The Life History of Clythra quadri-punctata. 15 



and then moved away again. To pupate, the larva, after 

 closing the open end, or fastening it to something in the 

 nest, turns round and faces the bottom of the case. The 

 beetle emerges by cutting round the inside of the case in 

 a circle with its mandibles, thus forming a cap, which it 

 forces off. 



We now come to my experiments with the perfect insect. 

 On May 13th I introduced into my nest a beetle, which 

 had hatched out from a case taken from a Formica rufa 

 nest in the Blean Woods. It was attacked by the ants, 

 dragged about, and later on thrown out of the nest half dead. 



On May 16th a Clythra had emerged from the pupa- 

 case in my nest ; three ants were dragging about the empty 

 case, and another the beetle, which remained quite motion- 

 less. From this date onwards many of the beetles kept 

 emerging, both in my boxes and in my nest itself. 



On May 18th a dead Clythra was removed from the 

 nest by the ants ; it had a hole bitten in its abdomen. 



I find that when a Clythra emerges in the nest, it 

 proceeds very cautiously to get away : remains quite 

 motionless when attacked, " feigning death," and holdino- 

 on to twigs etc.; when left alone it continues to walk again, 

 and is generally successful in making good its escape. 



Now it seemed to me that, as the beetle is so liable to 

 be attacked by the ants, it would be very dangerous for the 

 female, at such a critical time in the life history as the 

 egg-laying, to return to the nest to deposit her eggs. 

 The next question to settle therefore was how the larvse 

 got into the nest. In nature one finds the beetles flyino- 

 round and settling on birch and other shrubs in districts 

 where Formica rufa abounds. I placed some branches of 

 birch in a jar of water in a large breeding-cage, and intro- 

 duced all my beetles into it. They flew about in the sun, 

 and very soon many couples were in copulation. 



In copulation the ^ sits far back on the %, all three pairs 

 of tarsi resting on her elytra, the anterior pair just below 

 the scutellum, intermediate pair on about the centre of 

 each elytron, and the posterior pair two-thirds from the 

 base of the elytra. The claws do not clasp hold, the tarsi 

 holding on as if they were " suckers." The penis is fairly 

 long and broad at the end, being somewhat spade-shaped. 

 Copulation appears to take place many times, the same 

 female being served by several males. I tried intro- 

 ducing couples in copulation on birch twigs into my nest ; 



