30 



ANIMAL BIOLOGY 



23. Economic importance of grasshoppers. — Our laboratory 

 study of a grasshopper's mouth parts and our observations of its 

 methods of feeding^have shown that these insects resemble cater- 

 pillars, first, in having biting mouth parts (Fig. 18), and second, in 

 being voracious eaters. Hence, as we should expect, a large number 

 of grasshoppers in a given area would mean a considerable destruc- 

 tion of plant life. Many " plagues of locusts " (for grasshoppers 

 are more correctly known as locusts) have been recorded in history. 

 One of the first is that recorded in the Bible, which occurred before 

 the departure or " Exodus " of the Children of Israel from Egypt. 

 " And they (the locusts) did eat of every herb of the land, and all the 

 fruit of the trees . . . and there remained not any green thing in 

 the trees, or in the herbs of the field throughout all the land of 

 Egypt." (Ex. X. 15.) 



In our own country during the years 1866 to 1876 there were 

 several plagues of locusts in the grain-producing states of the West, 



notably in Kansas and Nebraska. 

 The Rocky Mountain grasshoppers 

 during these years migrated in such 

 numbers that the sky was dark- 

 ened during their flight, and the 

 result of their devastation was as 

 serious as that described in Exo- 

 dus. According to one authority 

 this species of iiisect destroyed 

 $200,000,000 of crops in the west- 

 ern states in the space of four 

 years. No great migrations have 

 occurred since 1876. 



Locusts have been used as food, 

 and even at the present day they 

 are commonly eaten by the Ara- 

 bians. In the Bible, it is related 

 of John the Baptist, that while 

 preaching in the wilderness "he did 

 eat of locusts and wild honey." 



Fig. 21. — Four walking sticks on 

 a branch. (Coleman.) 



