86 OKCHID-GROWEB S MANUAL. 



young growths were sufficiently formed to show whether or 

 not there was any appearance of the swelling of the bulb, and 

 if not he felt safe, and removed them to their permanent 

 quarters. This probationary treatment is a wise plan to adopt. 



Black Thrips. There is another new pest which has only 

 come under our notice during the past year ; that is a black 

 Thrips, much larger than the one we have been in the habit of 

 seeing. We have noticed it in several collections of East 

 Indian Orchids, and it must have been imported among some 

 of the Aerides or Vanclas. This pest finds its way to the 

 hearts of the plants, and causes the top leaves to become 

 spotted or yellow ; it must be closely and constantly 

 watched for, the hearts of the plants especially being well 

 searched ; and if any of them should appear their destruction 

 must be set about at once, no rest being given until they are 

 banished from their haunts. For the purpose of destroying 

 them use a fine hair brush wetted with tobacco water care- 

 fully, so that the young leaves may not be bruised ; then take 

 all the material out of the pot and burn it, wash the roots, and 

 supply fresh moss, as they might accumulate among the roots. 

 It is best to remove the infested plants to another house until 

 the pest has been entirely subdued. When the}- are thoroughly 

 cleared of the thrips take the plants back to the house, but 

 keep a close watch upon thsm. 



Stock-seed Scale. There is also a scale insect which has 

 made its way into our collections during the last few years ; it 

 is known to Orchidists as the Stock-seed Scale, and is so 

 named from its close resemblance to the seed of the stock. 

 This generally gets under the leaves and flower spikes, and 

 must be washed off" the plants. Some persons think they are 

 harmless, but they do harm, because they must exist upon 

 something, and that something must be the juices of the plant. 

 They increase rapidly, and go from plant to plant. Where 



