Zo Logy, Descriptive and Practical

Purchase of this book includes free trial access to www.million-books.com where you can read more than a million books for free. This is an OCR edition with typos. Excerpt from book: CHAPTER III. INSECTA (Continued). THE CRICKET. 1. In what respects are the cricket and grasshopper alike? 2. In what respects do they differ? 3. The female cricket has a long, slender ovipositor. Compare its parts with the parts of the grasshopper, s ovipositor, picking them apart with a dissecting needle. Use a lens. 4. A pair of tapering, jointed projections from the abdomen are the stylets. Of what use are the stylets ? 5. Compare the wings of the male and female. Look on the under surface of the outer wings of the male for a vein, running crosswise, near the anterior end, which has on it a row of teeth. By rubbing this file on the veins of the other wing, the cricket makes its chirping noise. Watch crickets to see how the wings are managed during this process. 6. With a lens look for the so-called hearing organ on the tibia of each fore leg. 7. Make a drawing showing all that can be seen from above (dorsal view), and name all the parts shown. Grasshoppers and crickets belong to the order of insects called Orthoptera, or straight-winged insects. THE DRAGON FLY. 1. Compare the shape and relative size of the parts of body with those of other insects. In some dragon flies the eyes have as many as 12,500 facets each. 2. What kind of mouth parts has the dragon fly? 3. How does the dragon fly compare with other insects in power of flight? To what bird should the dragon fly be compared in its habits? 4. Has the dragon fly a sting? Is it dangerous to man in any way? 5. Watch the dragon fly dipping the end of its abdomen into the water to lay its eggs. Compare the ovipositor with that of the grasshopper. 6. The larva of the dragon fly is called a nymph. It may be found on the bottoms of ponds and streams, and is very noticeable on accoun..