July, 1910.] 



83 



Plant Sanitation, 



" After much consideration and prac- 

 tical work on this subject," Mr. Antram 

 arrives at the conclusion that spraying 

 is not necessary during the cold weather, 

 immediately alter pruning, but is better 

 deferred until April or May, when the 

 first punctures of the insect can be 

 detected. 



The 1908 experiments were more or 

 less vitiated by the smallness of the 

 areas treated, which permitted the 

 incursion of fresh insects from the 

 neighbouring infected tea. In the 1909 

 experiments, the whole of the infested 

 area on a number of estates was subject- 

 ed to treatment. Some very conclusive 

 results were obtained from work on 

 Ghazipore Estate which had been regu- 

 larly blighted for the previous twelve 

 consecutive years. The manager re- 

 ports:— "The blight first appeared in 

 June, and we promptly attacked it with 

 the spraying machines and hand-catch- 

 ers, keeping at it steadily all the season, 

 with the result that our garden has baen 

 practically free of it and we have suf- 

 fered no loss of leaf. For the past 

 twelve years I calculate we lost about 

 120 maunds of tea per annum by 

 mosquito. This year, of gardens in this 

 corner of Lungla Valley, Ghazipore has 

 treated the blight, while the others 

 which have all suffered from mosquito 

 for many years past have not done so. 

 Ghazipore is practically free from blight, 

 and the neighbouring gardens are near- 

 ly as badly attacked as in previous 

 years. The result of our experiment 

 has removed all anxiety re mosquito 

 blight here. It has also convinced my 

 neighbour of its benefit, and he has now 

 decided to carry out the treatment 

 next season." 



Putting the previous annual loss from 

 blight at 120 maunds of tea, Mr. Antram 

 estimates the gain resulting from the 

 treatment at Rs. 2,460 against a cost of 

 Rs. 1,000, leaving a net profit of Rs. 1,460. 



The author draws attention to the 

 intimate connection between areas of 

 blighted tea and the presence of neigh- 

 bouring jungle. This fact is clearly 

 demonstrated by a coloured map of the 

 Ghazipore tea estate, which shows- by 

 heavy shading- " that blight is most 

 serious in that part of the garden border- 

 ing on heavy or bamboo jungle." 



On page 12 of the pamphlet will be 

 found precise directions for the treat- 

 ment of the pest. These may be summa- 

 rized as follows :— 



At pruning time, all primings in areas 

 affected by blight in previous year, to 

 be burnt while still green. " Light 

 prunings, which are difficult to collect 



for burning, should be at once hoed into 

 the ground. Thinning out in pruning 

 and clearing out of the bushe"s is neces- 

 sary for effective treatment of the 

 blight." 



Boundaries should be cleared back, 

 and any small patches of jungle or scrub 

 amongst the tea should be removed. 



A careful watch must be kept for the 

 first appearance of the pest. 



Hand collecting should be commenced 

 immediately after pruning. The des- 

 truction of the few insects at this time 

 of the year may ward off the blight 

 altogether. 



Wherever the hand-catchers find in- 

 sects or punctures, a stake should be 

 planted to mark the place. 



Spray the affected bushes, taking care 

 to ensure complete saturation, repeating 

 the process as often as possible until no 

 further signs of the pest can be observed. 



A sprayer with a powerful delivery is 

 best. A mist-like spray is not so 

 effective. 



When it is necessary to cover a large 

 area rapidly, the sprayers may be 

 supplemented by water cans fitted with 

 fine roses. 



Mr. Antram used, for these experi- 

 ments; small ' Standard pumps ' fitted 

 with Seneca or Hockley nozzles, and 

 knapsack sprayers of various types. 

 The pumps proved to be far more effec- 

 tive than the sprayers. 



The pamphlet concludes with a com- 

 plete life history of the ' Tea Mosquito ' 

 {Helopeltis theivora), with tables show- 

 ing the time occupied in the various 

 stages of growth month by month 

 throughout the year. Prom these it 

 appears that the development of the 

 insect is greatly retarded in January— 

 the coldest month, and correspondingly 

 accelerated during the hottest period- 

 July and August. 



Mr. Antram's exhaustive experiments 

 have for the first time placed us in 

 possession of a thorough knowledge of 

 the life history of this mischievous 

 insect. He appears also to have evolved 

 a practicable method of treatment. 

 Though the Indian system of cultivation 

 (resulting from different climatic condi- 

 tions) lends itself more readily to this 

 treatment, many of Mr. Antram's recom- 

 mendations are equally applicable to 

 the campaign against Helopeltis in 

 Ceylon. 



- Green Bug.' 



With reference to my remarks (in 

 the April number of this journal) on 

 the treatment of green bug, I have re- 



