Scotoleon marshi

Adults can be distinguished from damselflies by their short, clubbed antennae (damselflies have long, thread-like antennae). Within antlions, Scotoleon males are identified by their elongated abdomen with bracket-like terminal claspers, a trait especially pronounced in this genus. The genus Scotoleon differs from Myrmeleon, which is known for pit-digging larvae; Scotoleon larvae are thought to be pit-diggers based on genus affiliation, though this specific behavior has not been directly documented for S. marshi.

Antlions generally occupy dry, sandy, or powdery soil environments. Prime situations include the base of trees, beneath rock overhangs, under bridges, and the dirt floors of old barns and sheds—locations that remain perpetually dry. Adults are most often observed among tall grasses, especially at dusk.

North America. The species has been documented in the southwestern United States, with at least one observation from Arizona.

Adults are most frequently observed at dusk. They are attracted to lights at night. Activity patterns likely vary regionally based on climate.

Complete metamorphosis: egg, larva, pupa, adult. The larval stage is terrestrial and predatory. Pupation occurs underground within a sand-incorporated silken cocoon. Adult longevity is relatively brief compared to the larval stage.

Adults are weak, clumsy fliers. They exhibit remarkable crypsis: upon alighting on grass stems or twigs, they align themselves seamlessly with the substrate and flatten their bodies to become essentially invisible. Larvae are sit-and-wait predators.

Larvae function as subterranean predators of small arthropods, potentially regulating populations of ants and other ground-dwelling insects. Adults may serve as prey for aerial predators such as praying mantises.

Antlions, including this species, contribute to natural control of ant populations. The larvae are familiar to many people as "doodlebugs" and can be observed by tickling the bottom of pits with grass blades to elicit sand-throwing or grasping responses. They can be maintained in captivity with fine sand and provided prey.

• MyrmeleonBoth genera contain pit-digging antlion larvae, but Myrmeleon is the primary genus associated with this behavior in North America. Scotoleon males have more pronounced abdominal elongation and bracket-like claspers than Myrmeleon males.
• Damselflies (Zygoptera)Adult antlions superficially resemble damselflies in body shape and wing posture, but are distinguished by short, clubbed antennae versus long, thread-like antennae in damselflies, and by their weak flight and crepuscular activity.

• BugGuide
• iNaturalist taxon
• Catalogue of Life
• Bug Eric: "Doodlebugs" (Antlions)