scholarly journals Effects of co-habitation between Anopheles gambiae s.s. and Culex quinquefasciatus aquatic stages on life history traits

2012 ◽  
Vol 5 (1) ◽  
Author(s):  
Eliningaya J Kweka ◽  
Goufa Zhou ◽  
Leila B Beilhe ◽  
Amruta Dixit ◽  
Yaw Afrane ◽  
...  
Keyword(s):  
Life History ◽  
Anopheles Gambiae ◽  
Culex Quinquefasciatus ◽  
Life History Traits ◽  
Anopheles Gambiae S.S

scholarly journals Effect of DEET-multiple exposures on behavior and life history traits in the malaria mosquito Anopheles gambiae (s.s.)

2018 ◽  
Vol 11 (1) ◽  
Author(s):  
Margaux Mulatier ◽  
Ludovic Phamien Ahoua Alou ◽  
Fabrice Chandre ◽  
Cédric Pennetier ◽  
Laurent Dormont ◽  
...  
Keyword(s):  
Life History ◽  
Anopheles Gambiae ◽  
Life History Traits ◽  
Malaria Mosquito ◽  
Anopheles Gambiae S.S ◽  
Multiple Exposures ◽  
Mosquito Anopheles Gambiae

scholarly journals Anopheles Gambiae s.s Attraction to Floral and Human-Skin-Based Odors and Their Combination is Modulated by Previous Bloodmeal Experience

2020 ◽  
Author(s):  
ELISON ELIEZA KEMIBALA ◽  
Agenor Mafra-Neto2 ◽  
Jesse Saroli ◽  
Rodrigo Silva ◽  
Anitha Philbert ◽  
...  
Keyword(s):  
Life History ◽  
Anopheles Gambiae ◽  
Human Skin ◽  
Sensory Neurons ◽  
Olfactory Receptors ◽  
Developmental State ◽  
Monitoring And Control ◽  
Anopheles Gambiae S.S ◽  
Odor Coding ◽  
Activation Patterns

Abstract Background: Mosquitoes use odors in finding energy resources, blood hosts and oviposition sites. While these odor sources are normally spatio-temporally segregated in a mosquito’s life history, here we explored to what extent a combination of flower- and human-mimicking synthetic volatiles would attract the malaria vector Anopheles gambiae s.s.Methodology: In the laboratory and in large (80 m2) outdoor cages in Tanzania, nulliparous and parous Anopheles gambiae s.s. were offered choices between a blend of human skin volatiles (Skin Lure), a blend of floral volatiles (Vectrax), or a combination thereof. The blends consisted of odors that induce distinct, non-overlapping activation patterns in the olfactory circuitry, in sensory neurons expressing olfactory receptors (ORs) and ionotropic receptors (IRs), respectively. Catches were compared between treatments. Results: In the laboratory nulliparous and parous mosquitoes preferred skin odors and combinations thereof over floral odors. However, in semi-field settings nulliparous were significantly more caught with floral odors, whereas no differences were observed for parous females. Combining floral and human volatiles did not augment attractiveness.Conclusions: Nulliparous and parous An. gambiae s.s. are attracted to combinations of odors derived from spatio-temporally segregated resources in mosquito life-history (floral and human volatiles). This is favourable as mosquito populations are comprised of individuals whose nutritional and developmental state steer them to diverging odors sources, baits that attract irrespective of mosquito status could enhance overall effectiveness and use in monitoring and control. However, combinations of floral and skin odors did not augment attraction in semi-field settings, in spite of the fact that these blends activate distinct sets of sensory neurons. Instead, mosquito preference appeared to be modulated by blood meal experience from floral to a more generic attraction to odor blends. Results are discussed both from an odor coding, as well as from an application perspective.

scholarly journals Effects of larval diet on the life-history traits and phenotypic expression of pyrethroid resistance in the major malaria vector Anopheles gambiae s.s.

2022 ◽  
Author(s):  
Pierre Marie Sovegnon ◽  
Marie Joelle Fanou ◽  
Romaric Akoton ◽  
Oswald Yédjinnavênan Djihinto ◽  
Hamirath Odée Lagnika ◽  
...  
Keyword(s):  
Life History ◽  
Insecticide Resistance ◽  
Life History Traits ◽  
Wing Length ◽  
Larval Mortality ◽  
Adult Emergence ◽  
Developmental Time ◽  
Larval Diet ◽  
Anopheles Gambiae S.S ◽  
Permanet 3.0

The success achieved in reducing malaria transmission by vector control is threatened by insecticide resistance. To strengthen the current vector control programmes, the non-genetic factors underlying the emergence of insecticide resistance in Anopheles vectors and its widespread need to be explored. This study aimed to assess the effects of larval diet on some life-history traits and pyrethroid-insecticide susceptibility of Anopheles gambiae s.s. Three (3) An. gambiae strains, namely Kisumu (insecticide susceptible), AcerKis (homozygous ace-1 R G119S resistant) and KisKdr (homozygous kdr R L1014F resistant) were fed with three different diets (low, medium, and high) of TetraMin ® Baby fish food. Pre-imaginal developmental time, larval mortality, adult emergence rate and female wing length were measured. Mosquito females were exposed to insecticide-treated net (ITN) PermaNet 2.0 and PermaNet 3.0. In the three An. gambiae strains, significant differences in adult emergence rates ( F = 1054.2; df = 2; p <0.01), mosquito wing length ( F = 970.5; df = 2; p <0.01) and adult survival post insecticide exposure ( χ2 = 173; df = 2; p <0.01), were noticed among the three larval diets. Larvae fed with the low food diets took more time to develop, were smaller at emergence and displayed a short lifespan, while the specimens fed with a high regime developed faster and into big adults. Although being fed with a high diet, none of An. gambiae strain harbouring the kdr R and ace-1 R allele survived 24 hours after exposure against PermaNet 3.0. This study showed that variation in the larval diet significantly impacts An. gambiae life-history traits such as larval mortality and developmental time, adult wing length, and female susceptibility to pyrethroid insecticides. Further investigations through field-based studies would allow an in-depth understanding of the implications of these non-genetic parameters on the physiological traits of malaria vectors and consequently improve resistance management.

scholarly journals Impact of sublethal pyrethroid exposure on resistant Anopheles gambiae mosquitoes’ fitness

2021 ◽  
Vol 6 ◽  
pp. 204
Author(s):  
Behi Kouadio Fodjo ◽  
Alida Kropf ◽  
Marius Gonse Zoh ◽  
Christabelle Gba Sadia ◽  
Affoué France-Paraudie Kouadio ◽  
...  
Keyword(s):  
Life History ◽  
Insecticide Resistance ◽  
Vector Control ◽  
Anopheles Gambiae ◽  
Life History Traits ◽  
Indoor Residual Spraying ◽  
Laboratory Strain ◽  
Blood Feeding ◽  
Egg Laying ◽  
Bed Net

Background: There is increasing evidence of insecticide resistance spreading among wild mosquito populations, which is widely believed to compromise vector control once it reaches a threshold that enables mosquitoes to survive exposure to long lasting treated bed-net (LLIN) or indoor residual spraying (IRS). However, very little is known about the long-term impact of insecticide resistance on malaria transmission, which makes the consequence of insecticide resistance spreading difficult to predict. Methods: To gain more clarity, we have assessed five life-history traits of a resistant Anopheles gambiae laboratory strain that was repeatedly exposed to a LLIN and compared with individuals issued from the same strain but exposed to an untreated bed-net. Results: Out of the five measured life-history traits, four were significantly affected by exposure to insecticides. Indeed, the Kolmogorov-Smirnov non-parametric test revealed a significant (i) drop in blood feeding mean rates (P=0.000000494), (ii) increase in 24-hours post-exposure (P= 0.000008559) and (iii) end of gonotrophic cycle mortality (P =0.0005749), and (iv) drop in egg laying rate (P=0.000107) when mosquitoes were exposed. Conclusion: Our study shows that in a context of widespread of resistance to insecticides, current pyrethroid-based vector control tools can still confer protection against malaria

scholarly journals Putative pleiotropic effects of the knockdown resistance (L1014F) allele on the life-history traits of Anopheles gambiae

2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Adandé A. Medjigbodo ◽  
Luc S. Djogbénou ◽  
Oswald Y. Djihinto ◽  
Romaric B. Akoton ◽  
Emmanuella Abbey ◽  
...  
Keyword(s):  
Life History ◽  
Anopheles Gambiae ◽  
Blood Volume ◽  
Life History Traits ◽  
Blood Feeding ◽  
Malaria Vectors ◽  
Resistance Allele ◽  
Knockdown Resistance ◽  
Feeding Success ◽  
The Mean

Abstract Background Existing mechanisms of insecticide resistance are known to help the survival of mosquitoes following contact with chemical compounds, even though they could negatively affect the life-history traits of resistant malaria vectors. In West Africa, the knockdown resistance mechanism kdrR (L1014F) is the most common. However, little knowledge is available on its effects on mosquito life-history traits. The fitness effects associated with this knockdown resistance allele in Anopheles gambiae sensu stricto (s.s.) were investigated in an insecticide-free laboratory environment. Methods The life-history traits of Kisumu (susceptible) and KisKdr (kdr resistant) strains of An. gambiae s.s. were compared. Larval survivorship and pupation rate were assessed as well as fecundity and fertility of adult females. Female mosquitoes of both strains were directly blood fed through artificial membrane assays and then the blood-feeding success, blood volume and adult survivorship post-blood meal were assessed. Results The An. gambiae mosquitoes carrying the kdrR allele (KisKdr) laid a reduced number of eggs. The mean number of larvae in the susceptible strain Kisumu was three-fold overall higher than that seen in the KisKdr strain with a significant difference in hatching rates (81.89% in Kisumu vs 72.89% in KisKdr). The KisKdr larvae had a significant higher survivorship than that of Kisumu. The blood-feeding success was significantly higher in the resistant mosquitoes (84%) compared to the susceptible ones (34.75%). However, the mean blood volume was 1.36 µL/mg, 1.45 µL/mg and 1.68 µL/mg in Kisumu, homozygote and heterozygote KisKdr mosquitoes, respectively. After blood-feeding, the heterozygote KisKdr mosquitoes displayed highest survivorship when compared to that of Kisumu. Conclusions The presence of the knockdown resistance allele appears to impact the life-history traits, such as fecundity, fertility, larval survivorship, and blood-feeding behaviour in An. gambiae. These data could help to guide the implementation of more reliable strategies for the control of malaria vectors.

scholarly journals Larvicidal potency of Dioscorea sansibarensis leaf extract against vector mosquitoes: Anopheles gambiae s.s. and Culex quinquefasciatus

2021 ◽  
Vol 47 (2) ◽  
pp. 655-663
Author(s):  
Anitha Philbert
Keyword(s):  
Vector Control ◽  
Anopheles Gambiae ◽  
Lymphatic Filariasis ◽  
Culex Quinquefasciatus ◽  
Leaf Extract ◽  
Test Procedures ◽  
Public Health Importance ◽  
Anopheles Gambiae S.S ◽  
Vector Borne Diseases ◽  
Larvicidal Activities

Mosquitoes are responsible for transmission of illnesses of public health importance including malaria, lymphatic filariasis, dengue, chikungunya, and many other diseases caused by viruses. Vector control using synthetic insecticides has been the cornerstone for management of vector-borne diseases. However, the chemical based interventions have not been sustainable due to emergency of resistance against insecticides among disease vectors. Plant based mosquitocidal products can be potential alternative tools in vector control. Therefore, the present study aimed at exploring the larvicidal properties of Dioscorea sansibarensis leaf extract against malaria and lymphatic filariasis vectors; Anopheles gambiae s.s. and Culex quinquefasciatus. The larvicidal activities of Dioscorea sansibarensis were assessed following WHO test procedures. Ethanol leaf extract of Dioscorea sansibarensis was evaluated against all the four instar larvae stages of An. gambiae s.s and Cx. quinquefasciatus susceptible laboratory colonies. The highest larvicidal potency was shown against the 4th instar stages of both species with the LC50 values of 60.915 ppm and 80.700 ppm for Cx. quinquefasciatus and An. gambiae s.s., respectively. The respective LC95 values for Cx. quinquefasciatus and An. gambiae s.s. were 168.898 ppm and 249.295 ppm. This implies that the extract can be applied as mosquito larvicide should its impact on non-targeted species be established. Keywords: Dioscorea sansibarensis; vectors, mosquitoes, Zanzibar yams, Dar es Salaam, Tanzania

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