UNITED STATES 
DEPARTMENT OF AGRICULTURE 
Miscellaneous Publication No. 273 
Washington, D.C. February 1938 
INSECT ENEMIES OF WESTERN 
FORESTS | 
Compiled by F. P. KEEN, entomologist, Division of Forest Insect Investigations, 
Bureau of Entomology and Plant Quarantine 
CONTENTS 
Page Page 
TGANTRO COLOR OOS OE eS i ee eee 2 Key to diagnosis of insect injury to young 
Kinds of forest insects and the losses they (treeSea=eee = eee ee ieee ee pied Shae aT 28 
CLUS Famer fan te ergs 8 Loe, ee ee eis 2 Insects affecting twigs, terminal shoots, 
Winrectloscesmaser wes se A ke 5 GVO! WO so see cone ee sos pease ae 29 
hm Ginec tl OSSCSa mee wk Nee eee Rel ee 8 Sep su ee Ine Fa eae sented caare i a 
Relation of insects toforest management. 9) eedarson the inner bark of young tees. 
Determining causes of forest-tree damage__-__- 1 Insects injurious to mature forest trees________ 57 
Insects affecting seed production________-____- 15 Key to recognition of insect injury to ma- 
Key to diagnosis of insect injury to cones CHTECELOGS Bee et nak ene! S 58 
ROO! SEQ 2 5s = 5 es ee 15 Leaf feeders and defoliators.______________ 58 
Woneweellessae ase kee es A a SE ae 16 Miners in the inner bark and phloem____-_ 95 
Cone mmOth Sees een See Le To ee 16 | Insects injurious to wood and forest products__ 141 
WONne Mace OLSmas were Se er ge et 20 Key to diagnosis of insect injury to wood 
@oneiborerss sss ee AAPL ee Spee 21 and wood products______________-_______ 142 
Saag CTC Sw ey ne ee en aa 21 Insects working in unseasoned logs or lum- 
Nut and’acorm weevils:.-.-- 2. ee 22 ber_------- SS al ea ee eee ees, eR) 
NGS RN ne 2 ge 93 yasects working in seasoned or decaying ae 
. . . . . WwW SOS SSE SS SOS as soe esc essence See SoS3e5 ve 
Boat dae ee S ae = = a hd gues es 23 Insects injurious to forest range plants_______- 164 
Key to diagnosis of insect injury to seed- Natural control factors _________- p7n77-------- 166 
lingo eee wee EL ie Se 24 Climatic and environmental influences_-_ _ 166 
WihikGerUnsee meee Ae) o kee) oy. ls 24 Naturalionemicsssen=seas sees seer eee 169 
LOO CRW CC lS ee en a ad Bh 9¢ | Control of injurious forest insects_____-__-_-_-- 171 
NGC WOLIIGe nee ne eh et 26 Silvicultural control___._=..-___._=__-_--- 172 
@utworms..2... 2022: Be I antes ee, Oar 2%6 Biological control____- DE ce ae Det hoe Ms he Se 173 
OOD AR DCOtleS te Um an ee 27 Direct artificial or remedial control_____-_- 174 
EV OO LATO lal Gl See weep a eS gel Meiteratunrelcltedis ses ao) eae es Se 197 
Insects injurious to young trees (saplings and limndextof hosts treesemes sas eae on eee ieee 202 
OC 22 sane s ase 2. apf ap ee eeed De eR 3 ||. Craovrall waolsse oe ese 205 
1 For many years entomologists of the Bureau of Entomology and Plant Quarantine 
engaged in the study of forest-insect problems have considered compiling the great mass 
of records in their files so that it would be in more usable form. There has been a 
growing need for 2 manual or handbook for use by forest rangers and others entrusted 
with the administration of forest lands and the prevention of insect losses. Recently 
the tremendous impetus given to forest conservation by the establishment of the Civilian 
Conservation Corps camps has made insect control an actuality in many forests where 
previously it had been impractical. This called for the instruction and education of 
these men and of their leaders and has crystallized efforts toward bringing together the 
material in this handbook. In compiling this manual all sources of information have 
been drawn upon to make the presentation as comprehensive and up to date as possible. 
Published bulletins, records in the files, unpublished work of field men, and previously 
mimeographed manuals or instructions issued by the leaders of the forest-insect field 
laboratories of the Bureau of Entomology and Plant Quarantine in the Western States 
have been used as needed. It is obviously impossible to give full credit to all the workers 
who have contributed to the making of this publication. F. P. Keen has taken the 
initiative in its compilation, with the assistance of J. M. Miller, J. C. Evenden, and 
J. E. Patterson, and, in fact, the entire technical personnel of the Bureau’s western 
forest-insect laboratories have contributed parts in their respective specialties. This 
manual is restricted to the insects of the western forests, although the general discus- 
Sion and control methods are in a large measure applicable to any part of the United 
States. It is planned to follow this with another manual covering the eastern forests.— 
F. C. CRAIGHEAD, in charge, Division of Forest Insect Investigations. 
136650°—38——1 1 
