REPORT OF J. P. STELLE. [29] 



flying of its own accord late of an evening or at night, you will invariably find it 

 choosiDg its stopping places in obedience to the same rule ; you rarely see it stop on 

 any of these exposed plants of the border. 



Ti-ecs. — I have often been asked to explain why cotton i)lants growing in the imme- 

 diate neighborhood of trees are longer exempt from destruction by worms than those 

 growing where trees are not. Some investigators have attributed it to the work of 

 birds, which, finding a convenient lodging place upon the trees, have devoured the 

 insects ; while others attribute it to shade. I know it is not due to birds devouring 

 the worms, for I see the same thing around trees that birds never frequent ; and I 

 know shade is not the cause, for I find plants exempt all the same on the north sides 

 of the trees where shade cannot come. It is, evidently, this same peculiar sliyness 

 of the moth which causes it to avoid exposed situations. If you watch it in its vol- 

 untary flight, as I have done, you will see that it invariably gives all trees a wide 

 berth. This is, in all probability, due to its instinctive fear of birds that might be 

 lodging upon the trees. 



Shade. — This does, however, aftbrd a temporary annoyance ; not to the moths, for 

 they being nocturnal in their habits do all their work under shade, but to the worms. 

 In my search for a solution of this tree-problem, I stretched a tarpaulin upon stakes 

 above a number of plants so as to shade them. There was a goodly stock of worms 

 upon the plants at the time, but in a day or two afterwards they had all changed 

 their quarters to other plants and sunshine. But they returned to their work in full 

 force when a trimming out of the field had brought nice, fresh cotton leaves into 

 better demand. 



NATURAL ENEMIES. 



Entomologists who write on the subject of cotton insects usually find a great deal 

 to say with reference to the '^ natural enemies" of the Cotton Worm. These they 

 point out as existing among the quadrupeds and birds, and among other species of in- 

 sects. To the quadruped portion of the subject I have given no attention, but birds 

 as Cotton Worm destroyers and some of the insects I have studied extensively and 

 with great care. 



Birds. — Soon after I had located at Calvert reports were brought to me by several 

 planters setting forth that immense numbers of small but strange birds had appeared 

 on their plantations and were devouring the Cotton Worms. I found the '* strange 

 bird" to be a small black, white and buff sparrow of the species known to science as 

 Cottirniculus lecontei. As we approached the cotton fields it flew up in considerable 

 numbers from among the plants along the edges bordered by woodlands, where it had 

 been feeding upon the worms, as the contents of its stomach, examined in several 

 specimens shot, plainly demonstrated. I was rather surprised to see it in numbers so 

 large, owing to the fact that it has usually been regarded by naturalists as rather a 

 scarce bird. Of course it was not a strange bird for Texas; it had now for the first 

 time attracted the attention of these planters — that was all. 



The Texas bird that I found standing first in rank as a devourer of Cotton Worms 

 was the common Mocking Bird (Mimus polyglottus) ; and next to this, perhaps, was 

 the American Cuckoo (Coccygusamericanus). I saw neither of thcvse birds catching 

 moths ; the only bird I saw actively at that business to an extent worth naming 

 was the Bee Martin, or King Bird, of Texas (Tyrannus verticalis). It was quite plenti- 

 ful on the Brazos, and I often saw it in. the cotton fields after sunset catching moths, 

 and not unfrequently continuing at its work until twilight had considerably ad- 

 vanced beyond the half-way line between daylight and darkness. 



Ants. — I made many experiments with ants for the purpose of gathering some idea 

 of the extent to which they are the ''natural enemies" of the Cotton Worm. Put 

 chrysalides of Aletia at the openings of ant-hills of all the species I was able to find 

 in the cotton field, including those of the common and conspicuous Pogonomyrmex 

 harlatus, or "Agricultural Ant of Texas." When first put down the ants usually 

 tugged at the small extremities of the chrysalides for a few moments, after which 

 they left them undisturbed. In not one of the species was there ever evinced the 

 slightest disposition to break the shells. On one occasion I partially crushed several 

 chrysalides until the juices appeared ; these the ants of each species to which they 

 were offered worked upon vigorously until they were either devoured upon the spot 

 or dragged piecemeal into the habitation. 



One morning I placed a number of chrysalides of Aletia, still rolled up in the leaves, 

 at the opening of a strong colony of P. harbatus. Returning in the evening to see 

 what had happened I found the ants biisily engaged cutting the then dried leaves in 

 lueces for the sole purpose, evidently, of removing them from their clearing. It is a 

 peculiarity of this ant to keep every thing cleared away from the entrance to its den 

 for a space of 10 or 15 feet in diameter, not even sparing cotton plants or those of any 

 other crop that the farmer may happen to put within the boundaries of its claim. 



