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Updated: Apr 16, 2026
Embryo Microinjection Techniques for Efficient Site-Specific Mutagenesis in Culex quinquefasciatus
Published on: May 24, 2020
Wolbachia-based population control strategy targeting Culex quinquefasciatus mosquitoes proves efficient under
Célestine M Atyame1, Julien Cattel1, Cyrille Lebon2
1CRVOI, Ste Clotilde, Réunion Island, France; University La Réunion, Réunion Island, France.
Abstract:
In mosquitoes, the maternally inherited bacterial Wolbachia induce a form of embryonic lethality called cytoplasmic incompatibility (CI). This property can be used to reduce the density of mosquito field populations through inundative releases of incompatible males in order to sterilize females (Incompatible Insect Technique, or IIT, strategy). We have previously constructed the LR[wPip(Is)] line representing a good candidate for controlling field populations of the Culex quinquefasciatus mosquito in the islands of the south-western Indian Ocean. The main purpose of the present study was to fill the gap between laboratory experiments and field implementation, i.e. assessing mating competitiveness of these incompatible males under semi-field conditions. In a first set of experiments, we analyzed crossing relationships between LR[wPip(Is)] males and La Réunion field females collected as larvae in 19 distinct localities throughout the island. This investigation revealed total embryonic mortality, confirming the strong sterilizing capacity of LR[wPip(Is)] males. Subsequently, mating competitiveness of LR[wPip(Is)] males was assessed under semi-field conditions in the presence of field males and females from La Réunion. Confrontations were carried out in April and December using different ratios of LR[wPip(Is)] to field males. The results indicated that the LR[wPip(Is)] males successfully compete with field males in mating with field females, displaying even higher competitiveness than field males in April. Our results support the implementation of small-scale field tests in order to assess the feasibility of IIT against Cx. quinquefasciatus in the islands of southwestern Indian Ocean where this mosquito species is a proven competent vector for human pathogens.
Insights
Incompatible male mosquitoes carrying Wolbachia bacteria were tested for their ability to control Culex quinquefasciatus populations. These males successfully competed with wild males, showing promise for the Incompatible Insect Technique (IIT) strategy.
Area of Science:
- Vector Control
- Medical Entomology
- Microbial Control
Background:
- Wolbachia bacteria induce cytoplasmic incompatibility (CI) in mosquitoes, causing embryonic lethality.
- The Incompatible Insect Technique (IIT) uses CI for mosquito population control by releasing incompatible males.
- The LR[wPip(Is)] mosquito line is a candidate for controlling Culex quinquefasciatus in the southwestern Indian Ocean.
Purpose of the Study:
- To assess the mating competitiveness of LR[wPip(Is)] males under semi-field conditions.
- To bridge the gap between laboratory findings and field implementation of IIT for Culex quinquefasciatus control.
Main Methods:
- Assessed crossing relationships between LR[wPip(Is)] males and La Réunion field females.
- Evaluated mating competitiveness of LR[wPip(Is)] males against wild males in semi-field trials.
- Conducted trials in April and December with varying ratios of incompatible to wild males.
Main Results:
- LR[wPip(Is)] males demonstrated strong sterilizing capacity, causing total embryonic mortality in crosses with field females.
- LR[wPip(Is)] males exhibited successful mating competitiveness with wild males.
- Incompatible males showed higher competitiveness than wild males in April trials.
Conclusions:
- LR[wPip(Is)] males are effective in competing with wild Culex quinquefasciatus males under semi-field conditions.
- Results support the feasibility of IIT for controlling Cx. quinquefasciatus in the southwestern Indian Ocean.
- Small-scale field tests are recommended to further evaluate IIT implementation.
