48 



profile the metathorax is highest, and the body slopes gradually to 

 the tenth abdominal segment. Legs large. Prolegs very long and 

 slender ; anal claspers short and cushion-like. Head brown ; body 

 pale yellow ; dorsal vessel green. A reddish-orange line runs from 

 the prothorax to the tenth abdominal segment. This line disappears 

 during this stadium, and, as already pointed out, the larva becomes 

 flatter. Length of the larva 3 mm. The usual tubercles and setje 

 are present ; the setje very small and simple. Tubercle i is placed 

 further from the mediodorsal line than ii ; iv and v are separate, 

 subspiracular, and iv is also post-spiracular. Below these two is a 

 small tubercle, which, I think, must be tubercle vii. There are many 

 skin points. 



Fourth instar. — Width of head, o*6 mm. ; length of larva, 7 mm. 

 Larva rather flattened dorsally and ventrally, widest at the second 

 abdominal segment. The segmental divisions are well marked 

 laterally. The meso- and metathorax have three sub-segments, and 

 the abdominals two sub-segments. The tubercles are all simple, 

 each with a single seta, which is rather short. On the abdominal 

 segments tubercles i and iii are on the first sub-segment, and ii is on 

 the second subsegment and nearer the mediodorsal line than i. 

 Tubercles iv and v are both sub- and post-spiracular ; vi is rather 

 more central than in some other larvae, while tubercle vii has now 

 developed into the usual three tubercles, the posterior one bearing a 

 very long seta, the longest of all the set^e. This measures o"23 mm., 

 while tubercle iv only measures o"i5 mm. Tubercle viii is as usual 

 on the inner side of the proleg. The skin-hairs are very numerous, 

 but absent round the spiracle and round the bases of the tubercles, 

 and also in certain patches on the dorsum, viz. a small circular patch 

 behind tubercle i, and an elongate patch between i and iii, but behind 

 both. There are two very minute tubercles on the anterior of the 

 segment and one near tubercle iii. The prolegs are long and slender, 

 with about five crochets. The crimson spots, which develop when 

 the larva leaves the mine, are situated round the tubercles, except vii 

 and viii, which take no colour. The spot round tubercle i is rather 

 large, smaller round ii, very large round iii, and of moderate size 

 round iv, v, and vi. The largest spots of all on the larva occur on 

 the meso- and metathorax round the second pair of tubercles, 

 counting from the mediodorsal line downwards. These spots vary in 

 different larvce both as to size and brilliancy. 



Diary of Larva Labelled '''■No. i." 



August 17th, 1908. — No. I larva hatched. 

 1 8th. — Had mined about 3 mm. 

 19th. — A further 3 mm. mined. 



20th. — Had mined \\ mm. and laid up for change at i p.m. 

 2 1 St. — Twenty minutes past noon had changed, and was again 

 feeding. 



