200 THE COCCIDAE 



The female nymphs of all stages are provided with a rostrum and 

 rostralis. The three pairs of legs are present in the first nymphal stage 

 and in at least certain species in the second. The legs of the first 

 nymphal stage are similar in form, those of the second are not, the pro- 

 thoracic legs are smallest and the metathoracic are the largest, the pro- 

 thoracic and mesothoracic are much farther apart than the mesothoracic 

 and metathoracic. The profemora are never greatly enlarged and the 

 prothoracic legs are never fitted for digging. The hody is never provided 

 with an anal cleft and opercula, octacerores, pilacerores, or ceratubae. 

 The anal ring is distinct and hears six anal ring setae. The anal lobes 

 are inconspicuous in the first nymphal stage, but the anal setae are large 

 and prominent. The anal lobes are prominent projections in the second 

 nymphal stage and the anal setae are small. The body is depressed or 

 subdepressed, ellipitical or oval in outline, and completely margined with 

 flabellate scales. The caudal end of the rectum is not strongly chitinized, 

 forming a rectal tube with one or more rings of anacerores excreting a 

 long glassy tube of wax. 



The male apparently has four ocellanae, two dorsal and two ventral. 

 The abdomen is not provided with long lateral filaments or with tufts 

 of long wax filaments, but is provided with two white filaments at the 

 caudal end, which are probably formed of wax. The stylus is stout. 



The insects of this subfamily all produce galls. The species 

 are confined to Australia and New Zealand. The great majority 

 make their galls on different species of Eucalyptus, less than one 

 per cent produce galls on plants of other species. Both sexes 

 form galls and, what is very unusual, the galls formed by each 

 sex is different in size and shape. As a rule the males make their 

 galls on the leaves and the females on the stems and branches, 

 although there are some exceptions to this. The galls are appar- 

 ently in every species abnormal growths produced from the cam- 

 bium layer of the plant and not through modification of the buds. 

 The insects evidently attach themselves to the surface of the 

 leaves or stems where they normally produce their galls. This 

 effects in some way the cells of the plant and an abnormal growth 

 begins which surrounds and eventually covers them, forming the 

 mature gall. "Whether the galls are due to irritation produced by 

 the mouth-parts or from excretions from the salivary glands, Mal- 

 phigian tubules, rectal glands, or some other internal structure is 

 not known. 



The galls produced by the females of the different species 

 show a great variety of forms, varying in size from one-half to 

 seven or eight inches in length and in some species may be as 

 much as three inches in diameter although most are much smaller. 

 Some resemble conical fruits, others nuts and globular fruits. 

 While all the galls of a species are fairly constant, there is variation 



