Suppression of the Asian tiger mosquito (Aedes albopictus) populations using the boosted sterile insect technique in Greece

The boosted Sterile Insect Technique (SIT) by releasing sterilized males coated with the larvicide pyriproxyfen has been suggested for the control of Aedes container-breeding mosquitoes. In 2023, a boosted-SIT field trial was applied in Greece against Aedes albopictus by weekly releases of pyriproxyfen-coated sterile males at the beginning (12 May-16 June) and peak (1 September-6 October) of mosquito activity, including two Mark-Release-Recapture sessions in July. No overall effect on egg densities was noted in the treated site, while a significant decrease compared to a control site was recorded in specific locations. The egg hatching rate in the treated site (56-57%) was lower than the control site (84-85%) during the release cycles and one month following the second release cycle. During the second release cycle and the following month, an overall suppression of the adult population was achieved (85-93% reduction compared to the control site), and high boosted sterile-to-wild male ratio (15:1) and competitiveness index of boosted-SIT males (0.46) were recorded, respectively. The suppression of both adult and egg populations was more pronounced a month after the conclusion of releases, indicating a residual activity of boosted-SIT. Our findings demonstrate the potential of boosted-SIT against Ae. albopictus particularly in suppressing adult population.