outline of the Life History of Lycaena arion. 301 



the skin equally intact. The probable cause of the differ- 

 ence of appearance is that the larvae both died from ex- 

 haustion, from not reaching the ants' nests (and brood) 

 soon enough ; the one that died outside the nest, i. e. in 

 (light, dry) chamber, which the ants treat as not in the nest, 

 looking there for food and depositing their debris, was 

 never meddled with by the ants; the other, rather less 

 exhausted, did reach the nest, but too late, and, dying in 

 the nest, was examined and moved about by the ants, and 

 being limp and inelastic, preserved the impressions of their 

 jaws, without having been injured by them. The point is 

 interesting, as bearing on the question as to whether the 

 M. scabrinodis may be inimical to the larvae of arion in 

 any particular circumstances. 



" August 16th. — The old one in the earth nest is well 

 and larger and in usual spot. 



" August 18th. — Larva still larger, in other side of big 

 chamber. 



" August 19th. — ^Yesterday the larva was in the large 

 chamber in the earth nest, and was considerably larger. I 

 measured it by putting my micro, mm. slide on the glass 

 above it, and it was a little over 5 mm., and broad in pro- 

 portion. To-day I can't see or find it ; it is not in the box 

 outside the nest, as I have searched every corner and swept 

 up every grain of sand or remains of insects cast out by 

 the ants and examined it with a lens. 



" What can have become of it ? Can it have burrowed 

 into the earth? I take it, the ants would not have de- 

 stroyed it after it had been in the nest for fourteen days. 



" August 31st. — I have not seen my larva since ; I look 

 every day. I beheve its food in great part was the drop- 

 pings and pellets of the ants. I never saw it feeding on 

 the brood, but it was often apparently eating on the floor 

 of the nest. This is (as I proved, see Ent. Rec, vol. 24, 

 p. 35-6, 1912) the food of the larva of the fly Microdon 

 mutahilis. 



" September 14th. — -I have not seen my larva again, nor 

 have I found its body or parts of it." 



These observations of Mr. Donisthorpe's suggest one or 

 two points worth discussion. The most important is as 

 to the surmise that the larva hides for the winter in loose 

 earth in or near the nest. As my plaster nests were devoid 

 of earth, they afforded no facts bearing on such a point, 

 but my most successful larva was much larger and older 



