92 DECIDUOUS FRUIT INSECTS AND INSECTICIDES, 



In all, 43 experiments Avith remedial and preventive measures were 

 conducted during the summer, results of Avhich are given herein. 

 Field observations in this localitj^ seemed to show that apparently 

 healthy trees are attacked and, although the beetles probabh^ do not 

 form egg burrows in these, the loss of sap from the burroAvs made by 

 the adults in the bark is sufficient to cause the trees to become very 

 much Aveakened. 



HISTORY. 



The first published notes on this insect Avere made by Miss M. H. 

 Morris, about 1849-50. At that time Miss Morris credited Tomicuft 

 Ihninaris as being the cause of "peach yelloAvs," and so expressed her 

 belief in several articles published in different magazines of that time, 

 stating that the beetles were quite numerous about peach trees suffer- 

 ing from " peach j^ellows." These su.ggestions made by Miss Morris 

 probably led Harris to include the insect in his treatise on "The 

 Insects Injurious to Vegetation,'' published in 1852. Avhere he briefly 

 describes it under the name Tomicvs Vtminarh, this later being 

 changed to PhJwotrihus liminaris. The folloAving extract gives his 

 description : 



There is another small barkbeetle. the Tomlcuft liminaHs of my catalogue, 

 which has been found in great numbers by Miss Morris under the bark of 

 peach trees affected with the disease called the "yellows" and hence sui)posed 

 by her to be connected with this malady. I have found it under the bark of a 

 diseased elm. but have nothing more to offer frf)m my own observations con- 

 cerning its history, except that it completes its transformations in August and 

 Sei)tember. It is of a dark-brown color, the thorax all punctured, and the 

 wing covers are marked with deeply punctui-ed furrows and are beset with 

 short hairs. It does not average one-tenth of mu iiu h in length. 



The beetle spoken of aboA^e as Avorking in elm bark Avas later found 

 by Mr. E. A. SchAvarz. of this Bureau, to be Hylesinus opaculvs Lee, 

 he having examined the specimens used by Harris and named it the 

 elm barkbeetle." (This specimen, in Mr. Harris's collection, Avas 

 called TomuKx liminaris and catalogued as such, as is shown by 

 copies, taken by Doctor Hopkins, of the original notes.)'' 



For many A^ears this insect did not become sufficiently important 

 to demand special study, either of its life history or for the deter- 

 mination of remedial measures. Reference to this species has been 

 made at different times, as in the aniuuil reports of the entomologist 

 of the Canadian experimental farms, and by entomologists in the 



"Attention is here called to Mr. Schwarz's article on p. 149, Vol. I, No. .'>. 

 Proceedings of the Entomological Society of Washington (ISSO), on HyJemiiua 

 opaculuis. 



''The genus rtiUiafi ihii.s is Itciug rt-visetl l)y Doctor lloiikins, who will dis- 

 cuss the synonymy nnd other systiMinif ic fealnrcs in :i bulletin of the technic;il 

 series of this Bureau. 



