Fig 1.
Layout of equipment and examples of complete set up of modified forced oviposition technique for Aedes aegypti (Ae) and Culex quinquefasciatus (Cx).
(A) Oviposition containers consist of a 1.5 mL Eppendorf tube, a small piece of germination paper cut with a small taper at the end, and a piece of cotton. (B) Moistened cotton is pushed to the bottom of the tube and germination paper placed on top with only the tapered end covering the cotton. Excess water is removed from Ae tubes, with a ~ 1 mm water layer remaining (white arrow) only for the Cx tube set up. (C) A single female is aspirated into each container (Photo credit: Kendra A. Dagg).
Fig 2.
Example egg papers collected from oviposition tubes.
Eggs were collected between 24 – 168 hr after female transferred into oviposition tube for Culex quinquefasciatus (A) and 24 hr for Aedes aegypti (B) (Photo credit: Kendra A. Dagg).
Fig 3.
Impact of tube size on oviposition performance.
Four different tube sizes were used to determine if tube size affected oviposition performance; (from left to right) 50 mL, 15 mL, 5 mL, and 1.5 mL (Photo credit: Kendra A. Dagg).
Table 1.
Mean ± standard error of the mean (SEM) number and percentage of eggs hatched relative to number tested in two strains of Culex quinquefasciatus (CMAVE – lab strain; wild – field collected strain) and two strains of Aedes aegypti (ORL – lab strain; wild – field collected strain).
Fig 4.
Number of female lab strain Cx. quinquefasciatus that oviposited between 1 and 7 days in Experiment 1, utilizing a lab strain and a wild strain.
There was a statistically significant difference between the strains at α = 0.05, so mean ± standard error of the mean (SEM) was calculated for each strain separately. The mean days to oviposition was 1.6 ± 0.15 for the lab strain and 3.1 ± 0.60 for the wild strain (gray columns in the figures represent SEMs, with the dashed lines in the middle representing the means). The lab strain was replicated 13-18 times across each of four generational cohorts (N = 60) and the wild strain was replicated 11-13 times across two generational cohorts (N = 24).
Fig 5.
Differences for forced oviposition success frequency (A) and mean ± standard error of the mean (SEM) eggs when lab and wild strain female Cx. quinquefasciatus oviposited (B).
Different lowercase letters above bars indicate statistical significance of pairwise comparisons between strains, with significance set at α = 0.05. The lab strain was replicated 13-18 times across each of four generational cohorts (N = 60) and the wild strain was replicated 11-13 times across each of two generational cohorts (N = 24).
Fig 6.
Mean ± standard error of the mean (SEM) % eggs hatched when egg rafts from a lab strain and a wild strain of Culex quinquefasciatus were observed broken up versus being a single, intact egg raft.
Different lowercase letters above error bars indicate statistical significance of pairwise comparisons between the egg raft status, with significance set at α = 0.05. The lab strain was replicated 13-18 times across each of four generational cohorts (N = 60) and the wild strain was replicated 11-13 times across two generational cohorts (N = 24).
Fig 7.
Differences for forced oviposition success frequency (A) and mean ± standard error of the mean (SEM) eggs when lab and wild strain female Ae. aegypti oviposited (B).
Different lowercase letters above bars indicate statistical significance of pairwise comparisons between strains, with significance set at α = 0.05. The lab strain was replicated 9 – 13 times across three generational cohorts (N = 33) and the wild strain was replicated 10 – 13 across two generational cohorts (N = 23).
Table 2.
Mean ± standard error of the mean (SEM) number and percentage of eggs hatched relative to number tested in four centrifuge tube sizes for lab strains of Culex quinquefasciatus (i.e., CMAVE) and Aedes aegypti (i.e., ORL).
Fig 8.
Number of female lab strain Cx. quinquefasciatus that oviposited between 1 and 3 days in Experiment 2, utilizing different tube sizes.
No statistical difference was seen among the tube sizes at α = 0.05, so mean ± standard error of the mean (SEM) was calculated across all tube sizes. The mean days to oviposition was 1.2 ± 0.07 (gray column in the figure represents SEM, with the dashed line in the middle representing the mean). All four tube sizes were replicated 8 – 10 times across each of three generational cohorts (N = 114).
Fig 9.
Tube size effects on forced oviposition success frequency (A) and mean ± standard error of the mean (SEM) eggs when females oviposited (B) by female lab strain Culex quinquefasciatus.
Different lowercase letters above error bars indicate statistical significance of pairwise comparisons between different tube sizes, with significance set at α = 0.05. All four tube sizes were replicated 8 – 10 times across each of three generational cohorts (N = 114).
Fig 10.
Mean ± standard error of the mean (SEM) % eggs hatched when lab strain Culex quinquefasciatus rafts were observed broken up versus being a single, intact egg raft.
Different lowercase letters above error bars indicate statistical significance of pairwise comparisons of percent egg hatching across all tube sizes, with significance set at α = 0.05. All four tube sizes were replicated 8 – 10 times across each of three generational cohorts (N = 114).
Fig 11.
Tube size effects on forced oviposition success frequency (A) and mean ± standard error of the mean (SEM) eggs when females oviposited (B) by gravid female lab strain Aedes aegypti.
Different lowercase letters above error bars indicate statistical significance of pairwise comparisons between different tube sizes, with significance set at α = 0.05. All four tube sizes were replicated 15 times across two generational cohorts (N = 120).