140 ORDER HEMIPTERA 



Whale-oil soap is sometimes used, but the most favored 

 remedy at the present time is lime-sulphur wash formed by 

 boiling the ingredients together. This is applied by means 

 of a spray-pump so that it covers the trees. If these appli- 

 cations are made thoroughly the scales may be killed off to 

 a great extent, though it is is hard to completely exterminate 

 them. Badly infested trees will seldom recover and it is 

 about as well to cut out and destroy such trees. Remedies 

 that can be applied when larvae are travelling will be more 

 effective, but in San Jose scale larvse are travelling most of 

 the summer months. In those species where there is a 



Fig. 93. — Peach orchaid mjurod 1)\ Pan .lose tcale Nogleotcd, badly 

 infested orchard at right and injured rows adjacent in spite of careful 

 spraying with protection to rest of orchard at left. (Photo by author.) 



definite period for the larvae, spraying even with clear water 

 if the pressure is great will reduce their numbers considerably. 

 It is important to know the life histories perfectly. 



The Heteroptera include those forms which have wings 

 thickened at the apex and in which the mouth parts arise 

 from the most anterior portion of the head, and both in this 

 character and in the wing structure are evidently more 

 specialized than the Homoptera. It is not possible to say 

 that any of the Heteroptera present more specialization in 

 certain lines than some of the Homoptera. 

 [_ The families are pretty well marked, and a number of 



