16 BULLETIN 518, U. S. DEPARTMENT OF AGRICULTURE. 
TasBLeE I—Plants and insects fumigated with hydrocyanic-acid gas in green- 
houses—Continued. 
Name of plant. 
Geraniums: 
Do 
riety). 
Do 
Ipomoea sp. (morning 
lory). 
: Do 
i ee 
Sodium cy- 
anid. 
Potassium 
cyanid. 
a a ee ee | 
malas Results of treatment. 
2 m 
2 | 5 
Sis 
z By Infestation. 
2|§ | 
Sa ‘ 
rae On plants. _ On insects. 
a|3 
tal ° 
i ss 
°F! 
I Thread scale. -| Severe burning;| All stages killed. 
“el leaves 
knocked. In- 
jury largely 
due to close 
proximity of 
| generator to 
plant. 
tet ieee 4) eee pe Severe burn- 
ing of tender 
foliage. i 
Lo Aids 22a 3 No burning. .-| 100 per cent killed. 
GORA ae eS se dover eee 
HBTs 4 Val aa hoe eres ey 2 hd doses 
| 60 | Greenhouse |-....do......... All stages except eggs 
white fly. and late pupe killed. 
| 68 |.-..- Gores fa haaes do: a2 Do. 
Os a Ree eye ee Ae Slight brewing 
G2) .0 see. tes ee No burning... 
GU) 2 CESS See. oe a eee GOSS 4e 5 e0 
68 esate te eS eA af Bs UES 
PRG Ghee 2 
ist 2 |: Poca oe Sight ‘burning 
ieiirl ea 2; SER aaa es No burning... 
TAG ete el Se eae ee oe Flowers 
| burned. 
70) |: Aphids-sea: 548 New growth | 60 per cent killed.1 
burned. 
101. 2225 dos. 49.2 aide acethae nt eae 100 per cent killed.1 
(it) Pee ER | No burning... 
68))|\ 2 sere Bee ee kee doit: e485 
60 | Greenhouse }..... (3 Cs Seg All stages except eggs 
white fly. | and late pup killed. 
68s 2ee4 dois Pose ae S dof f.3ee Do. : 
G4 le eee ee eis New growth 
burned. 
G2.) 2 Bee cee NES No burning 
BoE aoe eee ese eee do. 454s 
20H cae Oau. Le ee do: fee 
6871-2. eeeeee Sis ee do. 
G7 (RRR © dl SoM Slight burning 
i Sel Pee SC ae Oe No burning 
GOH.) eee a Select ee dot. eo 
GOA: See ee eR ae: dost. 
Bo] ao: Sees coe kw se do. 
7S) Pe A ee es GOs St ee 
5D Nf Je ae ere dost 45.220 
G4) | one S Ree Se ka sace do:-3s 3-42 
0M eee Se ae aS eee domes 334 
DAN =: Sep en o rs cif eee 
ae bps ieee Sy Ts eee dos gee : 
66.) Aphids 22 L222. dO ce eee 100 per cent killed. 
GS. Sea eel ee dott 2ioses 
64 eas ceee ee Jeb. |p. oe d0.c 255.082 
Ce MR A 2 eee Same dos sabes 
GE bar Se Is Se ea dole re 
G6"): eee ee Tips burned.. : 
60 | Orthezia.....-.. No burning. .. 70 per cent killed. 
OM Roce ecb ssos Hema Mecfeccoss : 
52} Soft brown |)..... Osea Immaturestages killed. 
scale. ; 
ENS ee do.........|.....do.........] 90 per cent killed. 
1 The difference in results noted was due to the difference in the tightness of the two houses. 
