Developmental biology and field performance of Platygaster diplosisae Risbec (Hymn: Platygasteridae) an egg-larval parasitoid of african rice gall midge Orseolia oryzivora Harris and Gagné (Diptera: Cecidoymiidae)

The developmental biology and field performance of Platygaster diplosisae an endoparasitoid of African rice gall midge (AfRGM) Orseolia oryzivora were investigated. Experiments were conducted in the screen house, laboratory and fields during 2006/2007 farming seasons. The pre-oviposition period averaged 12.1 h. The mean number of eggs laid per female was 95.2 and mean oviposition period was 3.5 days. The average incubation period was 13.0 days with a hatchability of 67.3%. There were three larval instars with developmental duration averaging 2.2, 0.5 and 2.5 days for the 1st, 2nd and 3rd larval respectively. The prepupa and pupa developmental period lasted for 2.4 and 6.7 days respectively. The longevity of males and females were 3.0 and 4.1 days respectively without food, which varied when food was given. The parasitoid has total developmental period of 27.3 days. The results showed that P. diplosisae has an impact as a bio-control agent of AfRGM, but the percentage parasitism of the host was low at the beginning of the season and increased significantly later in the season with a peak in October of each season. It was recommended that mass rearing or conservation of the parasitoid be adopted to improve its efficiency in control of AfRGM.Keywords: Biology, Platygaster diplosisae, bio-control, field impact, Orseolia oryzivora

Estimating the burden of selected non-communicable diseases in Africa: a systematic review of the evidence

Background The burden of non-communicable diseases (NCDs) is rapidly increasing globally, and particularly in Africa, where the health focus, until recently, has been on infectious diseases. The response to this growing burden of NCDs in Africa has been affected owing to a poor understanding of the burden of NCDs, and the relative lack of data and low level of research on NCDs in the continent. Recent estimates on the burden of NCDs in Africa have been mostly derived from modelling based on data from other countries imputed into African countries, and not usually based on data originating from Africa itself. In instances where few data were available, estimates have been characterized by extrapolation and over-modelling of the scarce data. It is therefore believed that underestimation of NCDs burden in many parts of Africa cannot be unexpected. With a gradual increase in average life expectancy across Africa, the region now experiencing the fastest rate of urbanization globally, and an increase adoption of unhealthy lifestyles, the burden of NCDs is expected to rise. This thesis will, therefore, be focussing on understanding the prevalence, and/or where there are available data, the incidence, of four major NCDs in Africa, which have contributed highly to the burden of NCDs, not only in Africa, but also globally. Methods I conducted a systematic search of the literature on three main databases (Medline, EMBASE and Global Health) for epidemiological studies on NCDs conducted in Africa. I retained and extracted data from original population-based (cohort or cross sectional), and/or health service records (hospital or registry-based studies) on prevalence and/or incidence rates of four major NCDs in Africa. These include: cardiovascular diseases (hypertension and stroke), diabetes, major cancer types (cervical, breast, prostate, ovary, oesophagus, bladder, Kaposi, liver, stomach, colorectal, lung and non-Hodgkin lymphoma), and chronic respiratory diseases (chronic obstructive pulmonary disease (COPD) and asthma). From extracted crude prevalence and incidence rates, a random effect meta-analysis was conducted and reported for each NCD. An epidemiological model was applied on all extracted data points. The fitted curve explaining the largest proportion of variance (best fit) from the model was further applied. The equation generated from the fitted curve was used to determine the prevalence and cases of the specific NCD in Africa at midpoints of the United Nations (UN) population 5-year age-group population estimates for Africa. Results From the literature search, studies on hypertension had the highest publication output at 7680, 92 of which were selected, spreading across 31 African countries. Cancer had 9762 publications and 39 were selected across 20 countries; diabetes had 3701 publications and 48 were selected across 28 countries; stroke had 1227 publications and 19 were selected across 10 countries; asthma had 790 publications and 45 were selected across 24 countries; and COPD had the lowest output with 243 publications and 13 were selected across 8 countries. From studies reporting prevalence rates, hypertension, with a total sample size of 197734, accounted for 130.2 million cases and a prevalence of 25.9% (23.5, 34.0) in Africa in 2010. This is followed by asthma, with a sample size of 187904, accounting for 58.2 million cases and a prevalence of 6.6% (2.4, 7.9); COPD, with a sample size of 24747, accounting for 26.3 million cases and a prevalence of 13.4% (9.4, 22.1); diabetes, with a sample size of 102517, accounting for 24.5 million cases and a prevalence of 4.0% (2.7, 6.4); and stroke, with a sample size of about 6.3 million, accounting for 1.94 million cases and a prevalence of 317.3 per 100000 population (314.0, 748.2). From studies reporting incidence rates, stroke accounted for 496 thousand new cases in Africa in 2010, with a prevalence of 81.3 per 100000 person years (13.2, 94.9). For the 12 cancer types reviewed, a total of 775 thousand new cases were estimated in Africa in 2010 from registry-based data covering a total population of about 33 million. Among women, cervical cancer and breast cancer had 129 thousand and 81 thousand new cases, with incidence rates of 28.2 (22.1, 34.3) and 17.7 (13.0, 22.4) per 100000 person years, respectively. Among men, prostate cancer and Kaposi sarcoma closely follows with 75 thousand and 74 thousand new cases, with incidence rates of 14.5 (10.9, 18.0) and 14.3 (11.9, 16.7) per 100000 person years, respectively. Conclusion This study suggests the prevalence rates of the four major NCDs reviewed (cardiovascular diseases (hypertension and stroke), diabetes, major cancer types, and chronic respiratory diseases (COPD and asthma) in Africa are high relative to global estimates. Due to the lack of data on many NCDs across the continent, there are still doubts on the true prevalence of these diseases relative to the current African population. There is need for improvement in health information system and overall data management, especially at country level in Africa. Governments of African nations, international organizations, experts and other stakeholders need to invest more on NCDs research, particularly mortality, risk factors, and health determinants to have evidenced-based facts on the drivers of this epidemic in the continent, and prompt better, effective and overall public health response to NCDs in Africa

A year of genomic surveillance reveals how the SARS-CoV-2 pandemic unfolded in Africa.

The progression of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic in Africa has so far been heterogeneous, and the full impact is not yet well understood. In this study, we describe the genomic epidemiology using a dataset of 8746 genomes from 33 African countries and two overseas territories. We show that the epidemics in most countries were initiated by importations predominantly from Europe, which diminished after the early introduction of international travel restrictions. As the pandemic progressed, ongoing transmission in many countries and increasing mobility led to the emergence and spread within the continent of many variants of concern and interest, such as B.1.351, B.1.525, A.23.1, and C.1.1. Although distorted by low sampling numbers and blind spots, the findings highlight that Africa must not be left behind in the global pandemic response, otherwise it could become a source for new variants

The evolving SARS-CoV-2 epidemic in Africa: Insights from rapidly expanding genomic surveillance.

Investment in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) sequencing in Africa over the past year has led to a major increase in the number of sequences that have been generated and used to track the pandemic on the continent, a number that now exceeds 100,000 genomes. Our results show an increase in the number of African countries that are able to sequence domestically and highlight that local sequencing enables faster turnaround times and more-regular routine surveillance. Despite limitations of low testing proportions, findings from this genomic surveillance study underscore the heterogeneous nature of the pandemic and illuminate the distinct dispersal dynamics of variants of concern-particularly Alpha, Beta, Delta, and Omicron-on the continent. Sustained investment for diagnostics and genomic surveillance in Africa is needed as the virus continues to evolve while the continent faces many emerging and reemerging infectious disease threats. These investments are crucial for pandemic preparedness and response and will serve the health of the continent well into the 21st century

Management of african rice gall midge Orseolia oryzivora Harris and Gagn&#233 with reference to time planting and natural enemies in southeastern Nigeria

Field experiments were conducted at Abakaliki to evaluate the effect of time of planting (July 31, August 14 and August 28) and natural enemies in the control of African rice gall midge during the 2002 and 2003 cropping seasons. The experiment was laid out in randomized complete block design with three replications. The incidences of African rice gall midge were highest on rice planted on July 31 for both seasons and declined with the subsequent time of planting. The level of infestation by African rice gall midge was observed to depend on prevailing climatic factors. On the other hand, natural enemy found parasitizing African rice gall midge was Platygaster diplosisae Risbec. Parasitism by Platygaster diplosisae as a control measure of African rice gall midge was more severe as time of planting were delayed with 66.98 and 59.47% parasitism recorded on rice planted on August 28 for both years. This relationship was the significant negative correlation (r = -82 and -72 for 2002 and 2003 respectively) established between damage incidence and parasitism. Grain yield was least on rice planted on July 31 in all the experimental years. The highest grain yields were recorded on rice planted on August 14 for the two seasons. br> Journal of Agriculture, Forestry and the Social Sciences Vol. 3 (2) 2005: pp.106-11

Effects of planting dates and N-rates on african rice gall midge (orseolia oryzivora, harris and gagn&#201)

No Abstract.Global Journal of Agricultural Sciences Vol. 5 (2) 2006: pp. 155-16

Stem borer damage and rice yield as influence by transplanting date and N-fertilization

No Abstract. Bio-Research Vol. 4(1) 2006: 14-1

Effect of Mulching and Nitrogen Fertilizer on Growth and Yield of Okra (Abelmoschus esculentus)

A field experiment was carried out in 2008 cropping season at the experimental farm of the faculty of Agriculture and Natural Resources Management to evaluate effect of different rates of nitrogen (0,70, 140, 210 kg N/ ha) and mulching (grass mulch) on the vegetative growth and green pod yield of okra. The experiment was conducted as a 4 x 2 factorial laid out in Randomized Complete Block Design (RCBD) with four replications. The results showed that nitrogen rate of 140kgN/ha producedthe highest number of branches and leaves. Days to 50% anthesis (flowering) was longest at 140 kg N/ha and shortest where nitrogen was omitted. Mulched plots, which received 140 kg N/ha produced the highest number of fruits. The weight and length of fruits was higher on the mulched plots. Non– mulched plots consistently produced least values in all the parameters that were measured

Effect of Neem Seed Kernel Extracts in the Management of Rice Stem Borers in the Field in Nigeria

Stem borers are economic pests of rice and its management through conventional methods has not given the desired results. Hence in this study field experiments were conducted to determine the comparative efficacy of neem seed kernel extracts (Azadirachta indica; (Neem) and synthetic insecticide (Carbofuradan) against rice stem borers in Nigeria during 2006/07 farming season. The effect of these sprayings was also recorded on natural enemies and yield attributes. Results showed that the two pesticides significantly (p < 0.01) reduced stem borers damage (number of dead hearts, white heads) compared to untreated check, and also significantly (p < 0.05) increased number of productive tillers with resultant increase in grain yield than the control plots. Maximum numbers of different natural enemies were found in neem extract treated plots against the carbofuran treated plots. It is suggested that on the basis of infestation of borer, high yield and conservation of natural enemies, neem seed extract can be regarded as suitable alternative to synthetic insecticides for the management of rice stem borers in the field.Keywords: Botanical/insecticide, stem borer controlNig J. Biotech. Vol. 23 (2011) 13- 2

Neural Tube Defects In Rural Ebonyi State, Four Cases In Three Months – Co Incidental? Case Reports

No Abstract