Fig. 1.

Egg laying responses of Ae. aegypti to bamboo leaf infusions (a), white oak leaf infusions (b), and mixes of bacteria cultured from the infusions, in 24-h oviposition bioassays. Experiment 1: leaf infusion versus well water; experiment 2: leaf infusion versus filter-sterilized infusion; experiment 3: filter-sterilized infusion versus sterile water; experiment 4: filter-retained residue (filtrand) of leaf infusion resuspended in sterile water versus filter-retained residue from a second filtration of the same leaf infusion (rendered sterile after the first filtration) resuspended in sterile water; experiment 5: in each test cup, 5 ml of 2-day-old medium containing a mix of bacterial species (10⁹ cells per ml) was added to 25 ml of sterile water (final concentration, 10⁸ cells per ml) versus 5 ml of fresh sterile R2A medium added to 25 ml of sterile water; experiment 6: in each test cup, 5 ml of filter-sterilized bacterial culture medium was added to 25 ml of sterile water versus 5 ml of fresh sterile medium added to 25 ml of sterile water; experiment 7: filter-retained residue of 5 ml of medium containing a mix of bacterial species resuspended in 30 ml of sterile water versus filter-retained residue obtained from a second filtration of filter-sterilized medium resuspended in sterile water; experiment 8: bacteria harvested from 2-day cultures by centrifugation (1,254 × g, 10 min, 4°C) were resuspended in sterile 10% R2A medium (10⁸ cells per ml) versus 30 ml of bacteria-free sterile 10% medium; experiment 9: response of single gravid females (denoted with †) to lyophilized bacteria added to sterile water versus lyophilized bacteria-free medium added to sterile water. Experiment 9 was not conducted with white-oak leaf infusion *, P value represents results of a one-tailed paired t test of arcsin√x transformed data.