Insects are arthropods with jointed appendages, segmented bodies, and an exoskeleton composed of chitin. Insects are in the class Insecta, & are the largest and most diverse group of animals on earth. The genus Romalea is a large grasshopper common in the southeastern United States. Insects have three body regions (head, thorax, & abdomen), 3 pairs of legs attached to the thorax, a single pair of antenna attached to the head, mouthparts adapted for chewing or sucking, and two pairs of wings. Some insects may have a single pair of wings or be wingless. Insect legs are often adapted for digging, crawling, jumping, or swimming. The insects are mostly terrestrial, they breathe air which enters small lateral openings on the body called spiracles and circulates in a system of ducts to all organs and tissues. Their chewing or sucking mouth parts are adapted for feeding on plant or animal materials.
Kingdom - Animalia
Phylum - Arthropoda
Class - Insecta
Order - Orthoptera
Identify & label the internal & external anatomy of a grasshopper.
Lab apron, gloves, eyeglasses, dissecting pan, dissecting kit with forceps & scalpel, t-pins, magnifying glass, preserved grasshopper, paper, pencil.
Procedure (External Anatomy): Examine the entire grasshopper and identify the major subdivisions and parts of the body.
|2. Mandibles||5. Maxillary Palps|
|3. Labial Palps||6. Maxillae|
|7. compound eye||8. ocelli|
Legs (first 2 pairs are for walking & the last pair are for jumping)
Wings (forewings have a leathery appearance & protect the hind wings)
Spiracles (small openings on the side of somites or body segments)
Auditory Organs (two located laterally on the 1st body somite or segment)
Ovipositor (on female)
Observations & Conclusion:
Figure 1 - Grasshopper Head (Label ALL parts.)
Figure 2 - External Grasshopper anatomy (Label ALL parts.)
Table 1 - External Appendages of the Grasshopper (Attach ALL parts.)
|Sex of Grasshopper|
1. Which region of the insect's body is specialized for sensory functions? Explain your answer.
2. Which region of the insect's body is specialized for movement & explain why?
3. What is the purpose of compound eyes? of simple eyes?
4. List the grasshopper's mouthparts & their functions.
5. How are the ends of the legs adapted for holding onto plants?
6. How is the third pair of legs adapted for jumping?
7. Describe the differences between the two pairs of wings (appearance & function).
8. How does the tympanic membrane help a grasshopper?
9. What system do spiracles open into on a grasshopper?
10. Do all abdominal segments have spiracles? Are there any spiracles on the thoraic segments?
11. How did you determine the sex of your grasshopper?
12. Explain how grasshoppers dig holes to lay their eggs.