48 



274. The Four-Winged Parasites (( )r<li'r Ili/mrno/dini. Viun\\'n;>i Ichiieuiiionid.T, 

 Ilrnriiiiiihv, Chdlfiiliilir, ftc. ). 



Kxiiiiut: Two larval jialU-r'u's of the ri^id cypress hon'r {(Eine rif/ida), in one of 

 w liicli the insect attained full development, while in the other it was attacked and 

 killed i)y a j)arasite, Iir(i<-i»i sp. 



A<iiilts and cocoons of sevend species which attack larvir of Imttcrtlics and moths. 



Adults and cocoons of several species which attack larvii- of wood-l)inin'_' inst'cts. 



THE TROGOSITIDS. FAMILY TROGOSITID^ffi. 



275. The Green Trogositid {I'nxjdsilu rlri:'«riiti Fal). ). 



A very important enemy of nearly all the lari^erand moredestru(;tive Ijark-beetles. 

 The adults conceal themselves in the outer hark, and the larva^ enter tiie galleries 

 an<l prey upon the insects therein. 



Exhibit: Adults. 



THE COLYDIIDS. FAMILY COLYDILDiE. 



276. The Tuberculate Colydiid {Auloniurn tnberculatiun L^c). 



The adults entiT the galleries and with thelarvie feed upon various species of hark- 

 beetles in all their stages. 

 ExniHiT: Adults. 



277. The Line-Marked Colydiid {Coh/dium llneola Say). 



The adults enter the galleries and their larvic feed ui)on the developing hrood of 

 various species of Ambrosia l)eetles. 

 ExniniT: Adults. 



SECTION ITT. 



SPECIAL INVESTIGATIONS. 



[In (■Diiiiciiiiiii Willi thr ixliiliil 111 ilic Hiiri'iiu ni' Knrcstry.] 



DESTRUCTION OF PINE BY BARK-BEETLES IN THE BLACK HILLS 

 FOREST RESERVE, SOUTH DAKOTA. 



C^eVSE -40. 



278. The Pine-Destroying Beetle of the Black Hills ( J)i iidroct(mi(.-< pnnder- 



...x.r Ilopk.). 



Attacks healthy pine an<l spruce in the Black Hills of South Dakota, and Rocky 

 Mountain region. The adult beetles excavate characteristic galleries in the inner 

 bark of dca<l, dying, and healthy trees. Their eggs are deposite<l along the sides 

 of these galleries, and the larv.i' developing from them mine the inner l)ark. Very 

 dc.><tructive. 



Exhihit: Adults, larva', i>up,c, i)it«h tul>e on bark of living tree at entrance to 

 gallery of adult beetle; completed galleries of adults and mines of young larvie in 

 bark of living pine, showing characteristic appearance of bark in .Vugust of the year 

 of attack; surface <»f woo<l grooved by galleries of the adidt, showing characteristic 

 ajipearance in August of the year of attack; gallery of adult, larval mines, and 

 jiupal chandx'rs in inner bark, showing characteristic a(>pearance in Jiuie of the 

 year following attaik; appearance of inner bark in ,\ugust of the year following 

 attack, after the emergence of the bnxxl; .scoring chip from railroad cross-tie from 

 tree kiilrd by bi^'tles, showing charactfristir markings on surfarc of woimI. 



