R. T. LEWIS ON A NEW SPECIES OF ALET7RODE8. 89 



be considered as intermediate between the Coccididce and the 

 Aphides. In the adult form they are distinguished at once from 

 the Coccididce by the fact that both males and females possess 

 four wings, whereas the male Coccids have two only, and the 

 females none whatever ; they also, in both sexes, are furnished 

 with two joints to the tarsus, and with two claws, whilst it is 

 characteristic of the Coccididce to have but one tarsal joint and a 

 single claw. A further distinction is also insisted upon as peculiar 

 to the adults of this family, namely, their possession of divided 

 compound eyes, but although this is to some extent indicated in 

 the new species, it is not so well seen as in some of the figures by 

 Mr. Maskell of other species. In the pupa condition, however — 

 with which alone up to that time I had become acquainted — the 

 distinction between members of these two families is not so well- 

 marked, since both are found attached to the leaves of the plants 

 they affect, and both may also be covered with a floury secretion 

 or with a more or less abundant coating of exuded wax ; hence 

 they are not infrequently mistaken, and Mr. Maskell himself tells 

 us that in 1878 he inadvertently placed two species of Aleurodes 

 amongst the Coccididce under the generic name of Astero chiton. 

 But on removing the wax and examining the dorsal surface under 

 the microscope, with about a 1" objective, a well-defined sub-ovate 

 orifice will be seen upon the last abdominal segment, and by this 

 only identification is usually possible. 



Still greater difficulty, however, attends the effort to distinguish 

 between the various species of Aleurodes in their adult forms, and 

 a comparison between the larvas and pupa? is generally necessary 

 before a conclusion can be correctly arrived at. In the present 

 instance, the pupa alone had been found, and although it was 

 tolerably certain that the species was new, it could not be properly 

 described in the absence of the adult, and my correspondent in the 

 Colony was therefore asked to keep the plant under observation, 

 and specially to look out for the appearance of any quantity of 

 minute four-winged flies in its immediate neighbourhood. 



In the following February the owner of the plant in question 

 reported that the white things on the leaves had turned into flies, 

 and my friend took the earliest opportunity of going over to Byrne 

 to investigate the matter. He found, as stated, that the asparagus 

 plant was now covered with minute flies, which rose in a cloud 

 when the leaves were touched, but settled again at once if not 



