58 SCALE PESTS OF COFFEE 



until the adult stage is reached when, after gestation, they become obli- 

 terated as the insect assumes its final hemispherical form. The colour 

 of the early stages vai'ies considerably. On the tea plant, the young 

 larvae are of a pale straw colour. After a time three diffused crimson 

 transverse bands usually make their appearance. By their gradual 

 extension they eventually cover the dorsal surface with the exception of 

 the ridges which remain pale. On adiantum and other ferns, the crim- 

 son forms seldom occur, the immature insect remaining throughout of 

 a pale ochreous colour. In other examples there may be a brownish or 

 blackish suffusion, commencing in the form of transverse bands. 



The male insect, in any stage, is at the present time extremely 

 rare, though some forty years ago, when Nietner was investigating the 

 life history of the brown coffee bug, it appears to have been quite 

 common. I have myself found them only on a single occasion, on the 

 under surface of the coffee leaf, in 1889. The drawings then made (and 

 reproduced herewith) do not show as much detail as is required for 

 accurate comparison with other species. 



Male puparium colourless, glassy, transparent, divided into nine 

 plates. 



Adult male, minute, reddish, wings strongly iridescent, with crim- 

 son costal nervure. Antenna rather short, reaching to scutellum. 

 Genital sheath long and slender- A pair of slender, white caudal fila- 

 ments, equal to total length of body ; and a pair of moderately long 

 fleshy tubercles, exterior to the caudal filaments. 



Habitat on leaves, twigs and branches of coffee, cinchona, tea, 

 and innumerable other plants amongst which may be mentioned adian- 

 tum and other ferns, asparagus, gardenia, guava (Psidium guyava), 

 cobaea, anthurium, loranthus, bamboo, etc. In fact the species may 

 be considered as omnivorous as it is cosmopolitan. It has been recorded 

 from almost every country in which coccidaB have been collected in 

 both hemispheres. 



There is one peculiarity in brown bug as it appears 

 in Mysore which is not referred to in the above description. 

 Along what Green calls the " inner marginal surface " there 

 is sometimes more than white powder ; there is a definite 

 secretion of waxy filaments sufficiently abundant, in 

 some, to project outwards and form a white fringe. This 

 is apparently of the same kind as that found in the 

 mealy bug (Pulvinaria psidii). The point is of some 

 importance because it indicates that the characters on 

 which the classification of coccids is based are, as Green 

 remarks, " very relative and occur in all stages of modi- 

 fication." 



The life history of the pest follows much the same lines 

 as that of green bug. The brown bug, however, lays eggs 

 instead of bringing forth young. The process of moulting 

 is the same in both the species. Both young and adult 

 are less particular about the place of fixation. The period 



