317 



but may often be found where no scales are and the scales are never 

 found in the ants' nests. The scale was successfully cultivated on 

 coffee trees absolutely isolated from ai\ts and even on branches carefully 

 isolated by rings of tanglefoot from the rest of the tree on which the 

 ants were found, and it is by no means uncommon in a coffee garden 

 to find trees badly infested with scale but entirely free from ants. It is 

 difficult to understand how the idea that the ants spread the scale arose, 

 and still more how Zimmerman, Neumann and Pandan could have 

 supported it. It is possible that an ant has been seen carrying a scale, 

 but this w^as probably an accident, as this species never travels far 

 from its nest. On the other hand, Plagiolepsis is a very useful insect, 

 as it undoubtedly assists the spread of the white scale-fungus, Cephalo- 

 sjporium lecanii, by carrying the conidia from one scale-insect to 

 another. Oecophylla smaragdina is also very common in the coffee 

 gardens and is a cause of great annoyance to the labourers, who are 

 badly bitten by it, especially at plucking time. This ant is widely 

 distributed over Asia and Polynesia, and when it finds scale-insects 

 on leaves, protects them by binding down the neighbouring leaves 

 with web so as to make a cover for them. To this extent this ant may 

 be regarded as harmful to coffee, in that it protects C viridis from many 

 of its natural enemies. 



GooT (P. van der). De Stengelschidluis (Chionaspis tegalensis, Zehnt.) 

 en hare bestrijding. [The (sugar-cane) stem scale Chionaspis 

 tegalensis, Zehnt., and its control.] — Meded. Proefst. voor de Java- 

 Suikerindustrie, Soerabaia, iv, no. 30, 1914, pp. 655-688, 9 charts. 

 (Reprint from Archief voor Suikeritidustrie in Ned.-Indie). 

 [Received 19th January 1915.] 



Zehntner, in 1897, was the first to publish notes on the sugar-cane 

 scales, and recorded four species : — Odonaspis {Aspidiotusj secreta 

 saccharicaulis, Zehnt., Chionaspis madiunensis, Zehnt., Chionaspis 

 tegalensis, Zehnt., and Chionaspis sp. The first-named was found almost 

 exclusively on Saccharum soUwedli and is thus of minor importance, 

 and Zehntner did not regard any of the four as of real consequence. 

 Cutting out the attacked canes or rubbing them down with a cloth 

 soaked in petroleum emulsion was considered a satisfactory- method 

 of control ; it was suspected that the introduction of the pest had some 

 relation with the young plants. Nothing more appeared in sugar- 

 planting literature until 1911, when Van De venter drew attention to 

 the damage done by C. tegalensis. This results not only in an obvious 

 diminution of the total yield of sugar, but also of the weight of cane, 

 and Van Deventer estimated the financial loss at about 22 per cent. ; 

 he gave but Uttle indication as to how the pest was spread, and the 

 wind carriage of the larvae was suggested as a plausible theor}'. 

 Infection from the young plant was excluded, because the insect would 

 not live long on it when buried underground. Van Deventer was of 

 opinion that a large proportion of the scales, especially on the upper 

 parts of the canes, escaped the wiping process above mentioned. The 

 serious infection of the experimental cane fiehl of the Station afforded 

 an opportunity for studying the question in the course of the year 

 1913. The pest was common on Saccharum officinarum, but was found 

 to be capable of living on other species — e.g., on S. soltivedeli and 



