Figure 2.

Scanning electron micrographs that confirmed the Eristalis tenax species. (A) Extremity of the posterior telescopic breathing tube showing several spiracular openings (so) arranged in circle. Note the long hanging interspiracular setae (is). (B) Latero-dorsal view of the head showing several satellite sensilla positioned on top of the antennomaxillary organs (am), the lateral lips (lp), and the pair of the mesothoracic prolegs (mp); (C) Antero-dorsal view of an anterior retractile spiracle showing approximately 20 facets (f) arranged in one row around the edge. In E. tenax, the anterior spiracle is about two times longer than broad with rounded and slightly recurved tips. (D) Latero-ventral view of a pair of abdominal prolegs showing the crochets facing backwards, arranged in semi-circular rows. The spicules gradually become smaller below.