QQ THE EEPOKT OF THE No. 36 



Another species, Ericerus pela, secretes a pure white wax, which in China is 

 collected and made into candles for special use. In India similar use is also made 

 of a wax obtained from a species of C-eroplastes ceriferus. 



In India a species known as 'the Lac insect {Tachardia lacca) furnishes us witli 

 the useful product known as lac, which forms a basis for varnish, French polish 

 And other important products. It is collected in its native home, India or Ceylon, 

 and sent abroad on the twigs and branches upon which the insect has worked and 

 deposited the substance. This raw material is then subjected to a process of refining 

 by which the material is gathered in the form of shell-lac and is then ready for use. 

 It may be interesting here to offer a brief life history of the insect itself which pro- 

 duces this very valuable material. Mr. Robert Newstead, quoting from the Eoyal 

 Horticultural Journal in his work on the Coccidse of the British Isles, writes as 

 follows on the species : — 



"Like all other Coccids, the young (larvse) are active; they are at first very 

 tiny creatures, resembling mites, and are generally spoken of by the horticulturist 

 as 'lice.' These young arrange themselves in groups of various dimensions round 

 the twigs of the food-plant, and, having settled matters satisfactorily as to space, 

 insert their thread-like sucking-tube (mouth), into the plant tissues, and pump up 

 the sap of the tree. At the same time they commence covering their bodies with the 

 peculiar 'lac' which, by the time they are fully developed adult females, assumes the 

 form and size shown in the illustration. By taking a hot knife a transverse section 

 of the material may easily be made, when it will be seen that the covering material 

 or 'lac' is not a solid mass, but is honeycombed by large, somewhat ellipsoidal cells, 

 each of which was once tenanted by a single female . . . If we examine a 

 female we find she is shaped somewhat like the cavity in which she lives, with the 

 cephalic portion bearing the mouth parts touching the bark at the narrow end 

 of the cavity, and the abdominal extremity at the opposite end, having connection 

 with the exterior by means of a minute perforation; and she is destitute of legs 

 antennae, etc. Where she has lived she dies, leaving as a legacy the wonderful 

 product which she manufactured during life, and which all the world over is of so 

 great importance in commerce. And this is not all ; the bodies of the females also 

 furnish an excellent dye, which in former times was of much value also." 



Dissemination. 



The female scale is wingless, hence they must be borne from place to place by 

 agen3ies outside themselves, such as wind, water, plants and animals. It is very 

 noticeable that with such scales as the San Jose the spread is always greatest in the 

 direction of the prevailing winds. This, however, is possible only when tlie insects 

 are in the active moving stage; as soon as they come to rest and attach themselves 

 to their host no further spread occurs in this way. Eain too is supposed to help 

 spread the scale when they are in the egg or young active stage, by washing them 

 from the upper to the lower parts of the trees, but it is animals that effect the 

 greatest dissemination from tree to tree. Birds frequenting orchards and forest 

 trees undoubtedly carry numbers of scale insects attached to their feet and beak. 

 A very wide distribution may occur in this way, even across bodies of water or 

 mountain ranges. The insects and Acarids also assist in the local distribution of 

 the scales. Lady Bird beetles and Ants among the insects and the predaceous species 

 of mites are responsible for a great deal of the spread of the injurious scales. An- 

 other probable factor in distributing scale insects is the careless handling of the 

 infected fruits, such as apples and pears. Eefuse fruit is often allowed to come 



