NOTES AND OBSERVATIONS. 229 



Trochilium crabroniformis. — There is something ahnost un- 

 canny in the way the larva of this species behaves towards the end 

 of its larva hood, and just when it is preparing for its exit into the 

 world as a moth. Tliat it does leave a cap of thin bark over the exit- 

 hole is a matter beyond dispute; I have seen hundreds of them. No 

 doubt it requires a sharp eye, and even the finger-tips have some- 

 times detected these caps when the eye had failed to discern them. 

 And behind this cap the burrow is horizontal for half an inch, more 

 or less according to the thickness of the infested stump, then it 

 ascends for about four inches, and at the top of this tube a light 

 cocoon is spun, and the change to a pupa effected. Now, as this 

 final bore is always left clean and free of frass for the passage of the 

 pupa towards the open air, one is inclined to ask, "What has become 

 of the excavated materials " ? It is all dumped in the burrow below 

 the level of the horizontal cut, and is used to prevent the pupa from 

 falling down the old well, so to speak (on its way towards the exit), 

 where of course, if it did go down, it would be sure to perish. But 

 it is not actual excreta that is thus used for stopping — it might go 

 bad, get mouldy, and give trouble. An examination of this material 

 shows that it consists of sphnters of wood, which could never have 

 been passed through the creature's economy ; it is evidently bitten 

 off for the purpose for which it is used. I have opened many of these 

 tunnelings, and hatched out the perfect insects ; there were a few 

 failures at first until I studied the conditions more closely, and then 

 I began to see what was wrong. Often it will be observed on 

 opening a cocoon that the enclosed pupa is covered with beads of 

 condensed moisture ; it looks, in fact, as if it were sweating profusely, 

 which just means that the pupa is much colder than the surrounding 

 atmosphere, although it, too, must be cool, not to say cold, when you 

 consider it is in the heart of a sallow stump near the ground, shaded 

 by the bush itself and the surrounding herbage. So keep the puptB 

 in a cold room or outhouse with no sunshine near them, and lying 

 on the surface of some damp moss, but don't cover them with moss ; 

 provide means for reaching a position from which the wings can 

 hang whilst developing, but over and above all that don't by any 

 means cut out your pupae until a day or two before the time when 

 they hatch out under natural conditions in your district. Here, in 

 Renfrewshire, the average date of hatching in a wild state is the 

 last week of June and the first few days of July. I cut out these 

 pupiE when I want them about June '23rd to the 25th, keep them 

 cool, and now I rarely have a misfire. The pupa should be of a dark 

 orange colour inclining to blackness almost when ripe for removing, 

 and rather hard to the touch ; if a pale straw colour and rather soft, 

 it's a "moral" it will die, so it is best to leave all such in their natural 

 state, closing up carefully the damaged burrow, and leaving it for at 

 least a week or ten days, when it may be examined again. Mr. 

 Carter and Lt. -Colonel Nurse might try these methods with T. api- 

 formis ; I have never had this species in pupa, as it does not occur 

 in this district, but as the two species have evidently much in 

 common, the treatment might prove successful. — A. M. Stewart ; 

 3b, Ferguslie, Paisley, N.B. 



