Common Name: Assassin bug
Scientific Name: Zelus renardii (Kolenati)
Description: Common species in cotton include the leafhopper assassin bug, Zelus renardii (Kolenati), and the spined assassin bug, Sinea diadema (Fabricius). In both species, the head supports a strong beak. The leafhopper assassin bug is about 1/2 inch long and red, brown to yellowish-green. The front legs have no spines and are covered with a sticky substance with which they catch their prey. The spined assassin bug is similar in size but is dark brown to dull red-brown, not bicolored. The front legs are slightly swollen and covered with spines. The abdominal margins are expanded and flat with a pale spot on the rear margin of each segment.
Life Cycle: Assassin bug females deposit masses of brown, cylindrical eggs periodically. Immature nymphs resemble adults but are wingless and develop through five molts (instars) into adults in about two months. Nymphs of the spined-shouldered assassin bug are distinctly swaybacked.
Habitat and Food Source(s), Damage: In cotton fields, assassin bugs prey on a broad range of prey including fleahoppers, lygus bugs, aphids, caterpillar eggs and larvae and boll weevils. They will also eat other predaceous insects such as lady beetles and big-eyed bugs.
Pest Status: Beneficial insects/natural enemies; predatory on insect eggs, larvae and adults; capable of biting.
Management: None, this is a beneficial insect.
Literature: Bohmfalk et al. 1982; Frank & Slosser 1991; Kogan and Herzog 1980; Slater and Baranowski 1978.