posterior spiracle造句

• The posterior spiracles ( on the anal segment ) are usually on two cylindrical lobes.
• The terminal segments of the abdomen are glabrous, often partially sclerotized and bearing posterior spiracles.
• The instars are separable by examining the posterior spiracles, or openings to the breathing system.
• Entomologists are able to determine the instar stages by inspecting the posterior spiracles of the larvae.
• Each posterior spiracle ( anal spiracle ) lacks a clearly defined peritreme and each has three spiracular openings ( in mature larvae ).
• The posterior spiracles are relatively large and darkly pigmented; the anterior spiracles ( generally six to eight ) have relatively large branches.
• It has eleven posteriorly spinose dorsal segments with a median pair of tubercles on the upper border of the stigmal field . " Lucilia " larvae have posterior spiracles and tend to be larger larvae ranging from 9 18 mm in length.