1918] Smulyan — First Instar Stem Mothers of Three Species of Aphids 21 



cated, and varying in extent from beyond end of body to some- 

 what short of end of same; rostrum varying in extent from nearly 

 to end of body to about metacoxa (relative length varying, like that 

 of antennse and cornicles, with the state of advancement of the 

 insect — relatively shorter with feeding and consequent enlargement 

 of body); legs armed with spinelike hairs, anterior tibise .1540- 

 .1848 mm., intermediate tibise .1617-. 1925 mm., metatibise 

 .2002-.2464 mm.; anterior tangent of head usually faintly tri- 

 lobed; eyes somewhat large; usually a pair of minute tubercles on 

 each of last two segments (within transverse dusky lines or bands) , 

 and very often apparently a median double row of very minute 

 tubercles or dots on remainder of dorsum, a pair on each segment; 

 length of body .4620-.8316 mm., width at widest part .2464-.4312 

 mm. 



2. A. pomi DeG. (Green Apple Aphis). 



Dark green (well fed individuals may be lighter), anterior and 

 dorsal aspects of head dusky to blackish with a pale, or uncolored 

 median longitudinal, often quite wide, band or stripe (when latter 

 condition obtains the dark or dusky portion appears as two elon- 

 gate spots); antennae, base of rostrum, and legs dusky, tips of 

 femora, distal portions of tibi?e, and tarsi quite often blackish; 

 more or less of cornicles, and about § distal portion of rostrum black 

 or blackish; eyes black (in mounted specimens deep red); caudal 

 end of abdomen ventrally sometimes faintly 

 dusky; whole insect often slightly pruinose. 

 Newly-hatched specimens are bright dark 

 green, with head and more or less of anterior 

 portion of thorax as a rule lighter and usually 

 with a yellowish tint; antennse, rostrum, and 

 legs with a cast of the color of the body, tips 

 of femora and of tarsi and distal portions of 

 some of the antennal segments very often 

 darker green ; femora usually distinctly yellow- 

 green. 



Antennae reaching from end of second seg- 

 ment to end of thorax, base and unguis of last 

 segment equal or subequal (the inequality is 

 slight when the specimen is not too highly 



1^ 



B 



Fig. 2. — Antenna 

 and cornicle of Aphis 

 pomi DeG., about 

 X150. 



