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IX. Observations on the Life History of Tricboptilus 

 paludum, Zell. By T. A. Chapman, M.D. 



[Read March 7tli, 1906.] 



Plate VII. 



This species is the smallest and most delicate of our 

 British Plume moths, and also perhaps one of the least 

 common. It has up to the present been remarkable as 

 the only British species of the group, whose early stages 

 were quite unknown. 



For the discovery of its early stages we are altogether 

 indebted to Mr. E. R. Bankes, who by reasoning not only 

 scientific, but almost mathematical, arrived at the con- 

 clusion that its food-plant must be Droscra, although he 

 seemed to fear that this determination would be scouted 

 as absurd. 



He supplied me with eggs of the species, and with a 

 first installation of plants of Drosera ; and from this basis 

 I have succeeded in observing a srood deal of its life 

 history, and fully confirming Mr. Bankes' determination 

 of what its food plant must be. 



The food plant, Drosera rotundifolia (and probably the 

 other forms ; I found many larvae on rotiindifolia, but the 

 Dorset plants varied somewhat toAvards interracdid),\s>oxiQ 

 that was probably never suspected to support a Lepido- 

 pterous larva, and was therefore never searched for that of 

 tliis species. The prevailing idea is that the plant devours 

 insects, and though this is undoubted, it now appears that 

 to assume that insects would not and could not also eat it, 

 is to fall into a plausible but false method of reasoning. 

 Nevertheless, it comes as somewhat of a surprise to find 

 that a Lepidopterous larva, without any special means of 

 protection, but simply acting in the ordinary larval manner, 

 attacks it with entire impunity. No doubt it avoids 

 walking over, and especially resting upon the gluey glands, 

 but it does this apparently merely because it has no call 

 to do so, and the glands with their secretion are certainly 

 favourite items of its food, especially when it is small. 



My observations began in August 1904, when I received 



trans, ent. soc. lond. 1906.— part i. (may) 



