15 



practice in cotton growing in this state yet it is a change 

 that would benefit the industry were the Boll Weevil never 

 to get here. 



By this method an excessively long period of time results 

 in which no cotton is available as food for the weevils and 

 the number successfully hibernating is much reduced. It 

 is not in the intention of this bulletin to enter very deep- 

 ly into the subject of the Mexican Cotton Boll Weevil. It 

 is sufficient for our present purpose to merely call atten- 

 tion to the great importance of the method of "farm prac- 

 tice' 7 as applied in this and similar cases of insect attack 

 where other methods offer scanty or no relief. 



INSECTS WITH SUCKING MOUTH PARTS. 

 Our attention so far has been drawn to the insects that 

 have biting mouth parts and that obtain their food by ac- 

 tually eating out portions of the attacked fruit or plant. 

 There is, as was noted in our opening paragraphs, a series 

 of insect pests whose method of eating is quite distinct and 

 different from these so far spoken of. These insects have 

 mouth parts so adapted, structurally, that they pierce 

 through the outer covering of the plant or fruit attacked, 

 and suck out the sap or juice. They do not use as food 

 any of the outer part of the plant and as a consequence 

 none of the poisoning methods heretofore spoken of are 

 of my avail in their control. Another point of dissimi- 

 larity between these insects and the group designated as 

 having biting mouth parts is that while the latter insects 

 move about from place to place and do not, as a rule, gath- 

 er together in fixed colonies, the series with sucking mouth 

 parts have this bunching together, greg ious habit, strong- 

 ly developed. Not only is the colonizing habit character- 

 istic of these insects but in the most injurious representa- 

 tives of the group we find that when the sucking mouth 

 parts have been inserted in the plant tissue and feeding be- 

 gun the individuals remain fixed in the chosen situation 

 throughout the balance of their lives. This habit of re- 

 stricted motility, as it may be termed, is especially evident 

 among the so-called scale insects (coccidae) and in the 



