544 ANNUAL REPORT OF THE Off. Doc. 



but it should not be required as it is better to exterminate the in- 

 sects. For several insects that are difficult to combat, this practice 

 is often resorted to. 



8. Using Fertilizers. 



It is very desirable that all plants have a strong, vigorous growth, 

 for they are thus able to withstand the attacks of insects better than 

 can weaklings. Any kind of fertilizer is valuable in overcoming in- 

 sect attacks because it promotes vigor, but one of the best is a pinch 

 of nitrate of soda in each hill or at the root of each plant. This pro- 

 duces the needed rapid growth and also acts as an insecticide. To- 

 bacco dust is also a valuable fertilizer and insecticide. Its commer- 

 cial value as a fertilizer is |25.00 per ton. 



9. Starting Plants Earlv. 



The purpose of this practice is to have them as large as possible 

 before the insects appear. An attack that will kill a small plant will 

 but slightly injure a large one. There is an advantage in starting 

 plants indoors in order to have them large enough to withstand in- 

 sect attacks when set out, besides the early yield of produce. 



10. Late Fall Ploughing. 



This practice is valuable to destroy those insects, such as the 

 Squash-borer, the Striped Cucumber Beetle and perhaps the Spotted 

 Cucumber Beetle, that pass the winter in. the ground. If they are 

 turned over and exposed during the winter a great many insects are 

 killed by ploughing in the fall. Those that pass the winter as pupae 

 are especially likely to be killed by the breaking up of their pupal 

 cases or cells. 



11. The early Application of all Preventive and Remedial Meas- 

 ures. 



The importance of this can not be too greatly emphasized for all 

 species of insects, and there are many that can not be successfullj 

 combatted unless practical measures are taken as soon as they makf 

 their appearance. Among these are such as the Plant Lice or 

 Aphids. In June while the vines are small and the Aphids first 

 migrate to melons, etc., from their food plants of winter and spring, 

 they can readdly be killed by fumigating the vines or spraying as di- 

 rected elsewhere in this article; but if this is neglected until the 

 vines are large and fruit is set it is almost impossible to rid the field 

 of the pests. 



III. INSECTICIDES. 



As stated in the early part of this article, insecticides are of two 

 general kinds, according to the structure of the mouth and the feed- 

 ing habits of the insect to which they are to be applied. Those 

 species that chew their food can be killed with internal poisons (A), 

 if they live where they can be reached; and those that are suctorial 

 must be killed by contact applications (B). 



