Assassin bugs in the context of True bugs

Hemiptera (/hɛˈmɪptərə/; from Ancient Greek hemipterus 'half-winged') is an order of insects, commonly called true bugs, comprising more than 80,000 species within groups such as the cicadas, aphids, planthoppers, leafhoppers, assassin bugs, bed bugs, and shield bugs. They range in size from 1 mm (0.04 in) to around 15 cm (6 in), and share a common arrangement of piercing-sucking mouthparts. The name "true bugs" is sometimes limited to the suborder Heteroptera.

Entomologists reserve the term bug for Hemiptera or Heteroptera, which does not include other arthropods or insects of other orders such as ants, bees, beetles, or butterflies. In some varieties of English, all terrestrial arthropods (including non-insect arachnids and myriapods) also fall under the colloquial understanding of bug.