in HERMIT HOMES 99 



of a hundred and upwards. She then generally re- 

 treats to the entrance and dies. As soon as the larvae 

 are born they begin to feed. Urged by a wonderful 

 instinct each arranges its body at right angles with 

 the parent gallery, and proceeds to gnaw the wood 

 steadily outwards. These side alleys become grad- 

 ually larger to allow room for the growing tenants, 

 but they all radiate from the central tunnel, and 

 rarely interfere with each other by coalescence, their 

 radiation more than keeping pace with their increasing 

 size. Had the grubs all started parallel with each 

 other the tunnels must have joined, and confusion 

 and deprivation of sufficient food would have been 

 the consequence. Full-fed, the larvae turn to pupae, 

 and eventually pierce the bark and emerge. Large 

 species of Calandra larvae, some two inches long, com- 

 mit fearful devastation in the tropics, boring into the 

 pith of large trees and into sugar-cane. South 

 America suffers similarly from the immense beetle 

 Titanus giganteus. In the West Indies, while the 

 grubs of Lamia amputator and an allied species exca- 

 vate mimosa and acacia trees, the perfect insects 

 complete the mischief of their young by gnawing 

 round the branches in a circular line, all except the 

 central pith. Sooner or later the stems fall to the 

 ground by their own weight or by the force of the 

 wind. The parents' action, it is presumed, is directed 

 to the prevention of a large flow of sap into and 

 through the branch, which might harm the enclosed 

 larvae and impede their metamorphoses. 



The leaves of garden trees and plants, the rose 

 especially, are often traversed by white winding lines. 



H 2 



