PLANTS INSECTICIDAL PROPERTIES. 35 



Cytisus scoparius (L.) Link. Faba'ceae. Scotch broom. Europe. 



An infusion (8), made from fresh crushed broom tops, is recom- 

 mended to kill the larva? of cabbage butterflies. In France it has 

 also been found very effective for removing Cochylis larvae from 

 vines and various caterpillars from apple trees. 



The writers' results are given on page 22. 



Dasystoma flava (L.) Wood. Sckophtjlariaceae. Synonym: Gerardia flavali. 



Porcher (68, p. 509) says: "This plant, it is said, will prevent 

 the attacks of yellow and other flies upon horses." 



Datura stramonium L. Solanaceae. Jimsonweed. Jamestown weed. A 

 cosmopolitan weed. 



Riley (71, p. 184) reports that neither the alcoholic extract from 

 the dried seed or leaves, nor a decoction from the leaves, was effective 

 against cotton caterpillars. 



Fernald (2 If,, p. 10) determined that a strong infusion of the leaves, 

 had no effect on potato beetles, rose beetles, or the larva? of 

 Vanessa milberti. 



McClintock, Hamilton, and Lowe (58, p. 233) ascertained that the 

 leaves, used as a fumigant, were effective against bedbugs, roaches, 

 flies, clothes moths, and mosquitoes, but they were not efficient. 



Sprenger (88) recommends the decoction as an insecticide. 



Cook, Hutchison, and Scales (17, p. 14) determined that a sul- 

 phuric-acid extract of the leaves was of no value against fly larvae. 



The writers' results are given on page 22. 



Delphinium ajacis L. Ranunculaceae. Rocket larkspur. Southern Europe, 

 and cultivated in gardens. 



Greshoff (31, p. 8) lists it as an insecticide. 



Williams (95), after testing against bedbugs the extracts, derived 

 from the seeds by using various solvents, decided that the insecticidal 

 value of the seeds is due mostly to the oil present in them, while the 

 alkaloid in them plays an insignificant part. 



Delphinium bicolor Xutt. Low larkspur. Western North America. 

 The writers' results are given on page 22. 



Delphinium brunonianum Royle. Musk larkspur. Himalayan region. 



Greshoff (31, p. 7) reports that the juice is used to destroy ticks 

 on animals. 



Delphinium caeruleum Jacquem. Himalayan region. 



Greshoff (31, p. 7) reports that the roots are used to kill maggots. 



Delphinium consolida L. Field larkspur. Central Europe, cultivated in 

 gardens and adventive in the United States. 



Williams (94, p. 875) says : "A tincture, prepared by infusing an 

 ounce of the seeds in a pint of alcohol * * * kills lice on the 

 human head." 



Porcher (68, p. 18) reports that the tincture of the plant is de- 

 structive to insects on children's heads. 



Riley (71, p. 114), quoting a correspondent, says: "I have found 

 the common larkspur an effective poison on insects." 



