The Glow- Worm and Other Beetles 



in all its details after twenty-five years of 

 investigation. On six occasions, no oftener, 

 during this long period I have set eyes on 

 the pseudochrysalis which I am about to de- 

 scribe. Thrice I obtained it from old 

 Chalicodoma-nests built upon a stone, nests 

 which I at first attributed to the Chalicodoma 

 of the Walls and which I now refer with 

 greater probability to the Chalicodoma of 

 the Sheds. I once extracted it from the gal- 

 leries bored by some wood-eating larva in 

 the trunk of a dead wild pear-tree, galleries 

 afterwards utilized for the cells of an Osmia, 

 I do not know which. Lastly, I found a pair 

 of them in between the row of cocoons of 

 the Three-pronged Osmia (O. trident ata, 

 DUF.), who provides a home for her larvae 

 in a channel dug in the dry bramble stems. 

 The insect in question therefore is a parasite 

 of the Osmiae. When I extract it from the 

 old Chalicodoma-nests, I have to attribute 

 it not to this Bee but to one of the Osmiae 

 (O. tricornis and O. latreillii) who, when 

 making their nests, utilize the old galleries 

 of the Mason-bee. 



The most nearly complete instances that I 

 have seen furnishes me with the following 

 data: the pseudochrysalis is very closely en- 

 veloped in the skin of the secondary larva, a 

 136 



