82 BULLETIN 1357, U. S. DEPARTMENT OF AGRICULTURE 
TABLE 13.—Ezperimenis with arsenical dusts on caged strawberry re 
beetles—Continued 
} 
Sixth day | Seventh day Total 
i 
| 
i 
Material and strength “Feed | Feed- Feed- Control Remarks 
ing ing ing | 
Dead | _pune- eee pune- Dead punc- 
| tures | tures tures | 
| | | = 
Sulphur. 2. Se 90 parts_- : | Per ceni 
Arsenate of lead_--_- 10 parts__ } Se ee eee ee 2 21 100 
Sulphur —=-22e22 22 90 parts_- : 
Arsenate of lead____- 10 parts_. \ 0 0; 2 0 3 13 | 80 1 alive. 
SiTpnunse. see 90 parts_. 54 
Arsenate of lead__._- 10 parts__ } E ear - 2 = 60 1 dead on eighth day, 
s Tene se ee 80 parts_- % 1 dead on ninth day. 
Azsennce ofiead 2 - P0 parts =2|§-—— | 2 24 100 
SEL O) Cee ee 80 parts__ 5 1 109 
Arsenate of lead_---- 20 parts__ \ pois oe ae aCe ee 
Sulphurs: 22222252 80 parts_- 2 =| 
Arsenate of lead -_--- 20 Darts_|f : 0 |------)------- ens 2 100 
STELTC) C1 tes aa ee 80 parts__| 
Arsenate of lead__--- 10) pantse2 | oat ee eee ae ee ee 3 11 60 2escaped. 
Bordeaux, dry_--_--- 10 parts__ 
Sulphur-_._..-------50 parts__| 
Soars of lead ---_- 10 parts__|>__-_- (ee eee eee ee) Cees 5 10 100 
Kaolina- so ee ew 40 parts__| 
SJELEG Uh eas 5 eee 80 parts__ 
Arsenate of lead_-_--- 15 parts__ 0 6 0 1 0 11 OQ 1died on eleventh day. 
Powdered sugar-__-_-_- 5 parts__|!} 
Arsenate of lead, pure______-_- (Sess (Ei Se 0 oe ee 5 6 | 100 
Siinphure. to 90 parts__ \ eons 3 os 
Calcium arsenate_..--10 parts__)f----- fees Spa er al Seabee | 
SulphyT ae 90 paris__| } * Sol 
Calcium arsenzte___.10 nce 1 @ |------|------- 2 15 | 100 
Sulphur 22-222. Se 80 parts__ | 5 3 | 100 
Calcium arsenate_-_-.20 parts__|f----- | Pinan ea eat rae 
Salphunso= see 8 80 parts__| 4 
Calcium arsenate.___20 parts__ } ==5=5 | pret oor ipa: 2 a Whe 
i 2 s__| é Z 
ee eee --+--[------- ------ eee? 5 6) 100 | Solution sprayec- 
Saiphun oso eee 50 parts__| 
Caleium arsenate__._10 parts__-| 2 bya Bepea at Se fee reeeract 5) 5 | 100 | 
IGN G) ii eee Se ae et parts__ 
Supt so ee 72 parts__ ; ; 
Arsenate of lead ____- 18 parts__ 0 Dy | eee ee 0 16 | 0 3 died on eleventh day. 
Cornstarch 10 parts__| 
SHipRurs te seen ses 81 parts__| : : 
Arsenate of lead_____- 9 parts oo) pssees | | ae eee 0 8 | 0 | 1 died on eleventh day. 
Gormstarchs.-25." 10 parts_- 
Hellehocs ty. eee | QE) .de feat 0 57 | 0 Fresh untreated leaf 
given on sixth day. 
Sulphur, pures see = ese @)-).@) () () it 43 | 20 
Check (Gateated leah) See | @ @) (1) (2) 0 129 0 : 
OSES ee nae we ie ee 36 27 | 0 269 | 0 New leaf given on fifth 
day. 
ara Eee at eee ae Pl @) () () @) a 44 | 20 
Ghee (no food, 14 beetles) ____ Ais Pe hs ek See Se 2 0 | 40 All dead on fifteenth 
day. 
i No data. 
In the third establishment dusting was practiced to only a limited 
extent during 1920. In 1921 a heavy infestation existed and’ dusting 
was employed as one of several methods of controlling the beetles. 
After the plants had started new growth following the cut-back 
period (fig. 14), they were kept continually dusted until the middle 
of November, at which time very few beetles were to be found, and 
it was supposed that they were in their usual inactive state for the 
winter. For the first month the sulphur-arsenate of lead (10 per 
cent) mixture previously mentioned was applied, and after that the 
following dust mixture was used: 
Pounds 
superfine sulphur (200 mesh) = 2 eee 80 
Calcium: arsenate_...._. - 3205 eee eee eee 15 
Powdered sugar. a eee ee ee eee o 
