Gonad histology of 9.5 mg/L of imidacloprid exposed group, a) Granulomatous inflammation (star), hyperplasia at perifollicular cells (arrow), and openings at follicular layers (square), PAS stain, b) distortion at oocyte shape, fluctuation at zona radiata (yellow arrow), hyperplasia at perifollicular cells in higher magnification (black arrow), H&E stain, c) vacuolization and unification in cortical alveoli (red rectangle), openings at follicular layers in higher magnification (square), TB stain, d) interstitial fibrosis (IF) between tubules, PAS stain, e) hypertrophy at Leydig cells (green arrows) and vascular congestion (red star), PAS stain, f) hypertrophy at spermatogonia (red arrows), TB stain, Po: Primary oocyte; CoC: Cortical alveolar stage oocyte, Vo: Vitellogenic oocyte, N: nucleus, No: Nucleolus, T: seminiferous tubules, SGA: spermatogonia A, SGB: spermatogonia B, PST: primary spermatocyte, SST: secondary spermatocyte.