82 



The Supplement to the Tropical Agriculturist 



after a very dry year. In one season it did 

 more harm to coffee than two seasons of leaf 

 disease. Would not planting of wild sun-flower, 

 in the place of the lantana rooted out, prevent 

 the growing again of lantana ? Does wild sun- 

 flower (I do not know its botanical name) cause 

 much harm to tea adjoining it ?— Yours truly, 

 ENQUIRER. 



THE GOVERNMENT MYCOLOGIST ON 



" LANTANA. BUG ON TEA." 



This letter, which follows, should be read and 

 re-read by all planters who have (and even more 

 by those who have not yet) noticed this 

 trouble on their estates or near their bound- 

 aries. From one of the most affected pro- 

 perties the specimens sent to Mr Petch prove 

 to be green bug ; and though serious (for it 

 did such harm to coffee) be considers it not 

 so deadly as if it were the Lantana bug itself, 

 involving widespread and costly wrestling with 

 Lantana. But is Mr Bamber mistaken in 

 reporting that estates have been badly affected 

 by Lantana bug as well ? — Meanwhile Mr Petch 

 describes concisely what green bug looks like, 

 and in more detail what the remedy is and how 

 it must be applied. Let every planter respond 

 to the Mycologist's call : " It is imperative 

 that this pest shall be taken in hand at once, ' 

 and search for and tackle the insidious enemy, 

 Lecanium viride. Both the Entomologist and 

 his locum tenens being away, it is fortunate that 

 the Mycologist instead was able to give a prompt 

 and authoritative statement on this pest. 



Peradeniya, Dec. 22nd. 



Sm, — Since the publication of Mr. Beach- 

 croft's letter' re Lantana bug on tea, I have 

 obtained specimens from one of the worst 

 affected estates. Though the appearance is the 

 same as that of the blight on Lantana, a closer 

 examination shows that the insect in this case 

 is not "Lantana bug " (Orthesia insignis), but 

 "Green bug" (Lecanium viride). As "Green 

 bug" was one of the chief insect pests of coffee, 

 this makes the case rather more serious, though 

 it limits the work required to suppress the pest, 

 because we have not to deal with the Lantana of 

 the whole country. 



It is also reported that the same pest is 

 attacking roses, and killing " Madras thorn.' 

 As all these black fungi look the same, this 

 statement cannot be accepted unless supported 

 by specimens. These fungi live on the secre- 

 tions of scale insects, and the insects, as a 

 rule, are different on different species of plants. 

 It is more probable that favourable weather 

 conditions have led to the development of large 

 numbers of the various scale insects which 

 attack different plants in the district in question. 



As far as can be ascertained, " Green bug " 

 has taken about two years to spread to its pre- 

 sent extent in the affected district. This again 

 is a more serious feature, for it shows that the 

 present attack cannot be attributed altogether 

 to abnormal weather conditions during the 

 current year, but is rather the result of a steady 

 advance of the'pest. 



In addition to pruning, and burning the 

 prunings, as recommended by Mr Bamber, the 

 bushes ought to be sprayed, after pruning, with 

 kerosene emulsion, which is made as follows : — 

 "Kerosene .. 2 gallons 



Water . . a gallon 



Soap . . i pound 



" Boil the soap in water until all is dissolved ; 

 then, while boiling hot, turn it into the kero- 

 sene, and churn the mixture constantly and 

 forcibly with a syringe or force pump for five 

 minutes, when it will be of a smooth, creamy 

 nature. If the emulsion is perfect, it will adhere 

 to the surface of glass without oiliness. As it 

 cools, it thickens into a jelly-like mass. This 

 gives the stock emulsion, which must be diluted 

 with nine times its measure of warm water 

 before using on vegetation. The above quantity 

 of three gallons of emulsion will make thirty 

 gallons of wash." 



The wash should be applied by means of a 

 sprayer fitted with a Vermorel or Cyclone 

 nozzle : the simple jet used in spraying cacao 

 pods is useless in this case. There is a 

 sprayer on the market which automatically 

 emulsifies the kerosene and thus renders the 

 addition of soap unnecessary, but it is not likely 

 to be available locally. 



It is imperative that this pest should be taken 

 in hand at once, before it has spread to other 

 districts. Though it may not kill out the tea 

 bush, it effectually stops flushing. For the bene- 

 fit of those who are not acquainted with "green 

 bug," it may be stated that its presence is in- 

 dicated by the appearance of a black mould 

 which completely covers all the green parts of 

 the bush. The green, oval insects are usually 

 found on the under-surface of the leaves and 

 along the shoots. 



T. PETCH, 

 Government Mycologist. 



THE EARLY TAPPING OF RUBBER. 



Dr. Willis's Reply. 



7th December, 1908, Royal Botanic Gardens, 

 Peradeniya. 



Dear Sir, — With reference to your letter* 

 of 30th ultimo, I would refer your correspon- 

 dent to my published remarks. I have always 

 been against the tapping of trees below 5 or 

 6 years old, and I call a young tree anything 

 under 10 years. — Yours faithfully, 



JOHN C. WILLIS, 

 Director, R.B.G. 



[* A letter signed "Herring Bones" on page 

 607 of our December issue asked what exactly 

 Dr. Willis referred to as "young rubber " in 

 connection with the New tapping system appro- 

 ved by Dr. Willis, and being made known by 

 Messrs. Lee Hedges & Co. Will " Herring 

 Bones" say if he is satisfied? — Ed. CO.] 



TAPPING YOUNG RUBBER : AND 

 MANURING OF COCONUTS. 



Dec. 9th. 



Dear Sib,— I was interested to read Dr. 

 Willis's letter giving his views on what is young 

 rubber. 1 would not put the limit for tapping 

 age as high as the Director does ; 7 years, of fair 

 average growth, is old enough for trees to have 

 excellent rubber. 



