No. 4.] INJURIOUS INSECTS. 159 



Natural Enemies. 



The natural enemies of the San Jose scale, so far as 

 known, are comparatively few. Three or four minute 

 Hymenopterous parasites have been bred from it, but so 

 far as I can learn they produce no appreciable reduction in 

 the numbers of the scales. Several predaceous beetles are 

 known to feed on them, as the pitiful lady bird {Pentilia 

 misella) in the south and west, and the twice-stabbed lady 

 bird ( Ohilocorus hivulnerus) ; and Mr. Kirkland informed 

 me that he found the two-spotted lady bird (Adalia hipunc- 

 tata) feeding on the San Jose scale in Auburndale, Mass., 

 on October 9. 



Prof. P. H. Rolfs of the Florida Agricultural Experiment 

 Station issued a bulletin last August, in which he gave an 

 account of the discovery in that State of a fungus attacking 

 and destroying the San Jose scale and also other species of 

 scale. This fungus {8phaerostilbe coccophila) was found to 

 destroy the San Jose scale by penetrating all through the 

 substance of the insect, causing the death of large quantities, 

 and as they dried and shrivelled they fell off, leaving the sur- 

 face of the tree entirely clean, so that, when not too severely 

 aflfected, the tree entirely recovered. Professor Rolfs made 

 a careful study of this fungus, and, after experimenting with 

 it on various substances to obtain a pure culture, found that 

 he succeeded best when the fungus was grown on slightly 

 acid bread, for the fungus permeated the whole piece and 

 produced myriads of spores. A piece of this bread about an 

 inch square was placed in a quart of water and shaken until 

 it was broken up, and the spores evenly distributed in the 

 water. This was then applied to the scale-infested tree by 

 means of a sponge or cloth, or was sprayed on. Warm, damp 

 weather proved favorable to the development and multipli- 

 cation of the fungus and the consequent destruction of the 

 scales, while dry weather was unfavorable to its growth. It 

 was recommended to make the application after sundown on 

 a moist evening, or, if the weather was dry, to wrap moist 

 burlap or other cloth loosely around the treated limbs, for 

 he found that it was only a question of a few hours whether 

 the spores were to produce the disease, or die. If they were 



