290 



drical. Antennae black ; joint iii long, as long as iv plus v, which are subequal ; vi 

 short, slightly more than half as long v ; vii very long, longer than in ; all of the 

 joints much roughened. Cauda distinct, dusky. Wings sulvhyaline, insertions 

 greenish-brown ; base of veins and stigma light-brown or greenish-brown ; rest of 

 veins dusky. Body more or less covered with a glaucous bloom. Rostrum reaching 

 second cozae, dusky at tip. 



Oviparous female (Fig. 24, c, <?).— One and eight-tenths millimetres long by 1 mil- 

 limetre wide across middle of abdomen. Antennae 1.2 millimetres long. 



Body elongate oval, tapering both ways from the middle, the abdomen being almost 

 acutely pointed. General color pale-green; head dusky; a row of indistinct dusky 

 spots on dorsum of thorax each side the median line ; three longitudinal rows of in- 

 distinct small blackish spots on dorsum of abdomen as far back as cornicles ; similar 

 spots between cornicles; a transverse dusky patch on last two abdominal segments; 

 Cauda dusky. Cornicles short, cylindrical, black. Legs dusky, lighter proximally. 

 Antennae dusky ; joint in longest, equal to iv plus v, which are subequal ; vi short ; 

 VII rather long, twice as long as vi. All joints roughened. 



The egg. — Length 0.8 millimetre. Elongate oval. Light-green when first said, 

 but becoming black on exposure to air. Sometimes more or less covered with a glau- 

 cous bloom. Deposited on the cabbage leaves, especially in crevices and depressions. 



The Willow Grove Melauoxanthus. {Melanoxanthus salicti Harr.) 



In previous articles of this series I have described the various stages 

 of this insect, and have now to add only one or two recent observations. 

 The occurrence of this species upon Maple and Poplar was mentioned 

 in the last account as probably accidental, but this season's observa- 

 tions show that in some species of Poplar, at least, the insect finds a 

 congenial food plant. Colonies of these lice have repeatedly been ob- 

 served upon Cottonwood {Populus monilifera) at various times during 

 the season, apparently flourishing as well as upon Willow. 



To show that the finding of the sexes mating is not always proof 

 that the two forms belong to the same species, mention may be made 

 of an observation during October when a male M. salicti was found m 

 copula with an oviparous Lachmis platanicola. 



The Bicolored Melanoxanthus. (Melanoxanthus Mcolor Oestlund.) 



The sexed forms of a Melanoxanthus that appear to belong to the 

 species recently described by Professor Oestlund* as 31. hicolor oc- 

 curred rather commonly during October and Il^ovember on the twigs of 

 various willows in company with M. salicti Harr. The male is winged, 

 and differs considerably from the male of M. salicis or M. salicti. The 

 oviparous female represented magnified at Fig. 25, a, is at once distin- 

 guished from this form of either of the species named, by its general 

 brown color. Its eggs are laid upon the twigs, generally about the buds, 

 in the same situation as the eggs of M. salicti. A couple of them are 

 shown at Fig. 25, c. 



Synopsis Aphididae of Minnesota, p. 36, 



