480 
LEPIDOPTERA. 
cocoons may be crossed with a male of a poor race, and the crossing 
of a bivoltine race with a nnivoltine probably causes the irregular 
eclosion of moths that is such a handicap to the rearer. 
The different races have distinct periods of eclosion; there is a brood 
usually in July-August, followed by a brood in October-November in 
some; some eclose in September and are one brooded, some in July or 
June with one brood. Owing to the failure to domesticate fully, the 
variety of races which cross and the entire lack of control of fertilisa¬ 
tion, there is no distinct pure race that can be grown in domestication, 
and were tasar to be improved or the industry revived under an 
increased demand, these factors must be taken into account. 
Tasar is found on a great variety of trees, the asan (Terminalia 
tomentosa), the Urjun (T. arjuna), the sal (Shorea robusta), the ber 
(Zizyphus jujuba) being the more important; in gardens, it feeds on 
Lagerstrcemia indica. The cocoon is very dense and hard in some races 
with a long or short peduncle. As a rule, the summer cocoon is flimsier 
than the winter cocoon where there are two races. The silk is a reelable 
silk as in Bombyx silk and the moth must not be permitted to emerge, 
as the end of the cocoon is softened with alkali, then torn by the exit of 
the moth. 
The stages are figured on Plate XLII. The larva has the most 
beautiful metallic spots, silver or a reddish gold tinge; it is cryptically 
coloured, being leaf green, resting in a very characteristic attitude and 
possibly the metallic spots represent spots of light coming through 
leaves. The tusser worm is attacked by many foes and a very low 
percentage pass through their stages and attain maturity, even 
when the larger enemies are kept away ; the possible rate of increase 
is a hundred fold, each pair producing about 200 eggs; not more than a 
tenth of this is actually realised. Wasps (Vespa and Polistes) feed 
on them; Canthecona furcellata, a Pentatomid bug, sucks them ; 
Mantids eat them, birds, bats, lizards all eat them and a Tachinid 
fly parasitises them. The literature is extensive, but Cotes’ articles 
on the Domesticated and the wild silks of India give useful infor¬ 
mation and are well illustrated. 
The student may be cautioned against accepting some of the litera¬ 
ture as accurate ; notably much is said as to the possibility of the exten¬ 
sion of silk cultivation in India by English writers ignorant of the fact 
