COFFEA 



ARABICA THE COFFEE PLANT 



Diseases 



that it is due either to the self-same species, or an allied fungus to that jusb 

 described as the coffee-twig disease of Selangor. 



Borer. 5. Borer; Ind. Mus. Notes, ii., 153. This pest used to be known as 



" Worm " or " Coffee Fly." It is most troublesome in Mysore, South 

 Coorg and the Wynaad, where in 1865-6 it destroyed whole estates. It has 

 also appeared in the small coffee gardens of Assam and Burma. It is the 

 grub of a beetle, Xylotrechus quadrupes, Chevr., and is yellowish-red 

 with black transverse lines. It damages the tree by boring holes into the 

 stem, usually a few inches from the ground. These passages are at first 

 transverse, but soon ascend spirally to the growing tip, where the larvae 

 are matured. The plant early shows signs of death and ultimately withers 

 down to the point where the beetle entered. 



Him OIL This pest is most prevalent in hot, exposed gardens, and may be kept in 



check by free irrigation, good tillage and the growth of large shade-trees. 

 Cameron speaks of nim oil, poured into the openings made by the borer, as 

 being useful in either expelling or killing the grub. As a preventative it is believed 

 also desirable to encourage rather than interfere with the nesting of insectivorous 

 birds in the plantation. If the stems of injured trees are collar pruned, new 

 suckers are thrown out and the plants thus renewed, while the borers with the 

 channelled stems are destroyed. 



Another borer is the larvae of the moth zeuxera roffete, Nietner. [Of. Ind. 

 Mus. Notes, ii., 157 ; Watt and Mann, Pests and Blights of Tea, 200-1.] 



Bugs. 6. Bugs. Various insects are by planters all called bugs. They belong 



for the most part to the family known as the COCCID^K or Scale Insects. 

 There are four chief pests of this kind, known as Brown, Green, Black and 

 White Bug. 



Brown Bug. The Brown Bug, tecanlutn fteii0pftcerioMi>t, Targ. ; Green, Coccidce of Cey- 



lon, 232-4, pi. 86 ; Ind. Mus. Notes, ii., 168. " This insect was formerly known as 

 the ' Brown Bug ' of the coffee plant, and before the advent of the ' Green Bug ' 

 was considered the most serious insect pest of that plant." " For some years 

 before the coffee failed, the bug as a pest had practically disappeared." It is 

 met with now and again all over the coffee area of India, but nowhere to a very 

 serious extent. It is perhaps most harmful in the Shevaroy, Nilgiri and Mysore 

 plantations. \Cf. Agri. Journ. Ind., 1906, i., pt. i., 77-8.] 



Green Bug. The Green Bug, L. viHtite, Green ; I.e. 199-203, pi. 69; Ind. Mus. Notes, ii., 



168. This proved such a scourge in Ceylon that it was practically responsible for 

 the final abandonment of coffee cultivation over the greater part of the planting 

 districts. It first attracted attention in 1882, and by 1886 had been dispersed 

 all over the coffee districts of Ceylon. It attacks weakly trees and almost com- 

 pletely denudes them of all but the two or three terminal leaves. On healthy 

 plants the leaves become black through the attendant fungus, but do not fall 

 off, and the bushes make a vigorous effort to grow. In Ceylon the plants had been 

 weakened by Hentiiein when they became infested with green bug. In 1881 the 

 exports were 452,000 cwt., but ten years later they had fallen to 88,780 cwt., and 

 in 1902 were only 10,000 cwt. [Cf. Agri. Journ. Ind., 1906, i., pt. i., 78.] 



Black Bug. The Black Bug, Z,. *</>,. Nietner ; Green, I.e. 229-31, pi. 84 ; Ind. Mus. Notes, 



ii., 168. This bug, though found on coffee, is not so serious a pest as either 

 the brown or green bug. 



Mealy Bug. The White or Mealy Bug, f wewrfococcws n<l<t>iitinni , Linn. ; Ind. Mus. Notes, ii., 



1 68. This is a flat oval creature covered with white down arranged in parallel ridges 

 and running across its back. It prefers hot, dry plantations and would seem 

 to be harboured by the species of Erythrina now so largely grown for shade 

 purposes. In a plantation in the Wynaad where the trees had been cut down, 

 I observed white bug very prevalent on the underground portions of the stems, 

 as also on the roots, and swarming to the neighbouring coffee. Whether or 

 not this observation is of invariable application cannot at present be affirmed, 

 but plants seen to favour the growth of any species of bug should be discouraged 

 in coffee plantations even although the present species has not been recorded as 

 doing serious damage. 



Treatment. Every effort has been made to exterminate these pests. But in the case 



of green bug, the insect, being green in colour and small in size, was not noticed 



386 



