The structure and function of the larval siphon and spiracular apparatus of Coquillettidia perturbans.

The structure of the larval siphon and spiracular apparatus of Coquillettidia perturbans and the mechanism of attachment to roots of emergent aquatic macrophytes were examined by utilizing dissection and scanning electron microscopy. The roots of these plants contain large air-filled aerenchyma channels that larvae of Cq. perturbans pierce with their specialized siphon and spiracular apparatus to breathe. The siphon contains the spiracular apparatus, comprising the saw, postabdominal spiracles, inner spiracular teeth, and the spiracular apodeme. These are the primary structures that are utilized by larvae to pierce root tissue. Once entry is made into a root, the outer spiracular teeth open fully, anchoring the larva in place.