188 A Studij of the Cap^id Bugs found on Apple Trees 



grounds. The female must have a strong hold on the stem for the action 

 of its ovipositors and for this it seems necessary that she should hold on 

 in the direction of the stem and not crosswise. Moreover it is easier to 

 separate the fibres of the xjdem than to cut across them and a longitudinal 

 slit does not interfere with the growth of the surrounding parts and the 

 egg remains in a fresh condition. The tissue around the egg remains in a 

 healthy condition, except probabl}" around the collar of the egg. 



From the position of the egg it would appear that the female faces 

 the base of the twig when ovipositing, and this is borne out by the 

 structure of the ovipositor which is concave on the dorsal side [i.e. pos- 

 terior side when ovipositing] and by actual observation on the position 

 of an egg which was carried about by a female (its laying in tissue 

 somehow or other interfered with) with its convex side directed ventrally. 

 The direction of the egg shows that the ovipositor acts almost vertically 

 to the stem only a little upward in direction. We cannot suggest any 

 reason for the female facing towards the base of the shoot for oviposition. 



Structure of (he egg. 



The egg has been described by Fryer (12) as somewhat resembling the 

 rubber portion of a fountain pen filler. It is markedly curved along its 

 length, with one end bluntly rounded and thick, and gradually narrowing 

 towards the opposite end forming a neck-like region and slightly ex- 

 panding into a cap at the top end (see PI. IX, fig. 4: A). The egg is cream 

 coloured, the surface is smooth and glistening and the shell is strong and 

 elastic. The body of the egg is shghtly flattened by the fibres of the 

 plant pressing against it. This part of the egg is thus oval in cross-section 

 becoming almost circular in the region of the neck. The cap is dark 

 brown in colour and strongly cliitiuized. It shows strongly marked 

 longitudinal striations all round, which are probably hairs that hold the 

 cap to the egg-shell and at the base of it are seen a few scale-like mark- 

 ings. The function of these markings is obscure. The opening of the egg 

 is closed by a strong oval disc, brown in colour and showing curious 

 processes on both surfaces. The outer rim of the cap is whitish with 

 radially arranged lamellar-like structure when seen from above. 



As mentioned above, the egg dissected out of a twig is flatter than one 

 dissected out of a female. It measures 1-4 mm. in length, 0-3 mm. at its 

 greatest width, and 0-25 mm. in the region of the neck. 



In the body of a mature female the eggs lie in longitudinal direction, 

 all with their caps pointing forwards. The whole body is practically full 

 of eggs, which reach right up to the prothorax. The largest number 



