366 



AA^ ECO XO MIC EXTOMOLOGY. 



the latter type in the Eastern United States is seen in the round 

 swelHngs so frequently found on the stems of golden-rod. A 

 number of species are locally injurious to fruits, but there seems 

 to be no one injurious form generally distributed throughout this 

 country. In the Northern and Eastern United States the so- 

 called " apple" -maggot, Trypeta pomonella, is the only one 

 causing trouble, the fly laying its eggs in the tissue of the apple by 



Fig. 421. 



Trypeta pomonella, parent of the apple-maggot. 



piercing the skin with its horny ovipositor. The little maggots 

 channel the fruit in every direction, causing it to rot or become 

 unsalable. When full-grown they pupate below the surface of 

 the ground, or even among rubbish on the surface, or in crevices. 

 Indeed, they are not at all particular, and transform wherever 

 they can find an opportunity to do so, including the barrels, 

 boxes, or bins in which infested apples have been kept. None of 

 these fruit flies can be reached by insecticides, nor is there any 

 fair chance of reaching the adults, and the only method that 

 is effectual is the prompt removal and destruction of infested 



