A NATURALIST IN BRAZIL 



them again in Brazil, where this family has attained its greatest 

 development. 



The Sugar-beetles are shy of the light, and live in the interior of 

 decaying tree-trunks, where they are found in whole famiUes, for 

 since the larvae are no longer able to eat without assistance, the 

 parents have to masticate the rotting wood and feed them ; they also 

 watch over the eggs. But since the family does not remain in one 

 place, as it constantly eats its way forward through the wood, the 

 two parents have to go first and clear the way, while the young 

 follow. And just as our birds, wandering in the dark spring or 

 autumn nights, continually call to one another, so the Sugar-beetles 

 emit warning cries, lest their young should lose their way.^ On the 

 tip of the inner wing is a toothed plate, which is rubbed by a sort 

 of bow on the last segment of the body, producing a shrill chirping 

 sound, which may be so loud that Ohaus, who had placed a box 

 containing a Sugar-beetle on his wash-stand, was unable to sleep 

 for the truly infernal din of its constant chirping. The larvae too 

 possess a chirping apparatus, but of another kind. Even when the 

 larvae have pupated the parents remain protectively in their 

 neighbourhood. The offspring enjoy this family existence for more 

 than a year. 



The life of the Sugar-beetle shows how little Nature is inclined 

 to keep to a given scheme, and how, even in the insect world, she 

 is able to devise relations which otherwise are found only in the 

 higher orders of animals. The more profoundly we study the life 

 of insects, the more vividly we reaHze that although the actions 

 characteristic of the species as being necessary to their development 

 are instinctive, many insects have the faculty of modifying their 

 actions to meet altered circumstances, and of storing up experience, 

 and profiting thereby. The insects are not machines which merely 

 run down after being wound up. This will be shown in the next 

 chapter, in which we shall see the fulfilment of many things which 

 the insects hitherto described have but gropingly attempted. 



» According to the most recent observations, the larvae of the Sugar-beetle 

 chirp only when they are disturbed, and are able to eat vs^ithout assistance. 

 When they approach one another too closely in the wood they chirp, and are 

 thus able to keep their distance, and refrain from disturbing one another. 



