﻿IX 



know. When l^cnelicial insects, parasitic or predaceons, have 

 l)een successfully imported, no methods by which they may be 

 successfully estaljlished should be neglected. Predaceous in- 

 sects are generally comparatively large and hardy, and can be 

 safel}' liberated where their food is abundant. Parasites on the 

 other hand are often excessively minute and delicate and may 

 re(|uire the most careful handling. As a rule should some spe- 

 cies that it is desirable to establish be received in an\- num- 



bers, it is always safer to divide them, and adopt various meth- 

 ods. It may be safely said that in nearly all cases (unless climatic 

 conditions are ahogether unfavorable) half the specimens re- 

 ceived should be at once liberated in a suitable locality. Some 

 minute Chalcids and other parasites are very easily bred in 

 ca])tivity, but this is by no means always the case. In rearing 

 insects in captivity in tropical countries, there is one absolute 

 essential, which is ])erfect isolation from ants and other carni- 

 vorous creatures. Several years ago, I had built for this pur- 

 ])Ose a small house isolated from the ground, the supports rest- 



