Appendix. 505 



B. BENEFICIAL INSECTS. 



Little notice has been drawn to the many insects which can only 

 be looked upon as beneficial on account of their tending to keep down an 

 access of other insect life. After many years' observations the writer is 

 inclined to believe that they are quite competent to keep the balance of 

 Xature but are quite incompetent to restore that balance of Nature upset 

 by man. One or two cases of the benefit of such introduced " friends " are 

 known, such as the cushion scale and the Vedalia ladybird one hears so 

 much of, and which seems to have been made a jumping-plank for anyone 

 to write and talk about. 



t 



[F. Edenden. 



FIG. 326. APHIS DESTROYERS. 



1, Syrphus ribesii ; 2, Catabomba pyrastri ; 3, Syrphus balteatus ; 4, pupa of 

 Ladybird Beetle ; 5, Coceinella ~-pumtata ; 6, Chrysopa perla. 



Some references have been made in this work to what Mr. Froggatt 

 and Mr. Lounsbury in their travels have seen of these wonders in other 

 countries, and this must surely settle the minds of any of the blind 

 followers of the wonderful powers of insect friends. As Mr. Froggatt 

 told me, when one wanted to see the working, for instance, of the intro- 

 duced Codling Moth parasite in California, they were unable to show it 

 him in the field. 



That come insects prey upon others, every grower knows. When his 

 fruit has been spoiled by aphis, and his hops blighted by the same, swarms 



