There are many candidates for the world’s top 10 deadliest insects. Insects, not great white sharks or grizzly bears, are actually the most dangerous animals to humans. This is largely because they’re good at carrying and spreading deadly diseases, from malaria to the black death.
Many insects feed on vertebrate blood, making them prime carriers of harmful bacteria, viruses, and parasites, often passing them from animal to human. This list includes such disease – carrying insects, as well as those that can kill with toxic stings or bites, or by destroying crops. Insects have played a role in major historical events, shaping human evolution. Size can be misleading. Read on to learn more about the world’s deadliest insects.
- Blister Beetle
Blister beetles can be deadly to humans in theory, but it’s unlikely as you’d need to eat a lot of them. They’re more likely to kill horses if they get mixed in with the hay or alfalfa. These beetles secrete cantharidin, a toxin that causes skin blistering. It was used in folk medicine, for warts, rabies, and often as an aphrodisiac. But it can be fatal in large amounts. In the 1950s, a man was jailed for killing two women with cantharidin – laced candies.
- Locusts
Locusts are just a type of grasshopper, not scary on their own. But they can be devastating. In certain conditions, they gather in huge numbers, swarming across landscapes, destroying crops in minutes. Dry spells followed by rapid rainfall and vegetation growth trigger these swarms. The drought forces them together, and the new food allows rapid breeding. Their agricultural damage can lead to famine and human deaths.
- Assassin Caterpillar
The Assassin caterpillar, the larval stage of the giant silkworm moth, is deadly. Its name might overstate its kill count, but it’s responsible for some fatalities. It has venom – injecting bristles as a defense. Venom in a sac at the base of each bristle flows into the victim’s skin when punctured. The toxins prevent blood clotting. Symptoms include burning, vomiting, kidney failure, internal bleeding, and rarely, death.
- Fire Ants
Fire ants (genus Solenopsis with over 200 species) can cause human fatalities through anaphylaxis. They bite and inject a painful venom. Some people are extremely allergic. For most, it’s just a burning feeling and pustules at the sting site.
- Asian Giant Hornet
Also known as the “murder hornet,” it’s the world’s biggest wasp. It’s feared as an invasive species in the UK and USA. It’s aggressive and can be dangerous to humans like honeybees. But it mainly preys on bees, decimating whole hives by killing worker bees and taking larvae.
- Bees, Wasps, and Ants (Hymenoptera)
Few insects outside of disease carriers are deadly. But Hymenoptera (bees, wasps, and ants) can be. If you’re allergic and have an anaphylactic reaction, a bee sting can be fatal. In the UK, around ten people die from wasp or bee sting reactions each year.
- Kissing Bugs
Kissing bugs, from the Triatominae subfamily, are mostly in the Americas, with some in Africa and Asia. They feed on vertebrate blood and carry the parasite Trypanosoma cruzi, which causes Chagas disease. This disease infects 6 – 7 million people globally and causes about 10,000 deaths a year.
- Fleas
Fleas are well – known disease vectors. They transmitted the bubonic plague from rodents to humans, killing over 25 million in 14th – century Europe. They’ve even been used in biological warfare, like when the Japanese army dropped plague – infected fleas on Chinese cities in WW2.
- Tsetse Fly
The tsetse fly is second on the list. It has a big impact on human settlement in Africa and European colonialism there. It carries sleeping sickness, a disease transmitted by bite, caused by a single – celled parasite. Symptoms include fever, headaches, seizures, and sleep cycle disruption. Without treatment, it’s often fatal.
- Mosquito
The mosquito is the deadliest insect. It causes more human deaths per year than any other animal. It spreads many deadly diseases like yellow fever, dengue fever, and malaria. Malaria, transmitted by female Anopheles mosquitoes, caused an estimated 619,000 deaths in 2021.