84 CIRCULAR 16 8, U. S. DEPARTMENT OF AGRICULTURE 



List of forest insects — Continued 



Distribution 



Trees 



THYSAXOPTERA 



Liothrips floridensis Wats 



Liothrips setinodis Reut 



Phloeothrips nigra Sasaki 



ISOPTERA 



Rhinotermitidae: 



Coptotermes formosanus Shir... 



Leucotermes flaviceps Osh 



Leucotermes speratus Kolbe 



Termitidae: 



Termes formosanus Shir 



ORTHOPTERA 



Gryllidae: 



Brachytrypes portentosus Licht 



J. F. C. 



F. 



J. K. F. O. 



F. C. O. 



K. F. C. 



Camphor. 

 Do. 

 Do. 



Timber. 

 Do. 

 Timber, bamboo. 



Camphor, Cryptomeria, pine, 

 bamboo, timber. 



Camphor, Cryptomeria, acacia. 



INSECTS ATTACKING PINE 



The various species of pine are the trees of most common occur- 

 rence in the forests of Japan, and a number of insects are present 

 upon them which at times inflict serious injury. Among these may 

 be mentioned the two lasiocampids DendroUmus spectabilis (often 

 referred to in literature as D. remota TTlk.) and D. albolineatus. 

 The first named is distributed throughout the main islands of Japan, 

 and through Chosen, Manchuria, and Siberia. In Chosen (8) par- 

 ticularly the trees are frequently completely stripped of foliage. 

 In Japan the species is seldom sufficiently abundant to produce this 

 effect. There is one brood per year, and the winter is passed in a 

 half-grown larval condition in rubbish and grass, or just beneath 

 the surface of the soil, about the base of the tree. These larvae 

 ascend the trees and begin feeding about the middle of April; ma- 

 turity is reached in June, and the cocoon is spun among foliage, on 

 the trunk of the tree, or on weeds or grass stems near by. The 

 duration of the pupal stage is about 20 days, and the adult emerges 

 toward the end of July. The eggs are laid shortly thereafter in 

 rows or irregular masses upon the foliage, and hatch in about two 

 weeks. The larvae feed from the time of hatching until October, 

 when they descend for hibernation. Occasionally two broods per 

 year are produced {117). Effective control measures are not as yet 

 known, though in certain cases of severe infestation hand picking 

 of the larvae has been resorted to. 



The second species. D. alboJintatus. has come into prominence only 

 during recent years in connection with outbreaks in Hokkaido and 

 Sakhalin. Its distribution ranges from Sakhalin to Hokkaido and 

 the Kurile Islands. This species was originally determined as 

 D. sibiricus, but according to Matsumura the range of that species 

 does not extend to Hokkaido. The damage in all of these places 

 has been very great during recent years. In 1920 an area of 86,000 

 acres was almost completely defoliated in Sakhalin. The preferred 

 hosts in that section were Abies sachalinensis and Picea ajanensis, 

 and upon these trees defoliation was complete. An account of this 

 infestation was published by Kuwayama and Kuwahara (79) in 

 1922. They attribute the outbreak to climatic changes, these seasons 



