Entomology Research Papers/Topics

Spatial distribution and habitat characterization of mosquito species during the dry season along the Mara River and its tributaries, in Kenya and Tanzania

Abstract/Overview Background: Vector-borne diseases are increasingly becoming a major health problem among communities living along the major rivers of Africa. Although larger water bodies such as lakes and dams have been extensively researched, rivers and their tributaries have largely been ignored. This study sought to establish the spatial distribution of mosquito species during the dry season and further characterize their habitats along the Mara River and its tributaries. Methods: In...

Presence and distribution of mosquito larvae predators and factors influencing their abundance along the Mara River, Kenya and Tanzania

Abstract/Overview Among all the malaria controlling measures, biological control of mosquito larvae may be the cheapest and easiest to implement. This study investigated baseline predation of immature mosquitoes by macroinvertebrate predators along the Mara River, determined the diversity of predators and mosquito larvae habitats and the range of their adaptive capacity to water physico-chemical parameters. Between July and August 2011, sampling sites (n=39) along the Mara River were sele...

Laboratory tests of oviposition by the African malaria mosquito, Anopheles gambiae, on dark soil as influenced by presence or absence of vegetation

Abstract/Overview Background Physical objects like vegetation can influence oviposition by mosquitoes on soil or water substrates. Anopheles gambiae s. l. is generally thought to utilize puddles over bare soil as its prime larval habitat and to avoid standing water populated with vegetation. In Kisian, Kenya near Kisumu, water often pools in grassy drainage areas both during and after periods of infrequent rains, when typical puddle habitats become scarce because of drying. This raised th...

Mapping potential Anopheles gambiae s.l.larvaldistribution using remotely sensed climatic andenvironmental variables in Baringo, Kenya

Abstract/Overview Anopheles gambiae s.l. (Diptera: Culicidae) is responsible for the transmission of the devastating Plasmodium falciparum (Haemosporida: Plasmodiidae) strain of malaria in Africa. This study investigated the relationship between climate and environmental conditions and An. gambiae s.l. larvae abundance and modelled the larval distribution of this species in Baringo County, Kenya. Mosquito larvae were collected using a 350-mL dipper and a pipette once per month from Decemb...

Isolation and characterization of a novel Rickettsia species (Rickettsia asembonensis sp. nov.) obtained from cat fleas (Ctenocephalides felis)

Abstract/Overview A novel rickettsial agent, ‘Candidatus Rickettsia asembonensis’ strain NMRCiiT, was isolated from cat fleas, Ctenocephalides felis, from Kenya. Genotypic characterization of the new isolate based on sequence analysis of five rickettsial genes, rrs, gltA, ompA, ompB and sca4, indicated that this isolate clustered with Rickettsia felis URRWXCal2. The degree of nucleotide similarity demonstrated that isolate NMRCiiT belongs within the genus Rickettsia and fulfils the cr...

Influence Of Drought On Interactions Among Aphids, Aphid Predators And Fusarium Infection On Barley Crop In Sweden

Abstract Climate-change leads to extreme droughts, but it is difficult to predict how crop pests are affected. Drought may alter behavior of crop pests such as aphids that facilitate transmission of pathogens like Fusarium graminearum, causing Fusarium foot and root rot in barley crops by feeding close to the susceptible base of plants. Ground dwelling generalist predators like Carabid beetles, and wolf spiders are important aphid enemies during the aphid colonization phase in barley crops i...

Spatial Heterogeneity of Malaria Vectors and Malaria Transmission Risk Estimated Using Odour-Baited Mosquito Traps

Abstract/Overview Prior to the commencement of a large-scale malaria intervention study on Rusinga Island, western Kenya, intensive baseline surveillance of the mosquito population was performed using odour-baited traps. The survey aimed to determine the relative abundance and species composition of malaria vectors, and to measure seasonal and spatial heterogeneity in populations. Human malaria prevalence was combined with entomological data to provide information about malaria transmissi...

Profiles of bacterial communities and environmental factors associated with proliferation of malaria vector mosquitoes within the Kenyan Coast

Abstract Background. Since Anopheles mosquitoes which transmit and maintain the malaria parasite breed in the outdoor environment, there is an urgent need to manage these mosquito breeding sites. In order to elaborate more on the ecological landscape of mosquito breeding sites, the bacterial community structure and their interactions with physicochemical factors in mosquito larval habitats was characterised in Kwale County (Kenya), where malaria is endemic. Methods. The physical characterist...

Insecticide resistant Anopheles gambiae have enhanced longevity but reduced reproductive fitness and a longer first gonotrophic cycle

Abstract Widespread insecticide resistance in African malaria vectors raises concerns over the potential to compromise malaria vector control interventions. Understanding the evolution of resistance mechanisms, and whether the selective disadvantages are large enough to be useful in resistance management or designing suitable control strategies is crucial. This study assessed whether insecticide resistance to pyrethroids has an effect on the gonotrophic cycle and reproductive potential of ma...

Isolation and Characterization of Bacteria from Lakes Olbolosat and Oloiden, Kenya

Abstract There is still unexplored reservoir of microorganisms from sediments and water within Lakes Olbolosat and Oloiden using culture dependent technique. The current study compares bacterial diversity within Lake Olbolosat a freshwater lake and Lake Oloiden a saline alkaline lake. Out of 60 isolates obtained from sediments and water samples, 35 were from Lake Olbolosat and 25 from Lake Oloiden. Microbial count ranged between 0-1.75× 10 5 cfu/ml from both lakes. There was a significant d...

Mitochondrial DNA variation of Bemisia tabaci (gennadius) (hemiptera: aleyrodidae) infesting cassava in Kenya

Abstract Bemisia tabaci is a widely distributed crop pest affecting the yield of a broad range of agricultural, fiber, vegetableand ornamental crops. It is an extremely polyphagous pest that causes direct damage and can act as a vector ofviral plant diseases. Populations of Bemisia tabaci that are morphologically indistinguishable and with differentbiological traits have been known to exist; they show differences in rates of development, host range, insecticideresistance and virus transmissi...

Effects of pea aphid secondary endosymbionts on aphid resistance and development of the aphid parasitoid Aphidius ervi: a correlative study

Abstract In order to reduce parasite-induced mortality, hosts may be involved in mutualistic interactions in which the partner contributes to resistance against the parasite. The pea aphid, Acyrthosiphon pisum Harris (Hemiptera: Aphididae), harbours secondary bacterial endosymbionts, some of which have been reported to confer resistance against aphid parasitoids. Although this resistance often results in death of the developing parasitoid larvae, some parasitoid individuals succeed in develo...

Entomopathogenic nematode interactions with white grubs from forest and sugarcane plantations

Abstract: In South Africa, white grubs are important pests of sugarcane and wattle. There is need for a sustainable management alternative since their control has mainly been through the use of chemical insecticides. Such alternatives can include the use of entomopathogenic nematodes, EPNs. A review of the available literature revealed that EPNs can potentially provide a higher percentage control of white grubs, when compared to chemical insecticides. However, this control efficacy is charac...

Ant diversity and body size patterns across an altitudinal gradient in the Drakensberg Mountains, South Africa

Abstract: Patterns of invertebrate species richness and body size across elevational gradients have been well-documented in a variety of studies. However, very little is known about the factors that govern these patterns along elevational gradients. A number of studies have have reported a monotonic decrease in species richness with increasing elevation; while others have observed a hump-shaped pattern, where the peak of species richness occurs at an intermediate elevation. For body size, st...

Host plant preference of Rhopalosiphum padi (Hemiptera: Aphididae) and its role in selecting crop border plants to reduce Potato virus Y (PVY) in seed potatoes

Abstract: Winged Rhopalosiphum padi in search of good quality host plants transmit the non-persistent Potato virus Y (PVY) to seed potatoes. Planting a non-virus host plant as a border around the main crop can reduce PVY incidence, because aphids tend to land in high numbers at the edge of a field and the crop border acts as a virus sink. Using a trap crop could increase the number of aphids landing in the border. During host-plant searching behaviour, alate (winged) aphids respond to short ...


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