Taenidia (singular: taenidium) are circumferential thickenings of the cuticle inside a

trachea The trachea, also known as the windpipe, is a cartilaginous tube that connects the larynx to the bronchi of the lungs, allowing the passage of air, and so is present in almost all air- breathing animals with lungs. The trachea extends from t ...

or tracheole in an

insect Insects (from Latin ') are pancrustacean hexapod invertebrates of the class Insecta. They are the largest group within the arthropod phylum. Insects have a chitinous exoskeleton, a three-part body ( head, thorax and abdomen), three pa ...

's respiratory system. The geometry of the Taenidiae varies across different orders of insects and even throughout the tracheae in an individual organism. Taenidia generally take the form of either hoop or spiral thickenings of the tracheal cuticle.

References

* Mill, P.J., ''Tracheae and Tracheoles'' Microscopic Anatomy of Invertebrates, 11A, pp. 303–336, 1998. Insect anatomy {{insect-anatomy-stub