CULTIVATION. 
375 
and syringing the plant. They are generally found 
on species of Adiantum, Pellcea, Platyloma, Doryo- 
pteris, Hemionites cordlfolia, and other genera having 
fronds of a smooth, chestnut-brown colour. Within 
the last twenty years a small, white-winged insect, like 
.a midge, has made its appearance (supposed to have 
been first introduced with imported plants to Kew). 
They congregate on the under side of the fronds, and, 
when the plant is moved, dart off like a flock of 
white pigeons. At first it was supposed to be harm- 
less ; but such is not the case, as it has been found 
to feed on the cuticle like thrips ; but they are not so 
•easily caught. Repeated tobacco fumigation destroys 
it.* Red spider seldom attack Ferns ; when such is 
the case, it is a sure sign that the air of the house 
is too dry. 
Few plant-houses are exempt from the well-known 
cockroach, which when once introduced is one of the 
greatest of pests. They increase and multiply most 
rapidly, and are most voracious feeders, eating and 
gnawing the fronds of Ferns, old and young, often 
■completely in one night spoiling fine plants ; there- 
fore war in all its forms must be waged against 
them. They are night marauders, hiding and breed- 
ing in crevices of masonry in dark places, generally 
near the furnaces, or hottest parts of the heating-pipes, 
.and are even found lurking amongst the drainage, in 
large pots, from which they issue at dusk to commence 
their ravages. Many expedients are resorted to for 
their destruction, such as attacking them in their day 
* This insect has been described and figured in the 
■Gardeners’ Chronicle, of 1856, by Mr. Westwood, uuder the 
name of Aleyrodes vaporariorum. 
