FIELD NATURALISTS CLUB 



249 



number of flowers, in shape like those of 0. luridum, in size like 

 those of 0. lanceanum, and in colour, olive green or yellowish 

 green, spotted with chocolate brown, or reddish brown, as regards 

 the sepals and petals, but blood red and bright yellow as regards the 

 lip, with purplish violet tubercular processes and column, was the 

 result of a natural cross between the two species above mentioned. 

 In one of the two kinds, the lip is blood red with a narrow 

 border of yellow in which a few dots and dashes of blood 

 red appear. 



In the other, and perhaps the more beautiful kind, the 

 blood red blotch is very small, and the yellow border predomi- 

 nates, the column and operculum with the rather pronounced 

 tubercular processes being of a violet or purplish violet colour. 



This natural hybrid, grows easily and to perfection if 

 treated similarly to 0. lanceanum. It is very free flowering if 

 exposed to strong diffused daylight, and the flowers last about 

 three weeks in beauty. 



It is, however, extremely rare, and as it closely resembles 

 both 0. luridum and 0. lanceanum, it is very difficult, for 

 an inexperienced person to distinguish it from them when 

 it is out of bloom, and hence many amateurs have met with 

 sad disappointments in attempting to obtain a specimen. 

 The advice I would therefore give is : never buy a plant 

 out of bloom, unless guaranteed by a respectable person. 



The three Oncidiums just described though very easily 

 grown in this their native colony with ordinary care are never- 

 theless subject to the ravages of an insect, a species of Capsus, 

 one of the plant bugs, which if not speedily exterminated, raises 

 a large family on the under sides of the leaves and by sucking 

 the sap from these parts they dessicate the leaves and thus 

 destroy the healthiest plant. 



This Capsus is particularly fond of thick or coriaceous leaved 

 orchids and affects not only these Oncidiums but Epidendru,ms 

 also including the Cattleya genus and last year it nearly 

 destroyed a very fine plant of Diacrium bicornutum in my 

 collection, just as the plant was sending forth its flower spikes. 

 Through the kind assistance of Prof. Howard of the United 

 States' Department of Agriculture, an honorary member of 

 our Club, I was able to get the genus of this orchid 

 pest determined, and he suggests the application of a dilute solu- 

 tion of kerosine emulsion as an effective remedy. My own 

 method of getting rid of them was to seek them out and destroy 

 the whole brood, and this I did with such good results that on 

 the receipt of Prof. Howard's remedy I was not able to find a 

 single plant in my fairly large collection with Capsua on it, and 

 therefore I am not able to say what effect it has on them, though 

 I feel certain it is an excellent remedy. 



