Experiments in the Growth of Clover. 349 



eggs, most of which are deposited by the last of June. In a week or 

 so these hatch into the larva, which soon burrow down into the roots 

 of the plants. By the first of August most of these have developed 

 into the pupa form and by the first of October a part of them have 

 grown into the adult stage, in which form they are again ready for the 

 winter. 



Where prevalent, this insect may be found by pulling at the tops of 

 some of the older plants. If the root, instead of being pulled out of the 

 ground, breaks off at or near the ground, we may expect to find one of 

 the forms just described somewhere in the broken part of the plant. 

 The main tap-root is eaten and decayed. 



The effects produced are very marked. The holes made in the main 

 roots of the plant cut off the rise of plant-food in the roots affected 

 and the shallow surface roots left are insufficient to supply the needs 

 of the growing plant, especially in dry seasons. 



(4) Seed. — There is a large amount of poor clover seed on the market, 

 particularly imported low-grade seed, but this is not the reason for most 

 of the clover failures. * Good seed is usually obtained when the higher 

 priced seed is purchased. 



Some farmers attribute failure to the difhculty in securing mammoth 

 clover seed, but this does not seem to be the trouble. As a matter of 

 fact, the medium red clover has done better than the mammoth in these 

 trials. 



(5) Winter-killing. — Where winter-killing is more severe than for- 

 merly, it is usually due to poor physical condition of the soil. This 

 maybe remedied by adding manure, plowing under crops, or by drainage. 



(6) Type of farming. — In every location where clover is reported to 

 have failed, large, well-developed plants can be found in the neighbor- 

 hood of manure piles where the leachings have brought in considerable 

 amounts of the soluble parts of the manure. In such cases, the plants 

 are subject to exactly the same pests as in the field, and while the root 

 borer is found to be plentiful, the first crop of hay is good. 



An opinion has been gaining prevalence during the past few years 

 that clover can secure all of its nitrogen from the air and that it does 

 not need a fertile soil. It is true that a considerable amount of nitrogen 

 may be taken from the air, but it is likewise true that a considerable 

 amount of it usually comes from the ground itself. Clover requires a 

 fertile soil for success. 



In the same regions where clover fails there are farms on which it is 

 growing well. These are nearly always farms that have been well 

 manured continuously. It seems that continuous manuring has main- 



