Several kinds of assassin bugs are found in cotton farms but no one species is regularly abundant. The assassin bug is a stealthy hunter and often approaches its victims from behind and stabs them with strong stylet-like mouthparts that inject a debilitating enzyme. The enzyme dissolves the preys' inner organs and the bugs then suck out the contents using its hollow mouth part leaving behind an empty shell of the prey.

Identification:  Adults are brown and range from 10 to 30mm in length, have distinct heads with prominent eyes and their abdomens have a slight waist. Nymphs are black with bright orange abdomens.

Lifecycle: Adult females lay several clusters of 40-80 orange eggs that take 14-16 days to hatch into nymphs during summer. The wingless nymphs pass through five growth stages to adulthood. Nymph development to adult takes approximately 65-95 days depending on temperature and availability of insect prey. Adults may live about 6-10 months.

Habitat: Assassin bugs occur in field crops, but they are also found in urban areas, coastal heaths, forests and woodlands.

Targeted prey: Assassin bugs feed on many different insects, but due to their sucking mouthparts, tend to prefer softer-bodied prey such as caterpillars and small bugs such as green mirids. Assassin bug nymphs have large appetites and can consume up to 160 small to medium-sized heliothis larvae over a 9-12 week period.

“A newly hatched assassin bug nymph on a cluster of eggs.”  5mm Photo: C. Mares

 “This young assassin bug nymph is feeding on a cotton looper”.  5mm Photo: J. Wessels DEEDI

“Assassin bugs have a big appetite for a large range of soft-bodied prey.” 25mm Photo: L. Wilson