The sympatric occurrence of two molecular forms of the malaria vector Anopheles gambiae Giles sensu stricto in Kanyemba, in the Zambezi Valley, Zimbabwe

Introduction: This study was conducted in a sugar belt region of western Kenya interfacing epidemic and endemic malaria transmission. We investigated Anopheles gambiae sensu stricto (ss) and Anopheles arabiensis species compositions and densities, human host choice, and infectivity. Methodology: Mosquitoes were captured using pyrethrum spray catch technique and first identified based on morphology; species were confirmed by PCR. Blood meal preference and sporozoite rates were determined by ELISA. Parity rates and entomological inoculation rates (EIR) were determined. Seasonal densities were compared against environmental temperatures, relative humidity and rainfall. Results: In total 2,426 An. gambiae were collected. Out of 1,687 female blood-fed mosquitoes, 272 were randomly selected for entomological tests. An. gambiae ss and An. arabiensis comprised 75% (205/272) and 25% (68/272) of the selection, respectively. An. gambiae ss had higher preference for human blood (97%; n=263/272) compared with An. arabiensis, which mostly fed on bovines (88%; n=239/272). The sporozoite and parity rates were 6% (16/272) and 66% (179/272) for An. gambiae ss and 2% (4/272) and 53% (144/272) for An. arabiensis respectively, while EIR was 0.78 infective bites/person/night. Climate (ANOVA; F=14.2; DF=23) and temperature alone (r=0.626; t=3.75; p=0.001) were significantly correlated with vector densities. Conclusion: An. gambiae ss are the most efficient malaria vector mosquito species in Kopere village. Because An. gambiae ss largely rests and feeds indoors, use of indoor residual spray and insecticide-treated nets is likely the most suitable approach to malaria vector control in Kopere village and other parts of Kenya where this species is abundant.

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Chromosomal plasticity and evolutionary potential in the malaria vector Anopheles gambiae sensu stricto: insights from three decades of rare paracentric inversions

BMC Evolutionary Biology ◽

10.1186/1471-2148-8-309 ◽

2008 ◽

Vol 8 (1) ◽

pp. 309 ◽

Cited By ~ 48

Author(s):

Marco Pombi ◽

Beniamino Caputo ◽

Frederic Simard ◽

Maria A Di Deco ◽

Mario Coluzzi ◽

...

Keyword(s):

Anopheles Gambiae ◽

Malaria Vector ◽

Sensu Stricto ◽

Evolutionary Potential ◽

Anopheles Gambiae Sensu Stricto ◽

Paracentric Inversions

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Evidence of multiple pyrethroid resistance mechanisms in the malaria vector Anopheles gambiae sensu stricto from Nigeria

Transactions of the Royal Society of Tropical Medicine and Hygiene ◽

10.1016/j.trstmh.2008.08.021 ◽

2009 ◽

Vol 103 (11) ◽

pp. 1139-1145 ◽

Cited By ~ 83

Author(s):

T.S. Awolola ◽

O.A. Oduola ◽

C. Strode ◽

L.L. Koekemoer ◽

B. Brooke ◽

...

Keyword(s):

Anopheles Gambiae ◽

Malaria Vector ◽

Pyrethroid Resistance ◽

Resistance Mechanisms ◽

Sensu Stricto ◽

Anopheles Gambiae Sensu Stricto

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Bioefficacy of Larvicidal and Pupicidal properties of Clerodendrum capitatum and Bridelia machrantha leaves extracts against Malaria Vector, Anopheles gambiae giles [Diptera: Culicidae]

10.17352/jbm.000004 ◽

2018 ◽

pp. 007-011

Author(s):

David IK ◽

Peter AF

Keyword(s):

Anopheles Gambiae ◽

Malaria Vector ◽

Anopheles Gambiae Giles

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Testing a pyriproxyfen auto-dissemination station attractive to gravid Anopheles gambiae sensu stricto for the development of novel attract-and-kill strategies for malaria vector control

10.21203/rs.2.10940/v2 ◽

2019 ◽

Author(s):

Oscar Mbare ◽

Steven W. Lindsay ◽

Ulrike Fillinger

Keyword(s):

Vector Control ◽

Anopheles Gambiae ◽

Malaria Vector ◽

Sensu Stricto ◽

Sub Saharan Africa ◽

Malaria Vector Control ◽

Anopheles Gambiae Sensu Stricto ◽

Attract And Kill ◽

Bait Station ◽

Gravid Females

Abstract Background Larval source management is an effective supplementary tool for malaria vector control although it is not used widely in sub-Saharan Africa. This study explored whether an attract-and-kill strategy could contaminate gravid Anopheles gambiae sensu stricto with the insect growth regulator, pyriproxyfen, at a bait-station, for dissemination to larval habitats. Methods A bait-station comprising an artificial pond, containing water was treated with 20 ppm cedrol, an oviposition attractant, was covered with pyriproxfen-treated netting. Three identical semi-field cages were used to assess the potential of gravid Anopheles gambiae sensu stricto to transfer pyriproxyfen from the bait-station to three open ponds. Gravid females were released in the test and one of the control cages that had no pyriproxyfen on its bait-station. No mosquitoes were released in the third cage with a pyriproxyfen-treated station. Transfer of pyriproxyfen to open ponds was assessed by monitoring emergence of late instar insectary-reared An. gambiae sensu stricto larvae introduced into the open ponds. Liquid chromatography-mass spectrometry was used to quantify the amount of pyriproxyfen carried by a mosquito and the amount transferred to water. Results 86% (95% CI 81-89%) of larvae introduced into the open ponds in the two control cages developed into adults. Transfer of pyriproxyfen to the test cage depended on the distance of the pond from the bait-station. While only 25% (95% CI 22-29%) adult emergence was observed in larvae introduced into ponds 4.4 m from the bait-station, the emergence rates increased to 92% (95% CI 89-94%) in larvae introduced in ponds 10.3 m away. Each mosquito was contaminated with 112 µg (95% CI 93-123 µg) pyriproxyfen, whilst 230 ng/L (95% CI 180-290 ng/L) was transferred by a single female to 100 ml of water. Conclusions Pyriproxyfen was auto-disseminated by gravid females from attractive bait-stations, but mainly to aquatic habitats near the bait station. To make this approach feasible for malaria vector control, stronger attractants and better pyriproxyfen delivery systems are needed.

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Testing a pyriproxyfen auto-dissemination station attractive to gravid Anopheles gambiae sensu stricto for the development of novel attract-and-kill strategies for malaria vector control

10.21203/rs.2.10940/v3 ◽

2019 ◽

Author(s):

Oscar Mbare ◽

Steven W. Lindsay ◽

Ulrike Fillinger

Keyword(s):

Vector Control ◽

Anopheles Gambiae ◽

Malaria Vector ◽

Sensu Stricto ◽

Sub Saharan Africa ◽

Malaria Vector Control ◽

Anopheles Gambiae Sensu Stricto ◽

Attract And Kill ◽

Bait Station ◽

Gravid Females

Abstract Background Larval source management is an effective supplementary tool for malaria vector control although it is not used widely in sub-Saharan Africa. This study explored whether an attract-and-kill strategy could contaminate gravid Anopheles gambiae sensu stricto with the insect growth regulator, pyriproxyfen, at a bait-station, for dissemination to larval habitats. Methods A bait-station comprising an artificial pond, containing water was treated with 20 ppm cedrol, an oviposition attractant, was covered with pyriproxfen-treated netting. Three identical semi-field cages were used to assess the potential of gravid Anopheles gambiae sensu stricto to transfer pyriproxyfen from the bait-station to three open ponds. Gravid females were released in the test and one of the control cages that had no pyriproxyfen on its bait-station. No mosquitoes were released in the third cage with a pyriproxyfen-treated station. Transfer of pyriproxyfen to open ponds was assessed by monitoring emergence of late instar insectary-reared An. gambiae sensu stricto larvae introduced into the open ponds. Liquid chromatography-mass spectrometry was used to quantify the amount of pyriproxyfen carried by a mosquito and the amount transferred to water. Results 86% (95% CI 81-89%) of larvae introduced into the open ponds in the two control cages developed into adults. Transfer of pyriproxyfen to the test cage depended on the distance of the pond from the bait-station. While only 25% (95% CI 22-29%) adult emergence was observed in larvae introduced into ponds 4.4 m from the bait-station, the emergence rates increased to 92% (95% CI 89-94%) in larvae introduced in ponds 10.3 m away. Each mosquito was contaminated with 112 µg (95% CI 93-123 µg) pyriproxyfen, whilst 230 ng/L (95% CI 180-290 ng/L) was transferred by a single female to 100 ml of water. Conclusions Pyriproxyfen was auto-disseminated by gravid females from attractive bait-stations, but mainly to aquatic habitats near the bait station. To make this approach feasible for malaria vector control, stronger attractants and better pyriproxyfen delivery systems are needed.

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