Types of Mouths

Far from being a mere opening, the mouth is usually one of the most complex parts of an insect's body. The simple oral appendages of the most ^

primitive forms were gradually ^^ modified so that this zoological group has been able to expand its diet. Thus, a hunter's mouth is totally different from that of a sucking insect or a leaf-eater, such as the locust. »

Family Acriclidae Since ancient times, locusts have been feared as a great plague on crops.

1 day

THE TIME IT TAKES A LOCUST TO EAT ITS OWN WEIGHT IN FOOD

■Antenna

■Compound eye

■Antenna

Compound eye

Made to order

The oral appendages of primitive insects were modified considerably, and they took different forms according to the species. The first pair of upper jaws is for holding and sucking the food into the mouth. The second pair of upper jaws fuses at the midline during its development to form the lip, a structure with different functions, depending on the diet. The lower jaws and the first pair of upper jaws are at the side of the mouth, and an upper lip, the labrum, protects the front of the mouth. These parts form the basic biting-chewing apparatus. In more advanced forms, its modifications give rise to structures for sucking and licking or for biting and sucking.

PUNCTURING AND SUCKING

- Compound eye

BITING AND CHEWING

SUCKING

Antenna

Upper jaws

BUTTERFLY

With a small labrum and no lower jaw. The upper jaws form a suction tube.

MOSQUITO (FEMALE)

The lip and upper jaws form a tube; the lower jaws are for puncturing the skin, and the labrum forms a sheath.

LOCUST

PIERCING AND CHEWING

Compound eye

Lower jaw

Lip for nectar; lower jaws to chew pollen and mold wax

Strong lower jaws and dexterous upper jaws

Leaf Eaters

■ Insects such as locusts and some beetles, as well as caterpillars (and the larvae of many other species) need a mouth structure capable of cutting leaves into small pieces and then putting them into the mouth. For this purpose their large lower jaws have a series of serrated teeth, whereas the upper jaws and the lip have palps for manipulating and grasping the leaf pieces.

use their jaws as pincers to grasp their prey.

SEVEN-SPOT LADYBUG

Coccinella septempunctata feeds on aphids, plant lice, and sand flies.

Left serrated lower jaw

Left upper jaw, with palps upper jaw

Labrum m*

Was this article helpful?

0 0

Post a comment