MEANS OF DEFENCE OF INSECTS, 265 
Under this head I shall call your attention to another 
circumstance that saves from their enemies innumerable 
insects :—I mean their coming forth for flight or for food 
only in the night, and taking their repose in various 
places of concealment during the day. The infinite 
hosts of moths (Phalena, L.),—amounting in this country 
to more than a thousand species,—with few exceptions, 
are all night-fliers. Anda considerable proportion of 
the other orders,—exclusive of the Hymenoptera and 
Diptera, which are mostly day-fliers,—are of the same 
description. Many larve of moths also come out only 
in the night after their food, lying hid all day in subter- 
raneous or other retreats. Of this kind is that of Noctua 
pulla and Nycterobius, whose proceedings have been be- 
fore described?. The caterpillar of another moth (Noc- 
tua subterranea, F.) never ascends the stems of plants, 
but remains, a true Troglodyte, always in its cell under 
ground, biting the stems at their base, which falling, 
bring thus their foliage within its reach?, 
_ The habitations of insects are also usually places of 
retreat, which secure them from many of their enemies: 
—but I have so fully enlarged upon this subject on a 
former occasion ‘, that it would be superfluous to do more 
than mention it here. 
I am now to lay before you some examples of the con- 
trivances, requiring skill and ingenuity, by which our 
busy animals oc¢asionally defend themselves from the 
designs and attack of their foes. Of these I have already 
detailed to you many instances, which I shall not here 
* Vor. I. 4th Ed. 456. b Fab, Ent. Syst. Em. iii. 70. 200. 
© Vor. 1. 4th Ed, 434 — 
