178 THE PLUM CURCULIO. 
Taste LXXXIX.—Effect of stirring soil on destruction of pup of the plum curculio. 
Aver- 
Aver- 
Per- age ae Per- 
Num- centage] per- gal centage 
Adults centage . 
A Lot| ber of . nes . of centage ain 
Locality and date. || Jarve Treatment given soil. emare. aghries || shes gritty ati 
used. 8- | from | from | ‘To | treat- 
larve. | treated t q| ment. 
boxes, | Zeate 
* | boxes. 
1906. 
North East, Pass. 2.2. 1 200 | Soil disturbed July 11 25 |’. 12550 |s2asasscleeseeeas| oases 
and 20. 
Dot... ise eee ses 2 200052252 Os sl See eee 32 16:00" |: W4-260)e5.222 co) oe eaeee 
DO tee. sect eee 3 200 | Soil not disturbed....... Wh) 85:50) ls 20 tae reece eee 
DOAt soe sone ese 8 4 200° |5 =~ << Ose iweccce ese ae 75: (31/00) Saee sees 36. 50 22. 25 
1908. 
Siloam Springs, Ark....| 1 451 | Soil disturbed June 23... 601) °13330°| 18:30), |b ee ee pee 
1D ae ae nee 2 451 | Soil not disturbed.-.-..... 135) 29593; see aoe 29. 93 16. 63 
Washington, D. C...... 1 558 |! Soil ee July 8 20 8458 | cade toc] neeweterdaleeeusaee 
and 15. 
Ose seen ee 2 51 | Soil disturbed July 15... 24! 47.06 Wa Sc 2 |e 
1D eR eon e See eae | 3 468 | Soil not disturbed.....-- 267) 67205 | s<2e5500)-sncee se lseeeeee 
DOs SS oss s case See | 4 LSTA aaeae GOs 5282s es nsec 59) |! “4350 % sss oee 53.88 46. 66 
1910. | 
Douglas) Michi=< 3 2-3-.- 1 98 | Soil disturbed fre- 2 2.04 23045) 2 Scccees Bes ae 
quently. 
Wowseet. soos eee 2 98 | Soil not disturbed... ...-- UA AY RB eee noo iaoo 15.31 
Barnesville, Ga 1 173 | Soil disturbed June 17... 21 5 
Doss 2 191 | Soil disturbed June 8. 12 
Do. 3 173 | Soil not disturhed- . 119 
Do. 4 GUE eS 6 (a ee See 98 
Atverapeior totals |? 522) 452 Jan cite ccs ceets oe en Se ee ee Oo eee lee ee 
As will be noted, there is with one exception an important decrease 
in the number of adult curculios emerging from boxes in which the 
earth was stirred. In the case of lot No. 2, at Washington, D. C., 
an unusually large number of adults emerged. The larve were 
placed in this box June 29 and were doubtless all in the pupal stage 
by July 15, when the cultivation was given. It is to be noted, how- 
ever, that there is a considerable variation in the percentage of insects 
killed by stirring the soil from the different localities. This perhaps 
results from differences in the methods of treatment. The total 
average percentage of adults emerging from the treated boxes, 
namely, 10.20, as compared with the total average from all untreated 
boxes, namely, 43.85, shows a difference in favor of stirring the soil 
of 33.65 per cent. Comparing the total number of beetles emerging 
from the untreated boxes, 841, with the total number of beetles 
from the treated, 196, shows a probable number killed by treatment 
of 645, a percentage of benefit of 76.75. 
SPRAYING WITH ARSENICALS. 
It is impossible to state with certainty who first used arsenical 
poisons for the control of the plum curculio. They doubtless came 
in along with the use of Paris green against cankerworms and the 
codling moth. Paris green was recommended by Mr. G. M. Smith, 
