DIASPIS. 151 



cords it from Formosa, China, on Citrus and Psidium ; 

 and I have little doubt it has been imported into many 

 parts of the world on citrus fruits. 



EXPLANATION OF THE PLATES. 



PI. XXX, fig. 4. Puparium of adult female. X 15. 

 Fig. 5. Puparium of second-stage female. X 40. 

 Fig. 6. Puparium of male, x 20. 

 Fig. 7. Insects natural size in situ on orange rind. 

 Fig. 8. Adult female after treatment with potash. 



X 50. 

 PL XXXII, fig. 5. Fringe of pygidium of adult 



female. X 600. 



PL XXXIII, fig. 3. Pygidium of adult female. X 

 250. 



Genus DIASPIS (Costa). 



This genus is distinguished by the, more or less, 

 circular puparium of the adult female, and by the 

 exuviaB upon it being always placed well within the 

 margin. The larval exuviae are naked, or have an 

 imperceptible secretionary covering; those of the 

 second stage occupy about one fourth of the diameter 

 of the puparium, and are covered by a layer of se- 

 cretion. 



Of the species found in this country D. zamiae is 

 somewhat abnormal in the female having no circum- 

 genital glands, but in other respects the general 

 character of the pygidium does not materially differ 

 from the more typical species. 



The puparium of the male is strongly tricarinate in 

 7). boisduvalii and D. bromelise, but in D. calyptroides 

 the carinse are either absent or faintly indicated. The 

 non-carinated forms I consider imperfect ; and I do 



