20 BULLETIN 833, U. S. DEPARTMENT OF AGRICULTURE. 
EXPERIMENT 3. 
In the foregoing experiment it will be observed that good results were 
obtained with the nicotine sulphate diluted to 1-800. Another point 
upon which it seemed desirable to have more definite information 
was the effectiveness of applications made daily compared with 
those made two days apart. In the following experiment two lots 
were treated, while the third lot served asa check. The empty galls 
were punctured and all old pupal skins were removed from the 
plants in question. Eighteen plants were employed in each of the 
two treated lots, which were sprayed a total of five times. Five 
plants served as a check. 
TaBLE VII.—Results on first and second days after treatment. 
| | Results first day after'| Results second day after 
treatment. treatment. 
Lot. Treatment. 
ba Fe- | Total | Pupal Fe- | Total | Pupal 
| Males.| males.| killed. skins. | M#!es-| mates.| killed.| skins. 
1 | Nicotine sulpnate 40 per cent (1-800) | | 
andISO8D 222 =< 38 43 81 15 1 1 | 2 16 
2 | Volatile nicotine sulphate 40 per cent | | | 
(1-800) andysoap ass s2 seca ee ee ee 18 18 | 36 22 1 PA | 3 23 
or: Checks: 7 asec nosis Se esoo sce | 0 2 2 CAs ae | CReee ee renee Lae 
!~ 
Conclusions.—The results are very conclusive and show distinctly 
that the best results are obtained by daily application. There is a 
remarkable decrease in the numbers caught on the second day fol- 
lowing treatment. Nicotine sulphate, therefore, used at the rate of 
1-800 plus soap (1 ounce to 1 gallon) will control the adult on emer- 
gence, and hence is very well adapted to such cases where fumigation 
can not be followed consistently. 
EXPERIMENTAL WORK IN COMMERCIAL CHRYSANTHEMUM GREENHOUSES. 
Experimental work in a commercial greenhouse in Baltimore 
during the summer of 1918 seems to indicate that the chrysanthemum 
midge can be held well under control by spraying the infested plants 
with 40 per cent nicotine sulphate applied at the rate of 1 part of 
nicotine sulphate to 500 parts of water, with the addition of one- 
half ounce of soap to each gallon of solution. No appreciable injury 
followed the application, although the plants were sprayed every 
other day for a period of six weeks. The application of this treat- 
ment by the grower resulted in his producing especially fine chrys- 
anthemums. It would appear that a double benefit was realized 
by such practices. In the first place it controlled the insect, and, 
secondly, a distinct stimulation of growth followed. This seems to 
confirm the work of Gossard (30) and Guyton (31), who claim that 
40 per cent nicotine sulphate diluted with 500 parts of water and 
