Zoology Lab Exam 2 Grasshoppers and Insects

Franklin College BIO 230 Zoology Lab Exam 2 Grasshopper Anatomy

Chitinous exoskeleton

Hard exoskeleton consisting of numerous sclerites

Sclerites

numerous hardened plates on the chitinous exoskeleton

Sutures

thin membranous areas which separate the sclerites, helps provide flexibility for movement

Underlying Hypodermis

the middle layer of the body wall, secretes the cuticle

Basement membrane

a thin, noncellular layer of the body wall

Epicuticle

non-chitinous and consists chiefly of a network of fibrous proteins impregnated with wax

Compound eyes

two large of this occupy prominent sites on opposite sides of the head

Occeli

three of this form an inverted triangle on the front of the head between the compound eyes

Antennae

two of this jointed together arising anterior to the compound eyes serve as organs for touch, smell, and taste

Dorsal labrum

upper lip; apart of the mouthpart

Manibles

a pair of sclerotized (hardened); apart of the mouthpart

Maxillae

helps manipulate the food; apart of the mouthpart

Labium

lower lip; apart of the mouthpart

Cylindrical Hypopharynx

Tongue, at the base of which the salvitory glands empty — in the center of the outer mouthparts

Sensory palps

the labium (lower lip) and the maxillae (chews food) bear these, and are projected ventrally

Throax

consists of several fused segments, illistrating the multisegmented ancestry of the insects

Anterior Prothorax

bears one pair of legs, is a large segment of the thorax

Mesothorax and Metathorax

Two smaller segments that are included in the thorax, and bears one pair of walking legs and wings

Legs

clearly jointed and consists of 5 main elements

Coxa

attached to the ventral body wall; is short and apart of the legs

Trochanter

small, fused with the femur — apart of the legs

Femur

stout, fused with the trochanter, apart of the legs

Tibia

sometimes bearing spines, slender, apart of the legs

Tarsus

bears two claws on it, distal aspect of the legs

Claws

two terminal, on the tarsus on the legs

Arolium

a fleshy pad in between the claws, providing a grip on smooth surfaces

Metathoracic Legs

Specifically modified for leaping, also used for walking and climbing

Modifications of the metathoracic legs

enlarged femur and an elongated tibia for additional leverage, and the inner surface of the femur bears small spines in males that is rubbed against the lower edge of the front wing to create sound for mating

Forewings

Long and narrow, borne on the mesothorax and serves as a covering for the hind wings when at rest

Spiracles

10 pairs of small respiratory openings which open into the system of tracheal tubules

Tympanic membrane

serves as an organ for hearing, along the first abdominal segment and is large and oval shaped

No metamorphosis

hatch directly from the egg into a form resembling miniature adults (ex. silverfish)

Incomplete Metamorphosis

emerge from the egg generally resembling the adult but with a disproportionately large head and without wings

Complete metamorphosis

stages: egg, larva, pupa, and adult

undergoes striking changes in form