CHAPTER III. 



PRODUCTS OF THE COCCIDID.E. 



[Waxy or cottony matter : the " honeydew " and the black fungus " smut" or 

 " black blight " growing upon it.] 



THE Coccididse, in some parts of the world, excrete various 

 substances which are of commercial value, as, for example, 

 shellac, " manna," candle-wax, &c. Cochineal is not in the 

 same category, as it appears to be a colouring-matter pervading 

 every cell of the tissues of the insect from which it is extracted 

 Coccus cacti. But there is no need to dwell here upon the 

 ordinary excretions of the New Zealand insects, as they appear to 

 be not sufficient either in quantify or quality for any practical 

 service. The fibrous puparia of the Diaspidince appear to 

 be quite useless. The tests of the Lecano-diaspidce, such as 

 Cteno chiton perf or atus, Inglisia ornata, &c., although more or less 

 waxy (but of very brittle material, often more like glass) are 

 much too insignificant to repay any trouble taken to collect 

 them. Of all the family, Coelostoma zaelandicum, in its second 

 stage, seems to produce the greatest amount of material, its 

 large, hard, waxy tests being very thick and solid, and often 

 clustered in hundreds on a root or a twig of Muhlenbeckia ; but, 

 supposing this substance (of which the true chemical nature* is 

 not yet known) to be fit for some purpose, there does not seem 

 to be any means of cultivating the insect to profit. Dactylopius 

 alpinus produces in alcohol a rich red tint, and this not by 

 way of excretion, but from the colouring matters of its tissues, 

 as in the case of Coccus cacti ; but here, again, the rarity of the 

 insect and its out-of-the-way habitat would be a bar, even if 

 nowadays it were worth while to cultivate a New Zealand 

 cochineal. At present, therefore, there seems no reason to 



* A small quantity was submitted to Mr. Skey, Colonial Museum Laboratory, 

 for analysis, no more being available at the time. Mr. Skey considered it as a, 

 new substance, probably of the nature of a gum, not resinous ; but further 

 examination of larger quantities is necessary. 



