136 INDIRECT INJURIES CAUSED BY INSECTS. 



useful and agreeable, that what concerns the cane that produces it seems 

 to concern everyone. This also affords a tempting food to insects. The 

 caterpillar of a white moth, called the borer, for destroying which a gold 

 medal has been long offered by the Society of Arts, is, in this respect, a great 

 nuisance, boring into the centre of the stem, and often destroying a great 

 proportion of the crop. This insect (for his essay on which he received 

 the offered medal) has been described by the Rev. L. Guilding, in the 

 Transactions of the Society of Arts (xlvi. 143.), under the name of Dia- 

 tr<za Sacchari, which, however, Mr, Westwood conceives is identical with 

 Phalana saccharalis Fab.^ An ant also (Formica analis) makes a lodg- 

 ment in the interior of the sugar-cane in Guinea, and destroys it. — Ano- 

 ther species of the latter genus does not devour it, and is therefore impro- 

 perly called Formica saccharivora by Linne ; but, by making its nest for 

 shelter under the roots so injures the plants that they become unhealthy 

 and unproductive. These insects about seventy years ago appeared in 

 such infinite hosts in the island of Granada, as to put a stop to the culti- 

 vation of this plant; and a reward 'of 20,000/. was offered to any one 

 who should discover an effectual mode of destroying them. Their num- 

 bers were incredible. They descended from the hills like torrents, and 

 the plantations, as well as every path and road for miles, were filled with 

 them. Many domestic quadrupeds perished in consequence of this plague. 

 Rats, mice, and reptiles of every kind became an easy prey to them : 

 and even the birds, which they attacked whenever they alighted on the 

 ground in search of food, were so harassed as to be at length unable to 

 resist them. Streams of water opposed only a temporary obstacle to their 

 progress, the foremost rushing blindly on to certain death, and fresh armies 

 instantly following, till a bank was formed of the carcases of those that 

 were drowned sufficient to dam up the waters, and allow the main body 

 to pass over in safety below. Even the all-devouring element of fire was 

 tried in vain. When lighted to arrest their route, they rushed into the 

 blaze in such myriads of millions as to extinguish it. Those that thus 

 patriotically devoted themselves to certain death for the common good, 

 were but as the pioneers or advanced guard of a countless army, which 

 by their self-sacrifice was enabled to pass unimpeded and unhurt. The 

 entire crops of standing canes were burnt down, and the earth dug up in 

 every part of the plantations. But vain was every attempt of man to 

 effect their destruction, till in 1780 it pleased Providence at length to 

 annihilate them by the torrents of raiji which accompanied a hurricane 

 most fatal to the other West India Islands. This dreadful pest was 

 thought to have been imported.^ More recently great mischief has been 

 done to the sugar plantations in the island of St. Vincent, by a species of 

 mole-cricket (GryUotalpa didactyla Latr.), which destroys the young 

 shoots and bores into the plant''; and to those of the island of Granada 

 by the Delphax saccharivora, an homopterous insect, allied to that pro- 

 ducing the cuckoo-spit, which attacks the leaves in such numbers and 

 with such voracity, that some plantations which formerly made three 

 hundred hogsheads of sugar per annum, had not made more than eighty 



1 Westwood, Modern Classif. of Ins. ii. 411. 



« Caslle in Fki/os. Trans, xxx. 346. 



3 Trans. Ent. Soc. Land. ii. proc. x. xxiv. xxxi. 



