180 PLANT LICE. 
Prof. Webster has described and illustrated the apterous 
viviparous female. To give an idea how the insect looks it is 
illustrated in Fig. 150. In the same illustration is also shown 
the L. pini Linn. (The Scotch Pine Plant-louse). 
A number of other species occur on the willow, hickory, 
white pine, tamarack, spruce, oak and other trees. 
The genus Melanoxanthus contains species of lice which 
have the venation and feelers of Lachnus, but are different in 
general form and habits. The honey-tubes are short and stout, . 
but always longer than broad, being broadest in the middle. 
Melanoxanthus salicti Harr. (The Willow-grove Plant-louse.) 
This plant-louse is found upon a great variety of willow 
trees in the eastern states, and at times becomes exceedingly 
abundant; it also occurs upon the maple and poplar. It is shown 
in) Fag. “151. 
A related species, (M. bicolor Oestl.), was described from 
Minnesota by Prof. Oestlund upon the willow. It is a more 
elongated brownish insect, without a grayish white median line; 
the honey-tubes are paler, ‘1e wings clearer, and with more 
slender discoidal veins. 
The genus Chaitophorus. somewhat similar to the one just 
described. The insects belonging to it have an elongated body; 
their antennz are mostly a little longer than half the length of 
the body, hairy, and the last joint is always as long or longer 
than the sixth joint. The beak is short; the wings frequently 
have smoky bands and spots; the hairy legs are moderately long. 
The abdomen is usually tuberculate with long and slender hairs, 
which are never knobbed; the honey-tubes are short and thick, 
seldom longer than they are thick at the base. 
A number of species occur in our state, and some of them 
are decidedly injurious. The one described may serve as a 
type. 
Chaitophorus negundinis Thom. (The Box elder Plant-louse). 
This louse (Fig. 152) is green, the color of the tender twigs 
and leaves from which it abstracts the sap. “Early in spring, 
even before the tender leaves have made their appearance, the 
eggs that were deposited the , revious fall hatch, and the little 
