The main difference between a bug and a beetle is that a bug belongs to the order Hemiptera whereas a beetle belongs to the order Coleoptera. Therefore, bugs have needle-like mouthpartsmouthpartsThe mandible (from Latin: mandibula or mandĭbŭ-lum, a jaw) of an arthropod is a pair of mouthparts used either for biting or cutting and holding food. Mandibles are often simply called jaws. Mandibles are present in the extant subphyla Myriapoda (millipedes and others), Crustacea and Hexapoda (insects etc.).
› Mandible_(arthropod_mouthpart)Mandible (arthropod mouthpart) - Wikipedia while beetles have chewing mouthparts. ...Feb 20, 2019