OF THE STATE ENTOMOLOGIST. 105 



female of xS*. destructor are generally about two inches long, those of 

 S. carycB are seldom more than one inch. 



The natural history of the Hickory Bark-borer may be thus 

 summed up : 



It seems not to be very particular about the kind of hickory it 

 attacks, as, besides the Bitter-nut and Shell-bark, («ZJa), there is good 

 evidence that it affects the Pecan,* {olivceforinis) ; and Dr. A. H. 

 Barber, of Lancaster, Wisconsin, has favored me with specimens, and 

 an account of its injuries to the Pig-nut Hickory {porcina). The 

 beetles issue the latter part of June and fore part of July. Both sexes 

 bore into the tree — the male for food, and the female mostly for the 

 jjurpose of laying her eggs. In thus entering the tree, they bore 

 slantingly and upward, and do not confine themselves to the trunk, 

 but penetrate the small branches and even the twigs. The entrance 

 to the twig is usually made at the axil of a bud or leaf, and the chan- 

 nel often causes the leaf to wither and drop, or the twig to die or 

 break off. 



The female, in depositing, confines herself to the trunk or larger 

 limbs, placing her eggs each side of a vertical chamber, as described 

 by Mr. Bryant. Here she frequently dies, and her remains may be 

 found long after her progeny have commenced working. The larvas 

 bore their cylindrical channels, at first, transversely and diverging, 

 (Fig. 3S, i), but afterward lengthwise along the bark (-) — always 

 crowding the widening burrows with their powdery excrement, which 

 is of the same color as the bark. The full-grown larva (Fig. 38, ^, 

 natural size and enlarged) is soft, yollowish and without trace of legs. 

 The head is slightly darker, with brown jaws, and the stigmata so 

 pale that they are with diflSculty discerned. It remains torpid in the 

 winter, and transforms to the pupa state about the end of the follow- 

 ing May. The pupa (Fig. 38, 5) is smooth and unarmed, and shows no 

 sexual differences. The perfect beetle issues through a hole made 

 direct from the sap-wood, and a badly infested tree looks as though it 

 had been peppered with No. 8 shot. The sexes differ widely from each 

 other, the male having spines on the truncated portion of the ab- 

 domen, not possessed by the female. The eggs are deposited during 

 the months of August and September, and the transformations are 

 effected within one year, as no larvse will be found remaining in the 

 tree the latter part of July. 



t See Prairie. Farmer, August 10th, 1872, where Mr. Smiley Shepherd, of Hennepin, Ills. , writes: 

 ' 'I have inclosed lor your inspection a few specimens of a small beetle, found boring into the pres_ 

 ent year's growth of the Pecan-hickory. I also send you a package of the spray, that you may see 

 the evidence of depredations in fonner seasons. This is the fourth year since they were noticed on my 

 trees. The injury done is greater each year than the preceding. The trees can not survive such treat- 

 ment more than one or two years more. They have been planted about thirty years, and were abou t 

 fruiting."' 



These beetles are referred, by Dr. LeBaron, to ScoUjtus inuticus, Say, and S. i-spinosus, Say; but, 

 as I have since learned, they were $ cf of caryce. 



