40 The Humming Bird. 



A catalogue serves as an index to the entire collection,, 

 every individual bug having a number. Up to date, only a 

 small fraction of the insects in the world have been named 

 and classified, it being estimated that no fewer than 10,000,000 

 species exist. « 



In one jar are a few pieces of bark honey-combed by 

 woodborers. In this case, sawdust instead of sand is provided 

 for the larvae to bury themselves in, preliminary to coming out 

 as flies. A jelly glass contains a little wheat flour, together 

 with some beetles of a kind that devour stored grain and 

 flour. These latter are readily bred, and can be watched 

 throughout their development, from the egg to the larval form,, 

 and from the latter to the beetle. 



In like manner wheat moths are propagated in a vessel 

 with kernels of wheat, and "joint worms" are observed in 

 the act of feeding upon stems of the wheat plant. Root- 

 attacking bugs are propagated very simply in earth in pots, 

 together with the growing plants whose roots they feed upon. 

 To prevent them from escaping when they come out of the 

 ground, glass jars are inverted over the plants and pots. 



An important feature of this work is the study of parasites 

 of the insects themselves. There is hardly any kind of bug 

 which is not preyed upon by one or more other species. The 

 best way to exterminate a pestiferous bug is often to introduce 

 a hostile species to the region where the damage is being 

 done. In this manner the Department of Agriculture has> 

 saved the orange-growing industry of California from being 

 destroyed by the fluted scale insect from Australia, the lady 

 bug which preys upon the scale. 



The operations of such parasites are watched in the same 

 jars with the insects fed upon, and thus knowledge is obtained 

 of their habits which is likely to be most useful. In one jar 

 are several chinch bugs together with some of the fungus 

 which attacks them as a destructive disease. 



This vegetable parasite is being extensively utilised over 

 in Kansas, bugs affected with it being scattered broadcast to 

 spread contagion among their kind. In other receptacles are 

 combs of bumble bees and wasps, which are being kept for 

 the purpose of developing and breeding insect parasites that 

 have attacked the larvae in the cells. Of course, the bumble 

 bee is an animal of economic importance, inasmuch as it does 

 a great deal of useful work in the fertilising of plants. With- 

 out its aid in this way there would be no red clover. 



" Citizen, Brooklyn." 



