88 Diaspis. 



surrounded by a well-defined group of parastigmatic glands {fig. 22). Pygidium 

 {fig. 20) terminating in a pair of prominent pointed lobes, their bases confluent, 

 and their free margins minutely scalloped {fig. 21). There is a single very 

 prominent tooth-like lobe laterad of and close to the median lobes, followed at 

 intervals along the margin by three duplex lobe-like marginal prominences. 

 The squames, though apparently tapering and spine-like, are laterally com- 

 pressed, with the extremities divided into three or more points {fig. 21). The 

 squames are perforated at the extremities, and delicate silky filaments can be 

 seen to emanate from them if the insect be removed from its scale and left 

 exposed for a time {fig. 1 1). The number of the squames is somewhat variable, 

 and often differs on opposite sides of the same insect ; at the base is a group 

 of six or seven, and there are one or two in the usual positions in each interval 

 between the lobes and marginal prominences. The circumgenital glands are 

 in five groups, with a large but variable number of orifices, the median con- 

 taining from twelve to twenty-five, the upper laterals thirty to forty-six, and the 

 lower laterals twenty-eight to thirty-eight ; the upper laterals in nearly every 

 case containing the greater number. The tubular spinnerets are short and 

 cylindrical, opening by conspicuous oval pores arranged in definite series on the 

 dorsal surface ; there are two of these series on each side of the pygidium 

 exterior to the grouped glands, and one on each of he two preceding abdominal 

 segments ; there are also similar spinnerets and pores on the margins of the 

 pygidium and preceding four segments. The anal and genital apertures are 

 optically superposed. Length about i'35 mm. Breadth i mm. 



Adult male {fig. 9) bright red, head darker, legs and terminal joints of 

 antennae pale. Ocelli black, upper pair larger than lower. Terminal joint of 

 antennae as long as or longer than ninth, suddenly narrowed near the tip, 

 bearing a stoutish knobbed hair at its apex {fig. 26). Foot {fig. 25) with three 

 knobbed hairs, one on claw and two on tarsus — the latter often unequal in 

 length ; claw long and slender; tarsus considerably shorter than tibia. Genital 

 spike about as long as abdomen. Total length (including genital spike), about 

 075 mm. 



The newly hatched larvae are of two distinct colours, creamy white and 

 bright pink ; the difference is possibly sexual. The paler larvae, after fixing 

 themselves to the plant, secrete from a pair of dorsal pores immediately behind 

 the head a pair of long curling colourless filaments {figs. 14 and 15). These 

 are ver)' brittle, and are constantly breaking off", to be replaced by fresh growth 

 from behind, the broken portions accumulating round the body of the insect. 

 I have not noticed these dorsal filaments upon the pink-coloured larvae. The 

 posterior extremity of the body bears a pair of small but prominent tricuspid 

 lobes {fig. 15). 



I find a similar difference in the colour of the eggs, some being pale yellow, 

 and others pale pink, the two forms being laid by distinct individuals. It 

 seems probable, therefore, that special females, or females at some special 

 period, produce lan-te of one sex only. 



Professors Riley and Howard have published {Insect Life, Vol. VI. p. 287) a 

 most careful and valuable paper upon the life-history, habits, and distribution 

 of this insect. By direct observation they ascertained that from eight to nine 

 weeks were occupied in the development of the female insect, and that a 

 constant succession of broods occurred 



