Peoceeuings, 1!)1o. 2'-\ 



of wliicli are found on the ground surface in rows of strawberries, or any such insect 

 affecting small fruits or vegetables in cultivated field or garden rows; first stake off 

 1 foot of row, count the insects or insect forms as desired, and estimate the average 

 per 100 feet of row ; then divide the running feet of row per acre, coinciding with the 

 distance of rows apart, by 100, and then with the figure thus obtained (as per tal>lel 

 miiltii)ly by the number of insects estimated on the average of 100 feet of row. For 

 e.^ample : — 



In 1 foot of row 4 insects taken. 



„ 1 2 



„ 1 



„ 1 5 



„ 1 4 



Tims in 5 feet of row 15 insects were taken. 



The average per 100 feet of row is 300. Let rows be 4 feet apart. Thus 

 300 X 108.90 gives an estimate of insect-abundance of 32,670 to the acre. 



Supposing, once more, the above estimate referred definitely to the egg-notes of 

 the cabbage-maggot, by reference to the habits of the insect we know that each female 

 is capable of laying on the average fifty eggs ; thus by dividing 32,070 by .50 we 

 estimate with reasonable assurance the number of adult female flies at work on 

 the acre at any specific time. 



Of course, in a ca.se like the above the flies may be at work laying eggs at the 

 same time as our records were being taken, and the same might occur with any in.sect 

 liaviug a continuous generation, consequently our results taken two or three days 

 later might be ver.v different to the first ones taken ; thus it is advisable, in order 

 to obtain uniformit.v, moderate exactness with a minimum of error, to examine the 

 same pilants several days in succession or several times during a certain period. 



In the case of making estimates on nursery-stock rows, gooseberries, currants, 

 raspberries, or such-like bush-fruits. 1 foot of row is too small an area to obtain 

 results; consequently 100 feet of row or fractions of the same are taken. For 

 example : — 



In 100 feet of row 10 insects are observed. 



..100 2 



..100 



.. ino 14 



.,100 4 



Total 500 feet of row and 30 insects observed. 



Average per 100 feet is insects. Let rows be 4% feet apart. Thus G x 00.80 

 equals 5S0.S insects to the acre. 



In the case of young orchard trees set on the squai'e-planting jilan, coru-hills, 

 tomato-plants, or any jilants grown on the square equidistant hill s.vstera, the follow- 

 ing computation on tlie number of square feet of row per acre will be found most 

 useful as a basis for figuring : — 



Distance No. of I'lants 



in Feet. per .\cre. 



1 43,5(50 



1% 19,3G0 



2 10,890 



2% G,9G9 



3 4.S40 



3% 3.550 



4 2.722 



5 1,742 



G 1,210 



