area of about 6 acres, mostly in alfalfa. He stated that although 

 the live grasshoppers were vet ver}' thick, many appeared weak and 

 in a dying condition. ^Vhen received the material was simply a mass 

 of decaying bodies of grasshoppers and among them were both 

 maggots and j^upa? of Sareophaga georgina. These flies deposit 

 minute, elongated, ivory-white eggs on the surface of the bodies of 

 the grasshoppers. The young maggots hatching from these make 

 their w^ay directly into the bod}- of their host, and as they grow and 

 develoj) there they feed upon the living insect. "^^Hien full gi'own 

 the maggots go into the ground and within a brown case transform 

 to flies. 



"^^liile all of these natural enemies do much to hold the pests in 

 check, there are two or three vegetable parasites that also kill otf 

 myriads of them, the 

 dead bodies of the 

 grasshoppers destroyed 

 thereby often being 

 conspicuous objects as 

 they cling to the weeds 

 and grass where death 

 overtook them (see fig. 

 6). One of these fun- 

 gous i^arasites is the 

 same as that attacking 

 the chinch bug, and 

 is known to science as 

 Bporotrichum glohvli- 

 ferum. A group of 

 grasshoppers that have 

 been killed by this fun- 

 gus is shown in figure 7. 



While it will be seen that there is no lack of natural enemies of 

 these grasshoppers, and Avhile all of them are of benefit to the farmer, 

 they do not and never will afford absolute protection from the rav- 

 ages of these pests in the alfalfa fields. The reason for this is plain. 

 By growing a single plant over large areas the farmer produces an 

 unnatural condition and offers unnatural advantages for the devel- 

 opment of the enemies of this plant, the grasshoppers. It is really 

 the number of plants that invites insect attack. So, also, it is the 

 great number of grasshoppers congregated together in masses that 

 invites attack from natural enemies, and it is only when this condi- 

 tion is present that these natural enemies become sufficiently abundant 

 to offer the farmer prompt and efi^ective relief. In other words, the 

 natural enemies, however much restraining force they may present, 

 are always too far behind to wholly prevent occasional outbreaks of 



[Cli-. 84] 



Fig. 5. — Sareophaga georgina, a parasitic fly that destroys grass- 

 hoppers. Much enlarged (original). 



