Figure 5
Effects of the stressors, alone or combined, on the physiological state of drones including semen. The cluster analysis (hierarchical clustering results) after optimal reorganization100 (A) and the principal component analysis (B) show an integrative approach to assess the physiological markers studied in the head (h), midgut (m), abdomen (a) and semen (s) of drones. A color code is assigned to each treatment: “black” for the control group (Ctrl), “green” for the N. ceranae group (Nos), “red” for the fipronil group (Fip), and “blue” for the N. ceranae/fipronil group (Nos + Fip). In the cluster analysis, the first number indicates the hive, and the second number indicates the sample. The intensity of modulation in the clusters is illustrated by the range of colors, with green and red indicating that a physiological marker was downregulated or upregulated, respectively, in comparison with the mean value in the controls. Black indicates no change in comparison with the mean value in the controls. The correlation circle (C) indicates the significance of the markers in the PCA representation. For statistical analysis, a post-hoc Wilcoxon test was applied on the values of the two main axes of the PCA. P values are indicated in the table (D).
