.1%, Xiphinema spp., 64.8% and M. incognita, 83.4%. Grain yield in Siam weed –treated plants (0.8 t/ha) with a root galling of 1.7, was higher than that of control plants and population of Pratylenchus spp. was reduced by 49.9%, Helicotylenchus spp. by 59.1%, Xiphinema spp. by 63.2% and Meloidogyne incognita by 74.9%. Key Words: Meloidogyne; incognita; neem leaves; siam weed; leaves; siam weed roots; carbofuran Moor J. Agric. Res. Vol.4(1) 2003: 94-9

Effect of diets with different protein-energy density on the gastrointestinal nematode status of semi- intensively managed West African dwarf sheep

This study was conducted to determine the effect of different protein and energy density diets on the gastrointestinal parasite status of semi-intensively raised West African Dwarf (WAD) sheep. The different densities used were low energy-low protein (LELP); low energy-high protein (LEHP); high energy-low protein (HELP) and high energy-high protein (HEHP). Twenty four WAD sheep with an average weight of 11.5±0.41 kg, aged between 5 and 6 months were used. These were divided into four groups of six animals per group in a completely randomized design. Groups were each fed one of the diets, respectively, as supplement and released into a paddock grown with Stylosanthes hamata and Pennisetum pedicellatum, to graze for 12 weeks at 5 hours per day. The faecal egg count (FEC) ranged from 375 to 3483 eggs per gram (epg). The strongyle eggs had the highest (P&lt;0.05) number whereas moniezia eggs were the least. The effect of the different protein-energy densities on the final FEC and the differences between the final and initial FEC were significant (P&lt;0.05). The FEC obtained in animals fed LELP and LEHP showed 56.30 and 13.30 percentage reduction (P&lt;0.05) in epg, respectively, whereas animals fed HELP showed percentage increase (P&lt;0.05) of 104.30 epg. The highest trend (P&lt;0.05) of infestation was obtained in those fed LELP while the least trend was obtained in those fed HEHP. It could therefore be concluded that diets high in protein and energy levels reduced the gastrointestinal nematodes of WAD sheep compared to other nutrient combinations.Keywords: Gastrointestinal nematode, Nutrient density, WAD shee

Number of eggs laid by susceptible and resistant strains of in oily and non oily breeding sites

<p><b>Copyright information:</b></p><p>Taken from "Does the spillage of petroleum products in breeding sites have an impact on the pyrethroid resistance?"</p><p>http://www.malariajournal.com/content/6/1/159</p><p>Malaria Journal 2007;6():159-159.</p><p>Published online 3 Dec 2007</p><p>PMCID:PMC2222605.</p><p></p

Hatching rate of eggs laid by resistant and susceptible strains of in oily and non-oily breeding sites

<p><b>Copyright information:</b></p><p>Taken from "Does the spillage of petroleum products in breeding sites have an impact on the pyrethroid resistance?"</p><p>http://www.malariajournal.com/content/6/1/159</p><p>Malaria Journal 2007;6():159-159.</p><p>Published online 3 Dec 2007</p><p>PMCID:PMC2222605.</p><p></p

Mapping of susceptibility to pyrethroid (permethrin) in the South Western Nigeria

<p><b>Copyright information:</b></p><p>Taken from "Does the spillage of petroleum products in breeding sites have an impact on the pyrethroid resistance?"</p><p>Malaria Journal 2007;6():159-159.</p><p>Published online 3 Dec 2007</p><p>PMCID:PMC2222605.</p><p></p