418 ENTOMOLOGICAL NEWS. [Dec.. '07 



is evidently of great importance in insuring them safety from 

 parasites and predaceous insects. They cut from one to three, 

 or even four, encircling grooves around the inner surface of 

 the leaf, well up in the swell of the hood, and extending as a 

 tunnel out through the flat stiffening wing of the leaf. This 

 groove is at first so small that it is invisible until the leaf is 

 held to the light, and its effect varies with the age of the leaf. 

 In a tender unopened leaf, in which larvae are most frequently 

 found, it quickly causes a shrivelling and drying of that por- 

 tion of the leaf above the groove, so that while the lower 

 portion remains tender and juicy, entirely suitable for the 

 young larva to feed upon, the upper part ceases to grow, and 

 soon forms a hard dry cap to the leaf-tube which is thus ef- 

 fectually closed to possible intruders. (Plate XVI, first fig- 

 ure, healthy leaf ; second and third figures, leaves grooved 

 by lar-vse.) On older leaves, however, the groove seems to 

 have little effect, and in these the larvae feed until large enough 

 to undertake the ceiling of the open top with a web of silk. 

 This web is usually spun from the angle of the lips of the 

 pitcher in front, curving upward into the arch of the hood ; 

 but the habit is varied, and the web is occasionally spun di- 

 rectly across the tube at the highest possible point, just below 

 the lips, like ridingsii in ftava; and in a few instances a double 

 web, one from either side of the hood and meeting at the 

 angle of the lips in front, was noted (see Plate XVI, three 

 figures). The spinning of the web occupies only about thirty 

 minutes. A single leaf usually carries the larva to the last 

 or next to the last larval moult; on changing to a new leaf it 

 spins the ceiling web in one of the three ways described, and 

 sometimes also cuts an encircling groove which is usually 

 obliterated by feeding before it has any effect on the leaf. 

 Feeding from the top downward, the lower portion of the 

 tube becomes filled with frass, on approaching which the larva 

 reverses its position and feeds upward, sometimes even forc- 

 ing its way down in the frass-filled tube, that no available 

 portion of the leaf may be left unconsumed. 



The larva of scmicrocea is readily distinguishable from that 

 of ridingsii by the difference noted under that species. 



