Teretriosoma

Associated with stored grain products, particularly maize and cassava; also found in natural habitats where decomposing organic matter occurs. T. nigrescens has been documented in regions with varying climate conditions, showing reduced abundance where annual relative humidity exceeds 70%.

Americas; Mexico (documented across multiple regions including Veracruz, Chiapas, and drier upland areas). Individual species distributions vary within this range.

In West Africa (Benin), T. nigrescens exhibits a single peak in flight activity in June, approximately six weeks after the major peak of its prey Prostephanus truncatus. Flight activity is associated with precipitation patterns.

Predatory; T. nigrescens feeds primarily on Prostephanus truncatus. Laboratory studies indicate strong prey preference for P. truncatus over alternative prey such as Sitophilus zeamais, with predator densities tracking prey densities.

• Prostephanus truncatus - preyprimary prey species; T. nigrescens abundance correlates with P. truncatus density
• Sitophilus zeamais - preyminimal predation; plays little role as alternative prey or in interfering with T. nigrescens reproduction

T. nigrescens responds to the aggregation pheromone produced by its prey Prostephanus truncatus, with both sexes captured in pheromone-baited traps. Sex ratios among trap catches are slightly male-biased. The predator does not behaviorally differentiate between the two pheromone components (T1 and T2) of its prey. Flight activity is influenced by accumulated rainfall during the trapping period.

Biological control agent; T. nigrescens functions as a specialist predator of stored product pests, particularly the larger grain borer. Its population dynamics are tightly coupled with prey abundance, though relative predator abundance decreases as prey becomes more numerous.

T. nigrescens has been investigated and deployed as a biological control agent against Prostephanus truncatus, a destructive pest of stored maize and cassava that causes significant agricultural losses in Africa and Latin America.

• other Histeridae generaTeretriosoma can be distinguished from other histerid genera by its placement in the tribe Teretriini; specific diagnostic features for field identification are not documented in available sources
• Prostephanus truncatusco-occurs in pheromone traps and stored products; T. nigrescens is a predator while P. truncatus is a pest borer; can be distinguished by family-level characters (Histeridae vs. Bostrichidae)

• clown beetles
• Histeridae
• biological control
• stored product pests
• predator
• Prostephanus truncatus
• maize pest
• cassava pest
• pheromone response
• integrated pest management

• BugGuide
• Wikipedia
• GBIF taxonomy match
• iNaturalist taxon
• NCBI Taxonomy
• Catalogue of Life
• Life history of Teretriosoma nigrescens Lewis (Coleoptera: Histeridae) and its ability to suppress populations of Prostephanus truncatus (Horn) (Coleoptera: Bostrichidae)
• Distribution and abundance of Prostephanus truncatus (Coleoptera: Bostrichidae) and its predator Teretriosoma nigrescens (Coleoptera: Histeridae) in Mexico
• Laboratory studies on behavioural interactions of Prostephanus truncatus (Horn) (Coleoptera: Bostrichidae) with conspecifics, synthetic pheromone and the predator Teretriosoma nigrescens (Lewes)(Coleoptera: Histeridae)
• EAG and behavioural responses of the larger grain borer, Prostephanus truncatus , and its predator, Teretriosoma nigrescens , to the borer‐produced aggregation pheromone
• Seasonal and weather factors influencing the annual flight cycle of Prostephanus truncatus (Coleoptera: Bostrichidae) and its predator Teretriosoma nigrescens (Coleoptera: Histeridae) in Benin
• Studies on predation of Prostephanus truncatus (Horn) (Col., Bostrichidae) and Sitophilus zeamais Mots. (Col., Curculionidae) at different densities on maize by Teretriosoma nigrescens Lewis (Col., Histeridae)