Fig 1.
The survival curve of the honey bees in the cage experiment.
The survival curve of the honey bees in the cage experiment during 20 days. C0: cage experiment with not treated honey bees; C5: cage experiment with honey bees treated with 5 ppb imidacloprid; C200: cage experiment with honey bees treated with 200 ppb imidacloprid (average of bees in 3 cages per treatment).
Fig 2.
Differences in colony brood and population after 20 and 40 days of treatment with imidacloprid, in the field. Different number of * and different letters above the bars denote significant differences between the groups. F0: field experiment not treated; F5: field experiment treated with 5 ppb imidacloprid; F200: field experiment treated with 200 ppb imidacloprid (average of 10 colonies per treatment).
Fig 3.
A boxplot from the acini diameter (in micrometer) of the different experimental groups. Different letters below the bars denote significant differences between the groups, P<0.001 for each experimental design. C0: cage experiment not treated; C5: cage experiment treated with 5 ppb; C200: cage experiment treated with 200 ppb; F0: field experiment not treated; F5: field experiment treated with 5 ppb; F200: field experiment treated with 200 ppb.
Fig 4.
Heat map showing the relative expression profiles of immunity related and detoxification genes.
C5 T1 and C5 T2: cage experiment treated with 5 ppb for 10 and 20 days, respectively, compared to the cage control at 10 and 20 days; C200 T1 and C200 T2: cage experiment treated with 200 ppb for 10 and 20 days, respectively, compared to the cage control at 10 and 20 days; F5 T1 and F5 T2 a: field experiment treated with 5 ppb for 10 and 20 days, respectively, compared to the control at 10 and 20 days; F200 T1 and F200 T2: field experiment treated with 200 ppb for 10 and 20 days, respectively, compared to the field control at 10 and 20 days.
Fig 5.
Comparison of the microarray data with the qRT-PCR results.
The mean fold changes of mRNA expression of AChE-1 for the different conditions relative to their appropriate control are given on the y-axis. C5 T1 and C5 T2: cage experiment treated with 5 ppb for respectively 10 and 20 days compared to cage experiment non treated for respectively 10 days and 20 days; C200 T1 and C200 T2: cage experiment treated with 200 ppb for respectively 10 and 20 days compared to cage experiment non treated for respectively 10 days and 20 days; F5 T1 and F5 T: field experiment treated with 5 ppb for respectively 10 and 20 days compared to field experiment non treated for respectively 10 days and 20 days; F200 T1 and F200 T2: field experiment treated with 200 ppb for respectively 10 and 20 days compared to field experiment non treated for respectively 10 days and 20 days.
Fig 6.
Expression profile of different immunity related genes (panel A) and detoxification genes (panel B). The mean fold changes of mRNA expression for the different conditions relative to their appropriate control are given on the y-axis which represents the log2 transformed fold change. *P <0.05, one-way ANOVA. C5 T1 and C5 T2: cage experiment treated with 5 ppb for respectively 10 and 20 days compared to cage experiment non treated for respectively 10 days and 20 days; C200 T1 and C200 T2: cage experiment treated with 200 ppb for respectively 10 and 20 days compared to cage experiment non treated for respectively 10 days and 20 days; F5 T1 and F5 T2 a: field experiment treated with 5 ppb for respectively 10 and 20 days compared to field experiment non treated for respectively 10 days and 20 days; F200 T1 and F200 T2: field experiment treated with 200 ppb for respectively 10 and 20 days compared to field experiment non treated for respectively 10 days and 20 days.