No. I.] Further Notes. 31 



the anal angle ; body greyish-white ; thorax brown speckled; legs and antennae as in 

 the male. 



" Expanse — male 1 \ inches ; female 2f inches." 



Food-plants ; Moore quotes from Thwaites that the larva? feed on 

 Frythrma i?idica, while from the above we learn that it also feeds on tea, 

 sal, and Carey a arbor ea. 



A considerable number of cocoons were sent to the Museum, but al- 

 most all of them were destroyed by parasites, of 

 which the most numerous in individuals was a 

 tachinid fly. The pupae of the tachinid were found in great numbers 

 loose in the bottom o£ the breeding cage, where the larvse, after leaving 

 the caterpillars in which they had developed, had no doubt been overtaken 

 by their pupal stage, whilst endeavouring to hide themselves in the 

 ground after the manner of the " silk worm fly " with which they appear 

 to be identical. A few chalcid parasites also emerged, and these Mr. 

 P. Cameron has kindly examined : he finds that they belong to two 

 species, viz., Chalets (Brachymeria) euplcea, and a new species of Peri- 

 lampus. Of these three species of parasites, the tachinid flies, no doubt 

 did by far the most execution ; but the chalcids must have accounted for a 

 certain number of the pest, and altogether the parasites were so effective 

 that out of a very considerable number of cocoons of the pest, which the 

 writer attempted to rear, it was with difficulty that sufficient moths could 

 be obtained for the identification of the species. If, therefore, the 

 specimens sent to the Museum were at all representative of those left 

 on the bushes, but very few moths of the February generation will have 

 emerged to propagate the species, and there can be little to fear from the 

 pest next year. 



Dasychira thwaitesii seems to be singularly subject to the attack of 

 parasites, for Mr. Fisher's experience in 1878 with the sal pest is almost 

 identical with what has been above described, in the case of the tea pest. 



Mr. Fisher writes : l — 



" I collected several hundred chrysalids, intending to send specimens 

 for identification, but they all died, whether from a disease or ichneu- 

 mons I cannot now determine. Since May 1879 I have not noticed a 

 single specimen of the insect." 



He considers that the mortality amongst the chrysalids may pos- 

 sibly have been due to the unusual heat and dryness of the weather 

 in March and April 1879, but the writer is inclined to think that Dasy- 

 chira thwaitesii, like many other insects, is continually kept in check by 

 internal parasites, which have such vast powers of reproduction that 

 whenever their favourite food becomes abundant they multiply to such 

 extent as very rapidly to destroy the great majority of the insects on 

 which they feed, though they may never succeed in entirely extirpating 

 them. 



1 Indian Forester, 1. c, 



