58 BRITISH FERNS 



stage, the winged perfect insect commences to flit about. Keeping 

 this fact in mind it is obvious that we have about a month in which, 

 if attacked properly, we can absolutely clear all the plants without 

 a chance of reappearance, unless other infected plants be intro- 

 duced. Our remedy, which we have found to be exceedingly 

 efficacious, is to use the liquid form of the "XL All" insecticide, 

 which is vaporized by means of a small spirit lamp and an in- 

 expensive apparatus, and, if used about the end of April, entirely 

 kills out the larvae which by that time will have all been hatched 

 out. It is equally effective later on when the fly appears on the wing, 

 but as some of these may be at that time in the short chrysaloid 

 stage, and therefore dormant, these will escape the fumes and 

 appear later on in sufficient numbers to re-establish the pest by 

 fresh eggs, which they are not long in laying, thus rendering a second 

 fumigation necessary. The same remedy is equally fatal to Green- 

 fly, and should be applied directly that pest makes its appearance. 

 The same remark applies to Thrips, of which the White-fly is 

 really a species. When using it, all ventilators should be closed 

 and everything done to prevent the intrusion of fresh air or escape 

 of poisoned air during the operation. The comparative proportions 

 of space to be fumigated are marked on the bottles in so many 

 square feet, which are easily calculated by multiplying the width 

 of the house by the length, and then by the height, the average 

 height being taken of the sloping roof. When the lamp is lit, the 

 house should be closed at once and not opened until the following 

 morning, a calm evening being chosen. 



The Weevil is a far more insidious foe and one much more diffi- 

 cult to deal with, since it is immune from all fumigatory remedies, 

 and even defies to a large extent, and in its beetle form entirely, 

 the other insecticides put on the market. This pest is far more 

 drastic in its operations than those already mentioned, since 

 starting with it in its grub form, a curved, fat white maggot, about 

 half an inch long, it devours the very rootstocks and roots of the 

 plants, in the soil of which the eggs have been laid the previous 

 autumn, so that in the early spring we may find the Fern loose in 

 the soil and probably entirely dead, or only to be resurrected by 

 one of the processes we describe in our chapter on Propagation. 

 The Beetle, an almost black insect, with an oval body, about a 

 third of an inch long and with a long proboscis flanked by two 

 antennas half-way down it at right angles, emerges from the soil 

 towards the end of April, and climbing up the fronds, preferring 

 the rising young ones, eats pieces out of the edges, and as these 

 gaps grow larger with the fronds the result is terrible disfigurement. 

 Hartstongues are especially to their taste, but by no means ex- 

 clusively so. Having described the two forms in which this pest 

 appears and its different modes of attack, we may now consider 

 the best means to frustrate its malignancy. The presence of the 



