What Is the World's Most Venomous Insect?

Which insect's venom packs the biggest punch?

The most venomous insect in the world is the harvester ant.
Eric Lowenbach / Getty Images

The most venomous insect isn't some rare, exotic rain forest creature. You may even have them in your own yard. Can you name guess what it is?

The world's most venomous insect is an ant. Not just any ant will do since many ants don't sting. Of the ones that do, the award for most toxic venom goes to the harvester ant (Pogonomyrmex Maricopa). The LD50 for harvester ant venom (in rodents) is 0.12 mg/kg. Compare that to an LD50 of 2.8 mg/kg for a honey bee (Apis mellifera) sting. According to the University of Florida Book of Insect Records, this is "equivalent to 12 stings killing a 2 kg (4.4 lb) rat." Since most rats don't weigh 4-1/2 pounds, let's put this in perspective. It takes about 3 stings to kill a one pound rat.

Insect venoms are comprised of amino acids, peptides, and proteins. They may include alkaloids, terpenes, polysaccharides, biogenic amines (e.g., histamine), and organic acids (e.g., formic acid). Venoms also may contain allergenic proteins, which can trigger a potentially lethal immune response in sensitive individuals.

Biting and stinging are separate actions in ants. Some ants bite and do not sting. Some bite and spray venom on the bitten area. Some bite and inject formic acid with a stinger. Harvester and fire ants bite and sting in a two-part process. The ants will grab hold with their mandibles, and then pivot around, repeatedly stinging and injecting venom. The venom includes an alkaloid poison. Fire ant venom includes an alarm pheromone which chemically alerts other ants in the vicinity. Chemical signaling is why the ants all appear to sting at once... that is essentially what they do.

The most venomous insect isn't the most dangerous

You'd do best to avoid harvester ants, especially if you are allergic to insect stings, but there are other insects much more likely to kill you or make you sick. Driver ants, for example, form the largest insect colonies. Their venom isn't the problem. It's that the ants travel en masse, repeatedly biting any animal in their path multiple times. These ants can kill elephants.

The most dangerous insect in the world is the mosquito. While mosquitoes carry a variety of nasty pathogens, the big killer is malaria. Fortunately, only the Anopheles mosquito transmits the deadly disease. 500 millions of cases of malaria are reported each year, leading to more deaths (over a million) than from any other insect bite, sting or disease combined. The World Health Organization (WHO) estimates a death occurs every 30 seconds.