590 ENTOMOLOGICAL NEWS. [November, 



The European Pear Scale. 



DIASPIS PIRICOLA (Del Guercio) Saccardo, 1895. 

 By C. ly. Marlatt, Washington, D. C. 



Under the title Cherrnes pyri, Linnaeus in his Systema N^a- 

 iurcE (1758) named an insect which now falls in the Psyllidse. 



More than a hundred years later Boisduval (Ent. Hort., 

 1867, p. 315), under the supposition that he was dealing with 

 the Linnean insect mentioned, described as Cherrnes pyri b. true 

 coccid belonging to the genus Diaspis. It was a case of mis- 

 identification on the part of Boisduval, but, nevertheless, a 

 valid characterization was given to a species not before de- 

 scribed. 



The next reference to this insect is another misidentification 

 exactly similar to the last. Signoret (Essai, 1869, p. 439) de- 

 scribed and figured this Diaspis from specimens found in France, 

 referring it, however, to Aspidiotus ostreceformis described a long 

 time before by Curtis (Gard. Chron., 1843, p. 805). Curtis' 

 insect is an entirely distinct species and a true Aspidiotus, and 

 Signoret' s belief that this Diaspis was the same as the Aspidio- 

 tus of Curtis was based largely on the fact of the identity in 

 food plant, certainly most unsafe ground, and resulting in the 

 same error which similar action on the part of Boisduval had 

 caus2d a century before. 



On the .same faulty reasoning, namely, identity of food plant, 

 Signoret also as.signs (1. c. , p. 441) the Aspidiotus furfnnis 

 Fitch (1856) to the same insect. 



Later also in the same monograph (1876, p. 664) Signoret 

 makes a similar error when he designates Aspidiotus circu/aris 

 Fitch (1856) as another synonym of ostreceformis Curtis as he 

 denominates his Diaspis. Neither Aspidiotus ostreceformis 

 Curtis, a European .scale insect recently introduced into Am- 

 erica, nor Chionaspis furfurus (Fitch), the common .scurfy 

 bark-louse, nor Aspidiotus cirailaris Fitch, which with little 

 doubt is an early name for Aspidiotus ancylus Putnam, have 

 any connection with Signoret's Diaspis, which he himself 

 points out is the same as Boi.sduval's Pyri (see Essai, 1869, p. 



438). 



The confusion started by Signoret between those various 



