98 
PACIFIC SCIENCE, VoL VI, April, 1952 
Coccidae to the Aleyrodidae. Subsequently 
he obtained adults, realized his error, and in 
his paper on the Psyllidae in New Zealand 
(1890) he synonymized Powellia with Trioza. 
Ferris and Klyver, however, considered that 
the New Zealand species constituted a separ- 
ate genus and therefore resurrected Powellia. 
The bases of their distinction were the pres- 
ence of serrations of greater or lesser promi- 
nence on the base of the metatibia and the 
position of the large spines at its apex. These 
are not limited to the New Zealand forms nor 
are they, in my opinion, sufficient reasons for 
maintaining a separate genus. 
The genus Trioza is one of the largest, per- 
haps the largest, genus in the family. The 
forms found in New Zealand show consider- 
able diversity. With one exception (T. advert- 
ticia n. sp.), they are limited to endemic hosts 
and are undoubtedly endemic species. A very 
large number of species appears to have 
developed on the native Compositae, prin- 
cipally the shrubby ones. This is a family of 
plants which is not known to support many 
species of psyllids in other parts of the world. 
Trioza vitreoradiata (Maskell) 
1879 Powellia vitreo-radiata Masked, New 
Zeal. Inst., Trans. 11: 223, pi. 8, fig. 22. 
1890 Trioza pellucida Maskell, New Zeal. 
Inst., Trans. 22: 164, pi. 11. 
1903 Trioza alexina Marriner, New Zeal. Inst., 
Trans. 35: 305, pis. 33, 34. 
1932 Powellia vitreoradiata Ferris and Klyver, 
New Zeal. Inst., Trans. 63: 39, 42, pis. 7, 
8 , 16 . 
Large numbers of this species were taken 
throughout New Zealand on various species 
of Pittosporum, throughout the season, for I 
suspected that there were probably different 
species present on the different members of 
the host genus. After very careful examination 
of many specimens from many localities, from 
Spirit’s Bay to Oban, and from at least four 
species of Pittosporum, I am convinced that 
there is but one species of psyllid present. 
Minor variations in structure are present, of 
course, but none that seems significant or 
that is constant. The sclerotic points on the 
membrane of the forewing, for example, 
range from very prominent points over all 
the membrane to complete absence except in 
the extreme base, with a great range of inten- 
sity and a considerable range in size. There is 
no correlation with season, locality, or host 
plant. 
I can add nothing to the very complete 
description given by Ferris and Klyver except 
that the size range is 3.25 to 4 mm. and that 
the color variation is even greater than they 
stated, ranging to almost entirely black ex- 
cept for the thoracic pleura and the edges of 
the abdominal tergites. 
HOST PLANTS: Pittosporum spp., i.e., P. 
eugenioides, P. tenui folium, P. crassi folium, P. 
colensoi. 
Maskell recorded it as also occurring on 
Discaria toumatou and Geniostoma ligustri folium. 
Two species, both here described as new, have 
been taken from Discaria toumatou. The male 
of the more common one, Trioza discariae n. 
sp., is almost certainly the source of Maskell’s 
drawing of the male which Ferris and Klyver 
were at a loss to explain, resorting to an 
assumption of remarkable error on the part of 
Maskell. I have been unable to find any 
psyllid associated with Geniostoma but am 
confident that when it is rediscovered it will 
prove to be a distinct species. 
In addition to the specimens collected by 
myself, I have had for study material from 
the various collections in New Zealand. These 
are from several other localities and from 
several species of Pittosporum. 
Trioza discariae n. sp. 
Fig. 10 
1879 Powellia vitreoradiata Maskell (in part). 
New Zeal. Inst,, Trans. 11: 223. 
1890 Trioza pellucida Maskell (in part). New 
Zeal. Inst., Trans. 22: 164, pi. 11. 
Length to tip of folded wings 2.25- 
2.5 mm. 
