THK WESTERN PINE-DESTROYTNO H ARKBEETLE. 21 



to ntlnck and kill the titnlicr in udjoiniii'^ licaltliy forests. Indeed, my ol)servation leads mo 

 to ((mcliide llial a considerahle mimIxT of girdled jiiiie trees may easily form a nucleus for a 

 destructive invasion hy it. 



In the . same hiillct in, under the head of " The western yellow pijie," 

 ho says : 



It lia.s in Di iidrortoiius hn ricoinis a most pernicious enemy, wliic.li penetrates and exca- 

 vates wiiidin;^ >jalleries throufjli tlie livinp; hark of the finest trees, thus speedily causinj;; their 

 deatli. \'ery many trees have died and are <iying from this eau.se, and the dead ones arc 

 contributin<i to the spread of foicst fires. 



Spociine'is of the insect nud its work occupied a pi'ouiinent |)lace in 

 the exhaustive exhibit of insect enemies of forests and forest j)roducts 

 at the Louisiana Purchase Exposition at St. Louis, in 1904, and the 

 Lewis and Chirk Centennial Exposition at Port hind, Orefj^on, in ]i)()5, 

 and were referred to in the catah)o;ues of the exhibits hy tlie Bureau 

 of Entomology." 



OBSERVATIONS BY HOPKINS, 1899-1904. 



The fojiowinir summary relating to this species, prepared l)y Doctor 

 Hopkins from his field notes, includes many facts which have not been 

 published and which have a direct bearing on the life history and 

 habits of the species in difTerent sections of the country where it is 

 found : 



McCloud, Cai, April 21, 1899. — Work and dead adults were dis- 

 covered in a sugar pine log, evidently from a tree which was dying 

 when felled : also dead j>arent adults in primary galleries, and larva^ and 

 pupie abundant in outer bark of large dying western yellow ])ine with 

 the characteristic appearance of eastern pines when dying from the 

 attack of the destructive pine l)arkbeetle. D. fronfalis. A few iuuiia- 

 ture adults were found in the outer bark, and evidence that some had 

 emerged. This evidence was in the form of apparent exit holes in the 

 bark, which may have l)een ventilating lioles from main galleries, for 

 v.ith our j)resent knowledge it is not likely that jiny adults could have 

 emerged so early. 



Grants Pass, Oregon, ISf)9.- On Ajiril 24 numerous dying western 

 yellow ])ine trees were found here scattered through the forest where 

 a severe windstorm had blown down much large timber on Septem- 

 ber 24, IKOo. Young adults. hirv;e. and ])up;e w(m-(> foimd in the outer 

 bark of the standing tr<>es which had evidently b(>en tittticked tmd had 

 commenced to die th<' |)revious fall. April 2."), mimerous tre»»s were 

 observed which died the fall before and otluM's which w(>r(^ not yet 

 dead. One group of 'M) young trees about 2 miles north of town were 

 dying at the top. the leaves ttn-ning yellow and brown. .Ml trees, 

 without exce|)tion. were either inf<'sted or had been infeste(| with D. 

 breviconns. and every indication j)ointed to this species as primarily' to 



a Buls. 48 and 53. Bur. Ent., U. S. Dept. -\gric. 



