THE ENTOMOLOGIST 



Vol. XLII.] MAY, 1909. [No. 552 



THE FOOD-PLANT OF L. ORBITULUS. 

 By T. a. Chapman, M.D., F.Z.S., &c. 



Last summer (1908) I met with L. orbitulus abundantly in 

 several of the valleys south of the Khone, but especially in the 

 Binn Thai, in the first week in August. I had the pleasure of 

 observing it ovipositing in various localities on the slopes of the 

 Holzerspits. The plant on which the butterflies were laying was 

 Androsace (Gregoria) vitaliana. 



Having ascertained this, I noticed that this plant was com- 

 mon wherever the butterflies were most abundant. The plants 

 where the butterflies flew were beyond the flowering season, 

 possibly two or three weeks, but 1000 ft. or so higher up, where 

 there were no orbitulus — in fact, at about the highest limit of the 

 plant— it was still in flower, each plant presenting a beautiful 

 patch of crowded yellow flowers. The butterflies laid on and 

 under the leaves near the summit of each branch or rosette 

 of leaves. 



The larvae hatched in seven or eight days, and fed freely on 

 the leaves of the plant. I succeeded in getting several larvae 

 full-grown in the first skin, but failed to get further. The plants 

 I brought home with me soon died, and some I succeeded in 

 getting from a nursery were covered with aphides and very un- 

 healthy, and soon died, although I managed to clear off the 

 aphides, and so the experiment came to an end. I was thus 

 unable to tell at what stage the larva hybernates ; it can hardly 

 be later than the second instar, though on the sun-baked slopes 

 where much of the plant grew no doubt rapid progress might 

 be made. 



However, I have determined the food-plant, which is im- 

 portant, and have obtained photographs of the egg (by Mr. 

 Tonge), and obtained a preparation of the larva in the first in- 

 star showing its structure, well photographed by Mr. F. N. Clark. 



I add a note on the colouring, &c., of the larva when full- 

 grown in the first instar. My note was made on September 5th, 



BNTOM. — MAY, 1909. K 



