April 1887.] 



AND OOLOGIST. 



63 



ENTOMOLOGY. 



J. A. ■WRIGHT. 

 265 No. Beacon St., Brig-hton, Mass. 



ASSOCIATE EDITOH. 

 Aildress all coiiiiiiuiiicatious for this deparfnient as above. 



Observations on the Cotton Cat- 

 erpillar. 



BY WALTER HOXIE FKOGMOHE, S. C. 



ALETIA XYLINA, SAY. 



Last suniiuer the Cotton Cati-rpilhir was fear- 

 fully abundant on St. Helen's Island, and my 

 observations, though mahily eontifuiatory of 

 pi'eviously published accounts of its habits, 

 will perhaps be of interest to the readers of the 

 O. AND O. 



The first imago observed by me was in May. 

 By the middle of the month the worms were 

 quite abundant in the grass, and from that 

 time till frost were never absent from certain 

 localities. The August brood was the first to 

 do any considei'able amount of damage. Dur- 

 ing the early summer, few if any cotton plants 

 were stripped of their foliage, and in most fields 

 only a small per cent of the leaves exhibited any 

 punctures. The localities visited by these early 

 broods were mainly along the road sides and 

 near grassy spots, thus indicating that their 

 larvjc spread from the grass upon which the 

 eggs had been deposited. After the grass be- 

 came tough and the lains had induced a rich 

 and tender growth of cotton, the fields received 

 the full attention of the scourge. Localities 

 near hedges, woods and lone trees seemed to 

 be the most exempt. Mj observations led me 

 to the conclusion that these places received the 

 most attention from the birds. Tlie imagoes 

 were found indiscriminately in all parts of the 

 field, and were probably so abundant that no 

 special selection of suitable spots for depositing 

 could be made. The progeny were too numer- 

 ous to be held in check by their natural ene- 

 mies, and only showed a diminution of numbers 

 in the places where their enemies found it the 

 easiest to feed upon them. In one field, for 

 instance, that was nearly denuded of foliage, 

 the plants for a few rods around a sn)all cassina 

 bush were rank and green. A pair of Mocking 

 Birds had a nest in that bush, containing four 

 young, in the callow, "always hungry" stage 

 of existence. 



Night Hawks are the most abundant birds in 

 this locality that prey upon the perfect insect. 

 I have in mind several instances in which one 

 of them swooped down and made ott" with one 

 of the moths, which I, net in hand, was pursu- 

 ing. The Mantis, among insei-t foes is a most 

 ravenous feeder. It will frequently drop a li:ilf 

 devoured larva to pounce upon another which 

 makes an inadvertent movement liard by. 



But all natural enemies are of little avail 

 against an insect scoui'ge, when it has once 

 attained full headway. The Ichneuman files 

 are probably the most destructive to the full 

 grown larvas, of all their natural enemies. 

 They, however, do not attain sufilcient ninn- 

 bers to alleviate the i)est to any great extent. 

 This is due, first, to the fatit that the early 

 broods of caterpillars have accomplished must 

 of their destructive work befoi-e being attacked 

 by the parasites; and second, that the bulk of 

 the infected worms are eaten by ants and other 

 scavengers, thus keeping down the numbers of 

 the perfect files, which if matured, might go 

 far toward eradicating the last few broods. I 

 am forced to believe that for a relief from in- 

 sect pests of tliis nature, man must rely upon 

 his own agency. 



Substitute Food-Plants. 



liV TAl'L HEVEKE. 



The bi'eeder of lepidopterous larvji3 frequently 

 finds himself puzzled by circumstances over 

 which he has no control. He has larv;e either 

 from eggs imported from some distant state or 

 country, oi- captured upon a plant in a district, 

 which is scarce in the place where he i-esides. 

 It is then that a knowledge of botany, works to 

 the advantage of the breeder; and, by the way, 

 a good book on the subject, giving all the allied 

 plants in families, and kept for ready reference, 

 a standard work upon botany, tides the ento- 

 mologist over many an uncertain place. 



Manj^ of tlie moths bred by amateurs in New 

 England are general feeders, and the i)lants 

 which the larv;e brouse upon are often non- 

 allied. The foliage of the plants enumerated 

 below may be used for the rearing of the moths 

 named : 



Samia cccrnjiia, wild and cultivated plum, 

 apple, wild cherry, bay berry, alder, willow. 



Tclea Pohjphcmus, oak, wild cherry, buttei-- 

 nut, birch, chestiuit. 



Aetias Luna, hickory, oak, maple and butter- 

 nut. 



