Fig. 10
Impact of yeast species and their cell concentrations on oviposition behavior of Ae. albopictus gravid females. The impact of six yeast species (R. mucilaginosa, A. pullulans, H. uvarum, M. pulcherrima, T. delbrueckii, and M. asiatica) at two cell concentrations (3.102 and 3.105 cells.mL−1) on the oviposition behavior of gravid females was evaluated using two distinct and complementary laboratory bioassays. Oviposition preference bioassays (corresponding to A & B) consisted of small-cage three-choice oviposition tests, in which each single gravid female (n = 24) was allowed to choose between three oviposition sites (double-beaker systems) providing oviposition substrates containing waterborne substances (sterile water or sterile water inoculated with yeasts) and olfactory stimuli (volatile organic compounds emitted by sterile CYM medium or yeast cultures). A Total number of eggs laid by each female per cage, regardless of the selected oviposition site. The pie charts represent the percentages of females that have laid eggs (shown in gray) or have not laid eggs (shown in black). B Number of eggs laid by each female in each oviposition site during three-choice oviposition tests. These oviposition preference bioassays were used to assess short-range attractiveness or repellency of volatile compounds emitted by yeasts but only because they were systematically paired with oviposition stimulation bioassays conducted in 50-mL conical tubes (C), where a single gravid female (n = 25) was specifically exposed to either sterile water or water inoculated with one of the two tested yeast concentrations to enable the evaluation of stimulant or deterrent effects of yeast-derived waterborne substances. C Number of eggs laid by each female according to each type of oviposition substrate. Statistically significant differences between groups were identified with the Tukey post hoc tests. Columns labelled with different letters or with an asterisk (*) are significantly different with a p-value < 0.05. Columns labelled with a dot (•) are almost significantly different with a p-value < 0.1