OAK-BORERS. 69 



for them will be most successful, as they are then most active and show themselves 

 abroad. The larvjB, 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 oritice 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 appeariug 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 stiflf 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 Eiley to keep the 

 numbers of the larvte in check, besides a chalcid fly : Bracon charus 

 Riley and Gryptus or Labena grallator Say. 



8. The green-headed chrysobothris. 



Chryaobothris chlorocephala (Gory). 



Order Coleoptera; Family BuPRESTiDiE. 



Probably boring under the bark of the white-oak, with habits similar to those of 

 other flat-headed borers of the oak ; a Buprestid beetle. 



9. The northern brenthian. 



Eupsalis minuta (Drury). 



Order Coleoptera ; Family Brenthid^. 



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 ^botMr^Moro- 

 by Dr. Harris proving erroneous, his larva being that of cephaia. -smith, 

 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 I^ew England, or in May and June in !N'ew 

 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 



