scholarly journals A nationwide survey of the tabanid fauna of Cameroon

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Silas L. Sevidzem ◽  
Aubin A. Koumba ◽  
Genevieve L. Yao-Acapovi ◽  
Jacques F. Mavoungou
Keyword(s):  
Nationwide Survey ◽  
Current Data ◽  
Mechanical Transmission ◽  
Distribution Maps ◽  
Ecological Zones ◽  
The Mean ◽  
Sudan Savanna ◽  
Abundance And Distribution ◽  
High Diversity ◽  
Agro Ecological Zones

Abstract Background Tabanids are a neglected group of haematophagous dipterans despite containing 4434 species, regrouped in > 144 genera. They are mechanical vectors of important pathogens, including viruses, bacteria and protozoa of humans and domesticated and wild animals. As it is > 50 years since the publication of a preliminary nationwide record of the tabanids of Cameroon identified 84 species, updated information is needed. The aim of this study was to provide current data on the species composition, abundance and distribution of tabanids in the five main agro-ecological zones (AEZs) of Cameroon. Methods From 2015 to 2017, a systematic entomological study using Nzi, Vavoua, Biconical and Sevi traps (n = 106) was conducted in 604 trapping points over 11,448 trap-days in the five main AEZs of Cameroon. Results A total of 25,280 tabanids belonging to 25 species were collected, including eight species not previously documented in Cameroon, namely Tabanus latipes (1 female), Tabanus ricardae (1 female), Tabanus fasciatus (32 females and 6 males), Haematopota pluvialis (18 females), Haematopota decora (19 females and 3 males), Haematopota nigripennis (18 females), Chrysops distinctipennis (47 females and 5 males) and Ancala fasciata (34 females and 7 males). The distribution maps of the newly identified tabanids differed between AEZs, with most tabanids collected from the Guinean savanna. The highest apparent density of tabanids was recorded in the Sudan Savanna region, and the mean apparent densities of species with sites was statistically significantly different (Student t-test: 2.519, df = 24, P = 0.019). The highest species diversity was found in the rainforest. Conclusions This study increased the list of tabanids recorded in Cameroon from 84 species in the preliminary record to 92 species, with most of the newly identified species occurring in the Guinea Savanna AEZ. The high diversity and abundance of tabanids in the livestock/wildlife interface areas of the rain forests and Sudan Savanna AEZs, respectively, suggest risk of mechanical transmission of pathogens. Investigations of the microbiota of tabanids in the different AEZs to define their role as disease vectors are proposed. Graphical abstract

scholarly journals A Nationwide Survey of Tabanidae Fauna of Cameroon

2021 ◽  
Author(s):  
Silas Lendzele Sevidzem ◽  
KOUMBA Aubin Armel ◽  
Geneviève Lydie L. Yao-Acapovi ◽  
Jacques François MAVOUNGOU
Keyword(s):  
Nationwide Survey ◽  
Current Data ◽  
Transmission Risk ◽  
Mechanical Transmission ◽  
Distribution Maps ◽  
Ecological Zones ◽  
The Mean ◽  
Sudan Savanna ◽  
Abundance And Distribution ◽  
Agro Ecological Zones

Abstract Background: Tabanid flies are a neglected group of haematophagous dipterans, yet contains 4400 species, regrouped under 144 genera. They are mechanical vectors of important pathogens, including viruses, bacteria and protozoa of humans, domesticated and wild animals. As it is over 50 years since publication of a preliminary nationwide record of tabanids of Cameroon identified 84 species, updated information is provided.Objective: To provide current data on the species composition, abundance and distribution of Tabanidae of Cameroon in the 5 main agro-ecological zones (AEZs).Methods: From 2015-2017, a systematic entomological prospection using Nzi, Vavoua, Biconical and Sevi traps (N=106) was conducted in 604 trap-points over 11,448 traps days, in the 5 main AEZs of Cameroon.Results: A total of 25,280 tabanid specimens were collected, identifying 25 species with 8 not previously documented in Cameroon, including: Tabanus Latipes Macquart, 1838 (1 ♀), Tabanus ricardae Surcouf, 1906 (1 ♀), Tabanus fasciatus Fabricus, 1775 (32 ♀♀, 6♂♂), Haematopota pluvialis Linnaeus, 1758 (18 ♀♀), Haematopota decora Walker, 1850 (19 ♀♀, 3 ♂♂), Haematopota nigripennis Austen, 1914 (18 ♀♀), C. distinctipennis Austen, 1906 (47 ♀♀, 5 ♂♂) and Ancala fasciata Fabricus, 1977 (34 ♀♀, 7 ♂♂). The distribution maps of the newly identified tabanids differed between AEZs, with most from the Guinean savanna. The highest Tabanidae apparent density (ADT) was recorded in the Sudan savanna region and the mean apparent densities of species with type-localities was statistically significantly different (Student t-test=2.519, df=24, P=0.019). The highest species diversity was found in the rain forest.Conclusions: This study increased the list of Tabanidae recorded in Cameroon from 84 species in the preliminary record to 92 species, with most of the newly identified species occurring in the Guinean savanna AEZ. The high diversity and abundance of Tabanidae in the livestock/wildlife interface areas of the rain forests and Sudan savanna AEZs respectively, suggests risk of mechanical transmission risk of pathogens. Investigations of the microbiota within the Tabanidae in the different AEZs to define their role as disease vectors are proposed.

scholarly journals Towards Understanding Variability in Droughts in Response to Extreme Climate Conditions over the Different Agro-Ecological Zones of Pakistan

2021 ◽  
Vol 13 (12) ◽  
pp. 6910
Author(s):  
Adil Dilawar ◽  
Baozhang Chen ◽  
Arfan Arshad ◽  
Lifeng Guo ◽  
Muhammad Irfan Ehsan ◽  
...  
Keyword(s):  
Pearson Correlation ◽  
Principal Component ◽  
Mitigation Strategies ◽  
Precipitation Extremes ◽  
Climate Mitigation ◽  
Mean Annual Temperature ◽  
Climate Extreme ◽  
Ecological Zones ◽  
The Mean ◽  
Agro Ecological Zones

Here, we provided a comprehensive analysis of long-term drought and climate extreme patterns in the agro ecological zones (AEZs) of Pakistan during 1980–2019. Drought trends were investigated using the standardized precipitation evapotranspiration index (SPEI) at various timescales (SPEI-1, SPEI-3, SPEI-6, and SPEI-12). The results showed that droughts (seasonal and annual) were more persistent and severe in the southern, southwestern, southeastern, and central parts of the region. Drought exacerbated with slopes of −0.02, −0.07, −0.08, −0.01, and −0.02 per year. Drought prevailed in all AEZs in the spring season. The majority of AEZs in Pakistan’s southern, middle, and southwestern regions had experienced substantial warming. The mean annual temperature minimum (Tmin) increased faster than the mean annual temperature maximum (Tmax) in all zones. Precipitation decreased in the southern, northern, central, and southwestern parts of the region. Principal component analysis (PCA) revealed a robust increase in temperature extremes with a variance of 76% and a decrease in precipitation extremes with a variance of 91% in the region. Temperature and precipitation extremes indices had a strong Pearson correlation with drought events. Higher temperatures resulted in extreme drought (dry conditions), while higher precipitation levels resulted in wetting conditions (no drought) in different AEZs. In most AEZs, drought occurrences were more responsive to precipitation. The current findings are helpful for climate mitigation strategies and specific zonal efforts are needed to alleviate the environmental and societal impacts of drought.

scholarly journals Agro-ecological Variation in the Growth and Development of Grain Amaranth (Amaranthus sp.) in Nigeria

HortScience ◽  
1996 ◽  
Vol 31 (4) ◽  
pp. 652b-652
Author(s):  
A.O. Olufolaji ◽  
Lanre A. Denton
Keyword(s):  
Agricultural Research ◽  
Agronomic Characters ◽  
Yield Attributes ◽  
Ecological Zones ◽  
Qualitative And Quantitative ◽  
Quantitative Characters ◽  
Derived Savanna ◽  
Sudan Savanna ◽  
New Crop ◽  
Agro Ecological Zones

The pale yellow-seeded Amaranth is virtually a new crop in Nigerian agriculture. Under the sponsorship of the National Agricultural Research Project (NARP), 12 accessions were evaluated for agronomic characters and yield attributes in three agro-ecological zones of the country. The results showed significant variation in the agronomic characters of the accessions. Top accessions recorded average grain yields of 4.5, 3.5, and 2.6 t·ha–1 in Sudan savanna, derived savanna, and guinea savanna zones of the country, respectively. Response of the accessions to qualitative and quantitative characters in the zones are discussed.

scholarly journals Effect of Fertilizer Application on Soil Properties and Yield of Sesame (sesamum indicum l.) Varieties in Southern Guinea and Sudan Savanna Agro-Ecological Zones of Nigeria

2021 ◽  
pp. 89-108
Author(s):  
Usman M. ◽  
Ali A. ◽  
Olatunji O.
Keyword(s):  
Soil Properties ◽  
Fertilizer Application ◽  
Soil Samples ◽  
Improved Varieties ◽  
Ecological Zones ◽  
Local Variety ◽  
Significant Difference ◽  
Cropping Seasons ◽  
Sudan Savanna ◽  
Agro Ecological Zones

Field experiments were carried out in 2018 and 2019 cropping seasons to determine the effect of fertilizer application on soil properties and yield of sesame varieties in Southern Guinea and Sudan Savanna Agro-ecological Zones of Nigeria. Treatments consisted of three varieties of sesame (Jigida, NCRIBEN-01M and NCRIBEN-032) and four levels of NPK 15:15:15 fertilizer (0, 50,100 and 150 kg ha-1). Treatments were laid out in a randomized complete block design (RCBD) and replicated thrice. Prior to planting, surface (0-15 cm) soil samples were collected from eight points and bulked; post-harvest composite soil samples were also collected on the basis of treatments. All soil samples were analyzed using standard analytical procedures. Data on yield parameters collected include number of capsules per plant, number of seeds per capsule, length of capsule (cm), 1000 capsule weight (g), 1000 seeds weight (g) and seed yield (t ha-1). The crop data generated from the study were subjected to Analysis of Variance (ANOVA) using Genstat Release 10.3 DE after which significant means were separated using Least Significant Difference (LSD) at 5 % level of probability. Results indicated that the soils of both locations were inherently poor in essential plant nutrients. The improved varieties (NCRIBEN-01M and NCRIBEN-032) performed better than the local variety in terms of yields in both cropping seasons. Sesame yield increased with increase in fertilizer application rates up to 150 kg ha-1. The effect of varieties on soil properties did not differ significantly however, the improved varieties left lower essential nutrients in soil when compared with the local variety. Fertilizer application at 150 kg ha-1 favoured the retention of organic matter as well as other essential nutrient elements in soil. Location effect showed that the Potiskum soil had more nutrients than that of Makurdi. For sustainable sesame production and maintenance of soil fertility in both locations, application of 150 kg ha-1 of NPK 15:15:15 to sesame fields is recommended.

Stock and stability of organic carbon in soils under major agro-ecological zones and cropping systems of sub-tropical India

2021 ◽  
Vol 312 ◽  
pp. 107317
Author(s):  
Nirmalendu Basak ◽  
Biswapati Mandal ◽  
Ashim Datta ◽  
Manik Chandra Kundu ◽  
Arvind Kumar Rai ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Cropping Systems ◽  
Ecological Zones ◽  
Agro Ecological Zones

scholarly journals Comparative Experimental Effects of Intercropping and Cypermethrin on Insect Pest Infestation and Yield of Maize, Cowpea and Okra in Two Cameroonian Agro-Ecological Zones

2021 ◽  
Vol 3 (2) ◽  
pp. 383-393
Author(s):  
Patient Farsia Djidjonri ◽  
Nukenine Elias Nchiwan ◽  
Hartmut Koehler
Keyword(s):  
Field Experiments ◽  
Insect Pests ◽  
Cropping Systems ◽  
Insect Pest ◽  
Maize Yield ◽  
Ecological Zones ◽  
Pest Infestation ◽  
Final Yield ◽  
Cropping Seasons ◽  
Agro Ecological Zones

The present study investigates the effect of intercropping (maize-cowpea, maize-okra, maize-okra-cowpea, okra-cowpea) compared to insecticide application on the level of infestation of insect pests and the final yield of maize, cowpea and okra. Field experiments were conducted during the 2016 and 2017 cropping seasons in the Guinean Savannah (Dang-Ngaoundere) and Sudano Sahelian (Gouna-Garoua) agro-ecological zones in Cameroon. Our experimental design was a split plot arrangement in a randomized complete block with four replications. The main factor was assigned to the use of insecticide (Cypermethrin) and sub plots were devoted for cropping systems. We compared the efficiency of intercropping to that of Cypermethrin application on the Yield of maize, cowpea and okra as influenced by insect pest damages. The comparison of monocropped sprayed by Cypermethrin to unsprayed showed that, in Dang, insect pests reduced maize yield by 37% and 24% in 2016 and 2017, respectively, whereas in Gouna, it was lower than 8% during the both years. Reduction in seed yield by insect pests on cowpea in Dang represented 47% and 50% in 2016 and 2017, respectively, whereas in Gouna, it was 55% and 63% in 2016 and 2017, respectively. For okra, insect pests reduced okra fruit yield by 25% and 44% in Dang and 23% and 28% in Gouna, respectively, in 2016 and 2017. Crop yield was lower in intercropping compared to monoculture due to competition of plants in association on different resources. Considering the total yields obtained from each intercropping, intercropping trials resulted generally in higher yields compared to mono-culture (LER > 1) in both sites and years but the respective yields were quite different. On the basis of the results obtained, we recommend maize-cowpea intercropping as a sustainable solution to reduce the infestation level of their pest insects.

Evaluation of potential crop productivity based on remote sensing and agro-ecological zones around the world

2017 ◽  
Vol 33 (7) ◽  
pp. 713-722
Author(s):  
Hongyan Wang ◽  
Qiangzi Li ◽  
Xin Du ◽  
Longcai Zhao ◽  
Na Wang
Keyword(s):  
Remote Sensing ◽  
Crop Productivity ◽  
Ecological Zones ◽  
The World ◽  
Agro Ecological Zones
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