| Abstract: | Scanning electron microscopy is used to describe the ultrastructure of morphological features related to feeding, locomotion, respiration, and pigmentation in second- and third-instar larvae of Ephydra hians (Ephydridae: Diptera). Using larvae fixed with the head extended, the ultrastructural details of the mandibles, maxillary papilli, and antennae are described for the first time. The larvae possess finger-like projections at the anterior spiracle and a distensible bifurcated siphon at the posterior spiracle. Slit-like openings are found on each. The second- and third-instar larvae can be differentiated on the basis of dorsal pigmentation associated with extensive patches of spines. The larvae have regional specializations in spine distribution, particularly on the ventral and dorsal body surfaces, and the prolegs. © 1994 Wiley-Liss, Inc. |
