432 Forty- SIXTH Report on the State Museum 



subsequently found that the sprayings had failed to destroy the Qg^9. 

 Full success, however, was attained by a spraying of emulsion con- 

 taining thirteen per cent of kerosene, on April 24th, just as the buds of 

 the apple were beginning to burst. The aphides were hatching from 

 the eggs at this time, and they were almost entirely destroyed. This, 

 therefore, may be accepted as the most vulnerable period in the life of 

 the insect. (See the report above cited.) 



Soapsuds for the Cabbage Aphis. — Kerosene emulsion has been 

 recommended for killing the plant-lice that often congregate in immense 

 numbers on the leaves of cabbage, but if the emulsion is used of the 

 proper strength to kill the insect, it also imparts a permanent flavor of 

 kerosene to the plant. In trials made at the South Dakota Station of 

 various insecticides, strong soapsuds gave better satisfaction than any 

 other remedy and proved highly efficacious. While most fluid applica- 

 tions were found to roll off from the aphides without wetting them, the 

 soap solution readily penetrated the gray powdery substance which 

 covers their body and killed them. (South Dakota Agricultural 

 Experiment Station, Bulletm No. 30, March, 1892.) 



Plant-lice and Red Spiders on Rose hushes. — Professor C. H. Fernald, 

 of the Hatch [Massachusetts] Agricultural Experiment Station, reports 

 that potted rosebushes of different varieties, every twig of which was 

 literally covered with the aphides, and more or less the surface of the 

 leaves, and also having the red spider, Tetranychus telarius (Linn.) 

 exceedingly numerous on the leaves, were inserted and held for about 

 a quarter of a minute in a pailful of kerosene emulsion, with this 

 result: two days thereafter, examination of the bushes failed to show 

 either a single living plant-louse or red spider; and none appeared on 

 them for the rest of the season. 



Spraying ajsd Insecticides. 



A few notes on what is being done in spraying for insect pests, and 

 on some new insecticides, may not be out of place at this time. 



Experiiments with Paris Green on Tent Caterpillars. — Professor 

 Fernald reports that with one pound of Paris green to 1,000 gallons of 

 water, all the caterpillars placed on the leaves died within twelve days. 

 One pound to 150 gallons of water burned the foliage and injured the 

 tree considerably. The best proportion for use on apple trees appeared 

 to be, one pound of Paris green to 200, 250 or 300 gallons of water; 

 even the last-named strength killed all the caterpillars within two days; 

 with a dilution of 400 gallons, all were dead in three days. 



Paris Green on the Gypsy 3Ioth Caterpillar. — That Paris green has 

 failed to give entire success in killing the Ocneria caterpillar, is 



