ON SOME ENEMIES OF THE DIUENAL LEPIDOPTEKA. 37 



dahlias growing round it. I have found it otherwise, however, with 

 the Ehopalocera during their hours of sleep. For some years past, I 

 have noticed that the butterflies in my butterfly-house have had a way 

 of disappearing without any apparent reason, and, though I have 

 occasionally found their wings, sometimes scattered, sometimes still 

 attached to the headless thorax, lying on the ground, in the majority 

 of cases their mysterious enemies have left no trace of their victims 

 behind. My experiments have been principally concerned with the 

 Papilionidae, and, before their final disappearance, I have frequently 

 noticed that my butterflies have lost the tails of their wings, and one 

 or both of their antennae. I used to think that this Avas due to the 

 wear and tear of existence in a confined space, but I feel convinced 

 now that this was not always the case. I have read and been told 

 that ants sometimes attack butterflies when the latter are asleep, but 

 with the exception of one of the smaller species of garden ant, my 

 butterfly-house is free from this branch of Hymenoptera, and, though 

 I could imagine that the large black wood-ants would be able to seize 

 and kill insects of the power and size of Papilio turnus, P. machaon, 

 P. ajax, P. troilus, P. cresphontes, P. philenor, etc., I felt that this 

 would be most unlikely with such ants as those in question, to say 

 nothing of the fact that they were not particularly abundant. 



It became evident to me that I must look elsewhere, probably to 

 the predaceous beetles, many of which I knew to be nocturnal in their 

 habits, for this deadly and mysterious enemy. Events have confirmed 

 my surmise. 



In the late spring of last year, I was trying to procure ova of Araschnia 

 levana for Mr. Merrifield, and had a number of these butterflies alive 

 ^nd at large in my house. I had just previously lost at least a dozen- 

 and-a-half Euchlo'e cardaviines in one night, and was on the look-out 

 for fresh misfortune. The imagines of Araschnia levana have a habit 

 of roosting low amongst the herbage, and are consequently more 

 exposed to attack than the Papilionids, which. I find, generally sleep 

 at least four or five feet from the ground, unless benumbed by wet or 

 cold. 



During the course of my experiment some garden-pest traps, 

 which I had ordered from Mr. Gardner of High Holborn, arrived, and 

 within three days I was enabled to verify my suspicions by finding in 

 one of them two of the smaller black garden beetles, along with the 

 forewings and thorax of a female A. levana, the head, hindwings and 

 abdomen, having disappeared. As egress from the traps in question 

 is impossible for any insect which has once entered them, and as 

 they are placed underground, and are, therefore, unlikely to be chosen 

 as a resting-place by a butterfly, I felt confident that the A. levana had 

 been brought there by one of the carnivorous beetles in question. 

 Perhaps this habit of beetles of carrying their prey underground (I have 

 on many occasions found the wings of butterflies on turning up the 

 surface of the earth in my butterfly-house) is one of the reasons why 

 one so seldom sees a dead butterfly. 



To make certain that the beetles were my real enemies, I went 

 down to my house at nights with a dark lantern, and have there on 

 several occasions seen the beetles crawl up to the side of the structure 

 .and attack the sleeping butterflies. However, the darkness and the 

 beetles' aversion to light, made the attack difficult to observe in detail, so 



