1222 MEANS OF PREVENTION AND CONTROI. 



plants. On the other hand specimens were gathered on Cymbidium Tracya- 

 num, Aralia Reginae, Kentia sp. and Arenga sp., but in small quantity and 

 also attacked by the same endoparasite. 



No such effective parasitism takes place on the citrus plants in full 

 cultivation infested by the " bianca-rossa " {Chrys. dictyospermi) . The 

 case observed by the writer might therefore be explained by the mild 

 temperature and tranquillity which are peculiar to the environments consti- 

 tuted by glass houses, and in the fact that this polj^phagous (or, more accu- 

 rately, polj-xenous) insect was compelled for several successive generations 

 during the year to la^^ its eggs on the same diaspid, which relatively, was 

 not numerous. 



949 - An undetermined Nematode Worm Parasitic on Aphids.— d.wis j. John., in 



Psyche, Vol. XXIII, No. i, pp. 39-40, Fig i. Boston, Mass., igi6. 



The writer has discovered an as yet undetermined nematode in the in- 

 terior of the bod}' of some aphids [Anoecia sp.) li\4ng at a slight depth on 

 the roots of Mnhlenbergia in the evirons of Lafayette, Indiana. 



This is a very rare case of parasitism. In 1899, Del Guercio also de- 

 scribed a nematode as a parasite and natural enemy of Erama radicis Kal- 

 tenbach. Other cases of this kind had not been reported since. 



950 - Nicotine Products tried in Germany against " Cochylis " and " Eudemis. " — 



KoTZEL in LandwiitschoHlichc Zeilschrif fiir die R)uinp<ovinz. 17th Ytar, No. 18, pp. ;6i- 

 265. Bonn, May 5, 1916. 



In the spring and autumn of 1915, in two vineyards containing 2400 

 stocks, at Bullaya. d. Mosel, the writer carried out experiments of control 

 of "Cochylis" and "Eudemis, " with the following nicotine substances : 

 i) " Nikotin Florkus Pulver " of the brothers Nordhnger, at Florsheim ; 

 2) " Queria-Heu-und Sauerwurmpulver " of Otto Hinsberg, at Nackenheim 

 a. Rh.; 3) tobacco juice containing 9-10 % of nicotine, with the addition of 

 a I % solution of cotton oil soap. 



The nicotine powders considered to be most effective against " Coch^'lis " 

 were applied under strong pressure, on the ist June, when the larvae had 

 attained a length of 2-3 mm. The directions for use of the products in 

 question state that at that time alone it is possible to obtain the best results 

 with the powders. 



The tobacco juice was dissolved in water (1.5 gallons to 100 gallons 

 of water), then applied on different bunches on the 2nd June, immediately 

 after oviposition. 



The result of the treatment was observable as early as the end of June, 

 in counting the coccids on the different branches. A vineyard 5 years old, 

 which was divided into 3 plots, contained on 40 stocks, the following 

 numbers of larvae per plot. 



Plot I : treated with nicotine solution — 148 larvae 



" " " Queria " powder — 270 " 



" " " Nikotin- Florkus "' powaer . — 138 



In an old vineyard there were counted, for 40 stocks the following num- 

 ber of larvae : 



