INDIRECT BENEFITS DERIVED FROM INSECTS. 289 



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

 grubs o{ Melolontha, Tijmla, &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 Ameri- 

 can farmers in New England offered a reward of three- 

 pence a head for them, and they were in consequence 

 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''. Of this 

 order also is the bee-cuckoo {Cuculus Indicator) so cele- 

 brated 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 ex- 

 cites the attention of the Hottentots, colonists, and ho- 

 ney-ratel, by the cry of cherr, cherr, cherr, 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 



* Stillingfl. Tracts, 17o. Linn. Trans. V. 105. note \ 

 " Bingley, ii. 287-290. 

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