202 AFFECTION OF INSECTS FOR THEIR YOUNG. 



luirict) the skin of the grains of wheat, in which they respectively deposit 

 their eggs, prudently introducing one only into each nut or grain, which is 

 sufficient, but not more than sufficient, for the nourishment of the grub 

 that will inhabit it. 



II. Hitherto I have adverted to those insects only which perish before 

 their young come into existence, and can therefore evince their affection 

 for them in no other way than by placing the eggs whence they are to 

 spring in secure situations stored with food ; and these include by far the 

 largest portion of the race. A very considerable number, however, extend 

 their cares much further : they not only watch over their eggs after deposit- 

 ing them, but attend upon their young when excluded, with an affectionate 

 assiduity equal to any thing exhibited amongst the larger animals, and in 

 the highest degree interesting. Of this description are some solitary 

 insects, as several species of the Linnean genus Sphex, earwigs, field-bugs, 

 and spiders : and those insects which live in societies, namely, ants, bees, 

 wasps and termites : the most striking traits of whose history in these 

 respects I shall endeavour to lay before you. 



You have seen that the greater number of the Sphecina, after depositing 

 their eggs in cells stored with a supply of food, take no further care of 

 them. Some, however, adopt a different procedure. One of these, called 

 by Bonnet the Mason-wasp, but different from Reaumur's, not only incloses 

 a living caterpillar along with its eggs in the cell, which it carefully closes, 

 but at the expiration of a few days, when the young grub has appeared 

 and has consumed its provision, re-opens the nest, incloses a second cater- 

 pillar, and again shuts the mouth : and this operation it repeats until the 

 young one has attained its full growth.^ A similar mode, according to 

 Rolander, is followed by Ammophila vulgaris, as well as by the yellowish 

 wasp of Pennsylvania, described by Bartram in the Philosophical Transac- 

 tions'^, and by another related to Mellinus arvensis,ohserved by DuhameP; 

 both of which, however, instead of caterpillars, supply their larvae with a 

 periodical provision of living flies. 



What a crowd of interesting reflections are these most singular facts cal- 

 culated to excite ! With what foresight must the parent insect be en- 

 dowed, thus to be aware at what period her eggs will be hatched into 

 grubs, and how long the provision she has laid up will suffice for their 

 support ! What an extent of judgment, thus, in the midst of various other 

 occupations, to know the precise day when a repetition of her cares will 

 be required ! What an accuracy of memory to recollect with such pre- 

 cision the entrance to her cell, which the most acute eye could not dis- 

 cover; and without compass or direction unerringly to fly to it, often from 

 a great distance, and after the most intricate and varied wanderings ! If 

 we refer the whole to instinct, and to instinct doubtless it must in the main 

 if not wholly be referred, our admiration is not lessened. Instinct, when 

 simple and directed to one object, is less astonishing ; but such a compli- 

 cation of instincts, applied to actions so varied and dissimilar, is beyond 

 our conception. We can but wonder and adore ! 



The female of Perga Letvisii (Westwood), one of the Tenthredinidce, or 

 Saw-flies, was observed by Mr. Lewis at Hobarton, Van Diemen's Land, 

 to sit upon the leaf into which she has inserted her eggs, about eighty in 



» Bonnet, ix. 398. ^ Hii, 37. Pehpwus spirifex? ' Keaum. vi. 269. 



