98 
v/as all used on a certain bed. the other beds being prepared with 
composted manure. The bed with fresh manure was a total loss; 
the others showed no injury. The ruined bed was simply replanted, 
and there was no further injury. In another case the manure, al- 
tho obtained in fall, heated greatly in rotting, and no serious in- 
jury followed its use. 
One fact observed by Mr. Green may be of value in combating 
these pests. He found them much less numerous and troublesome 
in the drier houses than in those where water was freely used and 
moist conditions prevailed. 
It was thought that perhaps some repellent might be intro- 
duced about the bases of the plants to drive away the maggots, and 
Nickoteen, a proprietary decoction of tobacco stems, was tried for 
this purpose. It was found that ^ of i percent of Nickoteen in 
water repelled the larv?e without injuring the plants. A 6 percent 
application of Nickoteen caused a temporary wilting of the plants 
and higher percentages killed them. 
One curious result of the Nickoteen application should be espe- 
cially noted. In an infested forcing house 135 feet long, contain- 
ing three benches, the east bench was treated with i percent Nicko- 
teen, a gallon to each rod of bench, the west bench with 2 percent, 
a gallon to each yard, and the middle bench was left as a check. 
The treatment of both side benches had the effect of precipitating 
the transformation of the larv?e. These pupated prematurely, with- 
out waiting for complete development, and soon clouds of flies 
darkened the interior of the houses. These flies seemed to be 
weakened by their hasty transformation and died in unusual num- 
bers. Evidently, in cases of sudden wilting, when speedy relief 
might mean the saving of a large part of the crop, such a treat- 
ment might be of great value, and further experimentation with 
this and similar insecticides is especially to be desired. 
To summarize the results of the investigation, it may be said 
that all cases of severe injury to cucumbers in the forcing houses 
followed the use of fresh horse manure in fall; that if the manure 
had been gathered earlier in the season and well rotted or composted 
with lime, or gathered in winter, little or no damage appeared ; that 
the injury was much worse in the moister forcing houses than in 
the drier ones ; that Nickoteen in water, in strengths of ^ to about 
.6 percent, will force the insects prematurely thru their trans- 
formations to the adult stage, weakening them so that many die ; 
and that if the injury be of short duration the plants are likely 
to recover, but that if it continues more than a few days the plants 
will die and the crop may be a total loss. 
