Figure 1

Male reproductive tract and cells within the testis of N. vitripennis. The bilaterally symmetrical male reproductive tract is shown in (A), with the testis (B) and seminal vesicle and accessory gland (C) shown at higher magnification. In (A), the black arrows indicate ducts joining the testis with the seminal vesicle, and the seminal vesicle with the accessory gland, while the green arrow depicts the ejaculatory duct. (D–F) Three major pupal stages are shown: (D) white body stage; (E) yellow body/red eye stage; (F) fully pigmented black body stage. (G–I) Fixed testes from these three pupal stages shown at low magnification. Panels (J–R) are high magnification images taken from the three testis shown in (G–I), with all images pertaining to each testis shown below each testis’ column. (J) Spermatogonia at interphase. Circumscribed cystocytes are in interphase. (N) Spermatogonia with condensed chromosomes. The chromatin of circumscribed cystocytes appear condensed into chromosomes. Asterisks in (J,N) denote trophocyte nuclei. (K) Small cyst of spermatogonia at interphase. (L) Large cyst of germ cells with condensed nuclei, indicating their entry into spermiogenesis. (O) A cyst forming a ‘cup-like’ structure at the onset of spermiogenesis. (P) Bundles of elongating spermatid nuclei. (M) Germ cells beginning spermiogenesis but not yet in the ‘cup’ formation. (Q,R) fully elongated sperm nuclei. DNA is grey in panels (G–R). White arrows indicate trophocytes. Scale bar equals 150 μm in (A), 60 μm in (B), 75 μm in (C), 500 μm in (F), and 80 μm in (I).