120 • [October, 1888. 



Fig. 8 is Aspidiotus nerii, the most common of all species in Europe, 

 North America, and New Zealand. It is found in abundance on 

 the oleander and other trees. The figure shows the female crowded 

 with young, and the dots on the latter (which appear like eyes in the 

 figure) are the rostral setae, rolled up in the form of a coil on each 

 side of the mouth. This is characteristic of the larvae of the Diaspina, 

 and we may presume that the setae are not uncoiled until required for 

 extracting the juices of the food-plant, after the insect has once made 

 a settlement. Fig. 9 shows the larvae of A. rapax, Comstock, and it 

 will be observed that it is furnished with two caudal hairs, which is 

 the case with all the larvae of Diaspina. "When these first emerge 

 from the parent, they are enclosed in a pellicle, which, however, is 

 soon broken by the insect inside. The insect may be observed under 

 the microscope to push through head first. Fig. 5 represents the pupa 

 state of the male of Aspidiotus zonatus ; the antennae, legs and wings 

 will be observed all enclosed in their respective separate casing, and 

 this stage of the male is characterized by the formation of what 

 appear to be granulated protoplasmic bodies, which are also noticeable 

 in the perfect imago. The perfect winged male of this species is 

 shown in fig. 4, and is a type of the males of all the Diaspina. Indeed, 

 I have failed to find any reliable differences in the males of the different 

 genera, which seem remarkably similar to one another. The character- 

 istic inferior eyes of the male are shown in the figure, although, as 

 it is a dorsal view, these would not in fact be seen. The other 

 characteristic features of the male — the wings with one branched 

 nervure, the halteres with annexed hooked bristle, the exserted penis 

 enclosed in sheath, the pubescent 8-jointed antennae, and the one- 

 clawed tarsus — will not failed to be noticed ; and lastly, the remarkably 

 degenerated form of the apodous female presents a striking contrast 

 to the elaborated form of the perfect male, which, however, has lost 

 its mouth and promuscis, whilst the abdomen has become atrophied. 



EXPLANATION OF PLATE II. 



Fig. 1. — Diaspis ostreceformis, $ . 



Fig. 2. — Aspidiotus ostreceformis, $ . 



Fig. 3. — Mytilaspis pomorum, $ . 



Fig. 4. — Aspidiotus zonatus, S . ' ■ 



Fig. 5. — ditto , S pupa. 



Fig. 6. — Aspidiotus rapax, Comstock (? = A. camellia, Sign.), ? . 



Fig. 7. — Mytilaspis pandani, Comstock (? == M. huxi, Bouche), !j? • 



Fig. 8. — Aspidiotus nerii, $ . 



Fig. 9. — Aspidiotus rapax, larva. 



N.B. — The above figures are all magnified fifty times. 



Villa Nova da Gaya, Portugal : 

 August, 188S. 



