Dispersal and survival of radio-sterilised male Aedes albopictus Skuse (Diptera: Culicidae) and estimation of the wild populations in view of an sterile insect technique programme in Pointe des Lascars, Mauritius

The survival and dispersal of irradiated and non-irradiated Aedes albopictus Skuse (Diptera: Culicidae) males, bred in mass-rearing larval racks, were investigated during three mark-release-recapture trials in Pointe des Lascars (PDL), a village in Mauritius. Adult males of 1-day-old, 3-day-old and 5-day-old, were released in two different ecotypes (inhabited village center and forest). Overall recapture rates ranged from 2.9 to 8.6% which supports the use of the ‘Mosquibat’, a hand-held device conceived during this study, for collecting Ae. albopictus males. Irradiation and age of males at release, did not significantly affect their recapture and dispersal while ecotype and climatic seasons had a visible effect on both parameters. The average mean distance travelled (MDT) by males in the forest was greater than those in the village center (ranging from 89.6 to 120.8 m and 55.5 to 84.2 m respectively). Furthermore, an important Ae. albopictus population exhibiting characteristic seasonal fluctuations is present in PDL with mean male estimates ranging from 622 (95% CI, 471–773) to 3344 (95% CI, 2258–4429) males per hectare during the study. Hence, should an SIT programme be implemented against the vector in PDL, a reduction of its wild population by conventional control methods is highly desirable prior to releases.