Grasshopper Dissection

Students dissect a preserved grasshopper to investigate external structures (head, thorax, abdomen, legs, wings, spiracles, eyes, antennae, mouthparts) and internal organs (digestive, respiratory, reproductive). The activity emphasizes insect body plans and relates structure to function using safe, scissors-first technique.

• Follow instructions provided in the links below.

Grasshopper Dissection- Biologybyme:

How to Dissect a Grasshopper (“Bug Doc” Dave Shetlar) - OSU Extension Professionals:

📄 Grasshopper Dissection - Carolina: https://www.carolina.com/teacher-resources/Interactive/grasshopper-dissection-activity/tr10823.tr?srsltid=AfmBOorrINB1IZ5BMAjxMGqtpehmwFWIos_A08N4DWMLPvf48lwaHUDn

📄 Virtual Grasshopper Dissection: https://www.ent.iastate.edu/ref/anatomy/ihop/

• Compare male and female specimens and tabulate diagnostic features (ovipositor vs. claspers; gonad morphology).
• Dissect a second insect (e.g., beetle or cockroach) and create a comparison chart of shared and unique features.
• Focus study: isolate and diagram only the digestive system or only the tracheal system for deeper analysis.
• Use a stereomicroscope to examine mouthparts and spiracles before internal dissection.
• Relate function to form by measuring leg segment lengths and inferring locomotor adaptations.

• Wear gloves and a lab coat at all times.
• Use scissors as the primary cutting tool; cut slowly and keep the specimen flat on the tray (do not cut while holding it).
• Handle forceps, probes, and pins carefully; dispose of broken or bent pins properly.
• Treat preservatives and tissues as potential irritants; work in a well-ventilated area and avoid contact with skin and eyes.
• Keep food and drink out of the lab; disinfect work surfaces before and after the activity.
• Follow institutional guidelines for biological waste and sharps disposal.
• Provide nitrile gloves for anyone with latex sensitivity.

• What are the three main body regions of an adult insect, and where are they on the grasshopper? (Head, thorax, abdomen; easily identified externally.)
• Why does each thoracic segment bear a pair of legs, and why do wings attach to the posterior thoracic segments? (The thorax specializes in locomotion; wings are supported by the meso- and metathorax.)
• How does gas exchange occur without lungs? (Air enters spiracles and moves through tracheae directly to tissues by diffusion and body movements.)
• What is the function of the gastric caeca attached to the stomach? (They increase digestive surface area and secrete enzymes to aid digestion.)
• Which external features help you distinguish male from female grasshoppers? (Females have an ovipositor of four curved plates; males lack an ovipositor and have small claspers with a blunt abdominal tip.)
• How does the exoskeleton benefit and limit the grasshopper? (Provides protection and support but requires molting for growth and limits size due to diffusion-based respiration.)
• Why is scissors-first dissection recommended for insects? (Controlled cuts reduce damage to internal organs and prevent cracking the exoskeleton.)