104 
Fig. 14. Trioza panacis Maskell. a, Lateral aspect of 
male cauda; b, lateral aspect of female cauda. 
downcurved, blunt; ventral valve strongly 
sinuate also, apex sharp. 
Nymph (last stadium) 2.4 mm. long, 1.8 
mm. wide across wing pads. The nymph is 
very distinctive, being large, thick, very 
strongly convex dorsally, and highly pig- 
mented as described by Maskell. The promi- 
nent rounded protuberances on the thoracic 
dorsum are the most easily seen of the peculiar 
structures present. There is also a less promi- 
nent pair on the head. The derm of the dor- 
sum is grossly punctate throughout. The 
venter is minutely spinulose. Small setae 
scattered over dorsal surface including thor- 
acic and cephalic protuberances. The ab- 
dominal segments are distinctly marked. The 
PACIFIC SCIENCE, Vol. VI, April, 1952 
wing pads extend cephalad well beyond the 
eyes, nearly equaling the tip of the head. 
Marginal sectasetae goblet-shaped, those on 
caudal margin somewhat more elongate. 
Anal pore ring with ends as wide as center, 
transverse, flattened, broadly rounded at ends, 
consisting of a single row of pores enclosing 
a row of small teeth. 
SPECIMENS examined: Neoholotype, fe- 
male, and allotype, male, Manapouri, January 
24, 1951. The female was reared from a nymph 
on Pseudopanax sp. Many other specimens 
were taken at various localities, all on Pseudo- 
panax. Very few were found on the juvenile 
trees but they were abundant on mature 
specimens of the host at the time it was in 
bloom. 
HOST PLANT: Pseudopanax spp. 
Maskell in describing T. panacis did not 
distinguish between this species and the very 
closely related form found on Nothopanax 
spp. Ferris and Klyver had three female speci- 
mens of the latter which they described under 
the name Powellia irregularis. Fortunately 
Maskell included a rather good description of 
the nymph which is, in this species, much 
more distinctive than the adult. The highly 
convex body form, strong pigmentation, and 
especially the prominent protuberances on 
the thorax make it unmistakable. On the basis 
of his having actually described and figured 
this nymph rather than the other (the descrip- 
tion of the adult serving for either equally 
well) the epithet is established for the species 
which inhabits Pseudopanax. As confirming 
evidence, there is in the Maskell material at 
the Cawthron Institute a small pill box 
labeled "Trioza panacis (psyllid of Lance- 
wood),” which contains numerous nymphs 
of this species. 
Ferris and Klyver mention the presence of 
points ("punctations”) present on the mem- 
brane of the forewing of irregularis. This 
character (which seems to hold in this in- 
stance) plus their excellent drawing of the 
female genitalia leave no doubt as to the 
identity of irregularis. 
