Dadylopiince. 397 



ANTONINA BAMBUS^, Mask. 

 (Plate CLXVII.) 



Spharococciis bavibusce, Maskell, Trans. N.Z. Insf., Vol. XXV. p. 237, 

 PI. XVI. figs. 12-19(1892). 



Chcetococcus bainbuscT, Maskell, Trans. N.Z. Inst., Vol. XXX. p. 249 (1898). 



Adult female either naked or partially covered with white waxy secretion. 

 The development of this secretion varies according to the position of the insect. 

 It usually takes the form of a waxy cushion interposed between the venter of 

 the insect and the surface upon which it is resting {Jigs. 1,2). A similar waxy 

 pad protects the dorsum from the enfolding leaf-sheath of the plant, when the 

 insect is concealed beneath that covering. In situations where the insect is 

 exposed by the fall of the leaf-sheath, it may secrete a considerable quantity 

 of waxy matter on the sides of the body, and a dense column of white wax 

 covering the median dorsal area of the thorax and sloping in a forward direction 

 ( fiS- 3) ; but this process is very easily detached and is absent in most examples. 

 A stout but fragile tubular filament is produced from the anal orifice. The 

 insects show a considerable variation in size, form and colour, according to 

 their situation on the plant. Such as are permanently covered by the leaf 

 sheaths attain a much larger size, but are flattened by the compression in the 

 confined space ; these are of a reddish brown colour and the derm is less dense 

 {fig. a). Individuals that are exposed at a comparatively early stage of their 

 development, become strongly convex and assume a darker colour— dark casta- 

 neous to deep slaty brown {fig. i) ; the derm thickens and becomes roughened 

 and densely chitinous, arresting further growth. Examples that are partly 

 exposed and partly concealed often have the anterior segments flattened by 

 pressure {fig. 2). 



The cephalo-thorax, which occupies by far the greater part of the body, is 

 broadly rounded. The abdominal segments are sharply defined and narrow 

 consecutively to the anal segment, which is always more densely and evenly 

 chitinous than those preceding it. Antenna {figs. 9, 13) rudimentary; consist- 

 ing of a conical or truncate terminal joint with a group of stout setae at its 

 extremity, and one or two ill-defined basal joints. The tentorium is unusually 

 extended anteriorly {see fig. 12). The spiracles are large and conspicuous. 

 The anal segment {figs. 10, 11) is broadly rounded, with the anal pit opening on 

 the dorsal surface. In the larger depressed form this pit is situated just within 

 the margin {fijo. 10). In the smaller form it assumes a more vertical position, 

 at a little distance from the margin {fig. 11). The anal ring bears six stout 

 setae which scarcely project beyond the rim of the pit. There are a few short 

 seta; on the marginal area, those on the anal segment being stouter and more 

 conspicuous than the others. The dermal pores are of two distinct forms : — 

 numerous small trilocular pores (see y?o-. 13) evenly distributed over both sur- 

 faces of the body, and larger thick-rimmed circular pores {fig. 14) confined to 

 the venter of the anal segment. In old fully matured females the derm is 

 so dense that these pores are more or less obscured ; but their form and 



