I 



lU LIFE STORIES OF AUSTRALIAN INSECTS. 



are so tiny that they are not popularly known. 

 They are called the "micro-hymenoptera." 



They can be distinguished from the other small 

 wasps by the following: (a) The wing has no cell 

 system, but a solitary vein or nervure which runs 

 longwise with a short backward turn (Plate 15, 

 Fig- 7) ; (b) the antennae are elbowed, that is, there 

 is a long basal joint, and a jointed upper part stands 

 at an angle to the long, single, basal joint. (Plate 

 15, Fig. 5). Note the antennae of Some of the 

 male chalcids are branched and look like tiny 

 feathers. 



Life History. — The eggs of the chalcid are laid 

 by the mother inside the victim or host, such as a 

 grub, caterpillar, etc. A tiny legless grub hatches 

 out — it is white or cream, and delicate in texture, 

 for it is protected within the body of the host, 

 where it takes nourishment either by absorbing 

 the liquid food, or by sucking it through the mouth. 

 The host does not seem to be seriously inconven- 

 ienced by these self-invited guests, but just grad- 

 ually Aveakens and dies, leaving an empty shell of 

 the harder indigestible parts. If the chalcid is 

 small, many eggs may be laid in the one host. The 

 caterpillar, etc., may reach the pupal stage but does 

 not live to become a perfect insect. 



Chalcids are useful when they parasitise the 

 larvae of some of our pests such as the codlin moth, 

 grape vine moth, lucerne moth, scale insects. Gall 

 insects are also attacked by them while certain 

 species of chalcids are said to make galls. 



There is a very interesting- relation between some 



