Wycliffe Wanzala

Attractive and repellent host odours guide ticks to their respective feeding sites

Summary.We have studied on-host behaviour of adults of the brown ear tick (Rhipicephalus appendiculatus Neumann, 1901) and the red-legged tick (R. evertsi Neumann, 1897), which prefer to feed mainly inside the ears and the anal regions of bovids respectively. Both species were found to be relatively successful in orienting toward and locating their respective feeding sites from different parts of the host body. Our observations suggested the operation of both avoidance (closer to the feeding site of the other) and attraction (closer to its own feeding site) responses of the ticks. In the laboratory, odour trapped from cattle ears attracted R. appendiculatus but repelled R. evertsi, whereas that from the anal region had an opposite effect. This odour-based ‘push-pull’ pair of stimuli may largely account for efficient orientation behaviour of the two tick species to their respective feeding sites. We propose that such concurrent deployment of repulsive and attractive cues may be quite widespread among arthropods and related organisms that specialise on specific hosts or microenvironments in the performance of their biological functions.

Ethnoknowledge of Bukusu community on livestock tick prevention and control in Bungoma district, western Kenya

ETHNOPHARMACOLOGICAL RELEVANCE To date, nomadic communities in Africa have been the primary focus of ethnoveterinary research. The Bukusu of western Kenya have an interesting history, with nomadic lifestyle in the past before settling down to either arable or mixed arable/pastoral farming systems. Their collective and accumulative ethnoveterinary knowledge is likely to be just as rich and worth documenting. AIM OF THE STUDY The aim of the present study was to document indigenous knowledge of the Bukusu on the effect of livestock ticks and ethnopractices associated with their management. It was envisaged that this would provide a basis for further research on the efficacy of these practices that could also lead to the discovery of useful tick-control agents. MATERIALS AND METHODS Non-alienating, dialogic, participatory action research (PAR) and participatory rural appraisal (PRA) approaches involving 272 women and men aged between 18 and 118 years from the Bukusu community were used. RESULTS Ticks are traditionally classified and identified by colour, size, host range, on-host feeding sites, and habitat preference. Tick-associated problems recognised include kamabumba (local reference to East Coast fever, Anaplasmosis or Heartwater diseases transmitted by different species of livestock ticks) and general poor performance of livestock. Traditional methods of controlling ticks include handpicking, on-host use of ethnobotanical suspensions (prepared from one or more of over 150 documented plants) to kill the ticks and prevent re-infestation, fumigation of infested cattle with smoke derived from burning ethnobotanical products, burning pastures, rotational grazing ethnopractices, and livestock quarantine. CONCLUSIONS The study confirms that the Bukusu have preserved rich ethnoveterinary knowledge and practices. It provides some groundwork for elucidating the efficacy of some of these ethnopractices in protecting livestock from tick disease vectors, particularly those involving the use of ethnobotanicals, which may lead to the discovery of useful ant-tick agents.

A survey of plants and plant products traditionally used in livestock health management in Buuri district, Meru County, Kenya.

BackgroundUp till now, nomadic communities in Africa have been the primary focus of ethnoveterinary research. Although mainly arable and/or mixed arable/pastoral farmers, Ameru of central Kenya are known to have a rich history of ethnoveterinary knowledge. Their collective and accumulative ethnoveterinary knowledge (EVK) is likely to be just as rich and worth documenting. The aim of the study was to document and analyse the ethnoveterinary knowledge of the Ameru.MethodsNon-alienating, dialogic, participatory action research (PAR) and participatory rural appraisal (PRA) approaches involving 21 women and men aged between 50 and 79 years old were utilized. A combination of snowball and purposive sampling methods were used to select 21 key respondents. The methods comprised a set of triangulation approach needed in EVK for non-experimental validation of ethnoknowledge of the Ameru.ResultsA total of 48 plant species distributed in 26 families were documented with details of diseases/ill-health conditions, parts of plants used and form of preparation and administration methods applied to different animal groups. Of these families, Fabaceae had the highest number of species (16.67%), followed by Solanaceae (12.5%), Asteraceae and Euphorbiacea (each comprising 8.33%), Lamiaceae (6.25%), Apocynaceae and Boraginaceae (each comprising 4.17%), while the rest of the 19 families, each was represented by a single plant species. About 30 livestock diseases/ill-health conditions were described, each treated by at least one of the 48 plant species. Most prevalent diseases/ill-health conditions included: - anaplasmosis, diarrhea, East Coast fever, pneumonia, helminthiasis, general weakness and skin diseases involving wounds caused by ectoparasites.ConclusionThe study showed that there was a rich knowledge and ethnopractices for traditional animal healthcare amongst the Ameru. This study therefore provides some groundwork for elucidating the efficacy of some of these plants, plant products and ethnopractices in managing livestock health as further research may lead to discovery of useful ethnopharmaceutical agents applicable in livestock industry.

Repellent Activities of Essential Oils of Some Plants Used Traditionally to Control the Brown Ear Tick, Rhipicephalus appendiculatus

Essential oils of eight plants, selected after an ethnobotanical survey conducted in Bukusu community in Bungoma County, western Kenya (Tagetes minuta, Tithonia diversifolia, Juniperus procera, Solanecio mannii, Senna didymobotrya, Lantana camara, Securidaca longepedunculata, and Hoslundia opposita), were initially screened (at two doses) for their repellence against brown ear tick, Rhipicephalus appendiculatus, using a dual-choice climbing assay. The oils of T. minuta and T. diversifolia were then selected for more detailed study. Dose-response evaluations of these oils showed that T. minuta oil was more repellent (RD50 = 0.0021 mg) than that of T. diversifolia (RD50 = 0.263 mg). Gas chromatography-linked mass spectrometric (GC-MS) analyses showed different compositions of the two oils. T. minuta oil is comprised mainly of cis-ocimene (43.78%), dihydrotagetone (16.71%), piperitenone (10.15%), trans-tagetone (8.67%), 3,9-epoxy-p-mentha-1,8(10)diene (6.47%), β-ocimene (3.25%), and cis-tagetone (1.95%), whereas T. diversifolia oil is comprised mainly of α-pinene (63.64%), β-pinene (15.00%), isocaryophyllene (7.62%), nerolidol (3.70%), 1-tridecanol (1.75%), limonene (1.52%), and sabinene (1.00%). The results provide scientific rationale for traditional use of raw products of these plants in controlling livestock ticks by the Bukusu community and lay down some groundwork for exploiting partially refined products such as essential oils of these plants in protecting cattle against infestations with R. appendiculatus.

Chemical Composition and Mosquito Repellency of Essential Oil of Tagetes minuta from the Southern Slopes of Mount Elgon in Western Kenya

Ethnopharmacologically, Tagetes minuta has a lot of applications in the history of human life. The study aimed at characterizing the essential oil from fresh aerial parts of T. minuta and evaluating its repellent effect on the host-seeking female Anopheles arabiensis mosquitoes, the vector of African malaria. The oil was obtained by hydrodistillation and analyzed by gas chromatography (GC) and gas chromatographymass spectrometry (GC-MS). Compounds were identified by comparison of their mass spectra with those in Wiley NBS and NIST databases and GC retention times to those of authentic samples. The repellent effect of the essential oil was evaluated using a human-bait technique to simulate field situation. The percentage yield of the essential oil of T. minuta was 0.00029 % w/w with a specific gravity of 0.8953 mg/ml. The oil showed a complex composition of about 119 hydrocarbon compounds and may be richer in monoterpenes (47.90 %) than in any other type of compounds. The main principal constituents of the essential oil of T. minuta included: ocimene, dihydrotagetone, tagetones, ocimenones, piperitenone, 3,9-epoxy-p-metha-1,8(10) diene, βcaryophyllene, bicyclogermacrene and AR-turmerone. Some of these constituents reported in literature have shown insecticidal, acaricidal, pesticidal and/or repellent properties. Although not manifesting a clear general trend, the essential oil however showed a significant dose-response effect of repellency (p < 0.05). More mosquitoes significantly landed and bit the control arm treated with vaseline pure petroleum jelly than the arm treated with the essential oil of T. minuta (p < 0.05), thus showing repellency properties of the oil against An. Arabiensis mosquitoes. Nevertheless, the underlying mechanism of repellency remains unknown. However, the oil may represent a potentially new, most practical and economic way and readily available and applicable malaria vector control tool for incorporation into integrated vector management strategies and contribute to the provision of prophylactic measures, particularly at an individual level.

Characterization and evaluation of repellent effect of essential oil of Mangifera indica L. from Kenya.

Abstract Ethnopharmacologically, the mango has a lot of applications in life in human health and ethnoveterinary medicines since ancient times. The study aimed at characterizing the essential oil of Mangifera indica L. leaves and evaluating its repellent effect on the host-seeking female Anopheles gambiae, the vector of African malaria. The essential oil was obtained by hydrodistillation and analyzed by gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS). The repellent effect of the essential oil was evaluated using the human-bait technique to simulate field situation. Of the 26 major hydrocarbon compounds identified, α-pinene occurred in the largest amount (33.3 %), followed by α-phellandrene (22.6 %), Limonene (13.2 %), p-cymene (6.1 %), Heptane (3.8 %), β-pinene (2.6 %), Ledene (1.3 %), (-)-α-gurjunene (1.2 %), β-myrcene (1.1 %), γ-terpinene (1.0 %), (+)-2-carene (0.9 %) and trans (β)-caryophyllene (0.9 %) in that order. The oil showed a significant dose-dependent repellent effect on host-seeking female Anopheles gambiae s.s. The oil showed a complex composition of hydrocarbon compounds and may be richer in monoterpenes than in any other type of compounds. It showed the potential to repel mosquitoes.

Evaluation of an antigen-ELISA in the diagnosis of bovine cysticercosis in Kenyan cattle

A monoclonal antibody-based antigen-ELISA (Ag-ELISA) was studied in Kenyan cattle with the objective of evaluating its reliability in diagnosing bovine cysticercosis. A total of 55 cattle divided into artificially (n = 30) and naturally (n = 25) infested animals, were utilized. Total dissection was used as a gold standard of validity at autopsy. In natural infestations, the assay identified 16 cases as true seropositives, 2 cases as false seropositives, 3 cases as true seronegatives and 4 cases as false seronegatives. While in artificial infestations, the assay identified 9 cases as true seropositives, 14 cases as true seronegatives and 7 cases as false seronegatives. There weren’t any false seropositive cases identified with artificial infestations. The assay showed good precision level and kappa level in quantifying the relative quality of the amount of agreement in natural (n = 25; k = 0.482; p > 0.05) and artificial (n = 24; k = 0.374; p > 0.05) infestations. The study showed that, besides other advantages, the Ag-ELISA with its sensitivity of 60.00–80.00%, specificity of 60.00–100%, predictive value of 88.89–100%, apparent prevalence of 37.50–72.00% and accuracy of 75.00–76.00% may be recommended for use in combination with other control measures, viz chemotherapy, post-mortem diagnosis and or vaccination.

Ticks (Acari: Ixodidae) Associated with Wildlife and Vegetation of Haller Park along the Kenyan Coastline

Abstract This artcile describes the results obtained from a tick survey conducted in Haller park along the Kenyan coastline. The survey aimed at evaluating tick–host associations, assessing tick population density, and providing baseline information for planning future tick control and management in the park. Ticks (2,968) were collected by handpicking from eight species of wildlife and by dragging in 14 selected sites within the park. A considerable proportion of ticks were also collected from leaves, stems, and bark of most dominant trees, namely, Casuarina equisetifolia L. (Forst. & Forst.), Cocos nucifera L., Adansonia digitata L., Musa paradisiaca L., and Azadiracta indica Adr. Juss. Dragging was conducted in sites predominantly occupied by Cynodon dactylon L. (Pers.), Cenchrus ciliaris L., Stenotaphrum dimidiatum L. (Kuntze.) Brongn., and Brachiaria xantholeuca Hack. Ex Schinz Stapf. and Loudetia kagerensis K. Schum. Hutch. Eight tick species were identified, and the collection included Rhipicephalus pravus Dönitz 1910, Rhipicephalus pulchellus Gerstäcker 1873, Hyalomma marginatum rufipes Koch 1844, Amblyomma gemma Dönitz 1910, Amblyomma hebraeum Koch 1844, Amblyomma sparsum Neumann 1899, Amblyomma nuttalli Dönitz 1909, and Boophilus decoloratus Koch 1844. Given that the identified tick species are known to parasitize humans as well as livestock, there exist risks of emergence of zoonotic infections mediated by tick vectors. In the recreational environment of Haller park, where tick vectors share habitats with hosts, there is a need to develop sustainable and effective tick control and management strategies to minimize economic losses that tick infestation may cause.

Chemical Composition and Antibacterial Activity of Essential Oils of Tagetes minuta (Asteraceae) against Selected Plant Pathogenic Bacteria

The objective of this study was to determine the chemical composition and antibacterial activity of essential oils (EOs) of Tagetes minuta against three phytopathogenic bacteria Pseudomonas savastanoi pv. phaseolicola, Xanthomonas axonopodis pv. phaseoli, and Xanthomonas axonopodis pv. manihotis. The essential oils were extracted using steam distillation method in a modified Clevenger-type apparatus while antibacterial activity of the EOs was evaluated by disc diffusion method. Gas chromatography coupled to mass spectrometry (GC/MS) was used for analysis of the chemical profile of the EOs. Twenty compounds corresponding to 96% of the total essential oils were identified with 70% and 30% of the identified components being monoterpenes and sesquiterpenes, respectively. The essential oils of T. minuta revealed promising antibacterial activities against the test pathogens with Pseudomonas savastanoi pv. phaseolicola being the most susceptible with mean inhibition zone diameters of 41.83 and 44.83 mm after 24 and 48 hours, respectively. The minimum inhibitory concentrations and minimum bactericidal concentrations of the EOs on the test bacteria were in the ranges of 24–48 mg/mL and 95–190 mg/mL, respectively. These findings provide a scientific basis for the use of T. minuta essential oils as a botanical pesticide for management of phytopathogenic bacteria.

Potential of Traditional Knowledge of Plants in the Management of Arthropods in Livestock Industry with Focus on (Acari) Ticks

Antitick plants and related ethnoknowledge/ethnopractices with potential for integrated tick control and management strategies to improve livestock production are reviewed. About 231 plants reviewed showed a variety of bioactive properties, namely, being toxic, repellent, antifeedant, and antiovipositant and ability to immobilize target tick species. These ethnobotanical substances are potentially useful in developing sustainable, efficient, and effective antitick agents suitable for rural livestock farmers. Majority of these plants are holistic in action, economically affordable, user friendly, easily adaptable and accessible, and environmentally friendly and help develop community-driven tick control interventions well suited to local conditions and specific to different livestock communities. Such a multipurpose intervention best fits the recent ascendancy of individual livestock owners as the key players in tick control programmes, particularly following the withdrawal of subsidies accorded to tick control programmes by most African government agencies since mid-1980s. However, scientific validation of antitick ethnobotanicals on their efficacy and formulation of packages easily handled by local communities is necessary to achieve a significantly increased use of such remedies. It is envisaged that the results of validation may lead to the discovery of effective and affordable antitick products. The effectiveness of these “best bets” ethnopractices can be greatest, if they are appropriately blended with conventional technologies.