e. Flattened body, small size; no compound eyes. Springtails and fish moths Thysanura 10. SUMMARY OF THE STUDIES OF INSECTS The Effect of Great Numbers 1. Take some insect for illustration, as the house fly, mosquito, tussock moth, or aphis, and show how insects increase in numbers with great rapidity. 2. What can be said about the number of species of insects? 3. There is said to be great competition among insects. Why? For what? 4. How is the great increase of insects held in check by natural means? 5. What are the various habitats of insects? Give as many as you can with examples of insects that use the habitat. 6. Give examples to show how greatly the food of insects and the method of obtaining it varies. 7. Give some illustrations of the great muscular development of insects. Why is this needed? 8. In what various ways are insects protected against their enemies? Give examples to illustrate your statement. 9. Show how and why the great numbers of insects have affected the structure and mode of life of the insects. Classification 1. By means of illustrations from your studies of insects show how classification is based upon likeness of structure. 2. In the same manner show how differences in structure affect classification. 3. Show how variation in the wings and mouth parts is used to separate insects into orders. 4. What are the principles of classification? 11. REVIEW AND LIBRARY EXERCISE ON INSECTS General Topics 1. General characteristics of insects. 2. Principal orders of insects with characteristics and examples of each order. 3. Respiration and air sacs of insects. Use of air sacs in flight. 4. The heart and blood of insects. How the function of the blood differs from that of other animals, as man. 5. Special senses of insects: their character, location, and efficiency. 6. Sound-making organs of insects. 7. Power of communication among insects, as among ants, for example. 8. Organs for depositing eggs, ovipositors. How they vary. 9. Homes of insects. Evidences of architecture in some of the homes. 10. How some plants make homes for insects. Galls and gall insects. 11. In what various ways do insects survive the winter? Illustrate with examples. 12. Community life among insects. Types of communities. 13. Pollination of flowers by insects. Why insects do this work and how the flowers compel them to do it in the right manner. Value to the plants. Types of insects useful for this purpose. 14. Adaptations for protection against enemies. Classify these adaptations and illustrate with examples. 15. The principal insect pests of the orchard and their work. 16. The principal insect pests of the garden and the work of each. 17. The principal insect pests of shade trees and their characteristics. 18. The principal insect pests of the household and methods of extermination. 19. The work of birds in helping to keep the number of harmful insects down.