106 PROC. ENT. SOC. WASH., VOL. 22, NO. 5, MAY, IQ2O 



pv Penisvalvae, or valves of t Tegula. 



male genitalia. tb Tibia. 



s Sternum. tc Trochanter. 



sa Subalare, or subalar plates. ts Tarsus. 



sc Scutum. u Postuncus, or terminal hook of 

 scl Scutellum. penis valve. 



EXPLANATION OF PLATE. 



Fig. 1. Lateral view of head and thorax of dealated female. The parts of 



the neck and prothorax are abnormally distended. 

 Fig. 2. Lateral view of terminal structures of apterous male, with genitalia 



extruded. 

 Fig. 3. Dorsal view of genital valves of apterous male. The basal portions 



of the valves, being imbedded in the genital tissues, are not 



drawn. 



Fig. 4. Lateral view of terminal structures of dealated female. 

 Fig. o. Frontal view of head of dealated female. 

 Fig. 6. Dorsal view of thoracic region of dealated female. The parts of the 



prothorax are abnormally distended in this specimen. 



DIRECT SUNLIGHT AS A FACTOR IN FOREST INSECT CONTROL. 

 BY F. C. CRAIGHEAD, PH. D., Bureau of Entomology. 



Control and preventative measures in Forest Entomology are 

 necessarily based on different principles from those commonly 

 used against orchard, field or truck crops. The inaccessability 

 of many of the regions, the enormous area involved, and the low 

 annual returns on the investment demand protective measures 

 that can be correlated with systems of forest management or 

 lumbering practices at the least expense. 



This requirement has been the basis on which all control or 

 preventative measures are formulated. To quote from Dr. Hop- 

 kins: 1 



'The desired control or prevention of loss can often be brought 

 about by the adoption or adjustment of those requisite details 

 in forest management and in lumbering and manufacturing opera- 

 tions, storing, transportation, and utilization of the products 

 which at the least expenditure will cause the necessary reduction 

 of the injurious insects and establish unfavorable conditions for 

 their future multiplication or continuance of destructive work." 



As examples of such methods are the cutting or girdling of 

 certain woods at definite seasons of the year to prevent attack 



1 Some Insects Injurious to Forests: Insect Depredations in North Ameri- 

 can Forests and Practical Methods of Prevention and Control. Bulletin 58, 

 Part V, Bur. Ent., U. S. Dept. of Agric. 



