244 INDIRECT BENEFITS DERIVED FROM INSECTS. 



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 

 brought them back again at double the price. ^ 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 threepence 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 Penn- 

 sylvania, but even from Great Britain.^ Of this order also is 

 the bee-cuckoo (^Cuculus indicator), so celebrated for its in- 

 stinct, 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, 

 and conducts them to the tree or spot in which the bees' 

 nest is concealed, 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.^ The wryneck and the wood- 

 peckers, the nuthatch and tree-creeper, live entirely upon 

 insects and their eggs which they pick out of decayed trees, 

 and out of the bark of living ones. The former also fre- 

 quents grass-plats 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 this purpose is bony at the end and barbed. 



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



2 Bingley, ii. 287 — 290. 3 Sparrman, ii. 186. 



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



