August, '12] HOWARD: PROSPALTELLA WORK IX ITALY 325 



THE ACTIVITY OF PROSPALTELLA BERLESEI HOWARD 

 AGAINST DIASPIS PENTAGONA TARG. IN ITALY 



Diospis pentagona Targ., or the white scale of the mulberry, was 

 first observed in Italy by Professor Targioni Tozzetti of Florence 

 upon some branches of mulberry which were sent to him from com- 

 munes in the province of Como (Proserpio, Asso, Canzo). They 

 were mentioned in a letter dated May 10, 1886 addressed to Prof. 

 Franceschini and puljlished in the Rivista di Bachicultura, volume 

 VIII. 



Since that time Diaspis pentago'i-a, only feebly antagonized by ad- 

 verse indigenous conditions and by the activity of the agriculturists, 

 has spread with an increasing rapidity and occupies almost all the 

 centers of mulberry culture in Italy, and certainly all of north Italy. 

 We have then all of north Italy infested, together with a good part 

 of central Italy, and centers of infestation in south Italy. 



Targioni was the first to suggest, in 1892, that Diaspis pentagona 

 was of Japanese origin, and now every one holds this opinion. The 

 species was described for Japan by Sasaki, of Tokio, in 1894, under 

 the name Diaspis patelleformis, and for Australia by Try on in 1889 

 under the name Diaspis amygdali. In America it was described by 

 Morgan and Cockerell in 1892 under the name Diaspis lanatus. 



The spread of this species in Italy reached such proportions that 

 the Italian government-was obliged in 1891 to promulgate a law against 

 the Diaspis, compelling tree owners in infested localities to fight the 

 insect by mechanical means (scraping the trunk and the infested 

 branches, pruning, sterilizing by fire), and by insecticidal solutions. 

 In spite of these expensive measures, the ravages of the scale were 

 not sensibly diminished, and its rapid and intense propagation appar- 

 ently' could not be stopped by artificial means. 



In this deplorable state of affairs Prospaltella berlesei, reared by 

 Professor Berliese from Diaspis amygdali from America and described 

 by Doctor Howard, was introduced into Italy. As early as 1902 

 Professor Berlese thought that the great spread of this species in Italy 

 was due to the lack of natural enemies which held it in check in its 

 native country. Considering that all of the Diaspine scales are ener- 

 getically attacked by internal parasites (which destroy at least 90 

 per cent) and that Diaspis pentagona had no parasite in Italy, he sup- 

 posed that there must be in some part of the world an especial enemy 

 of this species which could fight it in Italy as well as in its native coun- 

 try. In the month of INIay, 1906, Professor Berlese received the first 



