A. W. Rymer Roberts 197 



above the surrounding area chiefly at the sides. Behind, it is less raised 

 and paler in colour. 



Third Instar. 



The second ecdysis occurs at the end of July or in August and the larva 

 passes its second winter in the third instar. At the beginning it is about 

 6-8 mm. in length and | mm. in breadth. In colour it is distinctly yellow 

 and in other respects also except size closely resembles the full-fed larva. 



The tergites are sparsely punctate but bear numerous irregular 

 striations, which may be seen under a low magnification. 



The sternites are smoother. Setae distinctly yellow. Nasale trifid, 

 with median dens the stoutest. Dorsal process of antenna about equal 

 to the second segment. 



Spiracles are now distinctly different from those of A. sputator at the 

 same age, being shorter and proportionally wider. 



The teeth or corrugations at the sides of the orifices number eight 

 to ten in the abdominal and fourteen in the thoracic segments. 



The stigmatic scar is thicker than in the previous instar. 



The 9th abdominal segment is broadest just posterior to the sensory 

 pits and from that point gradually tapers to the distinctly pointed cauda. 

 Sensory pits margined on all sides with brown. 



The following table gives some idea of the actual increase in length 

 of the larva during the early instars. All the larvae hatched in 1916 

 (or 1918) and were afterwards kept in pots under normal conditions as 

 far as possible. 



Eighth Early July 1920 17-0 3 16-0—18-5 



If this table of records is compared with the estimate made in Part I 



of this paper (p. 127) it will be seen that the larvae were about a year 



behind the estimate in 1920. It seems likely, therefore, that the length 



of life in the larval stage is, or at least may be, of six years' duration^. 



1 Some confirmation of this forecast has been obtained since the above was written. 

 Of three larvae of the 1916 brood, on August 22nd, 1921, one was found to have developed 

 into an imago (?), a scL^ond remained a larva (of length 22 mm.), the third was not found, 

 possibly having attained maturity and so having been overlooked in the soil. 



