Ithonidae

Definition

A family of lacewings (order Neuroptera) comprising the moth lacewings and giant lacewings. The family includes ten extant genera—such as Ithone, Rapisma, and Oliarces—plus numerous extinct genera known from fossils. Ithonidae is considered one of the most primitive living neuropteran families based on morphological and molecular evidence. Adults are typically nocturnal with broad, moth-like wings; larvae are fossorial, grub-like, and likely root-feeding. The family's modern distribution is notably disjunct (Australia, Southeast Asia, southwestern North America, and southern South America), contrasting with the broader global range of fossil taxa. Formerly segregated families Rapismatidae and Polystoechotidae have been synonymized under Ithonidae sensu lato following phylogenetic studies.

Etymology

From Ithone (type genus, from Greek Ithone, a nymph) + -idae (family suffix).

Example

The giant lacewing Polystoechotidae (now Ithonidae) was thought extinct in eastern North America until a specimen was collected in Arkansas in 2012, illustrating the cryptic biology of these subterranean-larva ithonids.

Synonyms

• moth lacewings (common name)
• giant lacewings (common name)
• Polystoechotidae (obsolete family)
• Rapismatidae (obsolete family)

Related Terms

• Neuroptera
• Ithone
• Rapisma
• Polystoechotidae
• Rapismatidae
• lacewing
• Ithonioidea
• fossorial larva
• phytophagous

Usage Notes

The family has undergone substantial taxonomic revision; older literature may treat Rapismatidae and Polystoechotidae as separate families. Use Ithonidae sensu lato for the expanded circumscription. The disjunct modern distribution makes this family of biogeographic interest. Larvae are rarely encountered due to their subterranean habit, so most records are of adults attracted to light.