1892.] 



THE BRITISH NATURALIST. 



109 



new to science under the name of scahiodadylus. Mr. C. G. 

 Barrett then found larvae and these were described by Mr. Buckler. 

 Mr. Barrett writes ("E.M.M.", VIII., 156) :— " On May 30th last, I 

 went over to my favourite chalk-pit, determined, if possible, to make 

 the acquaintance of the larva of Pteroplwrus plagiodactylus. The 

 sloping banks of the pit are covered with a profusion of wild flowers, 

 and among them Scahiosa colninbafia and avveusis grow in abundance. 

 At this time, these plants were throwing up strong shoots, and 

 growing so rapidly, that the infested portions of the plant were 

 almost directly covered, and concealed by the healthy shoots, so that 

 1 had no little difficulty in discovering the whereabouts of the larva. 

 The mode of life is this : — The larva gnaws a hole in the side of a 

 young shoot, and, working up, devours its anterior substance, 

 proceeding from shoot to shoot till full-fed, when it attaches itself to 

 the plant by the anal segment, and becomes an angular, bright green 

 pupa, beautifully edged and pointed off with pink, and entirely 

 without hairs. The favourite food-plant is Scahiosa cohmibana, but 

 S. arvensis serves as a substitute, and in the " fens " the moth is 

 common among 5. succisa. This species is double-brooded, appearing 

 in May and June, and again in August, the larva feeding in May and 

 doubtless again in July, but in the latter case the mode of feeding 

 has still to be observed, as the plants are then w^ell grown;" whilst 

 Mr. Buckler's description vvdiich immediately follows is-: — " The 

 larva 2)l(igiodactylus, when full-grown, is about five lines in length, 

 of moderate proportion, neither stout nor slender, tolerably cylindrical, 

 tapering a little posteriorly ; the head rounded and rather smaller 

 than the second segment, of a very pale colour and shining; the body 

 is very pale olive-yellow, with a conspicuous brown dorsal line 

 attenuated at each end, and with two faint lines along the side a little 

 deeper than the tint of the ground colour; on the lowest line are the 

 black spiracles each on a slight swelling ; the tubercular warts are of 

 the pale ground colour and furnished with rather long curved whitish 

 hairs; the head and other parts of the body emit short hairs" 

 (" Ent. Mo. Mag.," Vol. VIII., p. 156). Concerning the habits of 

 the larva of the second brood, Miss Kimber writes: — " 1 found the 

 larvae of M. bipunctidadyla feeding on the flowers of scabious. They 

 are very sluggish, and eat through the bases of several florets. Tl:ey 

 are thus completely hidden, and, until the flower head is pulled apart 

 there is no sign of the larva within" ("Ent. Record" &c., Voh 1,, 

 p. 264). Mr. Porritt writes : — " A larva which has baffled all my 

 attempts to find it, is that of PtevojjJionis hipunctidactylus. The imago 

 abounds among Scahiosa in some old rough fields here, and is on the 

 wing continuously from June until October. Mr. W. Warren informs 

 me he finds the larva: of the early summer moths feeding in the 



