252 ENTOMOLOGICAL SOCIETY 



Considering that over 50 species of ladybirds were sent over 

 by Mr. Koebele, it is remarkable that so few of them have held 

 their own in California or multiplied so as to accomplish any 

 good. Orcus chalybeus and O. australasice, of which so much 

 was expected by Mr. Koebele and by the State Board of Horti 

 culture, are practically unknown to-day among fruit-growers, and 

 only found in comparatively few numbers where they were in 

 troduced. The two species of Rhizobius which have maintained 

 themselves show great variation in different localities. As a 

 consequence, the gas treatment is still being vigorously employed 

 by most of the people concerned, and by the county commission 

 ers, and where some insecticides or other preventive means is not 

 adopted, the orange groves are yet suffering from both the Red 

 and the Black Scales. The policy, however, of introducing para 

 sites and predaceous insects from abroad has a very strong hold 

 on the people of the State, but the present condition of things 

 fully justified the position which he had taken, and confirmed the 

 generarconclusions in his paper on "Parasitic and Predaceous 

 Insects in Applied Entomology," read at the meeting of the As 

 sociation of Economic Entomologists at Madison in August, 1893 

 (vide Insect Life, Vol. VI, No. 2, pp. 130-141). 



As the speaker had often insisted, he was strongly of the opin 

 ion that careful study should always precede any attempt at in 

 troducing species, for practical purposes. We should satisfy 

 ourselves first as to the country of origin on the introduced inju 

 rious form ; we should then satisfy ourselves that in that country 

 it is held in check by natural enemies which do not occur in this 

 country. These facts having been ascertained, we may then en 

 deavor to introduce such natural enemies, with some hope of 

 beneficial results, especially if care be taken to introduce them 

 without their natural enemies. This favorable situation exists 

 in the case of the Gypsy Moth, and he expressed himself as sur 

 prised that the Gypsy Moth Commission had not sent over to 

 Europe for the natural enemies of this insect, as he had himself 

 urged them to, several years ago. 



As experience with the last introductions from Australia varied 

 somewhat with locality, he believed it would be advisable, even 

 though the chances might be against important practical results, 

 to introduce the Australian Rhizobiids that had maintained them 

 selves in California to the Atlantic coast, since one of them had 

 been found also to feed upon Aspidiotus perniciosus, which was 

 just now spreading in the Eastern States. He also believed that 

 good would result by introducing some of the insects of this 

 genus, as well as the two species of Orcus just mentioned, to 

 Montserrat, as they might do better there than they do in this 

 country in competition with our indigenous species. 



