32 INSECTS ON PLANTS. 



forest tress during one brief visit, and annihilate every appearance of 

 vegetation; as when they thus scourged Masinissa, causing the death 

 by famine of more than 800,000 persons ! Compared with such 

 effects, earthquakes and volcanoes dwindle into insignificance. 



Their numbers are so vast as often to overshadow immense tracts 

 of country. The swarm which passed over Smyrna, like a living 

 cloud, for three days and nights, was calculated to be 900 feet deep, 

 more than 40 miles wide and 50 miles in length ! The number ex- 

 ceeded 168,608,563,200,000, and the magnitude of the mass, if gathered 

 into a heap, would exceed by more than 1.030 times that of the largest 

 pyramid of Egypt, or would encircle the whole earth with a belt a 

 mile and a furlong wide. When borne down by tempests their bodies 

 have overspread large tracts of country four feet deep, or formed, when 

 thus driven into the sea, winrows along the shore 3 or 4 feet deep, 

 for 50 miles in extent ! 



The aphides, or rose bugs, the flies of the turnip fields, and the 

 timber grubs are also terribly destructive. The "great goat moth" 

 is likewise a powerful and destructive insect to plants. Its larvse are 

 proved to increase their weight 140 times within an hour, and when 

 full grown, are 72,000 times heavier than when hatched ! The 

 termes bellicasus lays sixty eggs per minute and continues to do so 

 without interruption for an incredible time ; thus laying, it is calcu- 

 lated, 3,600 eggs per hour, or 86,400 per day ! The common flesh 

 fly, it is said, will give birth to 20,000 young ; and the three flies, 

 musca vomitoria, Linnaeus and others have said, can derour a dead 

 horse as quick as a lion, or commit more ravages than an elephant. 

 They are thus important scavengers. The pine forests of Germany 

 have sustained immense injuries from a small beetle which has de- 

 posited 80,000 larva in one tree. Preying on the inner bark, they 

 have thus destroyed in one forest 1,500,000 trees and then, on maturity, 

 taken wing and flown to other forests with like results. It was a 

 subject of great wonder at one time in London, how the elm trees in 

 some of the parks became completely stripped of their bark. Sus- 

 pecting it to be caused by soldiers, many were arrested and watches 

 stationed to secure the depredators ; still the work of destruction 

 ceased not. Various other causes were supposed and severe measures 

 taken to punish the culprits ; until, at length, they were found to be 

 no others than insects, which were ultimately checked in their career 

 by art. 



The economy of plants, as observed in their habits, is strikingly il- 

 lustrative of the harmony of nature. We see them adapted to the 

 peculiarities of their situations. If indigenous to the tropical cli- 

 mate, they cannot live in our temperate zone without the aid of art ; 

 if inhabitants of the valley, they cannot dwell on the mountain's sum- 

 mit ; nor, if the rugged tenants of the bleak and frosty mountain^ caa 



