248 INSECTS INJURIOUS TO STAPLE CROPS. 



shrivels w}! and dies. But the maggot itself contracts into 

 a hard, brown pupa, from which the fly eventually 

 emerges. Thus in 1868, when first noted by Doctor C. V. 

 Kiley, he asserted that in Missouri fully ten per cent of the 

 second brood and one-half of the third were destroyed by 

 this parasite. 



Many of our common ladybird-beetles and their larvae 

 check the pest by feeding upon the eggs. Several pre- 

 daceous bugs are of value in destroying the larvae, into 

 which they thrust their short, powerful beaks, and then 

 suck out the juices of the body, leaving only an empty 

 skin. One or two of these closely resemble the common 

 squash-bug [Anasa fristis De G.), but are really very dis- 

 similar, and whereas the beaks of the predaceous forms are 

 short and thick, as in Fig. 139fr, those of plant-feeders, 

 like the squash-bug, are long and slender, as in Fig. 1396-. 



Several species of ground-beetles are often found preying 

 upon the larvae and beetles, but, unlike the bugs, attack 

 them by means of their powerful biting jaws. These 

 beetles are also exceedingly beneficial in feeding upon 

 many other injurious insects, and are among the farmers' 

 best insect friends (Fig. 141). 



Eemedies. — As an artificial remedy for this pest, Paris 

 green has long been proven to be both effectual and prac- 

 tical. 



For small areas it may be used dry by inixing it with 

 one hundred times its weight of dry flour, land-plaster, or 

 air-slaked lime, and should be applied while the plants 

 are still wet with dew, either by a perforated can, or, 

 better, by one of the improved powder-guns such as 

 Leggett's, by which two rows of plants may be powdered at 

 once. 



