202 BRITISH BUTTERFLIES. 



bulging a little below the middle, and becoming less in size on nearing 

 the base, which is rounded at the edge ; the base itself is slightly 

 concave ; the crown is rounded ; the operculum is small and rather 

 sunken and very finely punctured ; the entire surface is smooth, 

 showing only faint granulations and mere indications of striations on 

 the lower half, running from the middle to almost the base. It has a 

 pearly appearance, being whitish or yellowish -white in colour with 

 opaline reflections ; shortly before hatching the colouring becomes 

 opaque, and a dark leaden spot appears at the crown, caused by the 

 dark head of the larva showing through the shell. In ten days after 

 the egg is deposited the young larva emerges by eating away the 

 crown (Frohawk. June 24th, 1891). 



Habits of larva. — The young larva emerges by eating away the 

 crown of the egg and the sides until very little remains. Soon after 

 emergence it commences making for itself a little tubular dwelling, 

 drawing together the edges of the grass-blade by spinning about three 

 or four stoat cords of silk, each cord composed of a great number of 

 strands, which quickly contract, causing the edges to come together 

 and sometimes to overlap, forming a compact short tube ; the making 

 of one of these tubes occupies about four hours; generally, before 

 spinning, it nibbles off the extreme edge of the blade to which the 

 silk is afterwards attached. It feeds upon the blade both above and 

 below its abode, eating quite through the edge, devouring so much 

 that frequently only the midrib of the blade remains, and the tube is 

 only just long enough to conceal it ; it then shifts its quarters and 

 prepares a new home. As the larvae get older, these tubular residences 

 become more conspicuous. The larva is particularly active when disturbed, 

 and, upon the slightest touch, it rapidly runs out of its tube, either 

 backwards or forwards, and, after remaining quite still for a time 

 (sometimes as long as an hour), until all apparent danger has passed, 

 it retreats into its abode. Its natural movements, however, are very 

 slow, especially directly after a moult or when seeking a fresh spot to 

 make a new tube, and it appears to show no disposition to wander 

 away from the part of the leaf which it is eating. For moulting, the 

 tips of the leaves are usually drawn together so as to form little 

 cylindrical retreats securely fastened by spinnings of silk. From 

 mid-August to early September the larvae devour their cases very 

 quickly, first eating the lower part of the leaf all but the midrib, then 

 devouring the top of the leaf above the tubular part, and, lastly, the 

 tube itself, until it becomes too short to hide the larva, when it is deserted 

 and a fresh leaf selected. When nearly fullfed they make very 

 imperfect tubes and are content to lie along the underside of a leaf, 

 the top of which they soon devour. When fullfed in October the 

 larva draws a leaf round itself as it rests on the underside of the 

 leaf ; if not wide enough, the space between the edges is well filled 

 up with whitish silk, forming thus a complete cylindrical silk -lined 

 hybernaculum, or it may spin two blades of grass together at their edges 

 thus forming a closed tube. In this, they remain absolutely quiescent 

 from mid -October to March. The larva under observation moved to the 

 end of its hybernaculum on March 12th, remained there till the 21st, when 

 it quitted its abode, lying quietly for some days of low temperature 

 until April 1st, which, being warm and bright, caused it to move 

 restlessly, when it began its puparium. It pupated on April 8th. 



