MORE ABOUT INSECTS 8l 



Lead is the metal most commonly injured. Lead bullets 

 and cartridges, lead, and also tin. roofing, lead rain gutters, 

 lead stereotype plates, lead piping for both water and gas, 

 lead Hning of vats, tanks and cisterns, the sheet lead protection 

 for bee-hives, lead crucibles, lead fuses, telephone batteries, 

 the lead sheathing of aerial telephone cables, high tension 

 cables, and lead covered cables in wooden cased conduits, all 

 have suffered from insect attacks. But lead is not the only 

 metal to suffer. The quicksilver backing of mirrors, the gilding 

 of chandeliers, silver plate stored in closets, tin and zinc, are 

 also sometimes damaged. Shell, horn, and even asbestos are 

 bored by insects. 



The variety of insects which will damage metals is quite 

 considerable. It was a horn-tail that bored the French car- 

 tridges. A wasp has been found to damage lead cables in 

 China. White ants or termites have damaged lead cable 

 sheathing underground. The larva of the goat-moth some- 

 times causes trouble. But the worst culprits are beetles of 

 no less than eleven different families or major groups. 



At first it was believed that the insects fed upon the metal 

 through which they bored, and, indeed, lead and zinc have 

 actually been found in their stomachs. But with few excep- 

 tions the cases recorded are merely accidental, though none the 

 less troublesome, resulting from the fact that the metal blocks 

 the path of an emerging adult or of a boring larva, and do 

 not constitute direct attacks. As an example, near Saarau, 

 in Silesia, a new sulphuric acid factory was built of timber 

 infested by horn-tails. The adults emerged through the lead 

 floor plates causing a loss of about $25,000. But in some cases 

 the insects, for unexplained reasons, do make a direct attack, 

 often with serious results. 



