Aphididae of Formosa. — ^3. 115 



Pterochlorus roboris ( f.. ) 



Ijcwhnu.^ rohorix, Kaltenbaeli, Monog. PHanzeiil. p. 148 (1843). 

 jVph'iH roboris, Walker, Ann. Mag. Nat. Hist. 2n(l HtiricH, II, p. 106 (1848). 

 Dryobiuji rultoris, Kocli, Pflanzeul. p. 226 (1857); Buckton, Monog. Br. 

 Aphid. Ill, p. 71 (1880). 



Drilobiuj< criMdicus, Koch, Pflanzeul. p. 228 (1957); Buekton, Monog. Br. 

 Aphid. Ill, p. 74 (1880). 



Plcmehlon^s roboris, van der Goot, licitr. Kenntnis Holand. Blaltl. ]). 414 

 (1915); Baker, U. S. Dept. Agr. Bull. 826, pi. II, S-U ( 1920); Swain, 

 Eutom. News, xxxu, p. 21 1 (1921 ). 

 Host.- Qi«'rci(.s doitata. 

 Distribution.-Japan : Oi in Gifn-prefeeture, Tokyo. 



Enrope. 

 Hitherto unrecorded from Japan. 



The Japanese sjjeeimens difter somewhat from tlie description of van der Goot 

 in the following characters : 



( 1 ) All the legs of the viviparons female are black, with the tips and bases 

 of the femora brownish. 



( 2 ) The 6th antennal joint of the viviparous female is shorter; the relative 

 length ot the antennal joints is about as follows: in tlie wingless form-III-188, IV- 

 77, V-74, VI 35; in the winged form-III-1 73, IV-80, V-76, VI-35. 



The wingless viviparous female is provided with a small tubercle at the miikllc 

 of the dorsum of the abdomen. 



Lachnus laricis (Walker) 

 Aphis laricis, Walker, Ann. Mag. Xat. Hist. 2nd series, vol. II, p. 102 

 (1848). 



Lachnus laricis, Mordvilko, Horae Ent. Soe. Kossicae, XXXI, p. 666 

 (1898). 



Lachnus lariciis, van der Goot, Beitragc Kenntnis Holand. Blattl. p. 399 

 (1915). 



syn. Lachnm laricimliis, Matsumura, Jl. OjII. Agr. Sapporo, VII, pt. 6, 

 p. 380 (1917). 



HoBt.-iorf'x sj). 



Distribution.-Ja|>an: Sapporo, Abashiri, Monbetsu. 

 Europe. 



