542 Mr. John Scolt's Monograph of the 



Species 12. Psylla cratcegicola. 



Psi/lhi crafa'gicola, Forst. Vcrh. Ver. Ilhciiil. v. 72,6; 

 Flor, lihyu. Livl. ii. 474, 12; Leth. llem. Nord, 

 ed. ii. 91, 14. 



Green or pale yellow, or yellow and green irregularly 

 intermixed. Face: lobes somewhat elongate, stoutish at 

 the base, and narrowing gradually to the slightly stum])y 

 apex; length about equal to the crown down the centre. 

 Pro- and meso-notum yellow, or intermixed with green. 

 Elytra clear, transparent, glassy ; costal stigma distinct, 

 whitish. 



Head: croicn pale green or yellow, posterior margin 

 gently concave. Face: lobes generally pale green, some- 

 what elongate, proportionately stout at the base, and 

 tapering gradually to the slightly stumpy apex, where they 

 somewhat diverge ; length about equal to the crown down 

 the centre. Antennoi yellow, reaching almost to the base 

 of the stigma ; two last joints always, and sometimes the 

 apex of the 7tli and 8th, black ; 4th about three-fourths 

 the length of the 3rd. 



Thorax : pro- and meso-notum yellow, or the latter with 

 the anterior portion more or less green, and the posterior 

 portion Avith a broad green space down the centre. 

 Elytra clear, transparent, glassy; nerves fine, pale yellow; 

 costal stigma distinct, Avhitish. Leys pale green or 

 yellowish-green ; cUncs frequently dark brown or black. 



Abdomen greenish or yellowish. 



Length 1^ line. 



A very delicate species, and somewhat resembling pale 

 specimens of P. salicicola, to which it is related, but the 

 different form of the face-lobes, colom-ing of the antenn;e, 

 and Avant of the dark streak at the apex of the clavus, will 

 at once separate them. 



Very common in May and June on hawthorn ( Cratagus 

 oxyacantha). 



Species 13. Psylla mali. 



Psylln Mali, Forst. Verb. Ver. Ehcinl v. 72, 8 ; Flor, 

 khyn. Livl. ii. 476, 13; Leth. Hem. Aord, ed. ii. 

 91, 16 ; Psylla rubida, Meyer, Mitth. schw. ent. 

 Ges. iii. 393. 



Green, yellow, red or brown-red. Face: lobes some- 

 Avhat long, divergent at the apex, about as long as the 



