70 



PRACTICAL ZOOLOGY 



grown in the orchards of California, but since then the causes 

 have been found, and the remedy applied with satisfactory re- 

 sults. The figs did not ripen because their flowers were not 

 pollinized. When pollination was found to be accomplished by 

 a minute insect (Fig. 44, A), this insect was introduced into the 

 fig-growing districts of California and a successful new industry 

 established. 



Predaceous Insects. — Beneficial from another standpoint 



are predaceous and 

 parasitic insects. A 

 predaceous animal is 

 one that feeds directly 

 upon another. Most 

 insects feed on vege- 

 tation, that is, are 

 herbivorous, but a 

 goodly number devour 

 animal matter and 

 are carnivorous (Fig. 

 45). The latter per- 

 haps in the majority 

 of cases, feed upon 

 other insects, and 

 since as a general rule 

 insects are injurious, 

 it is safe to conclude 

 that predaceous insects are beneficial, although they may 

 occasionally destroy useful animals. 



Rivaling in interest the establishment of the fig industry in 

 California is that of the salvation of the orange and lemon trees 

 of the same region. Kellogg gives the facts in this case in the 

 following words: "In 1868 some young orange trees were 

 brought to Menlo Park (near San Francisco) from Australia. 

 These trees were undoubtedly infested by the fluted scale (Fig. 

 46), which is a native of Australia. These scale immigrants 



Fig. 46. — Australian ladybird beetle and fluted 

 scale, 

 a, larva; of beetle feeding on scale ; b, pupa of 

 beetle ; c, adult beetle ; d, orange twig showing 

 scales and beetles. (After Marlott.) 



