200 THE PLUM CURCULIO. 
Taste CI.—Summary of results in spraying apples for the plum curculio, in average 
percentages of sound fruit, various localities. 
Localities. 
Treatments. . 
West- Siloam Mount St. 
nag Ander- North : Crozet 
Illinois. oe Mo. feld, East, pe Springs, ve ’ Jackson, Joseph, 
deapplication.... <<< 2: shoes 2 SeSese bec cacsosd ence Se eel eee eee 86. 34 73. 93 57. 90 36. 80 
Dapplications. «... 522-2. .scesce|oe ww cse eee lsc oeeacet OSU BE e cd |spocnbobed pecooaSlzes|leoonce tons 
sapplications.. -..<2 2. 2) /J.<dc4¢ 4e|225-deesin- concn sees | sea scees ee se Sees ee eee 400/82) |S. amaseee 
4 applications.......- pase Adel BSdoahoo se OTS 073) easeece ee ote sae 86:89". 2osc eee 50. 10 
7 applications (Paris ; 
green) ton see 3 oe 45. AT Voc cets oa enll eclectic an Sella orga mere atts eta aero rete | |S 
7 applications (arse- 
nate of lead) ....... 44. 61 BY Ar Sie Bee segese scecesoee | peoceseete |= sace ara orn ossoce -\ss2- 52255 
7 applications (arse- 
nite oflime) ....... 7 ts} es (eee ee er | A el eee Os SooeGoms Sclistccesnccee 
8 applications. .....-- AAS OD ial eae seca cl cece ccd on dllecimiomche eel ete rane ee ell bees Aeterna eee 
10 applications... ...- 44 T4 ob oe cose oe Sede aes Secee = eres Ste aaa | nese eter eeste | Bt = tee 
13 applications(home- 
made Gusi)mees eee 
13 applications (com- 
mereisl uUsh)c sees alee capes 22.15 
16 applications. ...... 62) 08%). 3. ca doe loss Sees ae] eas eee clle2 coe ae Ree ee ee 
Unsprayed (check)... 25. 21 5. 5) 76. 21 25. 44 9.14 54. 02 27. 23 4. 05 
CONCLUSIONS. 
The records above given of results of spraying apples for the con- 
trol of the curculio indicate clearly that the injuries of the pest may 
be in all cases greatly reduced, although the degree of benefit varies 
widely. It is apparent that account must be taken of other factors, 
as the relative abundance of the insects as compared with the amount 
of fruit present on the trees. With a small fruit crop and abundance 
of curculios, the most thorough spraying will not serve to bring 
through a satisfactory amount of sound fruit, as will be noted in the 
results of experiments at St. Joseph, Mo. With a large crop of fruit 
and an abundance of insects, results will likewise be disappointing. 
If the curculios for any cause are scarce and there is a large fruit 
crop, injury is of course much less important. In other words, the 
degree of success in spraying varies with the abundance of the insects, 
and where the latter are numerous thorough treatments seem to fail 
to yield a desired freedom from injury. While spraying is undoubt- 
edly a most important adjunct, and if persisted in from year to year 
may answer for its control, as its effects are cumulative, yet it is 
clear that other control measures should also be employed. In all 
cases which have come under our observations the insects have 
always been found most abundant in orchards which are in sod or 
are poorly cared for and allowed to grow up more or less in weeds 
and trash. Also orchards adjacent to woods always suffer severely, 
especially along the border. (Pl. XVI.) As opposed to this condition 
is the notably less injury in orchards kept free from weeds and trash. 
In such cases sprayings usually given for other orchard insects, as 
the codling moth, serve to keep this pest well under control. In 
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