612 PROCEEDINGS OF THE THIRD EXTOMOLOGICAL MEETING 



The nyniplis as well as the females prefer to feed on the tender apical 

 leaves of mulberry plants. In order to determine when and how the 

 malformation of the mulberry shoots was caused a newly-hatched nymph 

 was taken and put on a healthy growing bush-mulberry cutting in a 

 pot. The nymph was transferred on the plant on 4th September 1916 and 

 on 12th September 1916 the place where the nymph had fixed itself to 

 feed in the axil of a leaf had turned deep coppery-green and the stem 

 flattened out laterally. Soon after the presence of the nymph on the 

 plant could be known easily by the presence of the ant, Monomorium 

 indicvm. The ants attend upon the nymphs and the maturing females 

 for the sake of the honey-dew. They have not been seen to attend 

 upon the full-grown male nymphs prior to their pupation. They have 

 also not been seen to attend upon the gravid females when they have 

 begun laying eggs and are covered with fine, whitish cretaceous threads, 

 especially towards the pygidial end. On the 18th September 1916 

 • the leaves had curled distinctly and had turned deep coppery-green. 

 The characteristic malformed head was formed and the leaves forming 

 these had changed colour and had become firm and crisp. The following 

 day one or two patches of the mulberry mildew, Phyllactinea corylea, 

 were visible on the leaves. The plant on to which the nymphs were 

 transferred had remained immune from the attack of the fungus, along 

 with another plant potted at about the same time as this, but now began 

 to show traces of the presence of the mildew. It was just possible, 

 because the vitality of the plant was lowered by the undue draining 

 away of the sap which would have gone ordinarily to the development 

 and maturing of the plant, that the mildew appeared. The other plant 

 was also unfortunately utilized for marking the development of the apical 

 malformation, otherwise if it had been kept separate it would have served 

 well for comparison. On the 23rd September 1916 I talked this over 

 with Dr. E. J. Butler, Imperial Mycologist, Pusa, and he very kindly 

 gave me access to literature* belonging to him, wherein it was recorded 

 that the plants at first immune from the attack of a fungus fell a victim 

 to it as soon as they became infested with Aphididse. The experience 

 gained by me was very much similar to this. Early in 1909 when the 

 mulberry leaf-mildew was very prominent on a few plants in a small 

 plot of broad-leaved mulberry plants in the compound of the bungalow 

 occupied by Mr. H. Maxwell-Lefroy, I found a large number of grubs 

 and adults of Thea cincta, feeding voraciously on the mildew on leaves. 



* 1. On Erysiphis graminis, Dc. and its adaptive parasitism witliin the geiwis Br omus . 



Emest S. Salmon, F.L.S., (Annales Mycologi, Vol. II, Nos. 3 and 4, 1914, pp. 24-25). 



2. Cultural experiments with " Biologic Forms " of the Erysiphacese Ernest 



S. Salmon, F.L.S. {Phil. Trans. Eoyal Soc. .London, Series B, Vol. 197, p. 112). 



