Natural and experimental studies on domestic animal infections with visceral and cutaneous leishmaniases in Kenya

The control of visceral and cutaneous leishmaniases in Kenya has been difficult due to poor knowledge of animal reservoirs of these diseases. Little is known about the feeding preferences of phlebotomine sand flies that transmit some of the leishmaniases that are endemic in some areas in Kenya, which makes it difficult to control the diseases by targeting the animal reservoirs. This article reviews the efforts that have been made to identify reservoirs of known Leishmania parasites that cause leishmaniases in Kenya. The account includes studies that have been carried out on Kenyan canids, felines, ungulates and murines

Stressed Out: Why Does Ancient Maize Thrive in High-Stress Conditions?

Why is understanding stress response in maize so important? Maize, along with rice and wheat, provide at least 30% of calories to over 4.5 billion people Increases in flooding events has heavily impacted natural vegetation and crop production Combinatorial stresses, particularly flooding and herbivory, remain understudied for both modern and ancient verities of maize Ancient maize may be a superior genetic resource for flood-tolerant cor

The Tomato Strikes Back: Plant Response to Environmental Stress

Introduction Tomato is an important vegetable. Its production is threatened due to altered weather patterns which increase environmental stressors such as flooding1, 2 and herbivory3 to crops. Plants respond in many ways. Stressed plants strike back to environmental stress by altering their chemistry4: Volatile Organic Compounds (VOCs) emissions Defensive secondary metabolites2 Stress induced physiological changes in plants impact growth and development of insects. This study is broken into two experiments: The plant response to flooding stress The insect performance on flooded plant

Sometimes, When it Rains it Pours: How Does Flooding Alter Plant-Herbivore Relationships?

Flooding, an under-studied abiotic stressor, creates hostile soil conditions, including hypoxia, which hinder the growth and development of plants. Plants respond to abiotic and biotic stressors. A common response is the production of volatile organic compounds (VOCs), which modulate stress responses and mediate plant and insect interactions. Flooding causes significant losses in crops of agricultural and economic importance including tomato. Understanding how flooding impacts plant growth, plant chemistry, caterpillar performance and chemical mediated plant-herbivore interactions will create fundamental knowledge to an emerging challenge brought about by climate change and inform pest management decisions post flooding events. This study investigated how flooding alters tomato plant volatile emissions and affects caterpillar growth and performance

Exploration of Squash Plant Floral Volatiles Influencing Beetle Attraction

Flowers emit volatiles to attract pollinators, but these volatiles can also attract pest insects. Our study builds on earlier findings that showed that cucumber beetle attraction to squash flowers is mediated by volatile release and cucurbitacin accumulation (Theis, 2014, DOI: 10.3732/ajb.1400171). Of the three main domesticated squash species, only a few varieties of Cucurbita maxima had large quantities of floral volatiles and cucurbitacin (Andersen and Metcalf, 1987, doi: 10.1007/BF01020152); however, these studies were limited in the number of varieties that were examined. Here, we increased the number of C. maxima varieties examined, to identify patterns in floral volatile production, with the goal of identifying correlations between specific volatiles and beetle attraction. The findings from this study support a larger project, Fighting Fire with FIRE: Exploiting Corn Rootworm Attraction to Manipulate Pest Behavior

Pathogenicity of Metarhizium anisopliae (Metch) Sorok and Beauveria bassiana (Bals) Vuill to adult Phlebotomus duboscqi (Neveu-Lemaire) in the laboratory

Background & objectives: Biological control of sandflies using entomopathogenic fungi is a possible alternativeto the expensive synthetic chemical control. It is potentially sustainable, less hazardous, and relatively inexpensiveand merits further investigations. The objective of this study was to identify the most pathogenic fungal isolate(s)to sandflies in the laboratory.Methods: Isolates of entomopathogenic fungi Metarhizium anisopliae and Beauveria bassiana were screenedfor their pathogenicity against Phlebotomus duboscqi. Adult flies were contaminated using the technique describedby Migiro et al (2010). Briefly, flies were exposed to 0.1 g of dry conidia evenly spread on a cotton velvet clothcovering the inner side of a cylindrical plastic tube (95 mm long × 48 mm diam). In all 25 sandflies weretransferred into the cylindrical tube and allowed to walk on the velvet for one minute, after which they weretransferred from the velvet into the cages in Perplex. Insects in the control treatments were exposed to fungusfree velvet cloth before being transferred into similar cages. The treatments were maintained at 25 ± 2°C,60–70% RH and 12L: 12D photoperiod. The experiment was replicated 5 times. The most pathogenic isolateswere selected for further studies.Results: A total of 19 isolates were screened against adult sandflies in the laboratory. Mortality in the controlswas approximately 16.8 ± 1.7 %. All the isolates were found to be pathogenic to P. duboscqi. Mortality rangedbetween 76.8 and 100% on all the fungal isolates tested. The lethal time taken to 50% (LT50) and 90% (LT90(mortality ranged from 3.0–7.8 days and from 5.3–16.2 days, respectively. The virulent isolates, causing mortalitiesof 97.5–100%, were selected for further studies.Interpretation & conclusion: The high susceptibility of sandflies to entomopathogenic fungi suggests that fungiare potential alternatives to chemical control methods. We conclude that application of entomopathogenic fungicould result in acute mortalities of sandflies and reduction of parasite transmission and subsequently, reductionof leishmaniasis risk. This method of biological control has great potential as a new strategy for leishmaniasiscontro

The viability of lifestyle audits as an emerging anticorruption tool in the public sector: Concepts, essentials and prospects

Lifestyle audits are viable tools in the fight against corruption. Unfortunately, they have not been sufficiently developed or adopted despite their effectiveness in combatting corruption. For long, countries have deployed diverse anti-corruption strategies under various international, regional and national legal frameworks. Despite these efforts, corruption continues to permeate every sector of national economies, with debilitating effects on development goals and the well-being of populations. Most of the anti-corruption strategies adopted, focus on the integrity of the operational systems of public institutions on the one hand, and personal integrity of their public officials on the other

Nocturnal activities of phlebotomine sand flies (Diptera: Psychodidae) in Baringo County, Kenya

Leishmaniasis is a disease of both humans and animals. It is transmitted by the bite of sand flies of the genus Phlebotomus in the Old World and Lutzomyia in the New World. Nocturnal activities of phlebotomine sand flies were monitored by trapping flies exiting and entering termite mounds and animal burrows in Baringo County. Exit/entrance traps were set from dusk to midnight and from midnight to dawn in the termite mound and animal burrow openings. The study which lasted seven months (November 1993/May 1994), was designed to reveal sand fly behavior in their natural habitats. A total of 11,787 sand flies was trapped and their nocturnal activities studied. Significantly more sand flies(85.6%) were caught exiting than entering animal burrows and termite mounds in the 1st half of the night p<0.05. This trend was reversed by sand flies (61.4%) caught entering the burrows termite mounds during the 2nd half of the night p<0.05. Most sugar/positive sand flies were collected after midnight in both animal burrows and termite mounds while more blood/fed sand flies were caught in the 1st than in the 2nd half of the night p<0.05. At Perkerra, 87.8% of the blood/fed female sand flies were trapped in the 1st half of the night compared with 12.2% caught in the 2nd half. At Rabai, 72.6% of the total number of those caught blood fed were in the 1st half and 27.4% in the 2nd half of the night. P. martini which is the vector of L. donovani which causes visceral leishmaniasis, was predominantly trapped in termite mounds whereas P duboscqi (vector of L. major) that causes cutaneous leishmaniasis, was trapped in large numbers in animal burrows. These habitats pre/dispose themselves as ideal targets for control measures of the vectors. Keywords: Sugar, blood feeding, sand flies, animal burrows, termite mounds, Keny

Laboratory and semi-field evaluation of long-lasting insecticidal nets against leishmaniasis vector, Phlebotomus (Phlebotomus) duboscqi in Kenya

Background & objectives: Phlebotomine sandflies are vectors of leishmaniases and other diseases.Long-lasting insecticidal nets (LLINs) as possible tools for control have not been widely testedagainst them. The objective of this study was to determine the efficacy of Olyset® Net and PermaNet®LLINs alongside a local brand, K-O Tab® treated net (Supanet) against Phlebotomus duboscqifemale sandflies.Methods: Four replicates of unwashed and 20x washed Olyset Nets and PermaNets, K-O Tabtreatedand untreated Supanet and ‘no net’ treatments were evaluated against sandflies within thelaboratory by tunnel tests and in semi-field conditions in the greenhouse model for their efficacy.Results: All bednets allowed entry of P. duboscqi sandflies and subsequent blood-feeding. Olysetnet’s blood feeding inhibition was significantly higher than that of Supanet in the laboratory butnot in semi-field condition. Of the LLINs, only Olyset net had sandflies that could not feedsignificantly more than those of Supanet. Additionally, no significant efficacy difference wasobserved between LLINs washed 20x and unwashed ones. The only significant difference noted innumber of sandflies that were found dead or paralyzed within bednets in the semi-field conditionwas between Olyset and K-O Tab treated Supanet. In the laboratory, unwashed Olyset had asignificantly higher number of sandflies killed than all other bednet treatments.Conclusion: Olyset net use in areas where sandflies are nuisance biters and/or disease vectorscould be more beneficial in preventing sandfly bites than other tested bednets. It is recommendedthat mesh sizes of LLINs should be smaller for control of sandflies than those used for control ofmosquitoes

Activity Budget and Foraging Patterns of Nubian Giraffes (\u3cem\u3eGiraffa camelopardalis camelopardalis\u3c/em\u3e) in Lake Nakuru National Park, Kenya

How animals decide to spend their time has a key impact on their survival and reproduction. These behavioral decisions are shaped by ecological and environmental factors, such as seasonal changes. Foraging patterns show how an animal chooses to forage in its environment as influenced by resource availability, competition, and predation risk. Giraffe activity budget has been investigated in populations across Africa and found to be influenced by body size, diet composition, and sex. The activity budget and foraging patterns of Nubian giraffes vary considerably between ecosystems. The Nubian giraffe, a subspecies of the Northern giraffe species (Giraffa Camelopardalis) is a critically endangered population and occurs only within Kenya, Uganda, Ethiopia, and Southern Sudan. We performed 3 months of behavioral observation on a population of Nubian giraffes in Lake Nakuru National Park, Kenya, to assess seasonal activity budgets and foraging patterns. We found that in the wet and dry seasons giraffe spent approximately the same amount of time (53% and 57%, respectively) foraging. Movement and resting duration decreased slightly from dry to wet seasons 22% to 20% and 25% to 22% respectively. Across both seasons, Vachellia xanthophloea (67%), Maytenus senegalensis (19%), and Solanum incanum (9%) made up the bulk of giraffe\u27s diet. In the dry season, giraffes additionally foraged on Maerua triphylla (2%), Vachellia gerrardi (2%), and Grewia similis (1%); in the wet season, they added Vachellia abyssinica (2%) and Rhus natalensis (2%) to their diet. The most utilized browsing height was 3.5 meters (level 5), below their average height. Giraffes browse at lower heights after they consume the young shoots from the top of the bushes. Overall, seasonality did not appear to influence the Nubian giraffe\u27s activity budget or foraging patterns in LNNP. Planting perennial plants encourage uniform park resource use, boosts forage diversity, and minimizes Vachellia browsing pressure