53 



A discussion on Immigration took place, and it was generally 

 agreed that with butterflies this took place against the wind. 



SEPTEMBER 22nd, f921. 

 Exhibition of Lantern-slides. 



Mr. Hugh Main exhibited slides of the life-history of the oil- 

 beetle, Mt'loe prnscarabaens, which he found in abundance in Epping 

 Forest and at Polegate, Sussex. The males have curiously angled 

 antennje, the female has large elytra. The larva is a parasite on 

 the bee Anthophora. The female scratched a cavity in the ground 

 and the next morning commenced laying. A slide showed a 

 vertical section of the cavity with a mass of bright yellow ova. 

 Each female deposited several batches of ova, the later ones being 

 less in size. About Whitsun he had found large balls of these 

 larvffi on grass heads, which often broke up and fell, but the 

 individuals soon crawled up again, and reformed a ball. The bees 

 were not noticed at that time, but at Easter frequented the sallow 

 in some number. The beetle larvae are very active, jumping on 

 any insect which approaches, even on a brush presented to it. 

 Those who are unsuccessful die. The feet of the larva have three 

 hooks, hence they were formerly called, " triungulins," bee-lice. 

 The larva which succeeds in landing on the back of a female bee 

 is carried to the nest and jumps on the ovum resting on the food 

 (honey) stored for the bees offspring. The ovum is consumed in 

 the course of a week and then the larva moults to a legless grub, 

 which from its raft attacks and consumes the honey. When 

 this is accomplished the larva moults to a pseudo-chrysalis, 

 a hard case with no wing-cases. At the next moult a definite beetle 

 pupa is produced and finally the beetle emerges. This is supposed 

 to take place in the autumn, but the beetle remains in the cocoon 

 until the following spring entices it out. 



The Anthophora also has a bee-parasite, a species of Melecta, 

 which makes no cells itself but appropriates the cell of the 

 Anthophora when it is fully supplied with a store of food. 



Mr. C. L. Withycombe exhibited slides showing the structure, 

 habit, growth, and development of the Bladderwort {(^tricidon'a) 

 which was very common in all the dykes in fen-land. The bladders 

 are not bouys, as first thought, but traps to capture prey, which 

 consisted of minute crustaceans and larva\ The bladders were 



