Stem Gall on Muehlenbeckia australis — Arnold 
491 
Cuttings of stems bearing galls with larvae 
were obtained with about 20% success by 
placing the specimens in jars of clean tap water 
which was changed two or three times a week. 
Roots appeared within 14 days at room tem- 
perature. 
Moths were raised under large bell jars in 
which gall-bearing twigs were enclosed, with 
the basal end of the twig in wet sand. 
On the first occasion in March a female and 
a male moth hatched within 24 hours of each 
other. They were placed overnight in a separate 
bell jar containing fresh Muehlenbeckia shoots 
set in moist sand. In the morning some 30 
orange-coloured eggs were found, laid in short 
rows, some on the glass walls of the bell jar 
and some on the Muehlenbeckia stems. Both 
moths were dead by the following day. Only 
one other moth hatched from the galls on this 
occasion, and that was a solitary female which 
emerged a few days later. 
On a second occasion, in December, a male 
and a female moth emerged about the same time 
under bell jars in the laboratory. They were 
placed overnight in a covered beaker with a 
fresh leaf of Muehlenbeckia. Again eggs were 
laid, all of them on the walls of the beaker, 
but they were almost white, lacking the colour 
of those laid in March. 
No eggs hatched, either of the white or the 
orange batch. 
An attempt to induce galls artificially was 
made by removing three small active larvae 
from galls and placing them on separate plump 
softwood cuttings of young M. australis shoots. 
The shoots were kept in large covered glass jars 
with the cut ends immersed in small flasks of 
fresh tap water. Overnight the larvae bur- 
rowed into the stems, entering near the axil 
of the first prominent leaf. After 24 hours the 
entry holes eaten by the larvae had been closed 
by a smooth dark membrane. Within a week 
the shoots with the larvae inside had blackened 
and were beginning to die. Control shoots lack- 
ing the larvae also died a few days later. 
Material of galls and normal stems for histo- 
logical examination was fixed in Formo-acetic- 
alcohol, embedded in paraffin, sectioned seri- 
ally at 10|x and stained in safranin and fast 
green (Johansen, 1940). 
Fig. 1. A gall still occupied by the larval moth. 
-3^ ; ' * 
lit 1 1 1 ! 1 1 i { I . 
1 * - • ■ ; 
* ?s ; Li ■ ■ ' - ; 1 A/..: 
GIVI 
.... .-. - : . .L L... 
I 
■ 
I f 
Fig. 2. Larva of Morova subfasciata. 
OBSERVATIONS 
Male adult moths were smaller, darker, and 
more active than females (Fig. 3). Neither 
survived more than a day after the eggs were 
laid. 
The dates of emergence of the moths from 
galls were in agreement with Hudson’s report 
(1928) that the perfect insect is to be found 
from December to March. Entomological de- 
tails of the dark brown insect pupa and the pale 
larva (Fig. 2) are included in Hudson’s descrip- 
tions and are not necessary here. 
Since the eggs laid in the laboratory did not 
hatch, it was decided to use larvae from existing 
galls to attempt to induce new galls artificially. 
The results of allowing larvae removed from 
galls to penetrate cuttings of Muehlenbeckia 
shoots were inconclusive because the cuttings 
did not live long enough for galls to form. 
(The control cuttings also survived only a short 
time. ) 
However, it was seen that the larvae retained 
the ability to eat instinctively into the pith and 
to seal the entry hole. (When similar experi- 
ments were carried out by the author with larvae 
