6 BULLETIN 1169, U. S. DEPARTMENT OF AGRICULTURE, 
TABLE 6.—Summary of results of different treatments of paradichlorobenzene on peach- 
borer larvx in 1 to 5-year-old peach trees, central Georgia, 1921-22. 
4-ounce dose. 3-ounce dose. 1-ounce dose. 
Larve. - Larve. - Larve. - 
Days larvse were exposed to 3 3 3 
gas (1921), a is = 
om ee + ie ie = 2 
/312/E| 8 |e(slSlE] 8 | elelSlel 8 
S| 8 Se 3 ge 3 | Bal 
Si/SlE2IS|] Sibe | ol eas | S121 5) BY Sass 
HIAlHA/4S4/&% |B#/Alalsa|]/& |Bl/Aaljali<| a 
ANE S ee See eee aye ne Sa SAT ets all as | Seeiotctete oll raera eae ce 5} 1} OF. 0/100 S:/=Olle 4 | Olean 
TPG 25 fe eget cea St ie Ep ge a cc a M2) Ol a D2) One Ou 100 a Lis 6} (Os 2100 
12 days eee tvell see's OOM MO nO Neate Se] Ob Onl Oa sees 
22 days 2 | 87.1} 24] 10 4 [> 0 | 9009-5 tS, She 5 | OWe seas 
28 days 1} 87.5 | 20} 19} Oj; O {100 1519} OO} O} 100 
42 days 0 |100 20! 5] 01} 07100 15} 8}| O} O| 100 
Over winter... 0 |100 15} 6; 0} O /}100 15|} 6| O| Of 100 
Chiecle-estti eae: ts sync Ne 559 heh eee [ee ale le aol ota oa eee scm ab at. Sep eecteie sales. c eae |e 
et eS. 
13-ounce dose. 2-ounce dose. 24-ounce dose. Check, 
Days larvae were Larve. 3 Larve. 3 Larve. 3 Larve. 
exposed to = a = 
gas (1921). td i od oS AP 
© Powahe ve Oo} 2/8 ao} .] & = 
-18 °o rs) amt Wass ° o | o ° . <>) 
e| Sis he o| 8 = = | al eshte mn S\a\x 
Che) St oe oper hs 1S yrs li sas worl SB hyo 1s) [ts pS 
Alaliat& IH JAslal/sa]/ a [Hh ljAlajai & |aelali4a 
Adnyset fh ck 5 P4 Py Of 5526 1/20 W221 13 | FOV 6219 1S PS 145 FO 56.3 Eel. yaa 
Sidavse seek sa 1D 1 Ou ake Qh. 7} 20st. | abel O000. OC LALS) |. Sites Ole ON TOO || 2 ah lete alee 
A shysi 222282 A822 25 6 8057 |) 208,719 fe 42") OFF 90-5 715 15 | OAT O00" ale 9. | eee Stee 
POON cers eoas a aie tae ee => fecgcinty o> -|aer57a sited eee Ee - - lor etas SS. Hey Sock cere! esas. seen ee 
2 ci systems SARS: acid A PEAS Soe Bieta |e apes a ERS eee gee hea Peak) bea lool paaleose gee cee 
ADU S ee Seta seals wes) eek eek | feta | Stee A= ee eeal eae ioe Weise oll arte <tatell re = tl Saad aiken Ml pee aes =r oral ee 
Overmwanteirte cota lstec|Sec: (eke alnsteOlepess ance spaces ee al sno goth so [a rsahe mE le an le oll oe 
NOG se eee cece accfoscoced [acta see cee e mee eae lees | PE lod Deel aock seme oeeCte eee 66 | 0} 135 
In making examinations for results many very small larve that were killed by the gas could not be 
located. This is proved by theinfestation of the check trees, which contained an average of over 2 borers 
per tree as compared with an average of less than 1 borer per tree located in the treated trees when 
making the examinations. 
The results of these experiments show that the large doses ex- 
posed for 4, 8, or 12 days are not as effective as the smaller doses 
exposed for 4 to 6 weeks. While the percentage of kill was high 
from some of the short exposures, yet thet were so low in percent- 
age of kill that the short-exposure treatments as a whole could not 
be considered effective. Both the three-fourths and 1 ounce doses 
exposed for 28 days or longer gave 100 per cent control. 
EFFECT OF PARADICHLOROBENZENE ON THE TREES. 
Three separate examinations for tree injury from the various 
paradichlorobenzene treatments were made on all trees from 1 to 
5 years of age. The first of these examinations was made in the 
fall of 1921, about six weeks after the material was applied. The 
second examination was made during the spring of 1922, and the 
third and final examination was made in July, 1922. The condition 
of the tree and trunk at the final examination is given in the follow- 
ing summary from the field notes: 
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