INDIRECT BENEFITS DERIVED FROM INSECTS. 165 



native of Africa and America, lives upon the locusts and Ixodes ricinus, 

 which it picks in great numbers from the backs of cattle ; but none are 

 greater devourers of insects in this order than rooks. It is for the grubs 

 of Melolontha, Tipula, &c., that they follow the plough ; and they always 

 frequent the meadows in which these larvae abound, destroying them in 

 vast numbers. Kalm tells us, that when the little crow was extirpated 

 from Virginia at an enormous expense, the inhabitants would willingly 

 have them brought back again at double the price. 1 The icteric oriole is 

 kept by the Americans in their houses for the sake of clearing them of 

 insects ; and the purple grackle is so useful in this respect, that when, on 

 account of their consuming grain, the American farmers in New England 

 offered a reward of three-pence a head for them, and they were in con- 

 sequence nearly extirpated, insects increased to such a degree as to cause 

 a total loss of the herbage, and the inhabitants were obliged to obtain hay 

 for their cattle not only from Pennsylvania, but even from Great Britain. 2 

 Of this order also is the bee-cuckoo (Cuculus indicator), so celebrated for 

 its instinct, by which it serves as a guide to the wild bees' nests in Africa. 

 Sparrman describes this bird, which is somewhat larger than a common 

 sparrow, as giving this information in a singular manner. In the evening 

 and morning, which are its meal-times, it excites the attention of the 

 Hottentots, colonists, and honey-ratel, by the cry of cherr, cherr, cherr y 

 and conducts them to the tree or spot in which the bees' nest is con- 

 cealed, continually repeating this cry. When arrived at the spot, it hovers 

 over it ; and then alighting on some neighbouring tree or bush, sits in 

 silence, expecting to come in for its share of the spoil, which is that part 

 of the comb containing the brood. 8 The wryneck and the woodpeckers, 

 the nuthatch and tree-creeper, live entirely upon insects and their eggs 4 , 

 which they pick out of decayed trees, and out of the bark of living ones. 

 The former also frequents grass-plots and ant-hills, into which it darts its 

 long flexible tongue, and so draws out its prey. The woodpecker likewise 

 draws insects out of their holes by means of the same organ, which for 



thinks that it impales only G. vernalis, which he has often found transfixed, but 

 never G. stercorarius. (Schneid. Mag. 259.) I must remark, however, that I last 

 summer observed two humble-bees quite alive impaled on the thorns of a hedge near 

 my house, which had most probably been so placed by this species, L. excubitor being 

 rarely found except in mountainous wilds. (Bewick's Birds, i. 61.) And Prof. 

 Sander states that on opening this bird (L. collurio) he has sometimes found in its 

 stomach nothing but grasshoppers, and at others small beetles and other insects. 

 (Naturforscher, Stk. xviii. 234.) Mr. Dunlop, in a letter in Loudon's Gardener's 

 Magazine for May, 1842 (No. cxlvi. p. 259.), states, that upon examining a branch 

 of hawthorn on w'hich he had for some days observed a pair of fly-catchers feeding 

 their young, he found upwards of a dozen humble-bees (o?nbus terrestris) fixed 

 iipon the spines as secure!}' as if done by the hand of man, some being alive, and 

 others dead arid partly devoured. Mr/Dunlop, after removing the bees to watch 

 the process of the birds in placing them, had soon the satisfaction of seeing the fly- 

 catchers catch them on the wing, carry them direct to the branch (which was a dead 

 one, apparently on account of the greater hardness of the spines), and thrust them 

 on the spines as above described. Mr. W. W. Saunders found a number of the 

 yellow underwing moth ( Triphcena pronuba) thus fixed. 



1 Stillingfl. Tracts, 175. Linn. Trans, v. 105. note b . 



2 Bingley, ii. 287290. 5 Sparrman, ii. 186. 

 * Bewick's Birds, i. Pref. xxii. 130. 



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