PLUME-MOTHS OF CEYLON. 
9 
STEGANODACTYLA, Wlsm. 
Steganodactyla concurs a, Wlsm. 
E. M. M., 1891, 241 ; Novitates Lepidopt., t. xii., f. 3. 
Distribution .—Colombo, Galle, Weligama, Kandy, Pundalu-oya, 
Madulsima, Diyatalawa, Haputale. 
Early Stages .—The larva feeds between the young unexpended 
leaves of a common climbing Argyreia and also of Ipomoea populi- 
folia, eating the upper cuticular surface of the leaf into tell-tale 
patches. 
The full-grown larva may be described as stout, rather flattened. 
Head pale yellow. Other segments a pale grayish-green, interstices 
of segments (only visible when expanded) darker green. Dorsal 
surface pale ; warts with a little orange-yellow about their bases, 
often forming a distinct orange-yellow or reddish median stripe. 
An ill-defined broad dark lateral shade appears to be caused by 
the contents of the alimentary canal, as it disappears towards the 
anal extremity when frass is voided. Hairs white, usually very 
conspicuous. (Plate E, figure 1.) 
In confinement the larva generally wanders off the food plant to 
pupate, but occasionally attaches itself to the upper surface of the 
midrib of a leaf. I have never found the pupa in nature. 
The pupa is usually suspended horizontally to a vertical support, 
being closely appressed ventrally to the resting-surface by the 
double set of cremastral hooks. Its colour, which is variable, is 
some shade of pale green, but it always has a broad reddish medio- 
dorsal stripe. These colours fade into a greenish-brown shortly 
before emergence, which takes place after about six days, the 
moth generally appearing in the late evening, quite contrary to the 
ordinary habits of plume moths. The pupa is comparatively 
extremely small, and it seems marvellous how such a large moth 
can emerge from a pupa-case which does not seem sufficiently large 
to contain its abdomen alone. (Plate E, figure 2.) 
'Habits. —Although the larvse are common and easy to find and 
rear up, the moth itself appears to be of a very retiring nature and 
‘is rarely seen in a wild state, although it occasionally comes into 
light. It is very difficult to beat from the food plant and, when it 
is disturbed, the flight is rapid and the moth easily overlooked. 
Observation .—It is noteworthy that up-country specimens— i.e., 
from Kandy and above—are distinctly larger than those from the 
coast districts, the former having an average expanse of about 
16-17 mm. as against about 12-13 mm. in the case of the latter. 
It may be permissible to conjecture that this difference is due directly 
to climate, the up-country specimens having had longer-feeding 
larvse which, as a rule, produce larger imagines than larvse which 
feed for a shorter period of time ; but, of course, this is one of the 
innumerable problems in Sinhalese entomology in which we require 
7(6)09 
c 
