INSECTS. 119 



The Migratory Grasshopper {Acrydium migratorium). 



If to 2^ inches long; spread of the wing, on the 

 average, 2^ inches. Greenish grey. Under side flesh 

 colour. Wing covers brownish, darkly flecked. 

 Colour very variable (Fig. 62). Excessive multiplica- 

 tion and migrations of this insect often take place in 

 South Russia and Turkey ; but they may also appear 

 in Central Europe. In North Germany, for example, 

 the following years of this century were " grasshopper 

 years:" 1803, 1825-27, 1853, 1875-76. In many 

 cases the appearance of swarms of grasshoppers in 

 Central Europe is due to migration from Russia and 

 Hungary ; but it also often happens that the insects 

 which appear in such large numbers have been bred 

 in the places where they are found. Since the female 

 lays, on the average, 150 eggs, excessive increase may 

 take place in any country to which they are indi- 

 genous — and therefore in Central Europe. It appears, 

 however, that a large number of grasshoppers are 

 usually killed by their natural enemies, such as cold 

 and damp weather. Excessive increase may, however, 

 take place in exceptionally favourable years; and 

 since the larvae, which are incapable of flight, devour 

 everything available, the mature insects developed 

 from them are forced to migrate. Where they descend 

 they destroy everything they flnd in the fields. 

 Remedies : Destruction of the longish eggs, which are 

 laid in heaps in the earth of fallow ground and 

 meadows. In all those places where dead insects are 

 found in Jarge numbers on the ground many eggs will 

 also be discovered, for the insects keep on laying till 

 they sink down dead in the place where the last heap 

 o£ eggs was deposited. Such places should be dug 

 or ploughed, and the eggs, which are present ia 

 thousands, either collected or else searched out by 

 pigs, ducks, geese, and fowls, which have been driven 

 to the spot. Destruction of the young animals while 



