Development of the Sterile Insect Technique to control the dengue vector Aedes aegypti (Linnaeus) in Sri Lanka.

<h4>Background</h4>The Sterile Insect Technique (SIT) is presently being tested to control dengue in several countries. SIT aims to cause the decline of the target insect population through the release of a sufficient number of sterilized male insects. This induces sterility in the femal...

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Main Authors: Tharaka Ranathunge, Jeevanie Harishchandra, Hamidou Maiga, Jeremy Bouyer, Y I Nilmini Silva Gunawardena, Menaka Hapugoda
Format: Article
Language:English
Published: Public Library of Science (PLoS) 2022-01-01
Series:PLoS ONE
Online Access:https://doi.org/10.1371/journal.pone.0265244
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author Tharaka Ranathunge
Jeevanie Harishchandra
Hamidou Maiga
Jeremy Bouyer
Y I Nilmini Silva Gunawardena
Menaka Hapugoda
author_facet Tharaka Ranathunge
Jeevanie Harishchandra
Hamidou Maiga
Jeremy Bouyer
Y I Nilmini Silva Gunawardena
Menaka Hapugoda
author_sort Tharaka Ranathunge
collection DOAJ
description <h4>Background</h4>The Sterile Insect Technique (SIT) is presently being tested to control dengue in several countries. SIT aims to cause the decline of the target insect population through the release of a sufficient number of sterilized male insects. This induces sterility in the female population, as females that mate with sterilized males produce no offspring. Male insects are sterilized through the use of ionizing irradiation. This study aimed to evaluate variable parameters that may affect irradiation in mosquito pupae.<h4>Methods</h4>An Ae. aegypti colony was maintained under standard laboratory conditions. Male and female Ae. aegypti pupae were separated using a Fay and Morlan glass sorter and exposed to different doses of gamma radiation (40, 50, 60, 70 and 80 Gy) using a Co60 source. The effects of radiation on survival, flight ability and the reproductive capacity of Ae. aegypti were evaluated under laboratory conditions. In addition, mating competitiveness was evaluated for irradiated male Ae. aegypti mosquitoes to be used for future SIT programmes in Sri Lanka.<h4>Results</h4>Survival of irradiated pupae was reduced by irradiation in a dose-dependent manner but it was invariably greater than 90% in control, 40, 50, 60, 70 Gy in both male and female Ae. aegypti. Irradiation didn't show any significant adverse effects on flight ability of male and female mosquitoes, which consistently exceeded 90%. A similar number of eggs per female was observed between the non-irradiated groups and the irradiated groups for both irradiated males and females. Egg hatch rates were significantly lower when an irradiation dose above 50 Gy was used as compared to 40 Gy in both males and females. Irradiation at higher doses significantly reduced male and female survival when compared to the non-irradiated Ae. aegypti mosquitoes. Competitiveness index (C) scores of sterile and non-sterile males compared with non-irradiated male mosquitoes under laboratory and semi-field conditions were 0.56 and 0.51 respectively at 50 Gy.<h4>Signification</h4>Based on the results obtained from the current study, a 50 Gy dose was selected as the optimal radiation dose for the production of sterile Ae. aegypti males for future SIT-based dengue control programmes aiming at the suppression of Ae. aegypti populations in Sri Lanka.
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spelling doaj.art-fce76aeb9ba04f3593e3c6743a45ab862022-12-22T00:24:31ZengPublic Library of Science (PLoS)PLoS ONE1932-62032022-01-01174e026524410.1371/journal.pone.0265244Development of the Sterile Insect Technique to control the dengue vector Aedes aegypti (Linnaeus) in Sri Lanka.Tharaka RanathungeJeevanie HarishchandraHamidou MaigaJeremy BouyerY I Nilmini Silva GunawardenaMenaka Hapugoda<h4>Background</h4>The Sterile Insect Technique (SIT) is presently being tested to control dengue in several countries. SIT aims to cause the decline of the target insect population through the release of a sufficient number of sterilized male insects. This induces sterility in the female population, as females that mate with sterilized males produce no offspring. Male insects are sterilized through the use of ionizing irradiation. This study aimed to evaluate variable parameters that may affect irradiation in mosquito pupae.<h4>Methods</h4>An Ae. aegypti colony was maintained under standard laboratory conditions. Male and female Ae. aegypti pupae were separated using a Fay and Morlan glass sorter and exposed to different doses of gamma radiation (40, 50, 60, 70 and 80 Gy) using a Co60 source. The effects of radiation on survival, flight ability and the reproductive capacity of Ae. aegypti were evaluated under laboratory conditions. In addition, mating competitiveness was evaluated for irradiated male Ae. aegypti mosquitoes to be used for future SIT programmes in Sri Lanka.<h4>Results</h4>Survival of irradiated pupae was reduced by irradiation in a dose-dependent manner but it was invariably greater than 90% in control, 40, 50, 60, 70 Gy in both male and female Ae. aegypti. Irradiation didn't show any significant adverse effects on flight ability of male and female mosquitoes, which consistently exceeded 90%. A similar number of eggs per female was observed between the non-irradiated groups and the irradiated groups for both irradiated males and females. Egg hatch rates were significantly lower when an irradiation dose above 50 Gy was used as compared to 40 Gy in both males and females. Irradiation at higher doses significantly reduced male and female survival when compared to the non-irradiated Ae. aegypti mosquitoes. Competitiveness index (C) scores of sterile and non-sterile males compared with non-irradiated male mosquitoes under laboratory and semi-field conditions were 0.56 and 0.51 respectively at 50 Gy.<h4>Signification</h4>Based on the results obtained from the current study, a 50 Gy dose was selected as the optimal radiation dose for the production of sterile Ae. aegypti males for future SIT-based dengue control programmes aiming at the suppression of Ae. aegypti populations in Sri Lanka.https://doi.org/10.1371/journal.pone.0265244
spellingShingle Tharaka Ranathunge
Jeevanie Harishchandra
Hamidou Maiga
Jeremy Bouyer
Y I Nilmini Silva Gunawardena
Menaka Hapugoda
Development of the Sterile Insect Technique to control the dengue vector Aedes aegypti (Linnaeus) in Sri Lanka.
PLoS ONE
title Development of the Sterile Insect Technique to control the dengue vector Aedes aegypti (Linnaeus) in Sri Lanka.
title_full Development of the Sterile Insect Technique to control the dengue vector Aedes aegypti (Linnaeus) in Sri Lanka.
title_fullStr Development of the Sterile Insect Technique to control the dengue vector Aedes aegypti (Linnaeus) in Sri Lanka.
title_full_unstemmed Development of the Sterile Insect Technique to control the dengue vector Aedes aegypti (Linnaeus) in Sri Lanka.
title_short Development of the Sterile Insect Technique to control the dengue vector Aedes aegypti (Linnaeus) in Sri Lanka.
title_sort development of the sterile insect technique to control the dengue vector aedes aegypti linnaeus in sri lanka
url https://doi.org/10.1371/journal.pone.0265244
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