Fig. 4: Suppression of egg hatching and female adults by HC release.

a The number of hatched eggs of A. albopictus per trap and suppression efficiency at the release site compared to the control site. The blue and green solid lines indicate the average number of hatched eggs (trap⁻¹ week⁻¹) in the control and release sites, respectively. The red dashed line presents the suppression efficiency of the release site compared to the control site. Each light blue and light green circle corresponding to a number of hatched eggs from an individual retrieved ovitrap in control site and release site, respectively. Two-sided Mann–Whitney test, pre-release phase: Release site: n = 90, Control site: n = 90, P = 0.9269; phase I: Release site: n = 143, Control site: n = 148, P = 0.0119; phase II: Release site: n = 269, Control site: n = 262, P = 5.5047 × 10⁻¹⁴; post-release phase-2020: Release site: n = 90, Control site: n = 89, P = 2.7849 × 10⁻¹⁰; post-release phase-2021: Release site: n = 147, Control site: n = 150, P = 0.1524. The vertical dotted lines indicate the interval of each release phase. b The number of females per trap per 24 h at the release site (light green circle) and control site (light blue circle). The green and blue solid line represent the average number of females per trap per 24 h in the release and control sites, respectively. The red dotted line indicates the suppression efficiency at release sites relative to control sites. Two-sided Mann–Whitney test, pre-release phase: Release site: n = 30, Control site: n = 30, P = 0.9441; phase I: Release site: n = 25, Control site: n = 25, P = 0.0391; phase II: Release site: n = 45, Control site: n = 45, P = 7.1467 × 10⁻¹⁰; post-release phase-2020: Release site: n = 15, Control site: n = 15, P = 0.0294; post-release phase-2021: release site: n = 25, control site: n = 25, P = 0.161. c Release schedule. The date on x-axis is the starting date of monitoring via ovitraps (a) and BG traps (b). The error bars present the standard error of mean.