TREATMENT OF EPIPHYTAL ORCHIDS. 19 



5. Insects. 



In building an Orchid-house it is very desirable to have no 

 crevices or apertures left in any part of the walls, or round the 

 pipes, in which insects can harbour ; if such is the case little 

 hopes can be entertained of effectually ridding the house of such 

 pests as the cockroach, or even of keeping them sufficiently 

 under. 



The cockroach, which is the greatest enemy to Orchids, only 

 feeds by night, or in the dark ; he frequently finds his way into 

 the interior of the pots amongst the broken crocks, and eats all 

 the young roots unseen. These pests delight in the hottest parts 

 of the house, either in a moist or dry heat ; their food is chiefly 

 the tender points of the young roots and flower buds, and it is 

 amazing the mischief a single insect will do in one night, for if 

 the points of tlie young roots are once eaten off", the root is 

 rendered of no service to the plant until it again forms a fresh 

 point. 



The cockroach, however, is by no means nice as to his food, 

 for he sometimes has no objection to eat his dead companion ; 

 he will also eat any kind of fat or greasy matter, and this is 

 sometimes mixed with arsenic for his destruction, but with little 

 success, for he certainly prefers the tender points of the roots to 

 such food. Some employ toads and frogs to catch them, but 

 these are slow, and the cockroach is very nimble : they therefore 

 seldom come into contact. I have found from experience that 

 the only way to destroy, or at least to keep such pests from 

 doing any great damage, is to constantly look after tliem every 

 evening after dark, and particularly in the winter time, and kill 

 them ; this may easily be done if there are no crevices in the 

 walls or round the pipes for them to escape into. 



The woodlouse is another pest to Orchids : he may easily be 

 trapped in the usual way in the dark and damp corners, or he 

 may be fed with slices of potato placed upon the surface of the 

 pots. As these insects feed in the daytime as well as at night, 

 they are easily destroyed. 



Our next pest is the small brown ants, which, if not kept under, 

 in time, become so numerous as sometimes to entirely destroy 

 the plants. They are day enemies, however, and are easily de- 

 stroyed by arsenic in the following way : pound some loaf sugar 

 very fine, and mix with it a small portion of arsenic ; then grind 

 the mixture on a smootli piece of slate with the face of a hammer 

 into an impalpable powder, so that the little creatures cannot 

 separate the sugar from the arsenic ; then take some small pieces 

 of wliite card paper, put as much upon each as would lie upon a 

 shilling, and place it near where the ants frequent. The dose 



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