PLANTS — INSECTTCIDAL PROPERTIES. 31 



Chilocoan or Chilcoagua. (See footnote on page 26.) 



Herrera (40, p. 21) obtained no practical results by using this plant 

 against the winged forms of fruit maggots. 



Chrosperma muscaetoxicum (Walt.) Kuntze. Liliaceae. Synonyms: Ami- 

 anthium muscaetoxicum A. Gray, Melanthium muscaetoxicum Walt., Zygadenus 

 muscitoxicum Regel, Helonias erythrosperma Michx. Crow poison. Eastern 

 United States. 



Elliott (23) says : " This plant is a narcotic poison, and is em- 

 ployed in some families for destroying the house-fly. The bulbs are 

 triturated and mixed with molasses or honey, and the preparation is 

 spread upon plates and placed in parts of the house most infested. 

 The flies are soon attracted, and the poison takes effect while they 

 are sipping it. They are perceived to stand unsteadily, totter, and 

 fall supine. The flies, unless swept in a fire or otherwise destroyed, 

 revive in the course of 24 hours." 



Lyons (53, p. 117) says that the bulbs are used as an insecticide. 



The writers' results are given on page 5. 



Chrysanthemum achilleae L. Asteeaceae. Synonym : Pyrethrum achilleae 

 DC. Italy. 



Passerini (66) found that the opened flower heads had some effect 

 on flies, fleas, and ants; they were not much inferior to those of P. 



cine rariaefo Hum . 



Chrysanthemum caucasicum (Willd.) Pers. Caucasian region. 



According to Bishop (11), Persian insect powder is made from 

 this species, but more reliable authors deny this statement. 



Chrysanthemum cinerariaefolium (Trev.) Vis. Synonym: Pyrethrum cin- 

 erariaefolium Trev. Dalmatian insect flowers. Dalmatia. Cultivated in 

 Japan and California. 



The powdered flower heads of this plant constitute the well-known 

 Dalmatian insect powder, and the Insecticide and Fungicide Board 

 of the United States Department of Agriculture (57, p. 1) recognizes 

 it as one of the three species from which genuine insect powder is 

 made. 



Passerini (66) tested the powdered heads and leaves of this plant 

 and 14 other species belonging to Asteraceae and concluded by say- 

 ing that not one of the 14 species has properties so powerful or so 

 swift in its action against the house fly (Musca domestica L.), or 

 the dog flea (Ctenocephahis canis Curt.) or against ants (Cremasto- 

 g aster scutellaris Oli v. ) , as has this species. He "states that when 

 all parts of the plant are reduced to powder, they are active; the 

 leaves, stems, and roots in a somewhat less degree than the flower 

 heads. Scott, Abbott, and Dudley (83, p. 7, 10) determined that pow- 

 dered pyrethrum stems had little or no practical value against bed- 

 bugs and cockroaches. Scott and Abbott (57, p. 81) ascertained that 

 the stems and bracts (small leaves) were ineffective against roaches. 

 Abbott (1, p. 8, llf) found pyrethrum stems to have no value against 

 chicken lice and the dog flea. Mr. Abbott, Entomologist, Enforce- 

 ment of the U. S. Insecticide Act, authorizes the writers to use the 

 following statement, taken from his unpublished notes : " Pyrethrum 

 stems are inefficient against 6 species of ants, 9 species of aphids, 

 bedbugs, 3 species of chicken lice, chicken mites, clothes moth larva?, 



