81 



r. .tujttastiffmalis is large, just as r. infrastigmalis. The setae 

 of these tubercula are ±2'/, "im. long. V. httsalis is small. 

 Seym. 3, 4. V. dorsalis is absent, the r. subilorsales of the left 

 and right sides have coalesced. They have setae as those 

 of 8t»gnient 1, but are a little shorter and are white in 

 colour. For the rest as in instar //. 

 „ 5. V. (iorsalh is absent, the other tubercula as in instar II. 

 y, 6, 7 as in instar //. 



„ 8. The two r. auMorsales of the left and right sides arc 

 united, but not coalesced. They project higher than in instar //. 

 The setae closely resemble those of the segments 1 and 2. 

 „ 9, 10. r. infrastigmalis of 10 remains large. 

 Instar IV. Duration 8 days. I^ength 15 mm. 

 Prothorax. V. «lormlis is small and ifl now to bo found as a 

 protuberance placed* in the median line on the base of the strongly 

 developed r. suprastigmalis. On its top is a black spot on which 

 are implanted short plumed setae, ± 3*/, mm. long and two 

 tufts of plumose setae viz. ± 1 — I'/j mm. and ±2'/, — 3 mm. 

 long. Each group consists of +6 — 10 setae. There are no tran- 

 sitions between these two, so that they clearly form two storeys. 

 The longest ones also have the largest side branches. The other 

 tubercula are as in instar ///. 



Mesothorax and Metathorax. As in instar /// but v. dorso- 

 lateralis has grown smaller. 



Abdomen 1, 2, The four warts which in instar III began to 



coalesce, now form a whole. For the rest as in instar III. 



Segm. 3, 4 = 1. It should be observed that here r. dorsalis has 



not been united with the median shield, but has disappeared. 



The colour and the form of the setae now agree with 



those of segment 1. 



The other warts on this segment and on the following 

 segments correspond with those of instar III but: 

 „ 8. The two v. subdorsales are almost united and between 

 the many plumed setae some plumose ones are found as 

 on the prothorax. 



6 



