1922.] -j^g 



Fontania piliserra Thorns. 



The larvae of this species were found during June on Osier in leaves longi- 

 tudinally rolled, vv'itLout any silken threads. About June 28th they appeared 

 to be full-fed. They agree completely with the description by Konow, kindly 

 quoted to me by Mr. Morice, of P. hypo.vanthus. The lai-va of hypoxxinthus, 

 however, has quite other characters and different habits. 



The length of the full-grown piliseiTa larva is about 12 mm., with a width 

 of I'o to I'Smm. Above, its colour is a dirty olive-green, with darker dorsal 

 line; this colour is only dorsal and, when viewed from above, a little of the 

 palter tint of the under surface, a palish green, is seen on either side of it. It 

 widens a little at the middle of each segment. The segments are divided 

 (dorsnlly) into three subsegments — a broad median, taking rather more than 

 half the segment, a naiTow anterior and a still narrower posterior one. There 

 are a number of very minute liairs which may be seen in a mounted skin. 

 The living larva looks quite smooth, the dorsal hairs beings visible, but are 

 more distinct in three white dots, with minute hairs, at the outer end of the 

 diiik dorsal area of the middle subsegment, and one close by the end of 

 the dorsal part of first subsegment. All the hairs are of about the same length 

 (0"07-0"09 mm.) and solitary, in patches nearly free from skin-points, and 

 they no doubt represent the ordinary tubercles. The general surface of the 

 dark area is thickly set with dark skin-points, and no doubt owes its darker 

 colour to them, laid flat with shai'p points directed backwards. There is a 

 patch of hairs on the sides of each segment with other scattered ones, and the 

 last two (or one ?) segments have a good many hairs several times as long as 

 the dorsal ones noted. The margin of the dark dorsal area is marked by the 

 nearly white line of the lateral trachea, which with some of its branches is 

 very conspicuous; the spiracles show a small thickening of the white line, 

 which looks superficial enough to appear to demarcate the darker dorsum 

 from the much paler green of the under surfnce. 



The head is pale rufous in front, darkening upwards into a dark brown 

 area along posterior margin, and widest dorsally. The antennae show a small 

 rounded brown eminence, with a minute tubercle (another joint ?) on tip. The 

 mandibles are asymmetrical. 



The larvae form very dark cocoons underground. The imagines emerged 

 during the third week of July. Attempts to get them to lay were not very 

 successful, still several eggs were laid and attempted layings were observed, 

 so that the following notes were made. A rather young leaf is chosen, and the 

 eggs are placed on the underside of it and slightly beneath the secondary ribs, 

 the incision being just where the front margin of the rib rises from the flat 

 surface of the leaf; the egg is almost but not quite hidden and theposition is half- 

 way between the mid-rib and the margin ; the rib over the egg appears to bend 

 buck a little, but a sufficient number of eggs was not obtained to show whether 

 this is usual. A series of eggs is laid on each leaf used under consecutive 

 lateral ribs on one (or both) sides of the mid-rib. One leaf measured was about 

 three-quarters of its length when fully grown and about half its full width, 

 actually about 0'27 inch (nearly 8 mm.) wide, not reckoning the margin, still 

 a little inturiied. Attempts to find eggs actually laid on growing osiers led 

 to no success, beyond the observation of some leaves on which a few eggs 



