April, '17] DAVIDSON: WESTERN PLANT LICE 295 



of the wild flowering currant (Rihes glutinosum Benth.). In most 

 of the curled leaves but one insect occurred and it is presumable that 

 a single individual was able to bring about the malformation. The 

 leaves bore noticeable yellow and pink blisters recalling those caused 

 by Myzus rihis. 



Apterous viviparous female, second generation (Fig. 16, 17-19). Yellowish- 

 green in ground color, marked very much as is the stem mother, but some individuals 

 lack the dark brown markings and have only orange-colored areas about the base 

 of the cornicles; antennae basally pale, apically dark brown; cornicles and cauda 

 brownish-black; coxae and tibiae dark brown; 4 anterior femora greenish-yellow; 

 posterior femora black, the basal half greenish-yellow; tarsi dark brown; antennae 

 reach to base of cornicles, relatively longer than those of the first generation but 

 similar in structure; III bears on its basal half 4 to 7 sensoria; IV is longer than 

 V; III and filament of VI sub-equal: cornicles and cauda much as in stem mother, 

 shape of former variable as base is sometimes constricted and at other times wid- 

 ened: beak reaches third coxae: hairs as in stem mother. Length of body 1.96 mm. 

 to 2.13 mm. Width (metathorax) .97 mm. to 1.07 mm. Cornicles .21 mm. to .24 

 nam. (average .23 mm.). Cauda .20 mm. Beak .53 mm. to .57 mm. Antennae; 

 III .33 mm. to .37 mm., IV .19 mm. to .23 mm., V .19 mm. to .21 mm., VI .07 

 mm. to .09 mm., filament of VI .33 mm. to .34 mm. 



Taken during March, April and May, 1914 and 1915, in curled 

 leaves. 



Alate vi\aPAROUS FEMALE (Fig. 16, 20-22). Apple green; head, thorax, antennae, 

 cornicles, apex of cauda, black or dark brown; legs yellowish-green; apical half 

 to two-thirds of femora, tibiae and tarsi, blackish; base of antennal III pale; transverse 

 rows of dark brown spots occur on disk of abdomen and lateral spots are sometimes 

 present : Antennae longer than the body, their structure as in stem mother. III with 

 from 29 to 35 tuberculate circular sensoria the whole length of joint, V and VI with 

 usual apical sensoria; hairs numerous, about equal in length to the width of the 

 joints: eyes dark red: beak reaches third coxae: wings as in Myzus; stigma and 

 insertions hght green; first and second discoidals narrowly clouded; second fork of 

 third discoidal nearer wing apex than first fork : legs rather long and narrow : cornicles 

 as in stem mother but considerably longer and not thickened basally: cauda as in 

 apterous forms: hairs of body are longer than in the apterous forms. Length of 

 body about 1.60 mm. Width (mesothorax) .67 mm. to .69 mm. Cornicles .25 mm. 

 to .27 mm. Cauda .20 mm. Beak .57 mm. Wing expanse 6.57 mm. to 6.66 mm. 

 Antennae; III .59 mm. to .66 mm., IV .33 mm. to .36 mm., V .30 mm. to .35 mm., 

 VI .08 mm. to .10 mm., filament of VI .50 mm. to .57 mm. 



Collected with apterous forms during March, April and May, 1914 

 and 1915. 



Oviparous female (Fig. 16, 23-26). Pale whitish-yellow; eyes bright red; thedark 

 markings of the viviparous forms appear very faintly on the dorsum of the body 

 in the ovipara; coxae, cornicles and cauda light grey; tarsi grey; joint VI of antennae 

 grey, rest pale: antennae half the body in length; joint III with 3 to 4 circular sensoria 

 on basal half; V and VI with usual sensoria; V slightly longer than IV; filament of 

 VI longer than III; frontal tubercles as in other forms; hind tibia is dilated for its 

 basal half and bears about 26 sensoria on this portion : cornicles and cauda as in alate 



