210 



PSYCHE. 



[May— July 1889. 



Length i.oo mm., oval, greenish at 

 first but becoming black in a short time. 

 Deposited on bark of twigs, especially 

 about buds. 



Myzus ribis (Linn.). 



Notwithstanding the abundance and 

 destructiveness of this species, its life- 

 history does not seem to have been 

 traced, nor the sexed forms described. 



During the past season I observed the 

 habits of the species which was abun- 

 dant on the currant bushes in my gar- 

 den, finding that the lice left the bushes 

 early in summer but was unable to 

 learn to what plant they migrated. In 

 September winged viviparous females 

 returned to the currants and gave birth 

 to }Oung which developed into ovipar- 

 ous females. The winged males flew 

 in from some other 2:)lants, presumably 

 being developed on the same plant as 

 the migrating viviparous females which 

 gave birth to the oviparous form. 



Winged viale. 



Length of body . . . 2.00 mm. 



" "antennae . . 2.70 mm. 



'■ "cornicles . . 0.50 mm. 



Wing expanse .... 8.50 mm. 



Antennae, head, band on dorsum of 

 prothorax, row of dots on each side of 

 dorsum of abdomen, and transverse 

 patch back of middle of same, black. 

 Legs very long, with coxae, apical half 

 of femora, and ajoical fourth of tibiae, 

 together with tarsi, black, the rest being 

 yellow. Cornicles long, slender, slight- 



ly incrassate. Antennae about ^ longer 

 than body, slender, roughened with 

 numerous sensoria ; joint I large, thick- 

 ened, about as long as II ; III longer 

 than any except VII ; IV and V sub- 

 equal ; VI shorter than V ; VII very 

 long and slender. Cauda minutely 

 tuberculate, with several curved stiff 

 hairs arising from the margin. 



Described from several specimens 

 taken on under surface of cultivated 

 currant leases, 31 October, 1888. 

 Oviparous female. 

 Length ... .75 mm. to i.oo mm. 



Body globose ; greenish, shade vary- 

 ing with age of specimen. Antennae 

 pale at base but blackish apically, and 

 at articulations. Legs pale, articula- 

 lations and tarsi dusky ; the thickened 

 posterior tibiae greenish brown. An- 

 tennae short, less than half the length 

 of the body : 6-jointed ; joints I and II 

 short, subequal ; III and VI subequal, 

 both longer than any of others ; IV and 

 V subequal, each about -^ shorter than 

 III ; joints III to VI strongly tubercu- 

 late, having numerous sensoria. Cauda 

 long and large, spinosel}' tuberculate, 

 with several long curved hairs arising 

 from its dorsal surface. Rostrum reach- 

 ing posterior margin of second coxae. 



Described from many specimens 

 taken on under surface of leaves of 

 cultivated currant, 31 October, 188S. 



In some specimens two large eggs 

 were, plainly visible. I did not find the 

 eggs iji situ but there is little doubt 

 that they are deposited on the twigs ^ 

 especiall}' about the buds. 



