THYS A.NOPTEKA. 
543 
on long hairs until deposited. The legs are formed for running, are 
rarely used for leaping, and terminate in a one or two-jointed tarsus 
and a peculiar vesicle. There are many peculiarities of structure in 
the trophi, tracheal system, etc., which we cannot touch on here. 
Extremely little is known of the life-history. Eggs are laid in or 
on the tissues of plants (usually leaves), under bark, in crevices on the 
soil and in other sheltered situations. There are said to be three moults 
in the life of the emerging nymph, which is similar in general structure 
to the adult; at the third moult the insect appears with external wing 
lobes and rests until with another moult, it becomes winged and mature. 
This fourth instar is then an intermediate state between an ordinary 
maturing nymph and a true pupa. Thrips are found on plants, usually 
in flowers and often in great abundance. Some are found only on leaves 
and they may cause damage to plants by lacerating the epidermal tissues 
and gradually destroying the leaves. Others are found only in flowers 
and it is surmised that they feed upon pollen. In Australia some are 
found causing galls. A large number are also found under bark and 
in turf. Thrips are commonly reckoned among injurious insects and 
Physopus mbrocincta, Giard, is a serious pest to cocoa in the West 
Indies, to which place it was probably introduced from Ceylon ; others 
are injurious to cereals, etc., in Europe. Two cases have been seen in 
India of very slight injury to plants by thrips, and we believe these 
insects are commonly harmless. The species attacking tea in Sikkim 
are of greater importance and have in recent years done much damage. 
Uzel observes that, while in some species both sexes occur, in some 
there are only a small number of males, the majority of the females 
reproducing parthenogenetically ; in others, there is one sexual genera¬ 
tion yearly, while in a number, no males have yet been found. He also 
notices that in some species normally wingless, winged females or 
winged forms of both sexes appear occasionally, for the purpose of 
spreading the species to new spots. 
The monograph of this order by Uzel is written in Bohemian (with a 
German synopsis) and mentions three Indian species out of 135 then 
known (1895). He divides the order as follows;—- 
