The Tea insects of India. 21 



for about a week. The caterpillar in the meantime lives on and may 

 even spin itself up into a cocoon. When full p^rown, the maggot, which 

 now looks much like a grain of boiled rice, endowed with movement, cuts 

 its way out of the caterpillar's body and crawls down to the ground, 

 where it buries itself. In cutting its way out of the caterpillar's 

 body it inflicts such severe injury that the caterpillar invariably dies. 

 In the ground the maggot transforms into a pupa enclosed in the brown 

 bean-shaped case shown in the figure. In this state, in warm weather, it 

 remains inactive for about a fortnight, the pupal case then cracks and 

 out of it emerges a full-grown winged fly which seeks a mate and becomes 

 in a few days the parent of another generation. The period spent in the 

 difierent stages of growth varies according to the time of year, the pupal 

 stage in particular being said to be protracted, in the cold weather, to 

 some months, during which period the insect hybernates. 



Suggestions have been made for importing the silk-worm fly from 

 the silk districts, in cases where defoliating caterpillars have multiplied 

 excessively, and the experiment would seem to be well worth trying, 

 though its success must depend largely upon the question, which has 

 not yet been sufficiently investigated, of the relative importance of the 

 part played by this particular species amongst the numerous forms which 

 attack caterpillars in India, From recent observations, now in course of 

 publication in the periodical Indian Museum Notes ^ it appears that TVy- 

 colyga hoTribyeis attacks such different caterpillars as the mulberry silk- 

 worm, the eri silk- worm, the tea Dasychira, and Olene mendosa^ Hiibu. 

 In the case of tlie mulberry silk-worm, we know that a very few flies, 

 when allowed unimpeded access, are able rapidly to destroy a very large 

 number of caterpillars. Indeed, so much is this the case that the doors 

 and windows in Bengal silk-rearing establishments have to be carefully 

 protected by screens in order to keep out the flies. Where this precau- 

 tion is not taken, the silk-worms are liable to be destroyed almost whole- 

 sale, Mukerji recounts how, upon one occasion, the fly destroyed ninety 

 per cent, of a lot of silk caterpillars he was rearing in Beihampore, and 

 his experience is a common one. It remains to be seen to what extent 

 it can he turned to practical account, 



Chalcis euplosa is likely to attack the caterpillar in a manner very 

 similar to that adopted by Tryffolyga lombyeis, the only point of much 

 practical importance in which it is likely to differ, being in the place of 

 pupation, for Chalcidse larvae often pupate in, or close to, the body of 

 their victim, instead of sheltering themselves in the ground as is the case 

 with Taehinse. The precise habits in this instance have yet to be ascer- 

 tained by actual observation. 



Olene mendosa, 'B.vhn.'^[ — I)asychira mendosa, Ilamp.) Cater- 

 pillars of this species were sent to the Museum in February 1890 from 



