1 154 VARIOUS 



list comprises among others Acacia arabica and A. catechu and the genera 

 Albizzia, Butea, Ceratonia, Ficus, Erythrina, Tectona and Zizyphus. 



Ricinus communis is inckided in the Hst given by the Assam Forestry 

 Department. The principal species, however, on which colonies of Tachardia 

 are usually found are chiefly Butea frondosa, Cajanus indicus, Ficus religiosa, 

 Zizyphus jujuba and finall}^ Schleichera trijnga which supplies the best gum 

 lac. 



The writer reproduces the principal passages of a study by Maxwell- 

 Lefroy on the lac insect Zizyphus jujuba. This insect has two generations 

 a year. The eggs hatch in June and the insects develop until the end of Sept- 

 ember-October, when oviposition takes place. This second generation com- 

 pletes its life cycle about the end of May. The trees require to be cut in time, 

 as it is important that the insects should be inoculated into strong shoots 

 with abundant sap, but the bark of which can be easily attacked by the ros- 

 trum of the insect. Inoculation is effected by taking a piece of gum lac 

 in which the eggs are about to hatch ; this is placed between two plates of 

 bamboo and tied to the shoot of the tree or shrub on which the rearing is 

 carried out. The emergence of the insects soon takes place, and in propor- 

 tion as they are hatched they range themselves round the parent or original 

 gum lac, going up the branch on which they were placed. It is important 

 that they should not be allowed to mount up too near to the end, where 

 the}' would not find sufficient food. As soon as the insects have discovered 

 a favourable point to insert their rostrum, they lose their legs in a first 

 moult, and if they are females they become motionless until the end of 

 their life-cycle. The males on the contrary, whether winged or wingless, 

 leave their scale within a few weeks and mate, but die soon afterwards. The 

 females, when once they have been fertilised, become gradually mature and 

 then commence oviposition, which weakens them gradually until death 

 ensues. The resin is formed between the time of fertilisation and that of 

 oviposition ; during this time the female projects out of her resinous coat- 

 ing white waxy filaments which give the colony a white dow ny appear 

 ance denoting its good state of health. According to Maxwell, the wild 

 jujube tree is particular^ adapted for this type of rearing ; a plant in good 

 condition and well inoculated should yield about 22 lbs. of lac. 



These insects usually have two generations in India. The}' are said 

 nevertheless to have three generations in the province of Madras, Mj'sore 

 and Burmah. Mr. vStebbing, zoologist to the forestry- department of In- 

 dia, advises the establishment of special plantations of the species on which 

 the insect lives best, and he adds that the colonies ready to swarm should 

 only be taken from trees of the species on which it is intended to settle the 

 insect, or in any case the colonies should have lived on harder species than 

 those on which it is proposed to settle them. The branches bearing the 

 future swarm must be cut so that the larvae do not swarm during transport 

 and the sap in the branches themselves does not dry up, which would cause 

 the death of the females before the maturity of the eggs. 



Com})arative data are supplied with regard to the production in 

 Indochina and India. The stick lac of India is more friable than that of 



