PACK.VED.] LN^SECTS OF THE POEEST. 225 



9* Itxsccts nt the Fur est. 



THE insects of the forest comprise a large proportion of 

 the entomological riches of the world. Those coun- 

 tries which have the most extensive forests have the 

 greatest number and variety of insects. The tropics, par- 

 ticularly Brazil and the East Indies, sustain the richest 

 assemblage of insect forms in the world. Their number 

 and beauty diminish as we go north or south. Luxuriance 

 of forests with great heat and moisture produces the widest 

 diversity of forms and richness of hues. A large proportion 

 of the insects sent home by collectors from tropical coun- 

 tries are the butterflies and large showy moths, with boring 

 beetles, the Scarabeids preying on rotten trees^ timber bee- 

 tles of all descriptions, and the parasitic or predaceous forms 

 which keep them in check. In the tropics when a tree dies 

 it must be removed to make room and supply food for the 

 growth of others. A wound made by some accident, such 

 as the fall of an adjoining tree, tiie browsing of deer or 

 bears, the gnawing teeth of mice or rats, leaves a scar, a 

 weak place, which is immediately utilized by some boring 

 insect as a place to deposit its eggs. Borers and timber 

 beetles of many different kinds, witli varied modes of attack 

 run their galleries under the bark, or bore into the sap wood 

 or straight into the heart of the tree. Their presence invites 

 a horde of smaller invaders. Tlieir parasites seek them and 

 fall upon them until the tree and perhaps its neighbors are 

 thoroughly worm eaten, when a tornado rushes through the 

 forest and leaves its track behind, marked by a holocaust 

 of fallen trees. Now these must, by the natural forestry 

 practised on a gigantic scale in nature, be removed. Squads 

 of Hercules beetles, Passali, and other devourers of decayed, 

 15 1 



