4 MODERN CLASSIFICATION OF INSECTS. 
pound eyes are replaced by conglomerate eyes ; the pupa ( fig. 57. 17., 
from De Geer) resembles the perfect insect, but the articulation of 
the limbs is obscured by a film, and the wings enclosed in short fixed 
sheaths. The antennez are turned back on the head, and the insect, 
though it moves about, is much more sluggish than in the other 
states.” (Haliday, Ent. Mag. 15. p. 440.) The larve are generally 
much paler coloured than the imago, being in some species blood red, 
whilst the imago is black ; in others, pale yellow. 
These insects are found upon various plants, sometimes swarming in 
immense profusion in various kinds of flowers, especially the large white 
hedge-convolvulus ; they are very agile, and often leap to a considerable 
distance when disturbed. They feed upon the juices of plants, and 
are often extremely injurious, especially in hot-houses and vine- 
houses; the leaves upon which they reside being marked all over 
with small decayed patches. They also, especially, infest melons, cu- 
cumbers, kidney beans, &c. Various plans for their extirpation are 
given in the Gardener's Magazine, and in Major's work on the insects 
which infest fruit trees. 
One species, to which Mr. Haliday has applied the specific name of 
Thrips cerealium, infests the wheat, sometimes to a mischievous 
extent. This species was observed by Mr. Kirby, between the 
internal valve of the corolla and the grain, and taking its station in 
the furrow of the seed, in the bottom of which it seems to fix its 
rostrum, and by depriving it of its moisture, occasions it to shrink up, 
and become what the farmers call pungled, One sex of this species is 
apterous ; the larva is yellow and very nimble, and the pupa whitish, 
with black eyes, and very slow and sluggish. (Linn. Trans. vol. iii. 
p: 247.) 
According to Vassalli Eandi (quoted by Mr. Haliday), this species 
also gnaws the stems above the knots, and causes the abortion of the 
ear. In the year 1805, one third of the wheat crop in Piedmont 
is said to have been destroyed by this minute insect ; and in the same 
year the wheat crops in England suffered materially from a similar 
cause. 
Another species is very injurious to the olive tree in the territory 
of Pietro Santa in Tuscany, fixing itself on the under side of the 
leaves. As early as the month of April, four or five eggs are de- 
posited on each bud; and, as the generations of the insect succeed 
from spring to the end of autumn, the number of insects becomes 
inconceivable. (Passerini, “ Alcune notizie sopra una specie d’Insetto 
