6 SOME INSECTS INJURIOUS TO TRUCK CROPS. 
No.6. The application was much more thorough, although barely 10 
per cent of the amount of mixture used in the previous experiment 
was applied. This would greatly lessen the quantity of the acid- 
producing material, the use of lime as a base for the powdered arsenic 
tending to correct any acidity in the soil instead of increasing the acid 
content. Moreover, the cost of this application is much less, as it 
can be applied at a cost of about $1.20 per acre, while the cost of the 
usual mixture is about $4.20 per acre. The efficiency of the mixtures 
is about equal in either case. 
Experiment No. &—TIn this plat arsenite of copper was applied at 
the rate of 4 pounds to 50 gallons of water. The poison was applied 
without lime. The weather was bright and warm with a northeast 
wind. 
This poison proved equally effective with Paris green used in the 
same quantity but differed in that no damage to the foliage was noted 
as a result of the application. The larvee were entirely destroyed. 
Experiment No. 9.—Arsenite of copper, 4 pounds, to 6 pounds of — 
lime in solution with 50 gallons of water was sprayed on this plat. 
This application was quite effective and at no time produced burning 
of foliage as an after-effect of the arsenic. 
The check plat was severely defohated by the beetles and larve 
and was undoubtedly injured by the neglect of spraying. The yield 
of potatoes from this plat was considerably less than that of the 
properly sprayed plats. 
SUMMARY OF EXPERIMENTS. 
The following table will show the results of experiments with vari- 
ous Insecticides: 
nr | 
os | 
Oa| Date. Insecticide used. | Effect on plant. Effect on insect. Remarks. 
3 BI | 
Z A) 
1 | May 26 | Arsenite of lime.....-.-- Badly burned..| Entirely destroyed in | Damage to plants too 
24 hours. | great to permit its 
use, although cheap- 
| est preparation of 
7 | those employed. 
2| May 27 | Arsenate of lead with | None..........- Entirely destroyed in Excellent yield from 
-| Bordeaux mixture. 48 hours. plat so treated. 
3 | May 26 | Arsenate oflead...-....'..--- do..........| All killed in 48 hours..| Applied at rate of 6 
pounds to 50 gallons 
: water. 
4 | May 26) Paris green without Slight burning.) Very effective........- 4 pounds to 50 gallons 
lime. | water. 
5 | May 27 | Paris green with Bor- '..--. GOR Ae ee Oka 2a eee 3 pounds Paris green to 
deaux mixture. | 46-50 Bordeaux 
\ mixture. 
6 | May 26 | Paris green dust with |...-.- dol 25-5 | Saete @OPs- en Seae- sees 4 pounds Paris green to 
| land plaster. | ton land plaster. 
7 | May 27 | Paris green dust with |..-.- Gow ste esse | 98 per cent destroyed..| 1 pound Paris green to 
lime. | 10 pounds air-slaked 
| lime. 
8 | June 17 | Arsenite of copper.....|...-- dos<...22- -|Viery.eliectiversaesesce 4 pounds arsenite of 
| copper to 50 galions 
| water without lime. 
9 | June 14 | Arsenite ofcopper with | 
Sone Oi. 55-.02-2)-n-. 2002-5. oka eee |) 4) pounds sarseniiogor 
lime. copper with 6 pounds 
lime to 50 gallons 
} water. 
TOR Maw e226 None.) asses eee | (Check ss). 42224 Cheeks eh i. ae eee Beetles very injurious 
June 14. 
