1021.] 



229 



Britisli Islands" (1802). A. befulae is an important and unexpected 

 addition to our list, and it seems strange that such a conspicuous 

 Hemipteron should have hitherto escaped notice in a well-worked locality 

 like Eannoch.— G. C. C] 



NOTES ON THE OVIPOSITION AND HABITS OF THE IRIS SAWFLY, 

 RHADINOCERAEA MICANS Klug. 



BY HUGH SCOTT, M.A., SC.D., F.E.S. 



This conspicuous, shining black sawfly, the very wings of which 

 share in its general blackness, looking as though they had been washed 

 over with dilute ink, was formerly known as Monojphadnus iridis Kalt. 

 It was introduced into the British list by Mr. F. D. Morice in 1904 (Ent. 

 Mo. Mag. p. 99) and referred to in his "Help-notes," no. 18, in 1907 

 (Ent. Mo. Mag. p. 79) ; but apparently no record of it as British was 

 published again till 1917, when Dr. T. A. Chapman described and 

 figured the larva, which was found abundantly on the wild yellow flag {Iris 

 pseudacorus) at Woking (Ent. Mo. Mag. 1917, pp. 224-8, pis. v-vii). 

 The following is not intended to be a complete account of the life-history 

 of the insect, but as it seems that certain points in its life-cycle, especi- 

 ally the method of oviposition, are not well-known, these notes are 

 offered for publication. 



On July 30th, 1920, my attention was called by Mr. Preston, 

 Curator of the Cambridge Botanic Gardens, to the presence of numerous 

 larvae on the yellow iris (as before, Iris pseudaconis) at the edge of 

 the large pond in the Gardens. The larvae had been very numerous, so 

 that throughout a long bank of the iris on one side of the pond nearly 

 every leaf had been eaten on one or both edges, but an isolated clump 

 of the plant a hundi-ed yards or more away on the other side of the pond 

 seemed entirely untouched. Nearly all the larvae had already left the 

 plants to go into the soil, but about 11 were found, and 9 of these were 

 kept and fed in a glass vessel with gauze stretched over the top and about 

 3 inches depth of soil at the bottom. By Aug. 9th only 3 remained, still 

 feeding, above the surface of the soil. On Aug. 12th only two remained 

 above and one of these had just moulted. By Aug. 16 the last larva 

 had disappeared below the surface. The vessel was kept through the 

 autumn and winter in the Insect Eoom of this Museum, where a fire 

 was burning in the cold weather during working hours, and the soil was 

 lightly moistened about once a week with one or two pipettes-full of 



