74 



THE NATURE BOOK 



to the ground and leaves the chrysahs 

 hanging. Thus we have an instance of 

 a chrysahs being produced without a 

 cocoon to protect it, for here we have a 

 butterfly developing and not a moth. 

 Some species of moth caterpillars, how- 

 ever, also become chrysalides without 

 constructing cocoons, but these generally 

 hide amongst fallen leaves, or are buried 

 in the soil. The butterfly that appears 

 from this chrysalis I hope to introduce in 

 my next article. 



In the illustration on page 72 we have 

 an example of an insect that has com- 

 pleted its development. This is the Lime 

 Hawk-Moth {Smerinihiis tilice), which in 

 early June will sometimes be found 

 resting as shown in the photograph. 

 It is a charming insect. Its rich, grey 

 browns, contrasted with patches of bright 

 olive green, together with its irregularly- 

 cut wings, simulate its surroundings so 

 well that amongst the leaves and branches 

 its harmony with its environment is 

 perfect ; the e^-e may glance over it 

 several times before it is realised that 

 it is a large moth that is looked upon. 

 Even in the photograph — although the 

 insect is there shown right in the 

 foreground backed by the bare branch — 

 it does not force itself upon the eye as a 

 moth. Much of this subtle effect is 

 doubtless due to its irregular blotches 

 of colour. It is interesting to note also, 

 that the individual moths vary immensely, 

 so that their enemies have little oppor- 

 tunity to accustom their eyes to its 

 scheme of colour ; and probably to them 

 the moth is even much less conspicuous 

 than it is to us. 



When gazing on the lovely wings of 

 the Lime Hawk-Moth as it rests, it 

 seems scarcely credible that, only an hour 

 before, the moth was buried a foot deep 

 in the earth ; yet such was the case. 

 From September, throughout winter until 

 June, it has been entombed, not as a 

 moth, but as a chrysalis formed from 

 the caterpillar that buried itself in the 

 soil. Now it has crawled through the 

 coarse earth to the surface, climbed the 

 tree, and developed its wings. When it 

 reached the branch it had no wings, at 

 least nothing more than dumpy apologies 

 for such. At the end of an hour, how- 



ever, its organs of flight were fully devel- 

 oped. How they developed I will show 

 by considering another example of a 

 familiar moth ; for all moths on leaving 

 the chrysalis develop their wings in 

 practically the same manner. 



Look at the long-bodied, short-winged 

 insect shown in the first illustration on 

 page y^, and then see it again in the second 

 photograph. In the latter the moth is 

 seen commencing to extend its wings. 

 Ten minutes later they appear as shown 

 in the third photograph, having elongated 

 more than twice the length shown in the 

 first. In the fourth illustration they are 

 shown some five minutes later when fully 

 developed and drying. In my first article 

 I pointed out that moths rest with the 

 upper sides of their wings exposed. This 

 moth, it will be noticed, is resting while 

 showing the lower sides of its wings, for 

 at present the wings are wet and there- 

 fore are not under muscular control. Later 

 on they dry and become rigid, and then 

 the moth suddenly reverses them into the 

 positions they naturally assume when the 

 moth is resting as shown in the final 

 photograph. Both moths and butterflies 

 select the under sides of branches and 

 leaves on which to develop their wings, 

 so that they can fall from their folds 

 and hang in space while they dry and 

 complete their development. Thus we 

 have produced the common Pale Tussock 

 Moth [Dasychira pudihtinda). This moth, 

 previous to the development of its wings, 

 crawled from the ground amongst the 

 dead leaves, leaving behind its cocoon 

 constructed from the quaint tufts of 

 hairs that clothed its body when a cater- 

 pillar and protected from view by lightly 

 attached leaves. This cocoon the cater- 

 pillar had formed the previous autumn, 

 and, in due course, it fell to the ground 

 with the leaves at the time of their 

 "fall." 



From the foregoing examples it is clear 

 that insect life does not begin in the spring 

 and terminate as winter approaches. 

 With a little knowledge of the habits of 

 insects, the Nature student may study 

 insect life at any time during the year: 

 It is obvious, also, that a few life-histories 

 completely investigated will lay the foun- 

 dation of much future knowledge. 



John J. Ward. 



