Mandibulate (chewing) Mouthparts - The classic depiction is shown in Figure 5. Chewing mouthparts are found in most insects, such as beetles and dragonflies. The labrum is the “upper lip” and the labrum is the Figure 6: Sickle-like mandibles used to “lower lip” of an insect. tear apart food. The labium has a feelerlike structure on both sides of the labium called a labial palp. Mandibles are the jaws and teeth wrapped up in one (Figure 6). They are located between the lips. Most mandibles have grooved surfaces or ‘tooth-like’ projections. They are aptly named, mandibular teeth (Figure 7). Mandibles move side to side instead of up and down as they masticate food. The shape of the mandible can be quite varied. The maxillae are another pair of feelerlike structures located behind the mandibles. Both maxillae and labial palps assist in the maneuvering of the food. The hypopharynx is a tongue- like structure located behind the mandibles and is not visible without the mandibles.
Figure 7: Mandibular teeth on a tiger beetle.
Haustellate (sucking) Mouthparts - The mandibles in haustellate insects are modified such that they are not used for Figure 8: Slender mouth of pythophagaous stinkbug chewing but are adapted for sucking. In (top); broad mouth of a predaceous assassin bug (bottom). some cases, the mandibles may even be lacking. This form of mouth is often referred to as Proboscis, or a beak, and is found on flies, true bugs, butterflies, and others. Within the haustellate groups, there are variations of sucking mouthparts.
Entomology
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