ENTOMOLOGY. 665 



insects, some of which have already been named, are briefly sum- 

 marized : 



In his historical review of investigations on the San Jose or perni- 

 cious scale (Aspidiolus perniciosus) the author states that probably the 

 insect was introduced into South America (its supposed original home) 

 on trees from California, for it has not yet been found there on native 

 plants, it has been supposed to have originated from Australia, the 

 Pacific islands, and Japan, but no known facts justify a definite state 

 ment as to its originating in any of these places. 



The history of the scale in the United States is briefly discussed, and 

 its introduction into New Jersey is treated at some length. On the 

 recommendation of the State board of agriculture the State legisla- 

 ture in 1896 appropriated $1,000 for studying the scale. The author 

 made a trip through the Southwest, California, and into Oregon to 

 study the scale, and an account of this journey is given. The accounts 

 ' of various people in California were very conflicting, witli the excep- 

 tion of those relating to the usefulness of Vedalia cardinalis, which is 

 stated to have almost exterminated the cotton cushion scale (Icerya 

 purchasi). In Santa Barbara olive orchards once badly infested with 

 the black scale were found among the cleanest seen, and this difference 

 in condition was said to be due to coccinelids entirely. Of these 

 Rhizobius ventralis was claimed to be most active. At Los Angeles 

 the twice stabbed ladybird {Ghiloeorus bivulnerus) i> chiefly relied upon 

 in combating the pernicious scale. At other places no dependence 

 whatever was placed upon predaceous insects, but a resinous spray was 

 used as a remedy. In other localities sprays were in disrepute. 



Relative to Rhizobius the author states that /.'. debilis plays the most 

 important role in the destruction of the scale, and that this species is 

 found abundantly only in Santa Barbara County. What was called 

 R. (lebilis elsewhere was found upon investigation to be R. lophantce or 

 Scymn us margin ieollis. 



Resummarizing his discussion and bringing out the question of the 

 desirability of introducing predaceous insects into New Jersey, the 

 author says, in substance, that the conditions in California can not be 

 duplicated in Xew Jersey. South of San Francisco some six or eight 

 weeks before the scale begins to reproduce it is preyed upon by Ghilo- 

 eorus bivulnerus and Aphelinusfuscipennis. \u some places these insects 

 may feed upon it during its entire dormant period. When the scale is 

 most sluggish and reproducing slowly (during the hottest season) 

 Rhizobius lophantce is most active, in Xew Jersey G. bivulnerus and 

 A. fuscipennis are native. R. lophantce might be introduced, but it 

 would be at a disadvantage, since it would not get as early a start as 

 in California, nor would it be favored by a decreased activity of the 

 scale. 



Further, the scale has in New Jersey the advantage over all its ene- 

 mies by breeding a month longer than they do. Another reason 



