Assassin Bugs and Kissing Bugs

Assassin bugs prefer a habitat near a good food source. During the day they hide under bark, between rocks, in certain plants, or in the thatched roofing of human structures.

Assassin bugs can survive as far north as Colorado and New Mexico. They extend through Mexico, much of Central America, and down to Colombia.

Assassin bugs are in the order of insects referred to as “true bugs” by biologists. Their colors vary among the thousands of species of Assassin Bugs, but all have a long, narrow head distinct from the wide body, long antennae, and nimble front legs good for grabbing other insects for food. Many have bright colors to warn predators that the bug is poisonous and not an easy meal.

The assassin bug gets its ominous name because it kills its prey almost on contact. The bug will sit and wait near flowers or other places where insects might land to feed such as animal droppings or tree sap. When the other insect hovers near or lands on these traps, the assassin slowly raises its front legs, snatches the prey, and punctures the exoskeleton with the tip of the assassin’s beak. The assassin’s saliva quickly paralyzes the prey. It also liquefies the other insect internally. The assassin can then either suck fluids from the body or carry the victim on its beak while it looks for more food.

This feeding behavior makes the assassin bug important to the balance of insect populations, including insects that are harmful to crops in Central America.

However certain assassin bugs are important for another, less beneficial reason. A few species of assassin bug, in the subfamily of kissing bugs, can transmit Chagas’ Disease. The common name comes from the bug’s tendency to bite a sleeping human on the face. Parasites living inside the kissing bug can pass from the bug to the sleeping victim through the bite wound or through a membrane on the face. Over many years, this parasite will slowly cause detriment to the host that can eventually be fatal. One of the most harmful effects of Chagas’ Disease is chronic heart failure. Millions suffer from this disease every year from parts of Mexico to South America but the disease is not at all a widespread threat in Costa Rica. Areas of risk are almost always rural, and high-risk areas are often where human dwellings have thatched roofing or grass components.

The aggressive nature of assassin bugs makes it difficult for individuals to mate. A male will advance slowly on a female one afternoon, then tackle her and climb onto her back before she can turn around to dislodge him. If she does shake him off, she might eat him. Males have better success if they pounce on a female who is currently eating. He will stay with her until the following dawn, when the two will separate cautiously. Occasionally separation will not go well, and one may cannibalize the other.

The assassin bug needs to consume blood. It will often kill other insects for food, but may also take from vertebrates, including humans.

Adult assassin bugs can be 10 to 45 mm in length.

Order: Hemiptera
Family: Reduviidae

Hogue, Charles L. Latin American Insects and Entomology. University of California Press: Berkely and Los Angeles, 1993.

Johnson, L. K., in Janzen, Daniel H. Costa Rican Natural History. Chicago: University of Chicago Press, 1983.

Amy Strieter, Wildlife Writer