308 THE INSECT WORLD. 



of the Commandant de la Place of Philippeville, M. Levaillant, 

 column of locusts alighted in the country round about that town o 

 the 1 8th of March, 1845, which extended from 30 to 40 centimetre; 

 and the locusts were found heaped upon the ground to the height ( 

 three de'cimetres. 



In the environs of .Algiers alone were destroyed, in 1841 

 369 quintals of locusts. It is computed that 400 locusts go to 

 kilogramme. This gives, then, a total of 14,760,000 inseci 

 destroyed. As in this number half were probably females, and : 

 each female lays on an average seventy eggs, the result we arrive at i 

 that this stopped the production of 516,600,000 larv^ on th 

 territory of Algiers alone. The invasion of locusts which took plac 

 in 1866 was as disastrous as that of 1845. It was in the month ( 

 April, 1866, that the vanguard of these destructive insects appeare( 

 Debouching through the mountain gorges and through the valley 

 into the fertile plains near the coast, they alighted first on the plain i 

 Mitidja and on the Sahel of Algiers. Their mass, at certain point 

 intercepted the light of the sun, and resembled those whirlwinds ( 

 snow which, during the storms of winter, hide the nearest objec 

 from our view. Very soon the cabbages, the oats, the barley, tl 

 late wheat, and the market-gardeners' plants, were partly destroyer 

 In some places the locusts penetrated into the interiors of the house 

 By order of the government of Algiers the troops joined the colonis 

 in combating the plague ; and the Arabs, when they found that the 

 interests were suffering, rose to lend their aid against the commc 

 «enemy. Immense quantities of locusts were destroyed in a few day 

 but what could human efforts do against these winged multitude 

 who escape into space, and only abandon one field to alight in tl 

 next? 



It was impossible to prevent the fecundation of these inseci 

 The eggs quickly producing innumerable larvae, the first swarr 

 were very soon not only replaced, but multiplied a hundredfold by 

 new generation. The young locusts are particularly formidable ( 

 account of their voracity. These hungry masses threw themselv 

 upon everything which was left by those which went before thei 

 They dioked up the springs, the canals, and the brooks ; and it w 

 not without a great deal of trouble that the waters were cleared 

 these causes of infection. Almost at the same time the provinces 

 Oran and of Constantine were invaded. At Tlemcen, where with 

 the memory of man locusts had never appeared, the ground w 

 covered with them. At Sidi-bel-Abbes, at Sidi-Brahim, at Mc 

 taganem, they attacked the tobacco, the vines, the fig-tree, and ev( 



I 



