Sisyridae

Definition

A family of lacewing relatives (order Neuroptera) commonly called spongeflies or spongillaflies, comprising roughly 60 extant species. Adults resemble delicate, small brown lacewings, but the aquatic or semiaquatic larvae are distinctive: they possess long, segmented mouthpart stylets used to pierce and feed on the tissues of freshwater sponges (Porifera), making them among the few insects with an obligate parasitic or predatory association with sponges. The family has a sparse but widespread distribution and a fossil record extending to the Eocene.

Etymology

From Greek sisura, a kind of water-dwelling insect (possibly a mayfly or caddisfly), combined with the family suffix -idae.

Example

Sisyra fuscata larvae bore into the gemmules and choanocyte chambers of Spongilla lacustris in temperate lakes, while adults are rarely encountered away from the immediate riparian zone.

Synonyms

• spongeflies
• Spongillaflies

Related Terms

• Neuroptera
• Hemerobiidae
• Sisyra
• Spongilla
• aquatic Neuroptera
• spongivory

Usage Notes

Sometimes confused with brown lacewings (Hemerobiidae) in the field; adults are distinguished by reduced wing venation and more slender bodies. The family is the only exclusively spongivorous lineage in Neuroptera, though some chrysopid larvae occasionally scavenge sponge tissue. Sisyridae is placed in the suborder Hemerobiiformia alongside brown lacewings and dustywings.