TRIBE ASPIDIOTINI 411 



Ckll. Massachusetts, Kansas, Arizona on Juneberry, maple, 



Gleditschia. -fernaUi Ckll. 



cc. Pygidium with second pair of lobes twice or more as broad as 

 long, projecting only slightly, entire or more or less serrate; 

 median pair of lobes broad, short, entire, broader than long, 

 hardly projecting; incisurae not prominent; densariae in me- 

 dian incisurae prominent, mesal margin of second and third 

 densariae broader than lateral, second densariae longer than 

 median; pectinae not as long as lobes, furcapectinae, arranged 

 2, 2, 0; setae of second pair of lobes and lateres large, promi- 

 nent; oraceratubae in longitudinal rows; genacerores 4-5(15- 

 18)7-10; anus small, over five times its width from caudal mar- 

 gin. Ohio on Pinus. glanduliferus Ckll. 



bb. Pygidium with median pair of lobes contiguous and without plates 

 in median incisura; median pair of lobes with lateral margin cren- 

 ulate; plates short and inconspicuous; genacerores 4-5(10-10)7-8. 

 Japan on Quercus. cryptoxanthus CklL 



SPECIES OF DIASPIDIOTUS 

 a. Pygidium always with pectinae or plates in median incisura. 



b. Pygidium with pectinae in median incisura, often minute and 

 lacinations difficult to identify. 

 c. Pygidium with median pair of lobes with distinct mesal and 



lateral notches. 



d. Pygidium with median pair of lobes entire, quadrangular,, 

 mesal margins oblique, convergent, mesal and lateral notches, 

 latter deepest; two pairs of densariae; pectinae not deeply 

 lacinate, arranged 2, 8-9, those of each lateris arranged in 

 three groups, two associated with each second densaria, three 

 with each third, and three or four cephalad of third densaria, 

 two cephalic groups unapectinae; genacerores 0-8(6-14)5-8. 

 Eastern United States, Colorado, New Mexico, Washington, 

 Germany on apple, pear, quince, cherry, peach, linden, oak, 



maple, beech, ash, osage orange, hackberry, currant, etc 



ancylus Putn. 



dd. Pygidium with median pair of lobes with distal ends finely 

 serrate; densariae of second incisura about equal in length. 



Iowa on willow ancylus serratus Newl. & Ckll. 



cc. Pygidium with median pair of lobes with mesal notch wanting, 

 lateral notch frequently obtuse or nearly wanting; mesal 

 densaria of each second incisura slightly larger than lateral; 

 densariae of median incisura larger and more marked. Iowa 



on Mountain ash. ancylus latilo'bis Newl. 



bb. Pygidium with plates in median incisura. 



c. Pygidium with two plates, often minute and process-like, in 

 median incisura and with more than three pectinae cephalad of 

 each third incisura. 



d. Pygidium with mesal margins of densariae longer than lat- 

 eral; median pair of lobes quadrangular, distal end bluntly 



