Insects

Features of the mouth parts are very helpful in classifying the many kinds of insects. A majority of insects have bitting mouth parts of mandibles as in grasshoppers and beetles. Behind the mandibles are the maxillae which serve to direct food into the mouth between the jaws. A labrum above and a labium below a similiar to an upper and lower lip. In insects with sucking mouth parts, the mandibles, maxillae, labrum and labium are modified to provide a tube through which liquid can be drawn. in a butterfly or moth the coiled drinking tube is called the proboscis. Composed chiefly of modified maxillae fitted together, the proboscis can be extended to reach nectar deep in a flower. In a mosquito or an aphid, mandibles and maxillae are modified to sharp stylets with which the insect can drill through surfaces to reach juice. in a housefly, the expanding labium forms a spongelike mouth pad used to stamp over the surface of food.