Psyllidae of New Zealand — Tuthill 
105 
As Masked mentions, the nymphs very 
commonly retain the cast exuvia attached to 
the rear end of the body; not only the pre- 
ceding one as he states but frequently a last 
stage nymph ("pupa” of Masked) will have 
a long '’tail” consisting of ad its exuvia. 
L. J. Dumbleton first called this to my atten- 
tion when giving me some nymphs which he 
had taken on the host plant in the Rai Valley. 
I have not encountered this phenomenon in 
psydids heretofore but at least one of the 
other New Zealand species (T. subvexa) has 
the same habit, as I have found one or two 
nymphs in this condition. 
Trio 2 a irregularis (Ferris and Klyver) 
Fig. 15 
1932 Powellia irregularis Ferris and Klyver, 
New Zeal. Inst., Trans. 63: 38, 47, pi. 11. 
The adult of this species is very similar to 
T. panacis. It is smaller than the latter (3.25- 
3.75 mm. long) and less robust in form. The 
vertex is proportionately narrower. The an- 
tennae are shorter in proportion to the width 
of the head, being about 1.5 times as long as 
the width of the head, whereas in panacis they 
are nearly twice as long. The forewings are 
more slender and somewhat more pointed at 
the apex, the cubital cell is smaller, Cui is less 
highly arched, the membrane is completely 
hyaline or very nearly so and has quite prom- 
inent points throughout except along the 
veins. (This is one of the most usable char- 
acters although, as pointed out previously, it 
is very variable in vitreoradiata, and its 
validity is therefore questionable.) In many 
individuals the thoracic dorsum is dark brown. 
The genitalia show differences from panacis, 
largely of degree. The dorsal valve of the 
female is distinctly less sinuate and is straight 
apically. The male shows only slight differ- 
ences as figured. 
The nymphs of the two species are by far 
more distinctive than the adults. The last- 
stage nymph of irregularis is smaller (2 mm. 
long, 1.25 mm. wide across the wing pads). 
Fig. 15. Trioza irregularis (Ferris and Klyver). 
a. Lateral aspect of male cauda; b, anal pore ring of 
nymph. 
is almost flat dorsally, lacks the dorsal pro- 
tuberances, is finely punctate dorsally, is 
without dorsal setae, has* numerous slender 
setae over the venter in addition to the 
minute spinules present, the wing pads do 
not extend forward beyond the eyes, and the 
anal ring is of a different shape, being more 
slender and angular. 
Many specimens were taken throughout 
New Zealand from North Auckland to 
Stewart Island, at all possible altitudes and 
throughout the season, from various species 
of Nothopanax, including N. arhoreum, N. 
simplex, N. edgerleyi, N. colensoi, N. anomolum. 
The nymphs cause the formation of pits on 
the leaves, within which they lie, surrounded 
