The basswood leafminer, Baliosus ruber (Weber), occurs in Canada and 
throughout most of the Eastern United States. Basswood is the favored host, but 
oak, maple, willow, birch, hophornbeam, apple, and cherry are also subject to 
attack. The adult is broad, flat, wedge-shaped, reddish yellow, and from 4.5 to 7 
mm long. There are indistinct markings on its sides and on the apical half of the 
elytra. Full-grown larvae are about 6 mm long. The head and thorax are brownish 
red; the rest of the body is white. 
The winter is spent in the adult stage under leaves and trash on the ground 
beneath infested trees (578). In the Lake States, the adults emerge in the spring 
about the time basswood leaves begin to unfold. They feed on these leaves, 
skeletonizing them. Eggs are deposited singly at the edges of skeletonized areas on 
these leaves about mid-June, and the larvae feed by mining the leaves (fig. 112). 
Trees heavily infested for 2 to 3 years are characterized by thin crowns and the 
presence of dead branches; some trees may be killed. There is one generation per 
year. 
F-506746 
Figure 112.—Leaf of basswood mined 
by the basswood leafminer, Baliosus 
ruber. 
The alder flea beetle, Al/tica ambiens alni Harris, occurs in southern Canada and 
from Maine to Minnesota and New Mexico. It is sometimes a pest of alders growing 
along roadsides and in parks and other recreational areas. The adult is cobalt blue to 
greenish blue above, bluish black beneath, and about 6 mm long. Full-grown larvae 
are dark brown to almost black above, dark yellow beneath, and a little longer than 
the adult. In Maine, overwintering adults emerge in early spring and feed for a 
short time by eating small holes in the leaves before laying their eggs on the lower 
surface of the leaves. The larvae feed on both leaf surfaces and become mature in 
about 5 weeks (1357). In the North there is one generation per year; in the South 
there may be two. The elm flea beetle, A. carinata Germar, a related species, feeds 
on elm; another, A. subplicata (LeConte), feeds on willow (30/). 
The pine colaspis, Colaspis pini Barber, occurs from Maryland to central Florida 
and westward to east Texas. It feeds mostly on southern pines but also occasionally 
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