OAK-BORERS. 
69 
for them will be most successful, as they are then most active and show themselves 
abroad. The larvae, when young, appear to have the same habit with most other 
borers, of keeping their burrow clean by throwing their castings out of it through a 
small orifice in the bark. They can, therefore, be discovered probably by the new 
sawdust-like powder which will be found adhering to the outer surface of the bark. 
In August or September, while the worms are yet young and before they have pen- 
etrated the heart- wood, the trees should be carefully examined for these worms. 
Wherever, from any particles of the sawdust-like powder appearing externally upon 
the bark, one of these worms is suspected, it will be easy, at least in young trees, 
where the bark is thin and smooth, to ascertain by puncturing it with a stiff pin 
whether there is any hollow cavity beneath, and if one is discovered, the bark should 
be cut away with a knife until the worm is found and destroyed. After it has pen- 
etrated the solid wood it ceases to eject its castings, and, consequently, we are then 
left without any clew by which to discover it. Hence the importance of searching 
for it seasonably. 
The following ichneumon parasites are said by Riley to keep the 
numbers of the larvae in check, besides a chalcid fly : Bracon charus 
Riley and Gryptus or Labena grallator Say. 
8. The green-headed chrysobothris. 
Chry8obothri8 chlorocephala (Gory). 
Order Coleoptera ; Family Buprestid^e. 
Probably boring under the bark of the white-oak, with habits similar to those of 
other fiat-headed borers of the oak ; a Buprestid beetle. 
9. The northern brenthian. 
Eupsalis minuta (Drury). 
Order Coleoptera ; Family Brenthid,e. 
Boring into the solid wood of the white oak, forming a cylin- 
drical passage, a slender grub £ inch long and not quite 0.05 inch 
thick, changing to a weevil with a large, very thick snout. 
The habits and transformations of this beetle were 
first described by Dr. Riley, the original account given ^thi^cM^ 
by Dr. Harris proving erroneous, his larva being that of 
a Tenebrionid beetle, as stated by Riley. This interest- 
ing weevil may be found on the trunk and under the bark of the white 
oak in June and July in New England, or in May and June in New 
York and Missouri, having then assumed the imago or beetle con- 
dition. Riley states that it is equally common on the black, red, and 
post oaks ; that it bores in all directions through the heart- wood, and 
is found most commonly in stumps or in felled trees the year after 
they are cut. 
The beetle differs from other weevils in that the snout projects straight 
out in front, not being curved downwards as in weevils in general. * In 
the male the snout is much broader and flatter than in the female, but 
cephala.— Smith, 
del. 
