1918.] 9 



from which it cannot be separated. The beetle eventually emerges (after 

 a period of about a fortnight), not by the pupal skin splitting along the 

 back as usual, but from the ventral side, the dorsal part remaining 

 entire and inseparably attached t() the waxy covering. 



It is interestino- to notice that befoi-e attainino: the fullv mature 

 condition the freshly developed beetle passes through stages of pig- 

 mentation, which are represented in allied species of Scymnus. First 

 of a uniform reddish-yellow colour it shortly after begins to darken 

 upon the posterior part of the pronotum and the anterior part of 

 the elj'tra, as in S. haemorrlioidalis, and, finally, the terminal part 

 of the elytra, and, in the female, the greater part of the pronotum, 

 also become black. 



Like many of the small Ooccinellidae belonging to the same group, 

 the male and female beetles are differently coloured, the former being- 

 decorated with yellow patches, which are not found in the latter. 



9 Rossdale Road, Putney, S.W. 

 ^'ov. 1917. 



THE EGG-LAYmG OF CLADIUS VIMINALIS Fallen. 

 ET T. A. CHAPMAX, M.D., T.Z.S. 



The few saw-flies of whose egg-laying I know anything present 

 some that lay their eggs superficially on leaves, closely related to others 

 that lay their eggs in shallow grooves ; at the other extreme, several, 

 such as JPteronus pini and sertifer, make deep hollows by turning out 

 the excavated material. Intermediate between these are those in which 

 I have most interested myself, that lay their eggs in pockets formed by 

 raising m.erely the delicate cuticle of the leaves or stems. Owing to the 

 transparency of the thin cuticle the action of the saws in forming 

 the pockets is not difficult to see. 



I have described what I could see in the cases of Tricliiosoma and 

 Cimhex and also in Phymatocera* Cladius viminalis lays its eggs in 

 a similar manner and the details of the procedure differ in a few 

 particulars only from those noted in the above-named species. 



On May 27th, 1917, I put several newly-emerged females of 

 C. viminalis on some twigs of Black Poplar, and on the 28th I found 

 that eggs had been laid, on the petioles of six leaves. It has long been 

 known as the habit of the species to lay the eggs in the petioles. On 



* Trang. Ent. Soc. Lond. 1914, p. 173; Ent. Eecord, xxvii, p. 145; Proc. Ent. Soc. Lond. 191(5, 

 pp. liii, Ixvii; and Mr. Morice'a Preoideutial Address, Ent. Soc. Lond. 1911. 



