Insect Study 



353 



A serpentine mine in nasturtium 

 leaf. 



the head of the serpent ; here it 



changes to a pupa, perhaps after 



nibbling a hole with its sharp little 



jaws, so that when it changes to a 



soft, fluffy little moth with mouth 



unfitted for biting, it is able to escape. 



In some species, the caterpillar comes 



out of the mine and goes into the 



ground to change to a pupa. By 



holding up to the light a leaf thus 



mined, we can see why this little chap 



was never obliged to clean house; it 



mined out a new room every day, and 



left the sweepings in the abandoned 



mine behind. Mines of this sort are 



often seen on the leaves of nastur- 

 tium, the smooth pigweed, columbine, 



and many other plants. There are 



mines of many shapes, each form 



being made by a different species of 



insect. Some flare suddenly from a 



point and are trumpet-shaped while 



some are mere blotches. The blotch 



mines are made, through the habits of 



the insect within them; it feeds around 



and around, instead of forging ahead, 



as is the case with the serpentine miners. The larvae of beetles, 



flies and moths may mine leaves, each species having its own 



special food plant. Most of the smaller leaf mines are made 



by the caterpillars of the moths, which are fitly called the Tineina 



or Tineids. Most of these barely have a wing expanse that will 



reach a quarter of an inch and many are much smaller; they all have 



narrow wings, the hind wings being mere threads bordered with 



beautiful fringes. The specific names of these moths usually end in 



"ella;" thus, the one that mines in 

 apple is malifoliella, the one in grain is 

 granella. One of these little moths, 

 Gelechia pinifoliella lives the whole 

 of its growing life in half of a pine 

 needle. The moth lays the egg at 

 about the middle of the needle, and 

 the little caterpillar that hatches from 

 it, gnaws its way directly into the heart 

 of the needle; and there, as snug 

 as snug can be, it lives and feeds until 

 it is almost a quarter of an inch 

 long, think of it ! Many a time I have 

 held up to the light a pine needle 

 thus inhabited, and have seen the little 



A serpentine mine in leaf of mi ?/F CG U and d itS ^ de 



columbine. as ^ ^ knew that something was hap- 



Comstock's Manual. pening. When it finally attains its 



