62 [March, 



Nurtliiini[)t(»iiHhire has never been ovcrwcn-ked, even by Lepido- 

 pterist.s, and the disappearance o£ Aporia cratcegi from the County, 

 simultaneously with its disappearance from Kent, Sussex, Hampshire, 

 Monmouthshire, and other Enp;lish and Welsh Counties, seems to 

 show that its extinction throughout the United Kingdom was due to 

 natural causes. Lyccena avion was extremely local in the County, 

 and it may possibly have been so reduced in numbers by the burning 

 of portions of its localities, and the consequent destruction of its 

 food plant, as to render its survival, after an exceptionally cold and 

 wet summer, almost impossible. At any rate, I am inclined to think 

 that its sudden disappearance was rather due to the cause mentioned 

 than over-collecting. Leiicophasia sinapis seems also to have dis- 

 appeared, or to be so rare as to render its present existence in the 

 County very doubtful ; and, as no recent records of the occurrence 

 of Melitcca artemis are known, it seems possible that this species also 

 may have become extinct* in the County, as it apparently has in 

 Suffolk, Cambridgeshire, Buckinghamshire, Kent, and in many of its 

 former localities in Sussex. 



The Avenue, Surbiton Hill : 

 December, 1900. 



ACANTRO PSYCHE OP AC ELL A: INSTINCT ALTERED WHEN 



PARASITISED. 



BY T. A. CITAPMAN, M.D., F.Z.S , &c. 



1 am able to add another instance to the several recorded in 

 which the instinct of a Lepidopterous larva is much altered when it 

 suffers from the attacks of internal parasites, usually Ichneumons. 

 These cases are for the most part of two kinds, the one consists of a 

 caterpillar being induced to suppose itself mature when it is not, and 

 to make a cocoon in the interests of the parasite, which is mature. 

 The other is a variation in the normal method of constructing the 

 cocoon again in the interests of the parasite. This instance, in the 

 case of A. opacclla, belongs to the latter class. 



When ready to pupate the ^J opacella lengthens its tube and 

 closes it with a dome shaped end, which readily opens out and forms 

 a portion of the tube. This portion grasps the pupa in its protrusion 

 and holds it firmly whilst the moth emerges, but it spins no silk 

 within the sac. The $ larva fills the end of the sac with an abundant 

 network of silk that completely fills the sac round the anterior end of 



* It still (locurs to rny knowledge in several localities in Hampshire, Gloucestershiro, and 

 Ciunbeilaud. — H. G. 



