Walter Ritchie 



303 



Egg of S. carcharias. 



The egg when newly laid is elongate, rounded at the ends and oval 

 in section. Its length ranges from 3-5 mm. to 4-1 mm., and it measures 

 from 1-5 mm. to 1-8 mm. at its greatest breadth. The shell is very tough, 

 being almost leathery in texture, has a smooth surface, and is dull 

 yellow in colour. In general, its colour resembles very much that of the 

 bast or outer wood in which it is deposited. It is not uncommon to find 

 in eggs which have been laid for some time, that as a result of the pressure 

 to which they are subjected, their shells have taken the pattern of the 

 grain of the fibres with which they are in contact. So closely does the 

 colour of the newly laid egg harmonise with that of the tissue in which 

 the egg is deposited, that on several occasions in my first attempts to 



I 



Fig. 3. Larva of S. carcharias, side view (greatly magnified), a = thorax; aa= ambulatory 

 ampulla; 6= abdomen; es = eusternum; /=frons; hyp = hypopleurum ; is = inter- 

 segmental skin; Z = labrum; »m = mandible; p = pronotum; pa = parascutal area; 

 pb = pleural band ; pi = pleural lobe ; ps = postscutellum ; sp = spiracle ; stl — sternellum 



expose the eggs to view by carefully tearing away the outer bast layers, 

 my eye was so deceived that the eggs were accidentally destroyed. 



In the case of over- wintered eggs the colour of the shell is dark brown 

 and the egg itself is much swollen, in fact such eggs look like small 

 Dipterous puparia. 



As compared with eggs found in situ, those dissected out of an egg- 

 laying female are somewhat different in shape and different in colour; 

 they are elongate-oval, circular in section and pure white in colour. 



Larva o/S. carcharias (Fig. 3). 



The larva of S. carcharias is a typical Lamiid larva and is extremely 

 well adapted to its mode of life. It is a soft, fleshy, legless grub, elongate 



20—2 



