Lesson 2a Insect External Structure and Function Flashcards
What are the three major body divisions in an insect body
- Head
- Thorax
- Abdomen
What structures “poke food into the mouth”?
Maxillary Palps
Labial Palps
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What appendages do you find on the three thoracic segments?
Prothorax: Fore leg; Pronotum
Mesothorax: midleg; forewing
Metathorax Hind leg; hind wing
What are the different examples of insect mouth types covered in this lesson? Give an example of an insect with each specific mouth type.
Sponging- Houseflies (Diptera)
Chewing – Caelifera (short horned grasshoppers)
Siphoning Tube – Lepidoptera (moths and butterflies) at full metamorphosis
Piercing Sucking- Anoplura (sucking lice)
Lapping - Flees
https://canvas.ubc.ca/courses/52107/pages/l2-dot-08-abdomen?module_item_id=2674929
Describe the feeding mechanism of housefly in relation to its mouth type.
Houseflies have a sponging mouth type that allows them to feed on liquid or semi liquid food.
The house fly must secrete an enzyme onto the food to liquify solid substrates to be able to absorb by sponging action of the modified mouth.
A proboscis, which is a modified labium contains a labella, which is a fleshy lobe that uses capillary action to draw food to the mouth.
Describe the evolution of piercing, sucking insect mouthparts from the chewing type.
Mandibles were biting chewing structures, and maxillary palps/labial palps helped shove food into the mouth.
in peircing sucking insects, mandibles and maxillae evolved to form nested tubes (stylets) and the labium into a folding sheath to house the stylets .
a sbustructure of the maxillae, the galea, forms a tubular probocis to help sucking mouthpars to siphon nectar from flowers.
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Name the external sensory organs found on the grasshopper’s head
Maxillary papes (taste); Eyes (compound and simple); Antennae (olfactory, auditory, thigmotactic)
pg 457
