162 FERNS AND LYCOPODS. 



Insect Enemies If the plants are not subjected to adverse condi- 

 tions, such as too high a temperature, or insufficient moisture in the air 

 or at the roots, they will seldom be attacked by insects. The Mealy 

 Bug, Thrips and Brown Scale, are sometimes troublesome. Scale is not 

 easy to remove, and the only efficacious method is to use a sponge and 

 water. For the other insects fumigation or vaporizing may be resorted 

 to, or, if only a few plants are affected, they may be laid on their sides 

 and the insects removed by using the hose. Slugs are the greatest ene- 

 mies of the Ferns, and a close watch should be kept for them. Various 

 methods are employed to capture them, such as a board smeared on the 

 under side with lard, cabbage leaves, and sliced turnips, or potatoes laid 

 among the plants; or by using camphor among the pots, and air-slacked 

 lime on and under the benches. If the slugs are numerous, hand-picking 

 should first be resorted to. They feed at night and rest during the day. 

 They will usually be found in the angular space beneath the rims of the 

 pots. 



