File:Science Uncovered 2011 Highlight- Dangerous Beetles (6641764943).jpg

Many beetles produce repulsive chemicals to defend themselves against predation. However, the only way to suffer 'death by beetle' would be to eat a significant number of the more poisonous species. For instance, you would only have to eat two or three of the above grey beetle (Epicauta immaculata) to get yourself into serious trouble!

From Top to Bottom, Left to Right: The domino beetle, Anthia sexguttata- produces an organic acid which it uses defensively. Despite this potentially painful habit- these beetles are sometimes sold as pets.

Bombardier beetles: Pheropsophus sobrinus, Brachinus sclopeta (UK BAP species), Brachinus crepitans (a slightly more common, but still rare, UK species). Bombardier beetles produce hydroquinone and hydrogen peroxide which they store in their abdomens. When disturbed, the chemicals are pushed into a reaction chamber where they pick up catalase and peroxidase, enzymes that induce a boiling hot reaction, and the beetle can direct this boiling concoction towards whoever is pestering it.

The famed ‘Spanish fly,’ Lytta vesicatoria- a type of blister beetle which produces a poison called cantharidin. One of the side effects of ingesting cantharidin led people to consider the beetle to be a type of aphrodisiac, however, eating one of these beetles is sure to cause you more pain than pleasure as the cantharidin destroys your gastrointestinal and urinary tracts.

Epicauta immaculata- another blister beetle which produces particularly large amounts of cantharidin.

Choresine pulchra- a malachite beetle suspected of being a possible source of sequestered Batrachotoxins found in poison dart frogs and poisonous birds.

Whirligig beetle, Gyrinus chalybaeus- many whirligig beetles produce volatile, strong-smelling chemicals to deter predation from fish. Some of these beetles smell somewhat reminiscent of green apples.

A seven-spot ladybird, Coccinella septempunctata- while a welcome sight in the garden, not so welcome in your salad. Many ladybirds produce alkaloids in their hemolymph (bug blood) which they can voluntarily release from their body when disturbed- this is a defensive strategy called reflex bleeding. You may have noticed a smelly orange substance on your hands if you’ve ever handled a ladybird. That’s it! (I wouldn't suggest licking it).

Spider beetles (family Ptinidae) and dermestid beetles (Dermestidae)- these beetles, among others, like to live where we live. Some people are sensitive to the proteins in their shed skins and frass- triggering allergic reactions.