Assassin Bugs

Using Deception to Lure Prey

As immature nymphs, assassin bugs employ a unique type of deception to help lure unsuspecting insects closer. Their natural colors can range from brownish-gray to bright orange, making natural camouflage nearly impossible. Instead, nymphs attempt to obfuscate their appearance by covering themselves with the husks of their previous victims and bits of plant debris. Many of the species preyed upon by assassin bugs tend to investigate the heap of debris, significantly reducing prey capturing time and providing the nymph with a better opportunity to successfully attack.

The behavior of decorating one's exterior with foreign material is known as “masking,” and its use as a feeding strategy has also been observed in spider crabs and in the larvae of the insect family Chrysopidae. One particular nymph, the dust bug (Reduvius personatus), masks itself with a layer of sand and dust particles in order to appear to its usual prey, the bed bug, as debris carried by the wind as the bed bug maneuvers for attack. Masking has limited value for preying on insects that have no visual capacity, such as termites and army ant workers.

An additional function of masking is as protection against visually hunting predators. Assassin bug nymphs are highly vulnerable to larger predators. Birds, geckos, rodents, and some species of arachnids are potential hunters of assassin bugs, but they have been observed failing to recognize the heap of organic material covering the assassin bug as anything edible. Predators that investigate the heap have been observed failing in their attack because of the “backpack” of debris ripping off the nymph's abdomen mid-encounter, much like a lizard's tail, allowing the nymph the opportunity to escape. Thus, the obfuscating behavior of masking can provide assassin bugs with both the opportunity to lure prey into its vicinity, and the possibility of becoming prey to other animals in turn. The particle-carrying capacity of nymphs decreases as the insect grows older and less vulnerable to predation.

Assassin bugs can commonly be found in vineyards, fruit orchards, cotton and soybean fields, and other vegetative habitats. Despite their appearance and behavior, they are generally considered beneficial to row crops because they are known to [Page 41]feed on harmful prey such as aphids, boll weevils, and caterpillars. Because of their quick adaptation to new environments and short life cycles, assassin bugs can be deployed as biocontrol agents meant to eradicate a harmful species.

Reduvius personatus, or the masked hunter, is an insect belonging to the assassin bug (Reduviidae) family. The name refers to the fact that its nymph camouflages itself with dust.

...