PEEVIOUS WORK WITH INSECT PARASITES. 29 



Alexandria. These multiplied so rapidly as to cause an almost 

 complete disappearance of the scales. Later the latter began to 

 increase, but the Novius had not died out and also increased. The 

 Icerya is still held in check in a very perfect way. 



In 1890 the Novius had been introduced into the Hawaiian Islands 

 for work against Icerya purcliasi with the same success. 



Icerya in Italy. 



In 1900 Icerya purchasi was found also in Italy, in a small garden 

 at Portici, upon orange trees. By the autumn of 1900 it had mul- 

 tiplied so abundantly that the owner of the garden tried to stop 

 the trouble by cutting down the trees most badly infested, without 

 bothering himself with the others, so that the infestation continued. 

 When Prof. Berlese's attention was called to it an attempt was first 

 made to destroy it by insecticides without success, and then Novius 

 cardinalis was imported from Portugal and from America. The 

 following June the ladybird in both sexes was distributed in the 

 garden, prospered wonderfully, and multiplied rapidly. In July the 

 results were already evident; one could hardly find patches of Icerya 

 which did not show the work of Novius, and at the end of the month 

 it was difficult to find adult Iceryas with which to continue the 

 rearing in the laboratory for food for the reserve supply of Novius. 

 At the present time the multiplication of the scale insect has been 

 reduced to the point of practically no damage, but the original infes- 

 tation still persists and^the area of distribution of the scale insect 

 is slowly enlarging. It is found not only at Portici but in all the 

 little towns around Vesuvius and in the gardens in Naples; but the 

 presence of the ladybird allows the culture of oranges and lemons 

 to go on without interruption. 



Icerya in Syria. 



The latest utilization of the beneficial Novius is recorded by Sil- 

 vestri. It seems that about the year 1905 Icerya made its appearance 

 in Syria, and in July, 1907, Selim Ali Slam wrote to Prof. Silvestri 

 that it had spread so greatly about Beirut that it had almost 

 destroyed the trees. Silvestri sent a shipment of Novius in July, 

 1907, and another one in August. The result was the same in Syria 

 as it had been in other countries; the Novius multiplied greatly and 

 produced the desired effect. 1 



The Reasons for the Success of Novius. 



It thus appears that in the Novius we have an almost perfect 

 remedy against Icerya. There have been no failures in its intro- 



1 Since the above was written (in the autumn of 1909) still another success with Novius has been by its 

 carriage from California to Formosa by Dr. T. Shiraki, the entomologist of the Formosan Government, 

 who writes, under date of Jan. 28, 1910: "To-day it has relieved the region from Icerya and has reduced 

 their number to a practically negligible quantity." 



