31G GREENHOUSE MANAGEMENT. 



spis, Lecanium, and others which differ principally in the 

 shape, or the markings of the scale. They are all suck- 

 ing insects and must be killed by the use of kerosene 

 emulsion and similar remedies. Using hydrocyanic acid 

 gas is among the most effective methods of treating 

 them. The males are nearly all winged, but the fe- 

 males have but little power of locomotion, being wing- 

 less and with but poorly developed legs. While often 

 found upon plants that seem in perfect health, as a 

 rule, weak, unhealthy plants are most likely to be at- 

 tacked, and are most injured by them. 



SLUGS, SNAILS AND SOW BUGS. 



The damage done by the above-named animals is 

 often very great, especially by the slugs, which seem to 

 delight in eating off young seedlings. In modern well- 

 built houses they are far less troublesome than in the 

 old style of houses, that are generally damp, dark and 

 with more or less of rotting wood. If flats, bits of board 

 and other rubbish are not allowed to lie around under 

 the benches, there will be little danger of their appear- 

 ance in houses that are well lighted and properly venti- 

 lated. Neatness, then, should always be used as a preven- 

 tive. If they make their appearance, they can often be 

 held in check by sprinkling air-slaked lime over as well 

 as under the benches. This will help both in drying up 

 the surplus moisture and by its caustic action destroy or 

 drive away the slugs and similar animals. "Traps" are 

 also quite useful, as, by placing cabbage or lettuce leaves 

 where they are numerous, the slugs and sow bugs will 

 collect beneath them and if they are sprinkled with Paris 

 green many of them will be killed. Sweetened bran also 

 has an attraction, particularly for the slugs, and the 

 addition of Paris green will soon clean them out. Bits 

 of carrot poisoned with some arsenite are also good traps 

 for sow bugs. 



