Brachypsectra

Adults distinguished from similar elateroid beetles by combination of pectinate antennae (especially males), lack of functional prothoracic clicking mechanism, and specific body proportions. Larvae unmistakable due to branched lateral lobes with feathery lobules on thorax and abdomen—morphology unique among beetle larvae. Larvae may be confused with neuropteran or other predatory larvae, but sclerotized scale-like setae and posterior tail structure are diagnostic.

Larvae occur under loose bark on trees, in leaf litter, and in cracks in rocks. Habitats selected for high abundance of insects and other arthropods rather than specific plant associations. Adults attracted to light.

Southwestern North America: Mexico and United States (Arizona, California, Colorado, New Mexico, Texas, Utah).

Adult males active May through August. Larvae can live over two years; pupation occurs after approximately six weeks in cocoon within silken net in narrow chamber.

Larvae are predators that ambush prey. Documented prey includes small spiders, pseudoscorpions, cockroaches, termites, and beetle larvae (Trogossitidae, Nitidulidae, Tenebrionidae).

Number of instars unknown. In captivity, some larvae lived over two years without feeding. Some individuals moulted twice before pupating. Cocoon surrounded by silken net connecting sides of narrow pupation chamber. Adult emergence after approximately six weeks.

Larvae are sit-and-wait predators, remaining stationary and well-camouflaged until prey approaches. Prey capture involves arching tail and head to trap victim between tail spine and mandibles. Possible use of allomone to attract spiders: in studies, multiple spiders congregated on larva's back without being pounced upon, suggesting chemical attraction. Adults attracted to light; seldom seen in field.

Predator in terrestrial arthropod communities, particularly in subcortical and litter microhabitats.

Larvae historically significant as 'entomological enigma' before adult association established in 1927. Subject of behavioral research on predatory mechanisms and possible chemical ecology.

• AsiopsectraOther extant genus in Brachypsectridae; distinguished by geographic distribution (Asia) and subtle morphological differences in adult and larval structure.
• Elateridae (click beetles)Related elateroid family with similar adult habitus; distinguished by presence of functional prothoracic clicking mechanism in elaterids, which Brachypsectra lacks.

• Elateroidea
• predatory larvae
• sexual dimorphism
• pectinate antennae
• ambush predator
• subcortical habitat
• nocturnal adults

• BugGuide
• Wikipedia
• GBIF taxonomy match
• iNaturalist taxon
• NCBI Taxonomy
• Catalogue of Life
• A New Species of Vetubrachypsectra from Mid-Cretaceous Amber of Northern Myanmar (Coleoptera: Brachypsectridae).