2'34 Leaf-Miner. [zoe 



foliage mentioned as the food of the grouse, but they probably eat 

 leaves of clover early in summer, just as valley quail do in win- 

 ter. The juveniles eat a great many ants. 



Some seasons, when there are no berries and very few seeds, 

 they live almost entirely upon the bulb of a species of grass, ap- 

 parently Melica bidbosa, which grows at the head of springs and 

 rivulets. The birds get the bulb by scratching. Such seasons they 

 start for the foothills sooner than when food is abundant. 



ON A LEAF-MINER OF POPULUS FREMONTI. 



BY C. H. TYLER TOWNSEND. 



Almost every spring the cottonwoods in the town of Las Cruces, 

 New Mexico, and its vicinit}^ are badly infested with a leaf-miner, 

 which up to the present time has baffled all attempts at breeding. 

 The cottonw'Ood is our only native shade tree in the Mesilla Valley, 

 there being only the one species, Populus fremo7iii; and as this in- 

 sect has proven a serious pest to it, the following notes on the larva 

 will probably be of interest, although the imago is unknown. A 

 very brief notice of this miner was published in Insect Life, vol. 4, 

 pp. 26-27. 

 ■ It was found on April 30, 1891, that nearly every tree in the valley 

 was most thoroughly infested, the majority of trees having almost 

 every leaf mined out and blistered. The larvae eat out the entire 

 inner portion or parenchyma of the leaf, leaving the two skins 

 whitened and inflated like blisters. They entirely and irrecoverably 

 ruin the foliage of the tree, giving it a most desolate and dying ap- 

 pearance. The trees, however, gradually put forth a new set of 

 leaves, and though they apparently soon recover their normal healthy 

 appearance it is clearly evident that this process must be a great tax 

 on their vitality. I have even been told that in some previous years 

 the second crop of leaves has been likewise destroyed, but I cannot 

 vouch for the accuracy of this statement. On the above date the 

 larvae were of several sizes, the largest being about seven-sixteenths 

 of an inch in length. In general color they are nearly white, with 

 some black dots on the anterior segments below and on the seg- 

 ments next the head above. Two larvae w^ere often found in one 

 leaf, their mines beginning in separate parts of the leaf and gradually 

 approaching until they coalesced. 



