399 



These results indicate that this sample of patchouli oil from the 

 Kellas Estate is of fair quality, and that it conforms to the general 

 type of patchouli oils exported from Singapore. 



Commercial Valuation. 



A small sample of the oil. was submitted, together with the results 

 of its chemical examination, to a firm of manufacturing perfumers 

 for commercial valuation, it is reported that the oil would pro- 

 bably be worth about 16s. per pound at present. It is also stated 

 that there has been a marked decrease in the consumption of pat- 

 chouli oil in perfumery in recent years, and that this, in conjunc- 

 tion with over-production in the Federated Malay States, Java and 

 Indo-China, has led to low prices for this oil. 



The results of the investigation of these two oils show that they 

 are both of good quality and compare favourably in composition 

 with oils of the same type already imported into' this country, and 

 that consignments would probably fetch good prices on the London 

 market. 



(Sd.) WYNDHAM R. DUNSTAN. 



i6tk June, 1905. 



ON 3 INSECT PESTS OP MANGO TREES 



By J. Hewitt. 



in the month of August of this year a gentleman living in Ku- 

 ching called my attention to the sickly condition of many of his 

 Mango trees. On inspection it was found that whole branches 

 gradually withered and died although the tree as a whole retained 

 its vitality. It was obvious that this was the ravages of some 

 insect for on splitting the dying branches one found the wood 

 penetrated by long tunnels which reached sometimes a length of 

 several feet. Apparently one individual insect can do much damage 

 for in these borings one branch never lodged more than one insect. 

 This was a large white fat grab with a small head and swollen 

 thorax, the anterior thoracic segment in particular being enlarged : 

 the thorax was provided with 3 pairs of rudimentary legs. The 

 abdomen was conspicuously segmented : dorsally and ventrallv all 

 the segments — with the exception of the last 2 abdominal, and the 

 first thoracic dorsally — bear tuberculated humps which seem to 

 subserve a gripping function. The length of the larva was 2 inches 

 or more. Fortunately I was able to find one adult insect and to rear 

 a pupa. As one could expect from a larva of the type des- 

 cribed it belonged to the longicorn beetles, the actual species being 

 Rhytidodera simulans White. This beetle of length usually just 

 over an inch, is of a dull reddish brown colour marked with yellowish 

 spots which on the elytra are longitudinally elongated and arranged 

 so as to mark it irregularly by transverse bands. 



