HA RD WICKE'S SCIENCE- GOSSIP. 



41 



mixing with it at the same time saliva of a glutinous 

 nature, which when dry is exceedingly hard and 

 stout; as the Rev. J. G. Wood says, "a strong 

 knife is required to make any impression on it." This 

 cocoon is not invariably situated on the bark ; I have 

 upon several occasions taken it under the bark of 

 willows. When the cocoon is completed, it in no 

 way differs from the remainder of the trunk, except 

 that it bulges out a very little from the general surface, 

 and usually being located in a slight hollow, even 

 this becomes invisible. In this secure and novel 

 retreat, on which storm, rain, and all natural in- 

 fluences, barring man, may fall ineffectually, the 

 larva, having smoothed down all the walls and both 

 ends, for the cocoon is cylindrical, undergoes its 

 metamorphosis to the pupa during the middle or end 

 of August, as almost all larvae which hibernate as pupae 

 do not take more than a week to change ; the latest 

 date on which I have ever taken this larva is August 

 _the 15th. I have very often found the empty cocoons 

 of this pupa on aspens, Lombardy poplars, and 

 willows, together with those of D. bifida, A. psi and 

 megacephala, but never have I found one with the 

 living pupa inside, that having fallen to the lot of 

 those energetic entomologists only, who spend most 

 of their time, and half their lives in quest of such 

 hidden secrets of Nature. It is also a remarkable 

 fact when one does find the empty cocoon, there is 

 rarely an empty pupa, or larva's skin inside ; this is 

 the more strange, since the moth, in escaping, makes 

 but a very small hole through which to reach the 

 light of day, and even then, often nearly fills th ; s up 

 with fur or scales. I can find in Nature no con- 

 firmation of the idea usually, I think, held by ento- 

 mologists, that this cocoon is generally found from 

 two to four feet from the ground. I have seen them 

 five and a half feet, and have a specimen before me 

 now, filled with the cocoons of some large ichneumon, 

 which I took from P. nigra at least five feet eight 

 from the ground, and have also taken others only just 

 out of reach of toads, moles, etc., at the base of the 

 trunk. 



The imagines begin to emerge about the 12th of 

 May, which is the earliest date on which I have found 

 them. They were then bred from pupae taken the 

 preceding autumn. The moth emerges, as a general 

 rule, between 8 a.m. and 1 .30 p.m., but I have seen a 

 specimen out at 6.0 a.m., with undeveloped wings, 

 which, however, were normal by 8 a.m. The female 

 lays nearly a hundred eggs, mostly, as previously 

 stated, in ones and two, like those of Smerintkus 

 poptdi. The eggs take from twelve to fifteen days to 

 hatch out from the time of being laid. The wonder- 

 ful way in which the imago similarizes itself to its 

 surroundings, and becomes virtually invisible, is 

 truly marvellous. I once put an ordinary-sized male 

 into a box covered on the inside with newspaper, 

 and when I went to look for the insect, I could find 

 it nowhere for a considerable time, till at last my eye 



seemed to catch sight of it, or notice it, all of a 

 sudden — there, in the centre of the box, right under 

 my very nose sat that moth, as it were winking 

 at me out of the corner of his eye (or rather those 

 lenses which pointed directly in my direction) ! I 

 wasn't long getting the killing-bottle ! Precisely the 

 same thing occurs, when one is hunting for them on 

 the trunks of trees, which is a thing I very rarely do, 

 the larvce being far more accessible — one seems to 

 catch sight of them suddenly in just the same manner. 



D. vinula is not attracted by light nearly so much 

 as is generally supposed ; in fact, only on four occa- 

 sions have I taken it in such a position. The first of 

 these was at Cowes, in the Isle of Wight, when one 

 flew into the drawing-room about 8.30 p.m. in June, 

 18S6; again, on Banstead Common, near Epsom, 

 a female was taken in a room, who laid seventy or 

 eighty eggs when placed in a large chip-box, in May, 

 1889. A third specimen was taken from a gas-lamp 

 in Epsom, in 1890 ; and the last, a dead one, I found 

 in a street-lamp at Peterboro', in 1 891. I have not 

 noted what position they take up when settled on the 

 lamp ; probably they madly gyrate round it for some 

 considerable time and then settle down underneath 

 or on the lower frame-work, like P. palpina, C. 

 cytherea, and others. 



Where I was enabled to carry on my closest 

 observation of this most interesting insect was at 

 Epsom in Surrey. Both the ova and caterpillars 

 were numerous on aspen and Lombardy poplar ; I 

 have also met with it — sometimes, it is true, only 

 with its empty cocoon— at Taunton, Brighton, and 

 Cowes ; but for the last year and a half, I have taken 

 it in all its phases, in many localities on the east coast, 

 from Goole in Yorkshire, to Ipswich in Suffolk, 

 including Peterboro' (fairly common), Worlingham 

 (rare), Geldston (common on willows), Woodbridge 

 (common), Felixstowe (fairly common), and several 

 other towns and villages. 



The imago is so plentiful (usually, however, bred) 

 that it calls for no description here, and I refer those 

 requiring one, to turn to that given at page 214 of 

 Newman's "British Moths," where a splendid figure 

 is drawn, both in words and woodcuts. Suffice it to 

 say, therefore, that the male is considerably smaller, 

 from the time it spins up as a larva, throughout its 

 pupa state, and as an imago, than the female ; and 

 that this insect, by no stress of imagination, having 

 been once seen, can be mistaken for any other. 



Careful as I have been to enumerate all the 

 peculiarities in the life-history of this insect that I 

 have had the pleasure of noticing, there is yet much 

 to be filled in, principally theoretically; viz., the 

 functions of the tentactda ; why the last pair of 

 prolegs are modified into tails— for I believe there is 

 a reason for everything ; what the object of emitting 

 saliva from the mouth when irritated, and for what 

 reason it is given off ; why this moth, contrary to the 

 habit of the majority of other moths, lays its ova on 



