CLICK ON PHOTO FOR LARGER VIEW
Zelus longipes Linnaeus is commonly called the ‘milkweed assassin bug,’ as it closely resembles the milkweed bug, Oncopeltus fasciatus. It is also known as the ‘longlegged assassin bug’ and the ‘Zelus assassin bug’. Members of the genus Zelus belong to the subfamily Harpactorinae and are diurnal in nature. They are generalist predators feeding on a wide range of soft-bodied prey in garden and fields such as mosquitoes, flies, earthworms, cucumber beetles and caterpillars (fall armyworm, rootworm etc.).
While not a threat to humans, if not handled properly, a Z. longipes ‘bite’ can cause a burning sensation with swelling that may last for several days.
The strategy Z. longipes uses to catch its prey is known as the “sticky trap strategy.” Like many ambush bugs, Z. longipes attacks prey after hiding inside foliage with its forelegs raised in the air. The forelegs of Z. longipes are covered with a viscous material which acts as a glue, trapping the prey. Zelus longipes then rapidly paralyzes its prey by inserting its stylets into the host body and and prepares to feed through extra-oral digestion. Extra-oral digestion is a mode of digestion where a predator releases enzymes into its prey to dissolve the host’s tissue, and later sucks up the dissolved liquid using its stylet as a straw. Zelus longipes can feed on prey that may be up to six times their own size. But with increasing prey size the handling and feeding time for Z. longipes also increases, allowing them to become vulnerable to other predators