Page 42 - Adventures through the World of Entomology

1. BITING-CHEWING — Biting-chewing mouthparts BITING-CHEWING MOuTHPARTS 1. BITING-CHEWING — Biting-chewing mouthparts BITING-CHEWING MOuTHPARTS
consist of a labrum (similar to your upper lip), a hypo Labrum consist of a labrum (similar to your upper lip), a hypo Labrum
pharynx, a pair of mandibles, a pair of maxillae, and pharynx, a pair of mandibles, a pair of maxillae, and
a labium (forming the lower lip). All of these parts Maxilla a labium (forming the lower lip). All of these parts Maxilla
of a biting-chewing type mouthpart can be studied in of a biting-chewing type mouthpart can be studied in
depth by reading the first few chapters of a college depth by reading the first few chapters of a college
entomology text. Many of you will wish to do just entomology text. Many of you will wish to do just
that in order to get a better understanding of insect that in order to get a better understanding of insect
mouthparts. However, for our purposes, a close-up look mouthparts. However, for our purposes, a close-up look
at the mandibles is all we need to understand the type at the mandibles is all we need to understand the type
of havoc these mouthparts can wreak on our food and Mandibles of havoc these mouthparts can wreak on our food and Mandibles
our structures. When a pest control service technician Labium our structures. When a pest control service technician Labium
takes a bite out of a sandwich, he or she uses their front Drawing Courtesy of Corky’s Pest Control, nc. takes a bite out of a sandwich, he or she uses their front Drawing Courtesy of Corky’s Pest Control, nc.
teeth (incisors) to bite off a piece of sandwich. This morsel is then passed backward into the mouth to teeth (incisors) to bite off a piece of sandwich. This morsel is then passed backward into the mouth to
be ground up by the molar teeth before swallowing it. Insects with biting-chewing mouthparts have the be ground up by the molar teeth before swallowing it. Insects with biting-chewing mouthparts have the
mandibles structured similarly. The front part of the mandibles have incisor cusps (teeth) used to tear mandibles structured similarly. The front part of the mandibles have incisor cusps (teeth) used to tear
off a piece of food. Further back on the mandible are the molar cusps used to grind up the food before off a piece of food. Further back on the mandible are the molar cusps used to grind up the food before
it is swallowed. While our jaws move up and down to bite and chew, insects “jaws” move from side to it is swallowed. While our jaws move up and down to bite and chew, insects “jaws” move from side to
side to accomplish the same purpose. Now, let’s think about some of the types of insects that have this side to accomplish the same purpose. Now, let’s think about some of the types of insects that have this
type of mouthpart. type of mouthpart.

FOR EXAMPLE — Cockroaches use the incisor area of their FOR EXAMPLE — Cockroaches use the incisor area of their
GERMAN COCKROACH GERMAN COCKROACH
mandibles to bite off a piece of that apple pie left out on the mandibles to bite off a piece of that apple pie left out on the
counter overnight, or to scrape off some of the grease that counter overnight, or to scrape off some of the grease that
has coagulated on the frying pan left on the stove overnight, has coagulated on the frying pan left on the stove overnight,
or to nibble at the particles of food that have accumulated or to nibble at the particles of food that have accumulated
in and under food processing equipment. The material is in and under food processing equipment. The material is
passed to the molar cusps where it is ground up before being passed to the molar cusps where it is ground up before being
swallowed. swallowed.

Photo Courtesy Of UNVAR Photo Courtesy Of UNVAR
FOR EXAMPLE — Adult Yellow jackets tear off a piece of FOR EXAMPLE — Adult Yellow jackets tear off a piece of
cellulose from a rotting fence post or a piece of cardboard or other YELLOW JACKET cellulose from a rotting fence post or a piece of cardboard or other YELLOW JACKET
source of cellulose material, and while they are flying back to source of cellulose material, and while they are flying back to
their nest they chew the cellulose material with their molar cusps, their nest they chew the cellulose material with their molar cusps,
adding a bit of saliva from time to time. They spit and chew and adding a bit of saliva from time to time. They spit and chew and
spit and chew, and by the time they reach their nests they have spit and chew, and by the time they reach their nests they have
a wad of “paper maché” which they use as a building material a wad of “paper maché” which they use as a building material
to extend their intricate nests. Yellow jackets also use their to extend their intricate nests. Yellow jackets also use their
mandibles to capture and tear apart caterpillars and other juicy mandibles to capture and tear apart caterpillars and other juicy
forms of insects. They feed the pieces to their protein-eating forms of insects. They feed the pieces to their protein-eating
larvae, who are waiting in their nest cells to be fed, much the larvae, who are waiting in their nest cells to be fed, much the
same as fledgelings in the nest, waiting eagerly with their mouths same as fledgelings in the nest, waiting eagerly with their mouths
wide open for the momma bird bringing the worm. wide open for the momma bird bringing the worm.

Photo Courtesy Of UNVAR Photo Courtesy Of UNVAR

32 32