50 MISCELLANEOUS RESULTS OF WORK OF BUREAU IX. 



While they will feed anywhere on the leaf, in many cases they will 

 cluster together in colonies between two veins of the leaf. In one case 

 observed by the author a number of larvae hatched from eggs on one 

 edge of the leaf and the next day were all feeding together on the 

 opposite edge. In another case a colony of 85 larvae was observed 

 collected in a circle between two veins near the edge of the leaf. 

 Man}^ of the larvae in this colony were moving around, but would not 

 separate from the colony. 



The larvae when first hatched are minute and colorless, but as soon 

 as they begin feeding the alimentary tract becomes plainly marked 

 from the dark reddish fluid contained in it. This fluid is excreted 

 and collects in globules on the tip of the abdomen, being held in place 

 by the terminal setae. The tip of the abdomen is elevated, and it 

 is an interesting sight to see numbers of these larvae moving over 

 the leaf with globules of red liquid suspended in the air on the tips 

 of the abdomen. When disturbed they become excited and move 

 around rapidly, jerking the abdomen from side to side. The globule 

 of liquid gradually increases in size until it is too large to carry, and 

 is then left on the surface of the leaf, where it dries as a small reddish 

 spot. 



As long as the food supply in the leaf is fresh and abundant these 

 arvae will remain on it, and thus the number becomes very large. 

 One leaf was found with about 250 larvae, besides a number of pupae 

 and adults. If disturbed, or if the leaf is beginning to wilt and lose 

 its vitalitj r ? the larvae become restless, separate, and move around 

 over the leaf in search of fresh food, but eventually many will collect 

 again in colonies. They feed unprotected on the leaf, as far as their 

 own efforts are concerned, but in many cases they secrete themselves 

 under a slight web made by red spiders and are protected by it. 

 Upon leaves exposed in part to sunlight the larvae seek that part of 

 the leaf which is the least exposed. They molt unprotected in the 

 midst of the feeding colony. These larvae are delicate little crea- 

 tures, and if for any reason they are knocked from the plant most of 

 them soon die, not being able to travel far in returning to the food 

 plant. 



HABITS OF THE PREPUPA AND PUPA. 



The larvae change to prepupae in the midst of the feeding colony 

 without seeking protected quarters, but nearly always on the under- 

 side of the leaf. The prepupae move around a little on the underside 

 of the leaf and generally are clustered in groups of from 4 to 10 pre- 

 pupae and pupae. In many cases they are under the web of red 

 spiders, but if no red spiders have been on the plant they are then 

 unprotected. 



