LLUSTRATIONS. 



PLATES. 



Page. 



Plate I. Map showing distribution of boll worm in world Frontispiece 



II. Life zones of the United States 



III. Fig. 1. — Egg of the bollworm 



Figs. 2-7. — Respective larval instars 



Fig. 8.— Pupa : 



Fig. 9.— Moth 



IV. Fig. 1. — Field of corn of age to attract moths for oviposition 



Fig. 2. — Bollworm eggs, enlarged, seen from above 



V. Tip of ear of corn showing bollworm eggs on silks 



VI. Fig. 1. — Bollworm on leaf stalk of cotton plant 



' Fig. 2. — Variation in markings of larvae, lateral view 



Fig. 3. — Variation in markings of larvse, dorsal view 



Fig. 4. — Dorsal pattern of markings of dark-brown larva 



VII. Fig. 1. — Young corn plant, showing injury to "bud " by bollworm. 68 



Fig. 2. — Bollworm and its work in corn tassel 68 



VIII. Fig. 1. — Bollworm and its injury in ear of field corn 68 



Fig. 2. — Bollworm and its injury in ear of sweet corn 68 



IX. Fig. 1. — Bollworm and its injury in cotton flower 68 



Fig. 2. — Cotton flower destroyed by bollworm 68 



Fig. 3. — Injury of very young larva to cotton square 68 



Fig. 4. — On the right, '* flared" cotton square due to bollworm 



injury ; on left, normal square 68 



Fig. 5. — Bollworm destroying young cotton boll 68 



X. Fig. 1. — Bollworm eating into a half-grown cotton boll 68 



Fig. 2. — Bollworm boring into full-sized cotton boll ,68 



Fig. 3. — Work of bollworm in interior of cotton boll 68 



Fig. 4. — Cotton boll only partially destroyed by bollworm, two 



''locks" open 68 



XI. Fig. 1. — Bollworm injury to tobacco 68 



Fig. 2. — Bollworm and its injury to tomato 68 



Fig. 3. — Bollworm boring into green peach 68 



Fig. 4. — Bollworm attacking okra ' 68 



Fig. 5. — Bollworm boring into cowpea pod 68 



XII. Fig. 1. — Larva entering soil for pupation 80 



Fig. 2.— Shrunken appearance of larvae just before molting into pupa 



stage 80 



Fig. 3. — Larva in its " (;ocoon," as made in sandy soil 80 



Fig. 4. — Bollworm pupae 80 



XIII. Fig. 1. — Pupal cell of bollworm in soil 80 



Fig. 2. — Plaster of Paris casts of pupal cells 80 



(8) 



