scholarly journals Learning influences host choice in tsetse

2006 ◽  
Vol 3 (2) ◽  
pp. 113-117 ◽  
Author(s):  
Jérémy Bouyer ◽  
Mathieu Pruvot ◽  
Zacharia Bengaly ◽  
Patrick M Guerin ◽  
Renaud Lancelot

A learning capacity for feeding is described in many insect species including vectors of diseases, but has never been reported in tsetse flies (Diptera, Glossinidae), the cyclic vectors of human (sleeping sickness) and animal trypanosomoses in Africa. Repeated feeding on the same host species by a disease vector is likely to increase the within-species disease-transmission risk, but to decrease it between species. An experiment with cattle and reptiles in a stable provides evidence that the species of host selected for the second blood meal in tsetse flies depends on the host encountered for the first blood meal when the between-meal interval is 2 days. This preference disappears when the between-meal interval is extended to 3 days. The energetic advantages of this acquired preference and its importance in trypanosomoses epidemiology are discussed.

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Fiona Teltscher ◽  
Sophie Bouvaine ◽  
Gabriella Gibson ◽  
Paul Dyer ◽  
Jennifer Guest ◽  
...  

Abstract Background Mosquito-borne diseases are a global health problem, causing hundreds of thousands of deaths per year. Pathogens are transmitted by mosquitoes feeding on the blood of an infected host and then feeding on a new host. Monitoring mosquito host-choice behaviour can help in many aspects of vector-borne disease control. Currently, it is possible to determine the host species and an individual human host from the blood meal of a mosquito by using genotyping to match the blood profile of local inhabitants. Epidemiological models generally assume that mosquito biting behaviour is random; however, numerous studies have shown that certain characteristics, e.g. genetic makeup and skin microbiota, make some individuals more attractive to mosquitoes than others. Analysing blood meals and illuminating host-choice behaviour will help re-evaluate and optimise disease transmission models. Methods We describe a new blood meal assay that identifies the sex of the person that a mosquito has bitten. The amelogenin locus (AMEL), a sex marker located on both X and Y chromosomes, was amplified by polymerase chain reaction in DNA extracted from blood-fed Aedes aegypti and Anopheles coluzzii. Results AMEL could be successfully amplified up to 24 h after a blood meal in 100% of An. coluzzii and 96.6% of Ae. aegypti, revealing the sex of humans that were fed on by individual mosquitoes. Conclusions The method described here, developed using mosquitoes fed on volunteers, can be applied to field-caught mosquitoes to determine the host species and the biological sex of human hosts on which they have blood fed. Two important vector species were tested successfully in our laboratory experiments, demonstrating the potential of this technique to improve epidemiological models of vector-borne diseases. This viable and low-cost approach has the capacity to improve our understanding of vector-borne disease transmission, specifically gender differences in exposure and attractiveness to mosquitoes. The data gathered from field studies using our method can be used to shape new transmission models and aid in the implementation of more effective and targeted vector control strategies by enabling a better understanding of the drivers of vector-host interactions.


2018 ◽  
Author(s):  
James Orsborne ◽  
Luis Furuya-Kanamori ◽  
Claire L. Jeffries ◽  
Mojca Kristan ◽  
Abdul Rahim Mohammed ◽  
...  

AbstractDifficulties with observing the dispersal of insect vectors in the field have hampered understanding of several aspects of their behaviour linked to disease transmission. Here, a novel method based on detection of blood-meal sources is introduced to inform two critical and understudied mosquito behaviours: plasticity in the malaria vector’s blood-host choice and vector dispersal. Strategically located collections of Anopheles coluzzii from a malaria-endemic village of southern Ghana showed statistically significant variation in host species composition of mosquito blood-meals. Trialling a new sampling approach gave the first estimates for the remarkably local spatial scale across which host choice is plastic. Using quantitative PCR, the blood-meal digestion was then quantified for field-caught mosquitoes and calibrated according to timed blood digestion in colony mosquitoes. We demonstrate how this new ‘molecular Sella score’ approach can be used to estimate the dispersal rate of blood-feeding vectors caught in the field.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Divine Ekwem ◽  
Thomas A. Morrison ◽  
Richard Reeve ◽  
Jessica Enright ◽  
Joram Buza ◽  
...  

AbstractIn Africa, livestock are important to local and national economies, but their productivity is constrained by infectious diseases. Comprehensive information on livestock movements and contacts is required to devise appropriate disease control strategies; yet, understanding contact risk in systems where herds mix extensively, and where different pathogens can be transmitted at different spatial and temporal scales, remains a major challenge. We deployed Global Positioning System collars on cattle in 52 herds in a traditional agropastoral system in western Serengeti, Tanzania, to understand fine-scale movements and between-herd contacts, and to identify locations of greatest interaction between herds. We examined contact across spatiotemporal scales relevant to different disease transmission scenarios. Daily cattle movements increased with herd size and rainfall. Generally, contact between herds was greatest away from households, during periods with low rainfall and in locations close to dipping points. We demonstrate how movements and contacts affect the risk of disease spread. For example, transmission risk is relatively sensitive to the survival time of different pathogens in the environment, and less sensitive to transmission distance, at least over the range of the spatiotemporal definitions of contacts that we explored. We identify times and locations of greatest disease transmission potential and that could be targeted through tailored control strategies.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Eve Afonso ◽  
Rong Fu ◽  
Amaël Dupaix ◽  
Anne-Claude Goydadin ◽  
ZhongHua Yu ◽  
...  

AbstractAn increasing number of studies have found that the implementation of feeding sites for wildlife-related tourism can affect animal health, behaviour and reproduction. Feeding sites can favour high densities, home range overlap, greater sedentary behaviour and increased interspecific contacts, all of which might promote parasite transmission. In the Yunnan snub-nosed monkey (Rhinopithecus bieti), human interventions via provisioning monkeys at specific feeding sites have led to the sub-structuring of a group into genetically differentiated sub-groups. The fed subgroup is located near human hamlets and interacts with domesticated animals. Using high-throughput sequencing, we investigated Entamoeba species diversity in a local host assemblage strongly influenced by provisioning for wildlife-related tourism. We identified 13 Entamoeba species or lineages in faeces of Yunnan snub-nosed monkeys, humans and domesticated animals (including pigs, cattle, and domestic chicken). In Yunnan snub-nosed monkeys, Entamoeba prevalence and OTU richness were higher in the fed than in the wild subgroup. Entamoeba polecki was found in monkeys, pigs and humans, suggesting that this parasite might circulates between the wild and domestic components of this local social–ecological system. The highest proportion of faeces positive for Entamoeba in monkeys geographically coincided with the presence of livestock and humans. These elements suggest that feeding sites might indirectly play a role on parasite transmission in the Yunnan snub-nosed monkey. The implementation of such sites should carefully consider the risk of creating hotspots of disease transmission, which should be prevented by maintaining a buffer zone between monkeys and livestock/humans. Regular screenings for pathogens in fed subgroup are necessary to monitor transmission risk in order to balance the economic development of human communities dependent on wildlife-related tourism, and the conservation of the endangered Yunnan snub-nosed monkey.


2019 ◽  
Vol 57 (3) ◽  
pp. 957-961
Author(s):  
Kyran M Staunton ◽  
Barukh B Rohde ◽  
Michael Townsend ◽  
Jianyi Liu ◽  
Mark Desnoyer ◽  
...  

Abstract Aedes aegypti (Linnaeus), the primary vectors of the arboviruses dengue virus and Zika virus, continue to expand their global distributions. In efforts to better control such species, several mosquito control programs are investigating the efficacy of rearing and releasing millions of altered male Aedes throughout landscapes to reduce populations and disease transmission risk. Unfortunately, little is known about Ae. aegypti, especially male, dispersal behaviors within urban habitats. We deployed Sound-producing Gravid Aedes Traps (SGATs) in Cairns, northern Australia, to investigate male Ae. aegypti attraction to various oviposition container configurations. The traps were arranged to include: 1) water only, 2) organically infused water, 3) infused water and L3 larvae, 4) infused water and a human-scented lure, and lastly 5) no water or olfactory attractant (dry). Our data suggest that males were more attracted to SGATs representing active larval sites than potential larval sites, but were equally attracted to dry SGATs relative to those containing water and/or infusion. Additionally, we found that female Ae. aegypti were equally attracted to wet SGATs, with or without infusion, but not dry ones. These results suggest that male Ae. aegypti within northern Australia are more attracted to active larval sites and equally attracted to dry containers as wet or infused ones. Additionally, female Ae. aegypti are unlikely to enter dry containers. Such findings contribute to our understanding of potentially attractive features for local and released Ae. aegypti throughout the northern Australian urban landscape.


2008 ◽  
Vol 8 (4) ◽  
pp. 565-574 ◽  
Author(s):  
Satoru Konnai ◽  
Hirohisa Mekata ◽  
Raadan Odbileg ◽  
Martin Simuunza ◽  
Mwelwa Chembensof ◽  
...  
Keyword(s):  

1983 ◽  
Vol 61 (8) ◽  
pp. 1888-1891 ◽  
Author(s):  
C. B. Carruthers ◽  
K. G. Davey

In tsetse flies, a larva grows to maturity inside the uterus of the female. The size of the blood meal imbibed by females is known to increase at ovulation and decrease as the larva gets larger, so that the total volume of the fly remains constant. This has led to the hypothesis that meal size is determined by cuticular elasticity. Direct measurement of the elasticity of abdominal cuticle in mated females, before and after ovulation, and in virgin females, which do not ovulate, demonstrates that cuticular elasticity is unrelated to ovulation. Further, meal size is not closely correlated with cuticular elasticity. The hypothesis is therefore rejected.


2014 ◽  
Vol 7 (3) ◽  
pp. 193-198 ◽  
Author(s):  
Solange Ribeiro Peixoto ◽  
José Jurberg

Rhodnius stali Lent, Jurberg & Galvão vetor da Doença de Chagas domiciliado na região do Alto Beni, Bolívia é uma espécie com a biologia pouco conhecida. Com o objetivo de ampliar o conhecimento acerca de sua biologia, observamos parâmetros de seu ciclo de vida, nos estádios de ninfa, comparando-os com Rhodnius pictipes Stål, espécie morfologicamente semelhante e filogeneticamente próxima. Os seguintes parâmetros foram observados: tempo de eclosão dos ovos, ciclo biológico de ovo-adulto (em machos e fêmeas separadamente), taxa de mortalidade, idade do primeiro repasto sanguíneo e volume de sangue ingerido pelas ninfas. De maneira geral observou-se que as R. stali tem um ciclo de vida mais longo do que R. pictipes e, em ambas espécies, o tempo entre a eclosão do ovo até a fase adulta é menor em fêmeas. Curiosamente para R. stali, que é sabidamente capaz de colonizar domicílios, foi observada uma taxa de mortalidade das ninfas mais alta que em R. pictipes, algo inesperado para a espécie que coloniza estruturas artificiais e foi observada em ambiente artificial. Para R. stali, o primeiro repasto sanguíneo ocorreu, em média, quatro dias mais tarde do que em R. pictipes, espécie que ingeriu um volume total de sangue maior, possivelmente pelo fato de seu corpo ser maior. Conhecendo-se com profundidade os aspectos biológicos dessas espécies será possível direcionar o controle vetorial com mais precisão, principalmente em regiões onde colonizam casas, como no Alto Beni, Bolívia. Biology of Rhodnius stali Lent, Jurberg & Galvão and Rhodnius pictipes Stål (Hemiptera, Reduviidae, Triatiminae) in Laboratory Conditions Abstract. Rhodnius stali Lent, Jurberg & Galvão is a Chagas Disease vector that colonize houses in the Alto Beni region, Bolivia and its biology is poorly known. Aiming to enhance the understanding about their biology, we observed a few parameters of its life cycle, at nymphal stages, comparing them with Rhodnius pictipes Stål a morphologically similar and phylogenetically close species. The following parameters were observed: time of hatching, development time from egg to adult (male and female separately), mortality rate, age at first blood meal and blood volume ingested by nymphs. In general, it was observed that the R. stali has longer cycle than R. pictipes, and in both species, the time between hatching the egg to adult in females is lower. Interestingly for R. stali, which is known to be capable of colonizing households, the mortality rate of nymphs was higher than observed in R. pictipes, something unexpected for species that colonize artificial structures and was observed in artificial environment. For R. stali, the first blood meal was, on average, four days later than for R. pictipes, species that ingested a greater total blood volume, possibly because of its bigger size. By knowing in depth the biological aspects of these species it will be possible to direct vector control more accurately, especially in regions where they colonize houses, as in the Alto Beni, Bolivia.


2017 ◽  
Vol 145 (12) ◽  
pp. 2582-2593 ◽  
Author(s):  
M. STRÖMGREN ◽  
E. HOLM ◽  
Ö. DAHLSTRÖM ◽  
J. EKBERG ◽  
H. ERIKSSON ◽  
...  

SUMMARYThis study aims to develop a typology of generic meeting places based on social contact and mixing of relevance for infectious disease transmission. Data were collected by means of a contact diary survey conducted on a representative sample of the Swedish population. The typology is derived from a cluster analysis accounting for four dimensions associated with transmission risk: visit propensity and its characteristics in terms of duration, number of other persons present and likelihood of physical contact. In the analysis, we also study demographic, socio-economic and geographical differences in the propensity of visiting meeting places. The typology identifies the family venue, the fixed activity site, the family vehicle, the trading plaza and the social network hub as generic meeting places. The meeting place typology represents a spatially explicit account of social contact and mixing relevant to infectious disease modelling, where the social context of the outbreak can be highlighted in light of the actual infectious disease.


Parasitology ◽  
2000 ◽  
Vol 120 (3) ◽  
pp. 319-327 ◽  
Author(s):  
D. W. KELLY ◽  
C. E. THOMPSON

Existing models of the basic case reproduction number (R0) for vector-borne diseases assume (i) that the distribution of vectors over the susceptible host species is homogenous and (ii) that the biting preference for the susceptible host species rather than other potential hosts is a constant. Empirical evidence contradicts both assumptions, with important consequences for disease transmission. In this paper we develop an Ideal Free Distribution (IFD) model of host choice by blood-sucking insects, predicated on the argument that vectors must have evolved to choose the least defensive hosts in order to maximize their feeding success. From a re-analysis of existing data, we demonstrate that the interference constant, m, of the IFD can vary between host species. As a result, the predicted distribution of insects over hosts has 2 desirable and intuitively plausible behaviours: that it is heterogeneous both within and between host species; and that the intensity of heterogeneity varies with host and vector density. When the IFD model is incorporated into R0, the relationship with the vector: host ratio becomes non-linear. If correct, the IFD could add considerable realism to models which seek to predict the effect of these ecological parameters on disease transmission as they vary naturally (e.g. through seasonality in vector density or host population movement) or as a consequence of artificial manipulation (e.g. zooprophylaxis, vector control). It raises the possibility of targeting transmission hot spots with greater accuracy and concomitant reduction in control effort. The robustness of the model to simplifying assumptions is discussed.


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