284 E. T. Atkinson — On the Homoptej'ous Family Coccidoe. [^"0. 3, 



parasites are very minute and are for the most part of a brilliant metallio 

 blue or green or gold. 



Lecanium nigrum, Nietner. 

 Enemies of Coffee-tree, p. 9 (1861). The black scale. 



2 . Shield-like, much larger than the brown scale, colour from 

 yellowish grey to deep-brown and almost black, according to age : sub- 

 oval, dorsum with one longitudinal and two concentric oval costse on 

 the disc, towards the margin slightly rugose. The scale under the 

 microscope is highly tesselated and the anal slit and flap as in L. coffees : 

 in old 9 the scale is black with a slight longitudinal costa. 



The larva has two long, black, anal seta3 and a projectile tube, 

 cf scarcely differs from that of L. coffees, the head and thorax are not 

 so bright in colour, but the wings appear more strongly hyaline. Mr. 

 Nietner remarks that this species occurs alone and in company with 

 the brown scale but is far less common, and Mr. Green notes its oc- 

 curence on Ghinchona o'ffi^cinalis and calisaya, Manihot ceara, and Croton 

 tiglium. It is found with L. coffece on the coffee-tree, but only in small 

 numbers. 



Trisjporiu'm gardneri, Berkeley : Syncladium nietneri, Rabenhorst. 



Mr. Nietner remarks that when the scales have been fairly estab- 

 lished upon a coffee-tree, .the tree becomes covered with a fine black 

 tissue formed of a fungus (T. gardneri), which comes and goes after 

 the scale and never alone. At first this fungus has the appearance of 

 a thin, diluted blackwash, but, rapidly increasing in density, within 

 two or three months it quite covers and blackens the leaves and other 

 parts of the tree, finally almost resembling moss. Its period of growth 

 seems to extend over about twelve months, when it is replaced by a 

 young growth or both it and the scale abandon the tree, and when 

 leaving the tree, the fungus peels off in large flakes. Mr. Nietner 

 writes : — * As the occupation of a coffee or any other tree (by scale- 

 insects), gives rise to the appearance of a glutinous saccharine sub- 

 stance (honey-dew, which is either a secretion of the scale or the extra- 

 vasated sap that flows from the wounded tree, but more probably a 

 combination of both) which disappears with the scale, and as the fungus 

 does exactly the same, I have no doubt that its vegetation depends upon 

 this glutinous saccharine substance." Whether Mr. Nietner's remarks 

 regarding the appearance of the fungus be correct or not, its occurrence 

 with species of Lecanium is marked in the United States, Europe (?), 

 and New Zealand. Mr. Maskell particularly notices that plants attacked 

 by insects of this sub-family have their leaves much blackened. 



