NOTES AND ABSTRACTS. 4I7 
Inobulbum muniflcum. By J. Poupion {Rev. Hort. vol. xcii. pp. 64-66 ; 
2 figs.). — Inobulbum munificum Kranzlin and Dendrobium muncatum Finet 
from Noumea and New Caledonia are identical. It thrives under the same con- 
ditions as D. senile. Finet's opinion that there are two varieties of this orchid 
is incorrect. — S. E. W. 
Insect Powder. By McDonnell, Roark, and Keenan {U.S. Dep. Agr., Bull. 
824, June 3, 1920, pp. i-ioo • 4 plates). — Investigations were undertaken into 
the composition of insect powders on account of suspected adulteration. 
The Insecticide and Fungicide Board of the U.S. Department of Agriculture 
recognizes as insect powder an insecticide made from the powdered heads of the 
following : Chrysanthemum {Pyrethrum) cinerariaefoliumJBocc, C. (P.) roseum 
Web. and Mohr., and C. Marshalli Aschers. (P. curneum M.B.). The history 
of the use of insect powders is given, and is followed by notes on the cultiva- 
tion and harvesting of the flowers, which are commercially grown in Dalmatia, 
Japan, Australia, Algeria, and California, the first three named being the most 
important for international trade. 
Adulteration is common, and substances, such as lead chromate, curcuma, 
yellow ochre, and flowers of Ox-eye daisy, etc., are substituted, the last named 
occurring as a mixture or alone. 
The ground stems of the plants constitute over 95 per cent, of the adulterants 
used, and they are of little use as an insecticide. 
Twenty microphotographs are given as an aid to detection of adulterants, 
but this method, as yet, is inadequate to make an accurate determination 
possible. Physiological and chemical means of detecting adulteration appear 
to be the comparison of the sample to be tested with a known genuine 
sample. 
A formula, developed from the data of several hundred samples tested, 
is given by which it is possible to determine in an insect powder the approximate 
amount of added Pyrethrum stems present. 
Pp. 83-100 are devoted to a very complete bibliography. — G. F. W. 
Insect Visitors to Fruit Blossoms, Notes on. By C. H. Hooper {Jour. Pomology, 
vol. i.no. 2, pp. 116-1^4). — Some few notes are given on insect visitors to orchard 
and bush fruits. It is intended as a preliminary list, so that some scientific 
worker may take up this most important economic subject. 
According to D'Arcy W. Thompson's translation of Hermann Miiller's " The 
Fertilisation of Flowers," the numbers of different insects visiting fruit blossoms 
are as follows: Apple (16), pear (31), plum and cherry (14), raspberry (17), 
black currant (i), red currant (5), gooseberry (13), strawberry {25), and black- 
berry (68).— G. F. W. 
Insecticide Investigations. By A. L. Lovett {U.S.A. Exp. Stn. Oregon, Bull. 
169, April 1920, pp. 5-55). — The results of spraying tests, started in 1914 
by Professor H. T. Wilson, are described. 
With the help of fifteen tables and a concise summary, the results are made 
plain. Lead hydrogen arsenate (acid lead arsenate) has a higher killing power 
than basic lead arsenate, probably on account of its higher percentage of arsenic, 
and a higher proportion is assimilated by caterpillars ; but it is liable to bum 
foliage where free arsenious acid is present. 
All the arsenic is not assimilated by caterpillars, but a part of it passes through 
the digestive tract in the excrement. 
Three pounds of lead arsenate to 200 gallons of water was an effective 
spray for the early control of codling moth, and should be applied as a fine 
spray. 
P owdered forms are superior to paste forms, especially when one is far removed 
from the manufacturers. 
Much useful information is given of the value of " spreaders," the most 
efl&cient being casein, gelatine, glue, soap bark or saponin, and oil emulsion. 
Nicotine acts as a repellent for tent caterpillars, as they will not usually 
feed on foliage sprayed with it. 
The author recommends nicotine sulphate as an ovicide for codling-moth 
eggs, the addition of soap rendering it practically perfect in this respect. 
G. P. W. 
Ipomaea Pes-tigridis var. longlbracteata Linn. By S. A. Skan {Bat. Mag. 
t. 8806 ; June 191 9). — Native of Ugogo, etc.. East Tropical Africa. The flowers, 
produced in a warm house, are infundibuliform, white, about 2 J inches in 
diameter. The plant is an annual. — P. /. C. 
VOL. XL VI. 
