208 MAIXE AGRICULTURAL EXPERIMENT STATIOX. I915. 



the direct weakening of the plant due to the loss of sap and 

 the withering of the tissue, the danger to the health of a plant 

 thus attacked by plantlice is considerable. Although exceedingly 

 minute, the beak of the plantlouse makes a wound which be- 

 comes in a short time surrounded by a discolored area, readily 

 detected by the unaided eye. As these wounds extend for some 

 little distance into the plant, a. favorable location for the entrance 

 of bacterial or fungus disease is thus secured even where the 

 infestation of plantlice is not excessive enough to wither the 

 tips of the stalk. Moreover it is perfectly possible for insects 

 to carry fungus spores from diseased to healthy plants. A^'here 

 the plantlice are abundant the leaves are covered with honey dew 

 which is soon attacked by a dark fungus, and which together 

 with the molted skins adhering to the sticky substance, gives 

 the leaves an unhealthy appearance and must interfere with 

 their natural function. 



DISTRIBUTION. 



Macrosiphiun- solanifolii has been recorded from Canada, 

 Florida, Maine and California, and from various intermediate 

 localities. Apparently it might be expected to occur in any of 

 our states. 



DESCRIPTION. 



Re.cognitwn- characters:. In general Macrosipkmn solanifolii 

 is a large species either green or pink. The apterous form's are 

 somewhat inclined to drop from the plant when disturbed. The 

 abdomen is not marked with dark, but is ordinarily clear in 

 color either pink or green, though sometimes late in the season 

 individuals may be found with a mottling part pink and part 

 green. The mature forms are rather glistening, but in the stage 

 previous to the last molt the insect usually has a mid-dorsal 

 line of dark green or pink (according to the color of the indi- 

 vidual) while tTie rest of the dorsum is paler by virtue of a very 

 slight powdery deposit. This appearance is more noticeable in 

 bright light. The beak is short, usually, not or barely reaching 

 the second coxa, though certain collections have been taken with 

 beaks a little longer. The cornicles are characterized by reticu- 

 lations at the tip. This reticulation holds true for all the mature 

 individuals, — alate and apterous viviparous females, oviparous 



