scholarly journals Diversité des insectes floricoles de Abelmoschus esculentus (Malvaceae) et leur impact sur les rendements fruitier et grainier à Maroua-Cameroun.

2020 ◽  
Vol 43:1 ◽  
pp. 7350-7365
Author(s):  
Joseph Blaise Pando ◽  
Denis Djonwangwé ◽  
Olivier Balti Moudelsia ◽  
Fernand-Nestor Tchuenguem Fohouo ◽  
Joseph Lebel Tamesse

Pour déterminer la richesse spécifique, la fréquence relative, les produits alimentaires recherchés, les insectes pollinisateurs et l’impact de ces insectes sur les rendements, deux traitements ont été formés à partir du marquage de 240 boutons floraux en 2015 et 2017 chacun selon la présence ou l’absence de protection contre les insectes. Les observations ont été faites sur les fleurs de Abelmoschus esculentus en libre pollinisation du 11 au 22 septembre 2015 et du 7 au 19 septembre 2017 à Wourndé et Palar respectivement. La diversité spécifique des insectes floricoles de gombo était de 17 et 20 espèces respectivement à Wourndé et à Palar. L’indice de Jacard (J = 0,15) révèle une similarité entre les deux sites, preuve que les conditions environnementales sont similaires dans les deux habitats. Les insectes butinaient les fleurs du gombo de 8 h à 13 h, avec le pic de l’activité de l’ensemble de visites de ceux-ci situé entre 10 h et 11 h. Les insectes développaient un comportement très élaboré lors de la récolte du nectar et/ou du pollen et la consommation du pétale. On peut regrouper ces insectes en pollinisateur majeur (Lipotriches collaris), pollinisateurs mineurs [Sphecodes albilabris, Camponotus flavomarginatus, le Vespidae (1 sp.), Lasioglossum albilabris, Seladonia sp., Lasioglossum albipes, Lipotriches pulchriventris et le Formicidae (1 sp.)] et pollinisateurs occasionnels. La comparaison des rendements des fleurs non protégées à celui des fleurs protégées des insectes ont montré que les insectes ont un impact positif sur ce rendement. L’influence de ces insectes est estimée à 9,57%, 7,18% et 4,34% pour le taux de fructification, le nombre de graines/capsule et le pourcentage de graines normales respectivement. Afin d’améliorer le rendement de A. esculentus, il est conseillé de préserver les insectes floricoles non nuisibles dans les champs de gombo en évitant les traitements aux pesticides pendant la période de floraison lorsqu’ils ne se justifient pas. ABSTRACT To determine the species richness, the relative frequency, desired food products, the pollinating insects and impact of these insects on the yields, two treatments were formed from the marking of 240 flower buds in 2015 and 2017, differentiated according to the presence or absence of protection against insect’s activities. Observations were made on free-pollinated Abelmoschus esculentus flowers from 11 to 22 September 2015 and from 7 to 19 September 2017 in Wourndé and Palar respectively. The specific diversity of the flowering insects of okra was 17 and 20 species respectively in Wourndé and Palar. The Jacard index (J = 0.15) reveals a similarity between the two sites, proof that the environmental conditions are similar in both habitats. The insects foraged the flowers of the okra from 8h to 13h, with the peak of the activity of the set of visits of them located between 10 h and 11 h. The insects developed a much elaborated behaviour during the harvest of the nectar and / or the pollen and the consumption of petal. These insects can be grouped into major pollinators (Lipotriches collaris), minor pollinators [Sphecodes albilabris, Camponotus flavomarginatus, Vespidae (1 sp.), Lasioglossum albilabris, Seladonia sp., Lasioglossum albipes, Lipotriches pulchriventris and Formicidae (1 sp.)).] and occasional pollinators. By comparing the yield of unprotected flowers to that of insect-protected flowers, it appeared that insects have a positive impact on this yield. The influence of these insects is estimated at 9.57 %, 7.18 % and 4.34 % for the fruiting rate, the number of seeds / capsule and the percentage of normal seeds respectively. To improve the yield of A. esculentus, it is advisable to preserve the flower-dwelling insects in okra fields by avoiding pesticide treatments during the flowering period when they are not justified.

2024 ◽  
Vol 84 ◽  
Author(s):  
J. S. Lima ◽  
G. L. D. Leite ◽  
P. F. S. Guanabens ◽  
M. A. Soares ◽  
J. L. Silva ◽  
...  

Abstract Acacia mangium is a pioneer species with fast growth and frequently used in the recovery of degraded areas. The objectives were to evaluate insects and spiders, their ecological indices and interactions on A. mangium saplings in a tropical degraded area in recovering process. The experimental design was completely randomized with 24 replications, with treatments represented by the first and second years after A. mangium seedling planted. Numbers of leaves/branch, branches/sapling, and ground cover by A. mangium saplings, Hemiptera: Phenacoccus sp. and Pachycoris torridus; Hymenoptera: Tetragonisca angustula and Trigona spinipes, Brachymyrmex sp., Camponotus sp. and Cephalotes sp.; Blattodea: Nasutitermes sp. and Neuroptera: Chrysoperla sp.; abundance, species richness of pollinating insects, tending ants, and the abundance of Sternorrhyncha predators were greatest in the second year after planting. Numbers of Hemiptera: Aethalium reticulatum, Hymenoptera: Camponotus sp., Cephalotes sp., Polybia sp., T. angustula, T. spinipes, tending ants, pollinating insects, Sternorrhyncha predators and species richness of tending ants were highest on A. mangium saplings with greatest numbers of leaves or branches. The increase in the population of arthropods with ground cover by A. mangium saplings age increase indicates the positive impact by this plant on the recovery process of degraded areas.


Irriga ◽  
2017 ◽  
Vol 22 (2) ◽  
pp. 204-219 ◽  
Author(s):  
Mariana Lays Andrade Oliveira ◽  
Vital Pedro da Silva Paz ◽  
Karoline Santos Gonçalves ◽  
Greice Ximena Santos Oliveira

Crescimento e Produção de girassol ornamental irrigado com diferentes lâminas E diluições de água residuária  MARIANA LAYS ANDRADE OLIVEIRA¹; VITAL PEDRO DA SILVA PAZ²; KAROLINE SANTOS GONÇALVES³ E GREICE XIMENA SANTOS OLIVEIRA4 ¹Núcleo de Engenharia de Água e Solo, Universidade Federal do Recôncavo da Bahia, UFRB, Cruz das Almas, BA, [email protected]²Programa de Pós-Graduação em Engenharia Agrícola, Universidade Federal do Recôncavo da Bahia, UFRB, Cruz das Almas, BA, [email protected]³Programa de Pós-Graduação em Engenharia Agrícola, Universidade Federal do Recôncavo da Bahia, UFRB, Cruz das Almas, BA, [email protected] do Meio Ambiente e Recursos Hídricos do Estado da Bahia, Salvador, BA, [email protected]  1 RESUMO O objetivo deste trabalho foi avaliar o crescimento e a produção de girassol ornamental submetido à irrigação com diferentes lâminas e diluições de água residuária. O experimento foi conduzido em delineamento experimental inteiramente casualizado em esquema fatorial 5x4 com 4 repetições, em casa de vegetação no Núcleo de Engenharia de Água e Solo (NEAS), pertencente à Universidade Federal do Recôncavo da Bahia, localizada no município de Cruz das Almas - BA. A cultivar utilizada foi a Anão de Jardim e os tratamentos foram constituídos por cinco concentrações de água residuária diluídas em água de abastecimento (0, 25, 50, 75 e 100%) e quatro lâminas de irrigação obtidas a partir das percentagens de evaporação do tanque classe A (70, 90, 110 e 130%). As variáveis analisadas foram: altura da planta (AP), diâmetro do caule (DC), número de folhas (NF), massa fresca e seca da parte aérea (MFPA e MSPA), dias para o aparecimento de botões florais (DABF), dias para o período de floração (DPF), dias para abertura total dos capítulos (DATC), diâmetros internos e externos dos capítulos (DI e DE), massa fresca e seca dos capítulos (MFC e MSC), além da estimativa do consumo hídrico da planta (CH). Os resultados obtidos mostraram que, com exceção da AP, todas as variáveis foram influenciadas pelas lâminas de irrigação ou pelas diluições de água residuária, não havendo influência significativa da interação entre os fatores para nenhuma das variáreis avaliadas. O uso de água residuária e a lâmina de 110% da evaporação do tanque classe A favoreceram o desenvolvimento do girassol. O menor e maior consumo hídrico da cultura foi observado nas lâminas de 70 e 130%, respectivamente. Palavras-chave: Reuso, cv. Anão de jardim, tanque Classe A.  OLIVEIRA, M. L. A.; PAZ, V. P. da S.; GONÇALVES, K. S.; OLIVEIRA, G. X. S.GROWTH AND PRODUCTION OF ORNAMENTAL SUNFLOWER IRRIGATED WITH DIFFERENT DEPTHS AND CONCENTRATIONS OF WASTEWATER    2 ABSTRACT The aim of this study was to evaluate the ornamental sunflower production subjected to different depths and concentration of wastewater. The experiment was conducted in experimental design completely randomized in a factorial 5x4 with 4 repetitions in a greenhouse at the Center of Water and Soil Engineering (NEAS), of the Federal University of Recôncavo da Bahia, located in Cruz das Almas, BA, Brazil. The cultivar used was cv. Anão de Jardim and the treatments consisted of five wastewater concentrations diluted in water supply (0, 25, 50, 75 and 100%) and four irrigations blades obtained through evaporation of the percentages of the class A pan (70, 90 , 110 and 130%). The variables analyzed were: plant height (AP), stem diameter (DC), number of leaves (NF), fresh and dry weight of the aerial part (MFPA and MSPA), days for the appearance of flower buds (DABF), days to flowering period (DPF), days for full opening of chapters (DATC), internal and external diameters of the chapters (DI and DE), fresh and dry weight of chapters (MFC and MSC), and the estimate of water consumption plant. The results showed that, except for the AP, all variables were influenced by the irrigation blades or the wastewater concentrations, and there was no significant influence of interaction between factors for any evaluated variables. The use of wastewater and 110% evaporation of the class A pan depth favored the development of sunflower. The lower and higher water consumption of the culture was observed in depths 70% and 130%, respectively. Keywords: reuse, cv. Anão de Jardim, class A pan.


2017 ◽  
Author(s):  
Abdel H. Halloway ◽  
Christopher J. Whelan ◽  
Çağan H. Şekercioğlu ◽  
Joel S. Brown

AbstractAdaptations can be thought of as evolutionary technologies which allow an organism to exploit environments. Among convergent taxa, adaptations may be largely equivalent with the taxa operating in a similar set of environmental conditions, divergent with the taxa operating in different sets of environmental conditions, or superior with one taxon operating within an extended range of environmental conditions than the other. With this framework in mind, we sought to characterize the adaptations of two convergent nectarivorous bird families, the New World hummingbirds (Trochilidae) and Old World sunbirds (Nectariniidae), by comparing their biogeography. Looking at their elevational and latitudinal gradients, hummingbirds not only extend into but also maintain species richness in more extreme environments. We suspect that hummingbirds have a superior key adaptation that sunbirds lack, namely a musculoskeletal architecture that allows for hovering. Through biogeographic comparisons, we have been able to assess and understand adaptations as evolutionary technologies among two convergent bird families, a process that should work for most taxa.


2006 ◽  
Vol 63 (1) ◽  
pp. 43-54 ◽  
Author(s):  
Christopher M Taylor ◽  
Thomas L Holder ◽  
Riccardo A Fiorillo ◽  
Lance R Williams ◽  
R Brent Thomas ◽  
...  

The effects of stream size and flow regime on spatial and temporal variability of stream fish distribution, abundance, and diversity patterns were investigated. Assemblage variability and species richness were each significantly associated with a complex environmental gradient contrasting smaller, hydrologically variable stream localities with larger localities characterized by more stable flow regimes. Assemblages showing the least variability were the most species-rich and occurred in relatively large, stable environments. Theory suggests that species richness can be an important determinant of assemblage variability. Although this appears to be true in our system, we suggest that spatial and temporal heterogeneity in the environment largely determines both assemblage richness and variability, providing a more parsimonious explanation for the diversity–variability correlation. Changes in species richness of local assemblages across time were coordinated across the landscape, and assemblages formed spatially and temporally nested subset patterns. These results suggest an important link between local community dynamics and community-wide occurrence. At the species level, mean local persistence was significantly associated with regional occurrence. Thus, the more widespread a species was, the greater its local persistence. Our results illustrate how the integrity of local stream fish assemblages is dependent on local environmental conditions, regional patterns of species distribution, and landscape continuity.


Botany ◽  
2009 ◽  
Vol 87 (3) ◽  
pp. 306-314 ◽  
Author(s):  
Robert S. Capers ◽  
Roslyn Selsky ◽  
Gregory J. Bugbee ◽  
Jason C. White

Invasive plants alter community structure, threatening ecosystem function and biodiversity, but little information is available on whether invasive species richness responds to environmental conditions in the same way that richness of native plants does. We surveyed submerged and floating-leaved plants in 99 Connecticut (northeast USA) lakes and ponds, collecting quantitative data on abundance and frequency. We used multiple linear and logistic regression to determine which environmental conditions were correlated with species richness of invasive and native plants. Independent variables included lake area, maximum depth, pH, alkalinity, conductivity, phosphorus concentration, productivity, and dominance (the proportional abundance of the most abundant and frequently found species), plus two estimates of human activity. Species richness of both native and invasive richness was correlated with alkalinity and human activity. Native richness also increased with water clarity, lake area, and productivity; invasive species richness also rose with pH. We found no evidence that richness of one group affected richness of the other. We also investigated patterns of dominance and found that native plants were as likely to become dominant as invasive species. Dominance occurred overwhelmingly in shallow lakes with high productivity.


2020 ◽  
Vol 12 (6) ◽  
pp. 2238 ◽  
Author(s):  
Enric Tello ◽  
Joan Marull ◽  
Roc Padró ◽  
Claudio Cattaneo ◽  
Francesc Coll

Could past land uses, and the land cover changes carried out, affect the current landscape capacity to maintain biodiversity? If so, knowledge of historical landscapes and their socio-ecological transitions would be useful for sustainable land use planning. We constructed a GIS dataset in 10 × 10 km UTM cells of the province of Barcelona (Catalonia, Spain) for 1956 and 2009 with the changing levels of farming disturbance exerted through the human appropriation of photosynthetic net primary production (HANPP), and a set of landscape ecology metrics to assess the impacts of the corresponding land-use changes. Then, we correlated them with the spatial distribution of total species richness (including vascular plants, amphibians, reptiles, birds and mammals). The results allow us to characterize the main trends in changing landscape patterns and processes, and explore whether a land-use legacy of many complex agroforest mosaics maintained by the intermediate farming disturbance managed in 1956 could still exist, despite the decrease or disappearance of those mosaics before 2009 due to the combined impacts of agroindustrial intensification (meaning higher HANPP levels), forest transition (meaning lower HANPP levels) and urban sprawl. Statistical analysis reveals a positive impact of the number of larger, less disturbed forest patches, where many protected natural sites have been created in 1956–2009. However, it also confirms that this result has not only been driven by conservation policies and that the distribution of species richness is currently correlated with the maintenance of intermediate levels of HANPP. This suggests that both land-sharing and land-sparing approaches to biodiversity conservation may have played a synergistic role owing to the legacy of complex land cover mosaics of former agricultural landscapes that are now under a serious threat.


Biologia ◽  
2008 ◽  
Vol 63 (6) ◽  
Author(s):  
Neti Ngearnpat ◽  
Peter Coesel ◽  
Yuwadee Peerapornpisal

AbstractThree peat swamps situated in the southern part of Thailand were investigated for their desmid flora in relation to a number of physical and chemical habitat parameters. Altogether, 99 species were encountered belonging to 22 genera. 30 species are new records for the Thai desmid flora. Laempagarung peat swamp showed the highest diversity (45 species), followed by Maikhao peat swamp (32 species) and Jud peat swamp (25 species). Despite its relatively low species richness, Jud swamp appeared to house a number of rare taxa, e.g., Micrasterias subdenticulata var. ornata, M. suboblonga var. tecta and M. tetraptera var. siamensis which can be considered Indo-Malaysian endemics. Differences in composition of the desmid flora between the three peat swamps are discussed in relation to environmental conditions.


Author(s):  
Jacqueline B. Pocklington ◽  
Stuart R. Jenkins ◽  
Alecia Bellgrove ◽  
Michael J. Keough ◽  
Tim D. O'Hara ◽  
...  

Canopy-forming fucoid algae have an important role as ecosystem engineers on rocky intertidal shores, where they increase the abundance of species otherwise limited by exposure during low tide. The facilitative relationship between Ascophyllum nodosum and associated organisms was explored using a frond breakage experiment (100%, 50%, 25%, 0% intact-frond treatments) in southern England, to assess the consequences of disturbance. Understorey substratum temperature was on average 3°C higher in 0% and 25% intact-frond treatments than in plots with 50% and 100% intact fronds. Light (as PAR during low tide) doubled in 0% intact-frond treatments in comparison to other treatments (which had similar light levels). Mobile invertebrate species richness declined by on average 1 species per m2 in the treatments with only 25% and 0% intact fronds, and the abundance of Littorina obtusata declined by 2.4–4.2 individuals per m2 in the treatments with 25 and 0% intact fronds. Sessile taxa, including Osmundea pinnatifida and encrusting coralline algae, declined by half on average in the 0% intact-frond treatment. These results suggest that the ability of Ascophyllum to mediate environmental conditions to the understorey is the mechanism responsible for species distributed in the understorey (autogenic ecosystem engineering). The results of this study imply that a pulse disturbance resulting in a 50% breakage of Ascophyllum fronds significantly increases temperature and decreases the abundance of mobile invertebrates usually associated with Ascophyllum. Sessile taxa associated with Ascophyllum can, however, withstand disturbances down to 25% intact Ascophyllum fronds.


10.12737/2227 ◽  
2014 ◽  
Vol 8 (4) ◽  
pp. 130-133
Author(s):  
Наимов ◽  
Alisher Naimov ◽  
Меликов ◽  
Kurbonali Melikov ◽  
Партоев ◽  
...  

The article presents the results of a study on the features on the formation of generative organs of potato (Solanum tuberosum L.) in mountainous areas of Tajikistan at a height of over 2700 meters above sea level. There is a difference in formation character of generative system of potato plants, depending on the genotype accessions. It was noted that the formation of flower buds on the total amount of from 5 to 95%, and the number of berries formed 1to 10 units /plant or from 7.7 to 20.6 % of the total number of flowers. Formation of berries of potato varieties in a little due to the amount of viable pollen grains per flower. The number of seeds in a berry varies from 51 to 150 units, and it is associated with the viability of the pollen grains of potato flower. One berry of potatoes in average contains about 96 pieces of seeds. It was determined that 16 % of potato accessions form less than 10 % have viable pollen grains, which is probably due to a partial cytoplasmic sterile pollen.


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