External morphological characters are described which permit larvae of the 2 spp. to be distinguished reliably in most, and perhaps all, instars without injuring or killing specimens. The characters occur on the head, thorax, abdomen and caudal lamellae.

Odonatologica

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Societas Internationalis Odonatologica

S.H. Chowdhury, & Philip S. Corbet. (1987). New external morphological characters for distinguishing larvae of Enallagma cyathigerum (Charpentier) and Ischnura elegans (Vander Linden) (Zygoptera: Coenagrionidae). Odonatologica, 16(4), 375–378.