8 DEPARTMENT OF AGRICULTURE BULS. 751—775, 
DEPARTMENT BuLuETIN No. 765.—STRAINS oF. Waite BuruEyY ToBACcCcO 
RESISTANT TO Root Ror: 
Relation of root rot to the cropping system in practical tobacco culture. . .. 
(Description of root rot..2. {yeimtttion }. ERP SEEOL toy: tee eee oe) epee oe 
Cause.of the disease... 020.002. o.,-.- eb BES Nplate ee 
Varietal resistance and susceptibility..232.0 0. Sie ag eee ee ee 
Development of Burley strains resistant to root rot. ..-......22...-.-.--- 
Experiments in the White Burley district of Kentucky. .-....-...-....--- 
Resistant Burley strains recommended for sick soils in White Burley dis- 
triets-2cG2 0. ce tle se eek 2 - Rees hl tore eee 
DEPARTMENT BuLLetiIn No. 766.-—A Srupy or ComMPSILURA CONCINNATA, AN 
ImporRTED TACHINID PARASITE OF THE Gipsy MotH anp THE BROWN-TAIL 
Mots: 
Introduction <2 2.205 Jee - - RR eo Pe 
History of Compsilura concinnata Meigen. ....-..2:------+---22226------ 
Description 32.2... 44sie0 sub 2. . Sos oss tlicied 4: 2 bed aaeeeeeeee 
Distribution an Wurope 2... -<.-.. - ee... se eae beads Bee 
Hosts,,European and: American. . 22565 .)5 2). 272 138e Sey pe ae ee 
Importationsifo United States.:. - 296 baad 52) te = Soci. steers 
Colonizatiomese 6 oa i. RUIN 2 ee oes es pe hoy ie a 
PTCA ies. S esis ie ele Bipot ele at a n,n + SR eae ee ea tea Eye lta ak ea eee 
RECOVERY :2 2 2 28 Pee Bee se ned. = SER ee ee sp NOE ee pee 
Discussion of classification of Compsilura concinnata..............+------ 
Discussion of larva stage of Compsilura concinnata......-.....-+----+------ 
Tate historyes oc ieels aoe oe he din =» SRE Ga oe ee eee ee 
Method ot handling. .-.... 5-22... SEY Sag haoge Sach ae eee 
Laryvajand, pupa 'staces:...fo2.... SERbs 52552 pe ee 
INGLE STAC te Mme ike. 5 ot Mee ee he er 
Gestation. 234420248046 sons. RR BPE a ee 
Parthenogenesis*<) 2.230250... . SER ee ee 
Copulation: ss: ke Sees eto... BBB ee ei 2 eo 
MarVIPOSItONs asic Se eee cas «=~ Seer pie see aee Saree see 
Action on hosts other than the gipsy and brown-tail moths.........-. 
Effect of temperature upon various stages of Compsilura concinnata. . - 
Seasonalvhistonyie Sse <5 see Bais 2 oc ~ RO Rae ecg: Oe ee 
Presence in field and number of generations. .....------------------ 
Habermatiomss: S224 )oohae eee = «2 Raps ae ee eae 
Secondary parasitism. 6... S4.H: ~ . Be eee ee ee eee ee 
SUPerparasipisme Ve awe sak... eee es onl ena ee eal ee wes 
Superbumerary parasitism -c--.. . . Beeceege  e ee 
Hconomic, importance: 5222. 4.5. 52s: .- SS ee oe ee oe Ce eee 
Bibliography = eee Meee ee ce... ee ee ey 
DEPARTMENT BuuueTixn No. 767.—Oxx-LEAr PorsoniInc or DOMESTIC 
ANIMALS: 
Historical summary and review of literature..........-.........-...---.-- 
Poisoning by oak-leaves in North America......................----.--- 
Experimental work with scrub oak..........-..-....----- Beers ileiobe 22 
Hxperumental work with.“shinnery ”” oake) 2. 2220 ee 
General results of the experimental work.....-......---.----.----------- 
SVMptoms. cs. ee. 2 NR ne ene ee oa pale ee 
Nutopsys nnd ines tomer er cle IRM cary eas Jp ear Ae eae 
Microscopiespatholooiya2 v2.2. eet es ee ee 
Length of time necessary to produce harm from oak feeding... -.---- 
itech omeatinoork math Obmer Teedsmeee sae see ae ee 
Active principle or principles causing oak brush poisoning-.....-.--- 
Summary of conclusions from experimental work......--.....----------- 
Discussion of results with relation to previous investigations.........--.-- 
Practical considerations for tance crazimopy es). -2 el we ee oe 
Literature cited....- saa eae enema DE Lait Mai aine me ie 
-_DepartMeNT BuLtietin No. 768.—PRopucTion oF: T.umBER, LATH, AND 
SHINGLES IN 1917: 
Introduction....-. Brae Bed, aS iae lah hoe. a eee a Me es rrr 
Totallumber produchons 2242.20). ee WA ae 
Lumber production by classes of mills) 52.22. 4) 242 
Page. 
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