1170 



ORCHID 



ORCHID 



aged, and enlist the energy of every Orchid culturist, 

 not necessarily for the production of hybrids alone, but 

 also for the reproduction of rare species and varieties, and 

 a number of species which are fast decreasing or becom- 

 ing extinct in their native homes. Aside from the finan- 

 cial inducement offered the commercial grower, it will 



apices and on new growths of deciduous and plicate- 

 leaved species, indicate either lack of suflficient water 

 at the roots or an overdry atmosphere, both of which 

 conditions can be easily changed. 



Snails and /nsee^s. — Orchids are attacked by many 

 forms of snails. Insect pests are a great annoyance 



1586. Eight months from 



{Phaius Wallichii.) 



1587. A year from the seed. 

 iCattleya intermedia X C. labiata.) 



prove instructive to the botanist and afford infinite 

 pleasure and pastime for the amateur. 



Z>iA-ertses. — Orchids are subject to many diseases. 

 Those having importance from a cultural standpoint and 

 most troublesome to the grower are known as wet- and 

 dry-rot and spot. Wet-rot is caused by an overmoist or 

 stagnant atmosphere, and is usually first detected by a 

 semi-transparent appearance of the parts affected, which 

 soon become dark brown. It spreads slowly along the 

 tissue. If noticed at the commencement it can be 

 readily checked by slitting the epidermis with a sharp 

 knife and removing the plant to a more airy position in 

 the house for a few days. Dry-rot is caused by a fun- 

 gus which attacks the rhizome of the plant. It is often 

 produced through burying the rhizome or base of the 

 plant with compost. Cypripediums are subject to it. 

 Large, healthy growths when attacked quickly show a 

 sickly pale color in the foliage, which, on examination of 

 the base, will be found discolored, and with a light 

 brown appearance. If the portion attacked is quickly 

 removed with a sharp knife it will usually give no fur- 

 ther trouble; otherwise it will travel through the en- 

 tire rhizome and destroy the plant in a very short time. 



Spot comes from various causes: the appearance of 

 small dark brown spots on the succulent leaves and 

 pseudobulbs is usually an indication of cold and over- 

 watering. Spot also arises through weak tissue, espe- 

 cially in Phalsenopsis, Saccolabiums and Angraecums 

 during winter, which have been grown too warm, shady 

 and moist. The affected parts should be slit with a 



1589. Two-year-old hybrid between a Cattleya 

 and Lselia. 



sharp knife and a little flowers of sulfur should be 

 rubbed over the wound. When they make new growth 

 the plants should be placed in a brighter and more airy 

 position to induce a better growth. The brown dots which 

 make their appearance on the leaves, especially at the 



to the cultivator. They can be kept in subjection only 

 by constant attention. Slugs and shell snails are very 

 destructive. If allowed to increase they devour young 

 shoots, roots and flower-buds. The best means of captur- 

 ing them is to place saucers of dry bran on the shelves 

 among the pots, and look them over morning and even- 

 ing. By this means many will be destroyed. Various 

 species of scale insects attach themselves to the leaves, 

 pseudobulbs and rhizomes of nearly all species of Or- 

 chids, and can be eradicated only by tlie use of a soft brush 

 and washing with a sponge and water. A little whale- 

 oil soap added to the water is of great assistance, and 

 also useful in destroying red spider and green and yel- 

 low fly. Black and red thrips attack the young growths 

 of many species and often become very troublesome. 

 Fumigating the houses with tobacco stems lightly about 

 three times during the week will soon cause them to dis- 

 appear. Fumigation is also a sure remedy for green fly. 



The Cattleya fly is very injurious to young growths of 

 Cattleyas, Lselias and some Epidendrums. The flies 

 lay their eggs in the very young growth at the base, 

 causing an enlargement which is easily distinguished. 

 The only remedy is to remove the growth, and burn it. 

 The mature fly can be eradicated by fumigating the 

 house with tobacco stems about three times each week 

 during early spring. 



The Dendrobixim beetle larva burrows in the stems of 

 various species of the genus, and is detected by a small 

 discolored spot. There is no remedy, except to cut 

 away and destroy the parts attacked. An insect which 

 is much more to be dreaded is the Dendrobium mite, 

 which perforates the canes and rhizomes of Dendro- 

 biums and many other Orchids, laying a number of 

 eggs in each perforation. On hatching, these eat away 

 a part of the plant around them, causing that portion to 

 decay. They can be found only by careful and close 

 observation, and this often after the plant is beyond 

 redemption. There is no remedy but cutting them out, 

 and unless the plant attacked is valuable it is best to 

 burn it and keep the pest from spreading-. 



Mealy bug is usually not very troublesome to Or- 

 chids. It is readily seen and destroyed without much 

 injury to the plant. 



Roaches are usually very troublesome, and hard to 

 eradicate, as they feed at night and remain hidden 

 through the daytime. They destroy roots, growing 

 shoots and young flower-buds and scapes. Bran, pow- 

 dered sugar and Paris green, mixed together and placed 

 around the houses in saucers, will usually keep them in 

 subjection, and they should be hunted down at night 

 l>y the aid of a lantern. Many can be caught in this 

 manner. 



Sow bugs or wood Hce are usually common in every 

 part of Orchid houses, pots and baskets. They do a 

 great deal of damae:e to young leaves, roots and the ten- 

 der portions of flower-scapes. The Paris erreen mixture 

 used for roaches is very effectual in reducing their 

 number, but it is impossible to be entirely freed from 

 tbem. Robert M. Grey. 



