Abstract
Some natures of the unknown growth promoting factor required by the smaller tea tortrix larvae, Adoxophyes orana FISCHER VON RÖSLERSTAMM, was elucidated by comparing feeding response of newly-hatched larvae to the synthetic food media containing various amount of boiling water extract of tea leaf and the growth response of the larvae on them.
The rate of larval growth was positively correlated with the dietary amount of the extract, the optimum range of the extract was considered to be 15 to 18 per cent of dry diet. But, percentages of larvae established on the food media were not correlated with amount of the extract. It was concluded that an unknown growth promoting factor contained in tea leaf was a nutriment essential for larval growth, but had no activity as a feeding stimulant.
