6 
POPULAR SCIENCE REVIEW. 
very simple dressing. He took some road dust, some soot, and a little guano, 
and mixing these together, sowed them along the rows in the middle of 
the day. In a short time he found that the crowd of flies had altogether 
disappeared.” — (Curtis’s “ Farm Insects,” p. 31.) 
Nets to catch tlie insects, newly painted ofl tarred boards to 
be drawn over the turnips, fumigation by “ burning stubble 
and weeds to windward of the field, so that the smoke drives 
along the ground,” watering the plants with brine, are all 
mentioned as remedies against the ravages of the turnip fly ; 
but although some of these may be efficacious in themselves, 
the practical application of them on a large scale renders them 
for the most part unavailable. The problem may be rather 
solved by considering not how we can put the fly out of the 
reach of the turnip, but how we can put the turnip out of the 
reach of the fly. “ Rapid growth of the plant is the best 
security.” The farmer must watch his opportunity : let 
him have his ground ready for the seed by the end of April. 
Should the weather be showery let the seed be put into the 
ground, but if there is appearance of continued dry weather, 
let him wait. 
The vegetation of the seed may he accelerated by steeping it in water for 
twenty-four hours, and the surest way to obtain a strong crop is to sow seed 
of the same age, otherwise the plants do not come up simultaneously, and the 
fly will attack and destroy the crop in detail ; for it is ascertained that young 
seed vegetates quicker than old : this year’s seed will therefore have the start 
of two or three years old, by as many weeks.* 
But we will suppose that our turnips have survived the 
attacks of the turnip-beetle, and are growing and looking well 
for some seven or eight weeks ; but what ails them once again 
now, we will suppose, about the end of July ? The leaves look 
sickly ; in a montUs time after this, the whole crop may be 
said to be destroyed. What is our enemy here ? Let us pull 
up a few plants by the roots ; why they are actually cut in two 
just beneath the surface of the soil ; the tap root remains in the 
soil, the broken stem and withered leaves alone we hold in our 
hands. And here we find the enemy in the shape of an ugly 
fat caterpillar, though he is not yet fully grown. These cater- 
pillars vary slightly in colour, being generally of a pale, dirty, 
greyish-green, with a number of black spots along the back. 
The position of these is shown in PI. I. fig. 8 6. Most formidable 
enemies are these caterpillars to the turnip crops. Here, in 
* “ Farm Insects,” p. 26. How necessary it is to sow new seed has been 
experimentally proved by Professor Buckman, who has shown that seeds that 
have been kept three years generally fail to the extent of about 38 per cent. 
M Science and Practice in Farm Cultivation,” No. 1, p. 38 (Hardwicke). 
