lA'CAlCNINAH: I'KN'ISECA TAUljllXlUS. 1025 



No panisitcs :ire known : wliicli is tlio more roniarkalilc as our knowlcilge 

 of tlie caterpillar is princ-ip;il]y of those taken in tlie Held ; evidently tlieii" 

 concealment and disguise must thoroughly protect them. But, Miss 

 Morton writes : — 



The ants do not lot tlio larvae alone hnt bite at them furionsly whenever they see 

 them ; bnt until nearly j;rown the larvae lie concealed under the aphides with a web 

 covering them, and cannot be got at by the ants without disturbing their cows. I 

 went to the swamp again to-day. . . . There were place.s on the limbs of the alder 

 where evidently full grown larvae had cleaned off the aphides. At one place, the 

 ants, a very large species, with black head and abdomen, and red tliorax, were in a 

 state of great excitement, running and biting in every direction, and h.ad probably 

 just discovered and routed a full grown larva, as a large brown spot witli all tlie 

 apliides cleared off showed itself on the limb. 



That the ants do attack the caterpillars is evidenced b}^ Mr. Edwards's 

 dii'ect experiments with them, and by an observation of Miss Morton's, 

 who, while wondering how she should obtain a caterpillar from a large 

 colony of aphides, found her way "suddenly made plain by a large ant 

 rushing at and biting it furiously, and the larva curled up and fell to the 

 ground." That they actually kill the caterpillar is certain, as the follow- 

 ing experiment shows. 



I stocked with Aphides an alder I had planted for the purpose in my gar- 

 den, and on July 31 placed there a cater[)iliar in the second stage. The 

 aphides were all small and in two large clusters. The caterpillar moved 

 about over the lower colony for an hour or more, apparently looking for a 

 good place to push under it, and I observed its contact with the ants on 

 twenty or thirty occasions. They tickled it with their antennae and it re- 

 mained at such times absolutely quiet, generally moving off when they left, 

 in the 0[)[)osite direction to that in which it had been touched. They offered 

 it no further attack. Having to leave for an hour, I found on my return, 

 just at nightfall, that the caterpillar had quitted the lower colony for the 

 upper, si.x to eight inches distant up the stem, and the same process was 

 repeating with the ants there. The next morning it was found dead beside 

 the colony, the outer edge of which it had eaten and removed, its body 

 bitten just in front of the middle on each side in two or three places. 

 The colony was composed of individuals too young to burrow under and 

 being unable to conceal itself, it had fallen a victim to the ants, then vic- 

 toriously nui-sing their colony. With the other attendants of the aphi- 

 des, the caterpillar of this butterfly a|)pears to be entirely at peace. 



Desiderata. The geographical distribution of this butterfly is imperfectly 

 known. INIoist spots where alders flourish and their bark is attacked by 

 the j)lant-lice are the places to search. Especially its westward and north- 

 ern extent should be looked to. In Massachusetts it appears never to 

 have been taken east of the Connecticut valley and yet just this region 

 contains most collectors. The reason of such a limitation, if it exists, 



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