128 THE ENTOMOLOGIST. 



NOTES AND OBSERVATIONS. 



The Pupal Habits of Cossus ligniperda. — Cossus ligniperda is so 

 common a species that one would suppose that even the most 

 superficial among entomologists would be well acquainted with its 

 life-history. That this is not the case is only too apparent from the 

 notes that have appeared from time to time in the entomological 

 journals, and I fear that on one simple point alone — namely, the 

 natural situation selected for pupation — our knowledge is by no means 

 clear. The older authors were unanimous in telling us that the pupal 

 cocoon was formed in the burrow in which the larva had fed, but I 

 find no evidence to support this theory ; the most modern authors are 

 equally assertive that the pupa is subterranean. In this gloriously 

 uncertain state of our information, I was well pleased at finding, in 

 June and July last, a considerable number of imagines, so freshly 

 emerged that their wings were but parti:illy expanded, and in almost 

 every case the pupae-skins that they had just vacated were also found. 

 The trees in which the larvae had fed, and which I bave known for 

 some years to be infested, grow just within a low park paling that 

 surrounds a small garden. The bottom of the paling having become 

 rotten, an oak skirting some six inches in depth has been fixed along 

 the fence from post to post. This skirting rests on an asphalt path 

 which borders the paling on the outside, and its bottom is also on a 

 level with a flower-bed that traverses the inner side of the paling. A 

 narrow space between the skirting and the paling forms a sort of 

 pocket, and this has in course of time become filled with dust and 

 twigs and so forth, forming a compact mass of dry rubbish, and from 

 the surface of this the pupas-skins were protruding. Some years ago 

 I found a number of pups in a very rotten willow-tree, not, however, 

 in the mines in which the larvae had fed. By way of experiment, I 

 have on several occasions placed full-fed larvae, found in the autumn, 

 in holes bored for their reception in a poplar-tree. Those thus placed 

 in the dry stump of a limb, the upper portion of which was cut off 

 some years ago, have invariably produced imagines in the following 

 summer, but one similarly treated in the growing wood died. These 

 facts, coupled with such other precise evidence as I have been able to 

 obtain, suggest to my mind that the pupa is not necessarily sub- 

 terranean, at any rate in the sense that many of the Sphingidae and 

 Noctuas are, but that the larva is guided in the selection of a suitable 

 situation for pupation rather by the presence of light friable material, 

 be it rotten wood, dry turf, or other fibrous earthy matter, that will 

 enable it to form its large tough cocoon. — Robert Adkin ; Lewisham, 

 February, 1900. 



Cossus ligniperda Larva. — In the middle of February last a man 

 brought to me two larvae of C. ligniperda, each about 2| in. in length, 

 which he had dug up in his garden that day. He told me that they 

 were both contained in the same spadeful of earth ; with the larva was 

 brought one cocoon (broken), formed, as usual, of silk and earth. It 

 contained fragments of a recently cast larval skin. One of the larvJB 

 was of a uniform canary-yellow colour, the usual orange band on the 

 dorsum being absent. This was apparently the larva which had 



