12 
about twice as broad as long, and has upon its upper surface a 
pale, horny, oblong, transverse shield or cover about two thirds as 
long as wide. This is roughened on the posterior half, but is else¬ 
where smooth. On the upper side of each remaining segment is 
an ovate, roughened, transverse area, slightly convex in front and 
slightly concave behind. 
The pupa, which may he found in a cell beneath the bark, is 
yellowish white, about half an inch long, and with slender an¬ 
tennae lying along each side and bent forward over the breast. 
Fig. 2. Adult, or beetle, of the Elm-borer, 
Saperda tridentata. (Enlarged 4 diameters.) 
The parent beetle (Fig. 2) is of a grayish color, due to a very 
fine gray down which densely clothes the surface. On each side 
of the thorax and on each wing cover is a submarginal reddish or 
yellowish stripe, and from each of these stripes three oblique bands 
project inward and backward to a variable distance in different 
specimens. Sometimes they extend across the wing cover to meet 
the corresponding bands on the opposite side, and sometimes they 
are short oblique branches only. There are often two black spots 
on each side of the thorax, and three on each wing cover. 
Strangely enough, the life history of this abundant insect has 
never been worked out, but there is good reason to suppose that 
it extends over two or three years. Indeed, in the northern part 
of the area of distribution of the species, as many as three distin- 
