“Bug” may be a generic term for any insect, and it’s even used for spiders. But a true bug belongs to the insect order Hemiptera, whose members all share a pointed proboscis, or beak, with mouthparts adapted to sucking plant sap, or blood. Some true bugs are pests, like the suborder Sternorrynchia, which includes the honeydew-producing aphids, scale insects and whiteflies, and the suborder Heteroptera, which includes the blood-sucking bed bug.

[Animalia > Arthropoda > Insecta > Hemiptera]