Sept., 1909.] Hayhurst : Two Species of Hyalopterus. 113 



tial characters of winged and wingless viviparae, and mention of winged male as a 

 known form. 



Passerini, G., Flora degli Afidi Ital. (Bull. Ent. Soc. Ital., Vol. 3), 1S71, pp. 

 150, 336. Aquilegia vulgaris in summer; Italy, also on Rosa iiidica and R. gallica 

 in summer. 



Ruckton, G. B., Brit. Aphid., Vol. 2, 1879, pp. 114-115, pi. 77, figs. 1-4. 

 Aquilegia vulgaris June to September, England ; descriptions and colored figures of 

 winged and wingless vivipara and pupa, line figure of antenna of winged vivipara. 

 H. aquilegiir Koch = Aphis trirhoda Walker. 



Del Guercio, G., Prospetto dell' Afidofauna Ital. (Nuov. Relaz. R. Staz. Ent. 

 Agrar., Firenze (l), No. 2), 1900, pp. 146, 147. From Passerini. 



Warren, Ernest, Biometrika (London), Vol. I, No. 2, 1902, pp. 129-154. On 

 variation and inheritance in the parthenogenetic generations. 



Mordwilko, A., Beitrage zur Biol. d. Pflanzenlause (Biol. Centralbl., Bd. 27, 

 No. 24), 1907, pp. 815-816. Reviews Passerini and Koch. Mordwilko collected 

 wingless viviparas and their larvae on Rosa centifolia at Warsaw, Russia, May 20, 

 old style (June i, new style), 1898, and winged viviparte were observed June 18 (n. 

 St. ). The last week in July the wingless viviparae and occasional winged viviparse on 

 the leaves of Aquilegia. On SepteiTiber 5, 1903, aphids were transferred from colum- 

 bine to the rose on which they lived until September 14. (He does not state whether 

 they deposited oviparae, this experiment did not therefore prove their migration. ) 

 Sexuparae and the true sexes can be found on rose in the fall. H. trirhodns is a 

 polyphagus species, judging from Koch's observation of the stem-mothers on colum- 

 bine in May. 



Winged vivipara Uom Aquilegia: Head blackish (Fig. 3); antennte (Fig. 4) 

 dusky, usual number of sensoria on III 80-90 (62, III), each sensorium on a pro- 

 nounced tubercle, sensoria on all aspects of the joint, most numerous on posterior 

 aspect, but fewer in number on anterior aspect, the other joints without sensoria, ex- 

 cept the usual ones on V and VI. Eyes blackish red ; beak passing anterior margin 

 of mesosternum but not attaining transverse sternal suture. Pronotum dusky, lateral 

 tubercle absent, represented by a short seta ; lobes black, lateral plates, mesosternum 

 and metasternum dark brownish or blackish ; forewing, Fig. 2, veins stout, vena- 

 tion not especially variable; legs yellowish brown, usual dark portions blackish. 

 Abdomen ( Fig. 5 ) yellowish ; the squarish dusky patch sometimes represented by 

 three broad transverse dusky bars ; the last dusky bar (on 8th segment) often indis- 

 tinct; no lateral tubercles. Cornicles (Fig. 8) and cauda (Fig. 6) pale yellowish or 

 the cornicles translucent, the cauda with 8-10 lateral setae. 



Measurements: Length of body (less cauda) 1. 907 mm. (1.74-2.08) ; greatest 

 width of abdomen .888 (.7S3-1.00) ; antennae (average Ill-filament inclusive) 1-537; 

 III .806 (.774-.929); IV and V each .209 (.172-.241); VI (scape) .147 (.110- 

 .172); filament .166 (.120-.189); forewing 3. 12 (3-045-3-393); cornicle .103; 

 cauda .220 (.206-. 241). 



Walker gives the colors of this form as follows : head, lobes of 



thorax, lateral and sternal plates, maculations of abdomen, antenn?e, 



eyes, apex of beak, of femora and of tibiee and the tarsi black; main 



• body color pale greenish yellow, varying to dark green, cornicles and 



legs pale yellow. Koch's description is essentially the same. 



