Aug. 1,1924 
The Greenhouse Leaf - Tyer 
155 
Table XI .—Results of tests to determine effect , on eggs of Phlyctaenia rubigalis , of 
spraying plants with arsenicals before and after egg deposition 
Date of— 
Experi- 
Date 
sprayed 
Dosage and treat¬ 
ment 
When 
sprayed 
Num- 
Observations and 
results 
ment 
No;" 
berof 
eggs 
Deposi¬ 
tion 
Hatching 
1921 
I. 
Apr. 25 
Lead arsenate, 1 
ounce to 1 gallon 
Before dep¬ 
osition. 
46 
Apr. 26. 
May 3_ 
May 3, no effect on 
egg stage; all 
water. 
larvae dead or 
missing 4 days 
later; severe 
burning on tips 
of plants. 
II...... 
...do_ 
Same as Experi- 
After deposi- 
46 
Apr. 24.. 
Apr. 30_ 
May 2, 8 eggs failed 
ment I. 
tion. 
49 
to hatch; larvae 
feeding, but dis¬ 
appeared May 3. 
May 3, all disap¬ 
peared. 
Apr. 29.. 
May 9_ 
Ill_ 
...do...- 
_do.. 
Before dep¬ 
osition. 
49 
...do. 
May 7_ 
May 7, some eggs 
failed to hatch; 
no live larvae on 
plant 5 days 
later. 
IV. 
...do. 
Same as Experi¬ 
ment I, plant 
After deposi¬ 
tion. 
89 
Apr. 17.. 
Apr. 25_ 
May 26, a few 
larvae dead; 
sprayed just be* 
some alive, but 
fore eggs hatched. 
suspended from 
leaves. 
May 27, 8 larvae 
dead. 
May 29, all larvae 
dead. 
V.. 
...do_ 
Lead arsenate, 1 
Before dep- 
73 
Apr. 26.. 
May 4_ 
May 3, some eggs 
scaled loose from 
ounce to 1 gallon 
osition. 
water; 40 per cent 
leaf; a few dried 
nicotine sulphate, 
and failed to 
1-800. 
hatch. 
May 9, no larvae 
remained; no in- 
jury to plant. 
VI. 
...do..... 
Same as Experi- 
After deposi- 
28 
Apr. 24.. 
May 2_ 
May 2, eggs 
hatched. 
ment V. 
tion. 
78 
May 1-2 
May 9-10.. 
May 9, all larvae 
dead. 
VII... . 
Control; no treat- 
90 
Apr. 27.. 
May 4_ 
May 4, eggs 
hatched and lar- 
ment/ 
v a e developed 
normally. 
VIII.... 
.....do... 
44 
Apr. 25.. 
May 3_ 
May 3, all larvae 
developed nor- 
mally. 
Table XII .—Control of larvae of Phlyctaenia rubigalis by spraying with or dipping 
in arsenate of lead 
Experi¬ 
ment 
No. 
Treatment, Apr. 8, 1921 
Total 
num¬ 
ber of 
larvae 
i 
Number 
of dead i 
larvae i 
! 
Date 
of 
death 
Observations and results 
! 
1921 
I_ 
Plant sprayed with lead arse¬ 
28 
21 
Apr. 9 
Apr. 16, 24 dead, 4 disappeared. 
nate, 1 ounce, powdered, to 1 
2 
Apr. 11 
gallon water. 
1 
Apr. 12 
II_ 
Plant dipped in lead arsenate, 
33 
22 
Apr. 9 
Apr. 20, 27 dead, 6 disappeared. 
1 ounce, powdered, to 1 gal¬ 
3 
Apr. 11 
lon water. 
1 
Apr. 18 
1 
Apr. 20 
III_ 
Plant dipped in lead arsenate, 
20 
12 
Apr. 9 
Apr. 20,16 dead, 4 disappeared. 
1 ounce, powdered, to 1 gal¬ 
3 
Apr. 11 
lon water, plus 40 per cent 
1 
Apr. 20 
nicotine sulphate, 1-800. 
IV. 
Control; no treatment_, 
■ 12 
0 
Larvae developed normally; 
i 
pupated April 16. 
