43 
The living larvae less active than those in experiment 1. The foliage in experiments 
1 and 2 was examined October 12 and November 28 and found uninjured. The emul- 
sion did not seem to render the foliage distasteful, for young larva- were subse- 
quently found feeding upon it with a relish. 
Experiment 3. 
October 24 (11: l'>). — A 13 per cent dilution sprayed upon 12 larva?; all nearly 
grown. At 4:43 1 seems slightly affected, others active. 
October 26. — All active and have fed freely; two have webbed. 
October 29. — Two larvae feeding vigorously; 1 webbed and .'! pupated. 
October SI. — Webbed larva} all pupated; 1 not perfectly formed. 
November 10. — Five imagos have issued. The imperfect pupa is dead, as also 4 
others, which do not seem to have been normally formed, due probably to the effect 
of the emulsion by inducing premature pupation. Foliage slightly injured. 
Experiment 4. 
October 30 (4:40). — A 19 per cent dilution used upon 10 larvae. 
October 31 (9:30 a. m.). — Three larvae badly affected; rest active and feeding. 
November 2. — Six are badly affected and will probably die; others feeding. 
November 3. — Six are dead, 2 pupated normally, and 2 are attempting to do so. 
November 4. — Last two have pupated, but only about half the normal size. 
November 17. — Two pupae are dead; one imago has issued. 
December 16. — Remaining pupa produced an imago. 
Foliage examined November 10 and found badly scorched. 
Pyrethkum Emulsions. 
cold-water decoctions. 
Method of preparing first Emulsion. — To one pint of cold water one-fourth ounce of 
pyrethrum was added, well mixed and left to stand over night in a sealed Mason jar 
at a temperature of 66° F. This was done at 4 :30, October (3. Filtered on the morn- 
ing of October 7. Of the resulting filtrate one part was emulsified with two of head- 
light oil and soap as before and left to stand in a sealed Mason jar. This is the emul- 
sion used in experiments 5 and 6. It is worthy of note that on October 10 the 
simple water decoction which was perfectly clear when filtered had undergone 
some chemical change — fermentation probably. It became very turbid, offensive in 
smell, and e\ idently unlit for further use. On the other hand, the emulsion was still 
perfect a month later. 
Experiment 5. 
October W(1:S5). — Four per cent dilution. Number of larva' sprayed, 16. 
October 12. — Both large and small active and feeding. One, about half grown, dead. 
Experiment G. 
October 10 (1:20). — Seven per cent dilution. Number of larv», 21. 
Date. Living. 
Dead. 
October 12 1 papa 
!» half gron a. 
'.' ball grown 
Total 12 
i) 
