280 THE ENTOMOLOGIST. 



As will be seen, on comparing the above description of the 

 imago with that of dichrodactylus (Entom. xv. 146), there is no 

 material difference between the two, except as regards the tone 

 of colour. 



In his differential note on Platyptilia dichrodactylus and 

 bertrami, Mr. Sang says of dichrodactylus (E. M. Al. xviii. 144) : — 

 " The imago fades — especially out of doors — sooner than any 

 other I have any experience of; for I never took an example at 

 large that was not more or less bleached : generally, they are 



almost white My only captures of bertrami have been 



at Witherslack, where it seems pretty abundant. Now, I never 

 took a faded one ; they were all well coloured : so one would 

 fancy that if they were identical, the food-plant must have caused 

 a very complete alteration in the qualities of the colouring-matter 

 of the scales." 



I have not had the pleasure of taking the tansy-feeding 

 insect ; but as regards the yarrow-feeder, that is bertrami, I have 

 been less fortunate than Mr. Sang, for a large proportion of the 

 specimens I have met with were decidedly bleached, though not 

 really worn. In the series now before me there are only seven 

 well- coloured specimens ; in the others the colour becomes 

 fainter and fainter, until it finally vanishes almost entirely in 

 the last two examples, which are nearly white, that is they 

 possess but the least possible trace of their pristine coloration. 



Mr. James Hinchcliffe, of Tillicoultry, was good enough to 

 send me larvae of this plume on the 24th of June last. One of 

 these, during transit through the post, unfortunately managed to 

 escape from the box ; and on opening the parcel it was found 

 flattened between an enclosed note and the top of the box. The 

 others, three in number, were found separately in shoots of 

 yarrow. Two of these appeared to be only half-grown when 

 removed from their respective mines ; but the third was nearly 

 or quite full-grown. On comparing this larva with my description 

 of the larva of dichrodactylus, as given in the 'Entomologist' 

 (xv. 146), I was unable to find any important points of difference. 

 Except that the prolegs and anal claspers of the yarrow-feeding 

 larva were tipped with black instead of brown, the description of 

 the tansy-feeder exactly applied. The position, appearance, and 

 hirsute adornment of the tubercles were identical. In due course 

 this larva pupated, and the pupa exactly agreed with my 



