Parasitism of Plutella xylostella (L.) (Lepidoptera: Plutellidae) Populations on Cabbage Brassica oleracea var. capitata (L.) by Cotesia plutellae (Kurdjumov) (Hymenoptera: Braconidae) in Ghana

The study was carried out at the Weija Irrigation Company site at Weija, in the Greater Accra Region of Ghana, to determine the seasonal abundance of the major parasitoid of Plutella xylostella (L.) populations on cabbage, Brassica oleracea var. capitata (L.) during the rainy and the dry seasons. The results indicated that Cotesia plutellae (Kurdjumov) was the most abundant and important parasitoid of P. xylostella on cabbage. It accounted for about 92% of the parasitoids, and occurred in all the three seasons of planting. The rest consisted of four facultative hyperparasitoids: Oomyzus sokolowskii, Aphanogmus reticulatus, Elasmus sp. and a Trichomalopsis sp., and two primary parasitoids, Pediobius sp. and Hockeria sp. A significantly higher rate of parasitism (68.6 ± 12.9%, P < 0.05) of P. xylostella by C. plutellae occurred during the major rainy season and the least (9.9 ± 7.1) in the minor rainy season. Cotesia plutellae acted in a density dependent manner, and its numbers increased as that of the host in all three seasons. The coefficient of correlation was highest in the major rainy season (r = 0.97) with a coefficient of determination of 0.97. In the minor rainy season r = 0.55, and in the dry season r = 0.66. The annual coefficient of correlation was r = 0.51 and the coefficient of determination = 0.262. Hence, in an annual production of cabbage, 26.2% of the variation in parasitism was due to the variation in the number of P. xylostella. The results, therefore, indicate that C. plutellae can be used in the development of an integrated pest management programme (IPMP), against P. xylostella in Ghana

Utility of Repeated Praziquantel Dosing in the Treatment of Schistosomiasis in High-Risk Communities in Africa: A Systematic Review

Infection by Schistosoma worms causes serious disease among people who live in areas of Africa, South America, and Asia where these parasites are regularly transmitted. Although yearly treatment with the drug praziquantel is fairly effective in reducing or eliminating active infection, it does not cure everyone, and reinfection remains a continuing problem in high-risk communities. Studies have suggested that a repeat dose of praziquantel, given 2 to 8 weeks after the first dose, can improve cure rates and reduce remaining intensity of infections in population-based programs. Our systematic review of published research found that, on average, in Africa, such repeated dosing appears to offer particular advantages in the treatment of S. mansoni, the cause of intestinal schistosomiasis, but there was less consistent improvement after double-dosing for S. haematobium, the cause of urogenital schistosomiasis. Based on this evidence, we used a calibrated life-path model to predict the costs and benefits of a single-dose vs. a double-dose strategy in a typical high-risk community. Our projections suggest cost-effective incremental benefits from double dosing in terms of i) limiting a person's total years spent infected and ii) limiting the number of years they spend with heavy infection, with consequent improvements in quality of life

Differential effects of weather, plant phenology and predators on the seasonal variation of aphids on cabbage

The aphids Lipaphis erysimi pseudobrassicae (Davis) and Myzus persicae (Sulzer) pose serious threats to the production of cruciferous crops in the tropics. Understanding their population dynamics is important for developing integrated pest management programmes to minimize their damage to crops. This study investigated the effects of climatic factors, natural enemies and plant age on the population dynamics of these pests. The population density of aphids and their natural enemies in 20 cabbage plants, and weather conditions were monitored for five cropping seasons from 2019 to 2021 in two agroecological zones of Ghana (Coastal Savannah and Deciduous Forest zones). The highest population density of L. e pseudobrassicae was recorded in January (dry season) in both agroecological zones, while the highest population density for M. persicae occurred in September (minor rainy season) and August (dry spell) in the Coastal Savannah and Deciduous Forest zones, respectively. The highest aphid densities were noted to occur during periods with low relative humidity and low rainfall. The population density of L. e. pseudobrassicae was significantly negatively related to plant age, air temperature and relative humidity, and positively related to syrphids (Paragus borbonicus) and spiders in the Coastal Savannah zone, while in the Deciduous Forest zone it was significantly positively related to coccinellids. On the other hand, M. persicae population density was significantly positively related to syrphids and coccinellids in the Deciduous Forest zone. Rainfall negatively affected syrphids in the Coastal Savannah zone, while air temperature positively affected syrphids and negatively affected spiders in the Deciduous Forest zone. Coccinellids had a significant positive relationship with relative humidity in the Deciduous Forest zone. This study provides important insights into the key factors that regulate aphid population densities on cabbage and will support development of timely interventions to manage these pests.Funding was provided by the German Academic Exchange (DAAD) for the PhD studies of FEE, the BBSRC CONNECTED Network Grant (BB/R005397/1) to K.O.F and J.P.C

Differential effects of weather, plant phenology and predators on the seasonal variation of aphids on cabbage

The aphids Lipaphis erysimi pseudobrassicae (Davis) and Myzus persicae (Sulzer) pose serious threats to the production of cruciferous crops in the tropics. Understanding their population dynamics is important for developing integrated pest management programmes to minimize their damage to crops. This study investigated the effects of climatic factors, natural enemies and plant age on the population dynamics of these pests. The population density of aphids and their natural enemies in 20 cabbage plants, and weather conditions were monitored for five cropping seasons from 2019 to 2021 in two agroecological zones of Ghana (Coastal Savannah and Deciduous Forest zones). The highest population density of L. e pseudobrassicae was recorded in January (dry season) in both agroecological zones, while the highest population density for M. persicae occurred in September (minor rainy season) and August (dry spell) in the Coastal Savannah and Deciduous Forest zones, respectively. The highest aphid densities were noted to occur during periods with low relative humidity and low rainfall. The population density of L. e. pseudobrassicae was significantly negatively related to plant age, air temperature and relative humidity, and positively related to syrphids (Paragus borbonicus) and spiders in the Coastal Savannah zone, while in the Deciduous Forest zone it was significantly positively related to coccinellids. On the other hand, M. persicae population density was significantly positively related to syrphids and coccinellids in the Deciduous Forest zone. Rainfall negatively affected syrphids in the Coastal Savannah zone, while air temperature positively affected syrphids and negatively affected spiders in the Deciduous Forest zone. Coccinellids had a significant positive relationship with relative humidity in the Deciduous Forest zone. This study provides important insights into the key factors that regulate aphid population densities on cabbage and will support development of timely interventions to manage these pests.Funding was provided by the German Academic Exchange (DAAD) for the PhD studies of FEE, the BBSRC CONNECTED Network Grant (BB/R005397/1) to K.O.F and J.P.C

Periodontal status, tooth loss and self-reported periodontal problems effects on oral impacts on daily performances, OIDP, in pregnant women in Uganda: a cross-sectional study

<p>Abstract</p> <p>Background</p> <p>An important aim of antenatal care is to improve maternal health- and well being of which oral health is an important part. This study aimed to estimate the prevalence of oral impacts on daily performances (OIDP) during pregnancy, using a locally adapted OIDP inventory, and to document how periodontal status, tooth-loss and reported periodontal problems are related to oral impacts.</p> <p>Methods</p> <p>Pregnant women at about 7 months gestational age who were members of a community based multi-center cluster randomized community trial: PROMISE EBF: <it>Safety and Efficacy of Exclusive Breast feeding in the Era of HIV in Sub-Saharan Africa</it>, were recruited in the district of Mbale, Eastern Uganda between January 2006 and June 2008. A total of 877 women (participation rate 877/886, 98%, mean age 25.6, sd 6.4) completed an interview and 713 (participation rate 713/886, 80.6%, mean age 25.5 sd 6.6) were examined clinically with respect to tooth-loss and according to the Community Periodontal Index, CPI.</p> <p>Results</p> <p>Seven of the original 8 OIDP items were translated into the local language. Cronbach's alpha was 0.85 and 0.80 in urban and rural areas, respectively. The prevalence of oral impacts was 25% in the urban and 30% in the rural area. Corresponding estimates for CPI>0 were 63% and 68%. Adjusted ORs for having any oral impact were 1.1 (95% CI 0.7-1.7), 1.9 (95% CI 1.2-3.1), 1.7 (1.1-2.7) and 2.0 (0.9-4.4) if having respectively, CPI>0, at least one tooth lost, tooth loss in molars and tooth loss in molar-and anterior regions. The Adjusted ORs for any oral impact if reporting periodontal problems ranged from 2.7(95% CI 1.8-4.2) (bad breath) through 8.6(95% CI 5.6-12.9) (chewing problem) to 22.3 (95% CI 13.3-35.9) (toothache).</p> <p>Conclusion</p> <p>A substantial proportion of pregnant women experienced oral impacts. The OIDP impacts were most and least substantial regarding functional- and social concerns, respectively. The OIDP varied systematically with tooth loss in the molar region, reported chewing-and periodontal problems. Pregnant women's oral health should be addressed through antenatal care programs in societies with limited access to regular dental care facilities.</p