lOI 



necessity of gathering all such refuse and destroying it 

 either by fire or by incorporating it into the compost heap. 

 The old rough bark of trees affords protection for insects 

 and their eggs. This fact is very good reason then for 

 scraping the trunks and limbs of the trees so as to keep 

 them always clean and smooth. It is customary to leave 

 the worthless remains of a crop upon the ground from 

 time of harvest until it becomes necessary to clear the 

 land for a new crop the following spring. For example, 

 squash vines are often allowed to lie about the field from 

 fall to spring. As these old vines harbor insects destruc- 

 tive to the squash, the3' should be promptly destroyed soon 

 after the crop is gathered. 



ROTATION OF CROPS. 



A continual rotation of crops exercises an important in- 

 fluence in holding insects in check. Growing the same 

 crop several years in succession upon the same ground 

 naturally provides plenty of food for whatever insects may 

 chance to live upon that crop, whereas a ceaseless change 

 of crops tends rather to starve out the pests. When the 

 squash crop has been grown more than one year in succes- 

 sion upon the same piece of land, it becomes more and 

 more difficult (if not impossible), each successive year to 

 save the crop from the ravages of black bugs and striped 

 beetles. By changing about and planting elsewhere how- 

 ever, this trouble is largely removed. 



FERTILIZATION. 



Liberal and generous manuring is a judicious practice 

 when it is aimed to secure comparative exemption from 

 serious insects and fungous difficulties. The crop with an 

 abundance of available plant food at its command will de- 

 velop a vigorous, robust habit of growth, much better cal- 

 culated to withstand the depredations of insects than the 



