INSECTS AFFECTING PARK AND WOODLAND TREES QI 



Linden borer 



Sapcrda vcstita Say 



Large, irregular galleries at the base of the tree, inhabited by a white, legless borer, 

 are very likely the work of this sjiecies. 



This insect is a rather comnion borer of the linden and is occasionally 

 quite injurious. It not only attacks full grown trees used for ornamental 

 purposes but soinetimes occurs in the nursery, where it may cause consid- 

 erable injur)-. 



Life history. The beetles appear toward the end of the summer and 

 feed on the bark and leaf stems and also the larger veins on the underside 

 of the leaves and on the green bark of the growing shoots, often killing 

 the tips of the branches. The injury by them is quite noticeable when the 

 insects are abundant. A female may contain as many as 90 eggs, which are 

 deposited two or three in a place on the trunk or branches, specially about 

 the forks in slight incisions and punctures made for their reception with her 

 strong jaws. The larvae mine the bark for a distance of 6 to 8 inches froin 

 the place where they hatch and often penetrate the wood to a considerable 

 extent, according to Dr Packard, who states that this insect works at the 

 base of young lindens, gouging two parallel rings around the trunk and 

 forming annular swellings. We have seldom found the work of this species 

 more than 12 inches above the ground, and in our e.xperience it occurs very 

 largely in exposed roots and subterranean parts, though.it has been taken 

 from the lower limbs of large trees \scc pi. 6]. Nothing is known con- 

 cerning the time required to complete the life cycle. 



Food plants. We doubt if this insect infests other than lindens, 

 though it has been recorded by some writers from poplar, elm and in apple. 



Description. The beetle is black and so densely covered by an olive- 

 yellow pubescence, that, as a rule, only a few black spots are observable 

 near the middle of the wing covers [pi. 6, fig. 16]. 



Distribution. This species has been recorded from Canada south to 

 Pennsylvania and westward to Iowa. It is probably generally distributed 

 in the eastern United States, at least. 



