Living With Tiny Antennae

Moth Antenna

Male Moth Antenna Is a Platform For Numerous Pheromone Receptors

Antennae are the primary olfactory organ (sense of smell) in most insects. The olfactory receptors on antennae are hair-like structures that contain fluid and one or more neurons. Most olfactory receptors are within a narrow range of size and shape. Insects that require extreme olfactory sensitivity, such as male moths, have antennae with side branches that greatly expand the surface area available as a platform for olfactory receptors. Insects with lesser need for olfactory information may have streamlined antennae with fewer receptors.

Tiny insects typically have tiny antennae, but larger in comparison to the size of the head than large insects. Tiny antennae have smaller surface area and can accommodate fewer olfactory receptors. As an adaptation to the smaller antennae, the receptors may be reduced in size. However, limited reduction is possible, generally less than 50%. As a consequence, the number of receptors is reduced. The smallest number* of recorded olfactory receptors is 38, on the tiny wasp, Megaphragma mymaripenne compared to 1000 or more in its larger relatives.

*Alexey Polilov. 2015. Small Is Beautiful: Features of the Smallest Insects and Limits to Miniaturization. Annu. Rev. Entomol. 2015. 60:103–21

About jjneal

Jonathan Neal is an 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, Taxonomy. Bookmark the permalink.

One Response to Living With Tiny Antennae

  1. Jordan says:

    Very in-depth look at antennae, written in a way that even a lay person can understand what they’re used for. That is also a very beautiful detail picture of a moth there. Thanks for sharing!

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