'46 



some of them being regularly infested, such as young elms and 

 pelargoniums, and others only occasionally. Both the upper and 

 underground portions of the plants are attacked and even the fruits. 

 Generally it is the underground portions only that sufier, but if the 

 branches are weakened or damaged in any way infestation frequently 

 occurs in such spots. 



After many preliminary trials with plants in pots, four substances 

 were selected for trial upon trees ; these were mercury bichloride and 

 sea-salt, potassium ferricyanide, potassium ferrocyanide and sodium 

 hyposulphite. These were used in a 3 per cent, solution of the liquids 

 applied in the preliminary trials. A trench was dug round each tree 

 large enough to take 40 to 60 gals, of water in which 3 per cent, of one 

 of the solutions had previously been mixed. This application was 

 repeated two or three times at two days' interval ; the hole was then 

 filled up. ' In 1911 a spring and autumn treatment was given, in 

 1912 a winter treatment was added. The results showed that at 

 least two years' treatment was necessary to make any very appreciable 

 difference to the trees. The sodium hyposulphite proved useless, 

 the trees showing no change after treatment. After two years, trees 

 treated with bichloride of mercury or ferrocyanide of potassium showed 

 no trace of termites ; those treated with ferricyanide of potassium 

 showed a decided improvement in their general condition. 



Another series of experiments was conducted with plants used for 

 food, such as potatoes, oats, etc., the same solutions at suitable strength 

 being used and applied to the soil only, never to the leaves. As 

 many as ten applications were made, and about 10 days after the 

 last one the plants were taken up and chemically examined. The 

 results of this analysis on potatoes, oats and wallflowers are given 

 and also of a similar experiment with cabbage, beans and potatoes. 

 The plants thus analysed showed distinct traces of the substances 

 with which they had been treated; their vitality with regard to 

 germination was, however, in no way impaired. Cabbages treated 

 with each of the three solutions were after 4 days given to rabbits 

 which had previously been fasting for 12 hours, apparently without 

 any harmful results. These experiments would have been continued 

 in the field during 1914 if the War had not intervened. 



RoEPKE (W.). Het Orchideeen-Blauwtje {Chliaria dendrobii). [The 

 Orchid Lycaenid, C. dendrobii.] — Teijsmannia, Batavia, xxx, 

 no. 3, 1919, pp. 115-121, 1 plate. 



At the end of 1917 a Lycaenid caterpillar was observed destroying 

 the flowers of an orchid, Dendrobium jjhalaenopsis, and it is here 

 described as Chliaria dendrobii, sp. n. These butterflies are often 

 seen near orchids on the flower-clusters and stalks of which the eggs 

 are laid, the buds of SjMthoglotti^ being especially preferred. 

 The young caterpillars immediately bore into the buds and feed in 

 the interior. The open flowers of Spathogloltis seem unsuitable and 

 the majoritv of young caterpillars found in them perish. The orchids 

 attacked include Dendrobimn spp., Phalaenop.sis spp., and Arimdina 

 spp. To combat this pest the captur*^ of the adults is advised, or the 

 eggs may be collected from the plants. 



