Fig 1.
Longevity of male and female Nasonia giraulti treated with acetone (Ac) and untreated control wasps (Con).
Box-and-whisker plots show median (horizontal line), 25–75% quartiles (box), maximum/minimum range (whiskers) and outliers (° > 1.5 x above box height; * > 3 x above box height). Data analysis was done by Mann-Whitney U-test, n = 30).
Fig 2.
Results of the mating trials with male and female Nasonia giraulti.
Newly emerged virgin females were treated with acetone (Ac) and mated with males either 3–4 h after application (0d) or the next day (1d). Females of the control couples (Con) were subjected to the same procedure without acetone application. (A) Time until males mounted, (B) time between mounting and the female receptivity signal (lowering of the antennae and opening of the genital orifice), (C) copulation rate, and (D) copulation duration. Box-and-whisker plots in panel A, B, and D show median (horizontal line), 25–75% quartiles (box), maximum/minimum range (whiskers) and outliers (° > 1.5 x above box height; * > 3 x above box height). Data analysis by Mann-Whitney U-test (A, B, D) or Fishers exact test (C).
Fig 3.
Fitness parameters of the acetone-treated Nasonia giraulti females and untreated control females from the mating trials.
Newly emerged virgin females were treated with acetone (Ac) and mated with males either 3–4 h after application (0d) or the next day (1d). Females of the control couples (Con) were subjected to the same procedure without acetone application. After mating, females were provided with five fresh host pupae per day for oviposition and host feeding until they died. (A) Longevity, (B) offspring number, and (C) offspring sex ratio (given as % female offspring). Box-and-whisker plots show median (horizontal line), 25–75% quartiles (box), maximum/minimum range (whiskers) and outliers (° > 1.5 x above box height; * > 3 x above box height). Data analysis was done by Mann-Whitney U-test.
Fig 4.
Pheromone titers of Nasonia giraulti males treated with acetone (Ac) and untreated control wasps (Con).
The pheromone component (4R,5S)-5-hydroxy-4-decanolide was extracted two days after the treatment. Box-and-whisker plots show median (horizontal line), 25–75% quartiles (box), maximum/minimum range (whiskers) and outliers (° > 1.5 x above box height above box height. Data analysis was done by Mann-Whitney U-test (n = 20).
Fig 5.
Effect of insect hormones on the pheromone titers of Nasonia giraulti males.
Newly emerged males were treated with acetone solutions containing 1.04 μg or 103.5 ng juvenile hormone III (JH 1000 and JH 100) or 1.04 μg 20-hydroxyecdysone (20-OH-E 1000). Control wasps (Con) were treated with the pure solvent. The pheromone component (4R,5S)-5-hydroxy-4-decanolide was extracted two days after the treatment. Box-and-whisker plots show median (horizontal line), 25–75% quartiles (box), maximum/minimum range (whiskers) and outliers (° > 1.5 x above box height; * > 3 x above box height). Different lowercase letters indicate significant differences at p < 0.05 (data analysis by Kruskal-Wallis ANOVA followed by multiple Mann-Whitney U-tests after sequential Bonferroni correction, n = 20).
Fig 6.
Results of the 13C-labeling experiments.
GC/MS analysis of pheromone extracts from (A) male Nasonia giraulti wasps treated with an acetone solution containing fully 13C-labeled linoleic acid and (B) control males treated with pure acetone. Shown are the total ion current chromatograms (TIC) and the extracted ion chromatogram of the diagnostic ion m/z 90, 107, and 120 (magnification factors given in parentheses) indicating the incorporation of the 13C-labeled precursor into the sex pheromone component (4R,5S)-5-hydroxy-4-decanolide (RS-HDL). The dotted lines indicate the peak maxima of the TIC to illustrate the slightly decreased retention time of the diagnostic ions due to the inverse isotope effect of heavier isotopes. (C) Structures of monitored diagnostic ions (black dots indicate 13C-atoms).
Fig 7.
Effect of dopamine application on the pheromone response of Nasonia vitripennis females.
Virgin females were treated with 20 ng dopamine (DA) dissolved in a 1:10 water/acetone mixture (H2O/Ac) or for control with the pure solvent. Given is the residence time of females the test and control areas of a two-choice olfactometer. The test area was equipped with a filter paper disk treated with the male sex pheromone (Pher), the filter paper disk in the control area was treated with the pure solvent (Con). Box-and-whisker plots show median (horizontal line), 25–75% quartiles (box), maximum/minimum range (whiskers) and outliers (° > 1.5 x above box height). Data analysis was done by Wilcoxon matched-pairs test (n = 20).