Abstract

Background: Culex quinquefasciatus is a major vector of filariasis and other mosquito-borne diseases. The sterile insect technique (SIT) has been widely used to suppress mosquito populations, but its effectiveness depends on the dispersal, survival, and competitiveness of sterile males.
Aim: This study evaluated the dispersal range, survival rate, and recapture success of gamma-irradiated Cx. quinquefasciatus under field conditions.
Methods: A mark-release-recapture (MRR) experiment was conducted using sterile male and female Cx. quinquefasciatus. Two release events were conducted, and recapture data were collected over seven days using BG-Sentinel-2 traps baited with octanol placed within a 250-m radius.
Results: The irradiated males traveled an average of 143.18 m (FR50: 92.78 m; FR90: 220.02 m), and the females dispersed 146.26 m (FR50: 95.26 m; FR90: 227.25 m). Dispersal distance was significantly influenced by release site in males (p = 0.0089) and females (p = 0.0042) but not by recapture day (p > 0.89). Recapture location significantly affected dispersal in both sexes (p < 0.0001). The daily survival probabilities of males and females were 0.88 and 0.69, respectively, with corresponding life expectancies of 7.57 and 2.71 days.
Conclusion: The dispersal and survival of sterile Cx. quinquefasciatus are affected by release strategies. To optimize SIT, further studies should refine the marking techniques, explore a combination of trapping methods, and evaluate the dispersal patterns across varied landscapes. These findings offer valuable insights into improving the implementation of SIT for Cx. quinquefasciatus population control.

Key words: Culex quinquefasciatus, sterile insect technique, mark-release-recapture, dispersal, survival, vector control.