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. tridentata, 

 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 Osmia: 

 (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 



