28 
PAPERS READ BEFORE THE SOCIETY. 
ARE THE ATTACKS OF LEPIDOPTEROUS LARVAE BENEFICIAL 
TO THE PLANTS THEY ATTACK? 
(Head December 15th, 1903, by T. A. CHAPMAN, M.D., F.E.S.) 
I give you here a very small bit of bread and a great deal of sack. 
The small item of novelty I have to report to you seems to me to be, 
so far as my knowledge goes, a rather isolated phenomenon ; and I 
bring it before you in the form of a question, not with any view to a 
discussion after the manner of a debating Society, but simply to ask 
for any further items that may be regarded as tacking my observation 
on to the great mass of facts to which it is related. 
I daresay that on reading the question proposed for discussion, a 
majority of us would incline at once to answer it in the negative, with 
perhaps a little contempt towards its being asked. I may best perhaps 
introduce it, by approaching it in the manner in which I was myself 
induced to consider it. 
During several recent seasons at Cannes, I have found the 
relation subsisting between Tortrix unicolorana and its foodplant 
Asphodel ns albas (whether I have correctly (or not) named the 
Asphodel is for the present an unimportant detail), afforded matter for 
observation and thought. The plant is very abundant in the Esterel, 
a wild mountain and forest region, not far from Cannes, and the moth 
is also very common there, it has been well known for over 70 years, 
but I have not noticed any record of the precise points I desire to call 
your attention to. The Asphodel is a tall liliaceous plant, with a 
flower spike some three or four feet high. The leaves come up first 
in a little pointed bundle, standing erect to a height of four to six 
inches or so, as they grow longer they fall apart and display the 
flower spike in their centre, and finally the leaves, twelve to twenty or 
more inches long, lie about, flat on the ground if on a bare place, and 
the spike stands erect. 
The winter climate at Cannes is traditionally fine and summer-like, 
and the first season I was there it was so, and Colias fdasa, Argj/nnis 
lathonia, Pieris dajdidice, etc., were on the wing early in February. But 
this is really exceptional; as a matter of fact, though warmer than with 
ns, the weather is as varied and uncertain as here, and once I saw six 
inches of snow quite late in the season, and in two seasons there was ice 
of many inches in thickness in the Esterel, where water tiickled over 
rocks, and a good inch and a half in pools in the streams. In such 
seasons butterflies did not show freely till April. It is, therefore, only 
correct for some seasons to say that in early February the asphodel 
leaves, little more than an inch or two above the ground, are found to 
have a larva of Tortrix unicolurana burrowing amongst them, and ap- 
