Pump It Up

Monarch Butterfly

Monarch Butterfly Feeding

Butterfly mouthparts are long tubes that can be inserted into the narrow channels formed by flowers to reach a nectar reward. Flying or walking while dragging an extended tube would be awkward. Packaging the mouthparts into a tightly coiled tube under the head makes movements less awkward. The mouthparts coil when at rest due to the resilin component. Resilin can be stretched under pressure, but when relaxed, will return to its original shape.

How does a butterfly extend its mouthparts? The butterfly lifts its mouthparts in an action that partially uncoils them. At the base of the mouthpart in the head, muscles repeatedly compress a tube called the stipes. The movement of the stipes pumps hemolymph into the mouthparts and the hydraulic pressure forces the mouthparts to extend. When the butterfly finishes feeding, the valve of the stipes opens and the resilin forces the hemolymph out of the mouthparts as they coil under the head.

About jjneal

Jonathan Neal is a retired Associate Professor of Entomology at Purdue University and author of the textbook, Living With Insects (2010). This blog is a forum to communicate about the intersection of insects with people and policy. This is a personal blog. The opinions and materials posted here are those of the author and are in no way connected with those of my employer.
This entry was posted in by jjneal, Environment, Taxonomy. Bookmark the permalink.

1 Response to Pump It Up

  1. Pingback: Pump It Up – Entomo Planet

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