Reduviidae

Lore & Background

The family members are almost all predatory, except for a few blood-sucking species, some of which are important as disease vectors. About 7000 species have been described, in more than 20 recognized subfamilies, making it one of the largest families in the Hemiptera. The name Reduviidae is derived from the type genus, Reduvius, which comes from the Latin reduvia, meaning 'hangnail' or 'remnant', possibly inspired by the lateral flanges on the abdomen of many species.

Adult insects range from roughly 12 to 36 mm, depending on the species. They most commonly have an elongated head with a distinct narrowed 'neck', long legs, and prominent, segmented, tubular mouthparts called the proboscis or rostrum. Most species are bright in colour with hues of brown, black, red, or orange. The most distinctive feature is that the tip of the proboscis fits into a ridged groove in the prosternum, where it can be used to produce sound by stridulation, often to discourage predators. When harassed, many species can deliver a painful stab with the proboscis, injecting venom or digestive juices.

Predatory Reduviidae use the long rostrum to inject a lethal saliva that liquefies the insides of the prey, which are then sucked out. The saliva contains enzymes that digest the tissues they swallow, a process called extraoral digestion. The legs of some Reduviidae have areas covered in tiny hairs that aid in holding prey. Some species, such as Reduvius personatus, camouflage themselves with dust or debris. Some species feed on pests like cockroaches or bedbugs and are bred as pets and for pest control. The blood-feeding habit is thought to have evolved from species that lived in the nests of mammalian hosts. Several Triatominae species transmit the potentially fatal trypanosomal Chagas disease.

Reader's Guide

The Reduviidae family holds significance as one of the largest families in the Hemiptera, with about 7000 described species across more than 20 subfamilies. Their ecological role as terrestrial ambush predators is notable, as most other predatory Hemiptera are aquatic. While the vast majority are beneficial predators that help control pest populations, a few blood-sucking species in the subfamily Triatominae are medically important as vectors of Chagas disease, which causes 12,000 deaths annually. The family's distinctive morphology—including a narrow neck, sturdy build, and curved proboscis used for stridulation and venom injection—makes them easily recognizable. Their feeding strategy of extraoral digestion allows them to kill prey substantially larger than themselves. Some species are adapted to hunt specific prey, such as millipedes or ants, and certain species are bred by humans for pest control. Research on the venom of some species has shown insecticidal activity and antibacterial properties against human pathogenic bacteria. The oldest fossils of the family are from the Lower Cretaceous Yixian Formation, indicating an ancient lineage. Current taxonomy is based on morphological characteristics, though molecular analysis has called into question the monophyly of some groups.

Did You Know?

• Some species, like Reduvius personatus, camouflage themselves with dust and are known as masked hunters.
• The saliva of Rhynocoris marginatus has shown insecticidal activity against lepidopteran pests in vitro.
• The oldest known fossils of Reduviidae are from the Lower Cretaceous Yixian Formation.