No, I,] Rhynchofa. 7 



accumulation that occurs on bottles in cellars and which wine-mer« 

 chants sometimes exhibit in situ on bottles, as evidence of the time that 

 they have been kept. That which accompanies the Lecanium nigrum, 

 Nietner, in Ceylon, has been named Trisporium gardneri by Berkeley, 

 and is described as having at first the appearance of a thin, diluted 

 black-wash, but, rapidly increasing in density, within two or three 

 months it quite covers and blackens the leaves and other parts of the 

 trees, finally almost resembling moss. Its period of growth, in Ceylon, 

 appears 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 leav- 

 ing 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 substance (honey-dew, which is either a secretion 

 of the scale, or its extravasated sap that flows from the wounded tree, or, more pro- 

 bably, 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 the glutinous sac- 

 charine substance." 



Mr. Anderson also noticed the occurrence of this honey-dew in con- 

 nection with Bactylopius adonidum in Mysore, and writes that the tree, 

 when attacked, bleeds or gums so profusely that the ground all round the 

 stem is made moist. 



Mr. Maskell, in his account of the scale-insects -of New Zealand, 

 (p. 15), also calls this transparent, gelatinous, fluid excretion, 'honey- 

 dew,' and remarks that it is apparently analogous to that exuding from 

 the Aphides, Psyllidse and Aleurodidse. It varies in quantity with the 

 species present, and appears to be excreted by a cylindrical tube, exserted 

 from the ano- genital orifice after the manner of a telescope, the furthest- 

 extended portion of the tube, being the most slender. In the genus 

 Coelostoma, when this tube is pushed out to its full extent, there appears 

 at its furthest extremity a minute globule of yellowish, nearly transpa- 

 rent, glutinous fluid, which rapidly expands like a soap-bubble, and, then, 

 suddenly breaking off, falls in spray on the leaf beneath, as the coccids 

 are usually attached to the underside of a leaf. It therefore injures the 

 leaf in two ways, by stopping up the stomata of the leaf itself, and by 

 forming a nidus for fungoid growths which rapidly accumulate and kill 

 those portions of the plant on which they appear. Removing the fun- 

 gus is not sufficient, but, in addition, the scale-insect itself must be sought 

 out and destroyed by the kerosine emulsion described in No. 2 of these 

 Notes and which for reference is reproduced here — 



" An emulsion resembling butter can be produced in a few minutes by churning 

 with a force-pump two parts of kerosine and one part of sour-milk, or soap solution 

 in a pail ; emulsions, made with soap solutions being generally found to be the more 

 effective. The liquids should be at about blood-heat. This emulsion may be diluted 

 with from nine to fifty parts of water, which should be thoroughly mixed with one part 

 of the emulsion. 



" The strength of the dilution must vary according to the nature of the insect to be 

 dealt with, as well as to the nature of the plant ; but finely sprayed in twelve parts 



