276 



STATE BOARD OF AGRICULTURE. 



Pi}^. 25.— Banded Purple butterfly, nat. size, Orif^iiiul. 



THE HICKORY BARK-BEETLE. 



{8colytus 4-spinosus.) 



About the middle of August, the writer, in company with Prof. C. F. 

 Wheeler, visited Belle Isle park of Detroit, at the request of Mr. M. P. 

 Hurlbut. Secretary of the Commission of Parks and Boulevards. The 

 trouble was due to a small beetle found by Mr. Alexander to be working 

 in the twigs in the new growth of the shag-bark hickory {Hicoria ovata). 

 and the pignut hickory {H. glabra). The damage to the twig is caused 

 by the boring of a hole just inside the petiole of the leaf, where it joins 

 the twig. This usually kills the bud, and the insect usually bores into 

 the new growth often killing that also, almost invariably doing so if the 

 work is done just below the terminal bud. 



Professor >\'lic{'ler, after an examination of the l)ranclies, decided that 

 almost all the injury had been done during the last three years, a little 

 work showed as the result of injury done four years ago. 



The work of this insect is quite conspicuous even at a distance, the 

 large leaves at the tips of the twigs being dead and discolored. On open- 

 ing the tunnels in some of the twigs, beetles, belonging to the family 

 of bark-beetle, or Scolytidae, were found* This lead to an examination 

 of the bark, which was found to be pitted Avith small, round holes. On 

 removing the bark in the vicinity of these holes, the brood chambers with 

 the radiating tunnels leading from them were found. Most of the brood 

 chambers seemed to be comnleted at this time, and, in many cases, the 

 dead beetles were found in the openings. Such beetles were short semi- 

 cylindrical creatures, about three-sixteenths of an inch in length, polished 

 and black, except for the wing-covers, which were, in some cases, dark 

 brown. 



»Thi« insect was Uindly determined for me by Mr. T. Chittenden, of the Department of Agriculture 

 at Wdshinfrton, D. C. 



