b THE BEAN THKIPS. 
Page. 
Seasonal history in the Imperial Valley 37 
Egg period 37 
Larval period 38 
Prepupal and pupal periods 38 
Seasonal history at Tempe, Ariz 33 
Hibernation 39 
Notes on occurrence 40 
Natural control 40 
Rains = 40 
Natural enemies 41 
Artificial control 42 
Cultural methods 42 
Spraying 43 
Distributing the parasites 44 
Bibliography 44 
Index 47 
ILLUSTRATIONS. 
Page. 
Fig. 1. Side view of the head of a thrips, showing the mouthparts 8 
2. The bean thrips (Heliothrips fasciatus) : Adult female and details 9 
3. The bean thrips: Eggs 10 
4. The bean thrips: First-stage larva 11 
5. The bean thrips: Second-stage larva ]2 
6. The bean thrips: Prepupa 12 
7. The bean thrips: Pupa 13 
8. Map showing present known distribution of the bean thrips (Heliothrips 
fasciatus) 15 
9. Alfalfa showing injury by the bean thrips 29 
10. The bean thrips: Prepupse parasitized by Thripoctenus russelli 41 
11. A hymenopterous parasite, Thripoctenus russelli: Adult 42 
