144 



THE INSECT WORLD. 



are numerous, and those which nourish themselves on the pulp of 

 fruits are rare. In general, after the leaves, the caterpillars prefer the 

 flowers : in this they certainly do not show bad taste. Their growth 

 is more or less rapid, according to the species, according to the 

 nourishment they take, and according to the season of the year. 

 Those whose food is succulent grow more rapidly than those which 

 have for their food dry gramineous plants and coriaceous lichens. 

 Most of them eat at night, and remain during the day motionless, 

 and as it were in a state of torpor ; others are so voracious that they 

 are constantly eating. Tliis voracity is indeed sometimes surprising. 

 Malpighi has observed that a silkworm often eats in a day mulberry 

 leaves equal to its own weight. How could we provide our horses 

 and oxen with provender, if they required each day their own weight 

 of hay and grass ? There are even some caterpillars which are still 

 more voracious than that. Reaumur weighed several caterpillars of 

 a species which lives on the cabbage, and gave them bits of cabbage- 

 leaves which weighed twice as much as their bodies. In less than 

 twenty-four hours they had entirely consumed them. In this space 

 of time their weight increased one-tenth. Fancy a man whose 

 weight is i8o lbs. eating in one day 360 lbs. of meat, and gaining 



18 lbs. in weight ! Caterpillars 

 eat by the aid of two jaws or 

 mandibles so broad and solid 

 that, considering the smallness 

 of the insect, they are equi- 

 valent to all the teeth with 

 which large animals are fur- 

 nished. It is by the alternate 

 movement of these mandibles 

 that the caterpillars devour the 

 leaves with so much greedi- 

 ness and ease. 



" A caterpillar, when it 

 wants to gnaw the edge of a 

 leaf," says Reaumur, "twists 

 its body in such a way that at 

 least one portion of the edge 

 of this leaf is passed between its legs. These legs hold fast that 

 portion of the leaf which is to be cut by the insect's jaws (Fig. 

 101). To give the first bite the caterpillar elongates its body, and 

 carries its head as far forward as possible. The portion of the leaf 

 which is between the open jaws is cut through the instant the teeth 



Fig. loi. 



-Looper Caterpillar eating the leaves of the 

 Apricot (after Rdaumuri. 



