314 LEPIDOPTERA. 



ber 19th, I was in the field examining the forms (buds before 

 flowering) and the young bolls (fruit after the floral organs 

 have fallen off). I examined all carefully, with no signs of eggs 

 or worms. On Sunday I did not see it. On Monday I passed 

 it as usual and observed nothing unusual. On Tuesday morn- 

 ing I passed it and noticed nothing unusual. On Tuesday noon 

 every plant in the field was stripped of all its upper leaves ; 

 not one remaining as far as could be seen, and the plants were 

 covered with millions of worms. I counted on one plant forty- 

 six worms. They commence at the top of the plant, eating 

 every leaf. When the leaves were gone they attacked the 

 young bolls, eating through the perianth and consuming the 

 young cotton. In the course of four days the work was done. 

 They did not touch the grape or any other plant in the field, 

 so far as I have been able to see. 

 Many left the field and thousands were 

 i n ^ ne roa d and on the fences, but not 

 one in a thousand thus escaped. To- 

 day, September 23d, there is scarcely 

 one to be seen. Their disappearance 

 is as mysterious as their coming. They 

 have left no signs that I can see, 

 either on the stalks or in the ground. 



They have extended over hundreds of miles, and nothing 

 has proved a barrier to them, having been as destructive 

 on islands in the river, as elsewhere. One-third of the 

 cotton crop has been destroyed. Nothing of the kind has 

 occurred in thirty years past to my knowledge." The larva 

 is reddish brown, with distinct black spots, the dorsal line 

 being streaked with yellow and black. It hibernates as a 

 moth. The presence of this caterpillar in the West Indies 

 caused the cultivation of cotton to be abandoned. The same, 

 or another species, also appears often in Guiana and other parts 

 of South America. A good remedy against the worm is a mix- 

 ture of two parts of carbolic acid with 100 of water, to be 

 sprinkled on the leaves of the plant. Heliotliis has pubescent 

 antennae, the thorax and abdomen are smooth, and the fore 

 wings slightly acute at tip. The larva is elongated, but not 

 attenuate, with a large head and distinct lines along the body. 



