REPORT OF THE ENTOMOLOGIST AXD BOTAXIST 249 



SESSIONAL PAPER No. 16 



easy to detect at first sight when a tree is in a reduced state of vigour, and hidden 

 injury may sometimes be going on in an apparently healthy tree. In estimating the 

 effects of a remedial measure upon a tree which fails suddenly, a close examination 

 should always be made to see if this may not have been due to some other cause. There 

 are many insidious insect and fungous enemies of fruit trees, such as the various wood 

 and bark borers and root-attacking enemies. As is well known, the brush pile, contain- 

 ing much more than the annual primings, is a conspicuous object on all fruit farms. 

 Dead trees — dead from various causes — are often found in all orchards, necessitating 

 frequent renewals. Moreover, there is always a tendency to try experiments which are 

 considered dangerous, upon trees which are injured or thought to be of little use. If 

 these die while under treatment, care must be taken to attribute the loss to the right 

 cause, and not unjustly to charge all losses to the remedy. There are certain indica- 

 tions of impaired vigour which may be recognized at sight by an observant investigator, 

 while others, again, are more obscure. In Ohio orchards, Prof. Webster pointed out 

 to me — and Prof. Forbes tells me that he has noticed the same thing in Illinois— that, 

 when a tree is from any cause in an enfeebled condition, this may be frequently 

 detected by the well-known evidence of the presence of the Fruit Bark-beetle (Scolytus 

 rugulosus, llatz.), which burrows into the bark and causes gum to exude at the open- 

 ings of the galleries. This beetle, it is thought, does not attack perfectly healthy trees, 

 but, nevertheless, its work is frequently conspicuous on trees which as yet have not 

 shown any evidence, by the foliage and general appearance, that they are sickly. While 

 discussing this matter recently in an Ohio orchard with the two gentlemen above 

 named, we found an apparently healthy peach tree, which had green leaves and was 

 bearing fruit, but the trunk and limbs were dotted with the gummy exudations which 

 mark the work of the Fruit Bark-beetle. Upon digging around the roots of this tree, 

 it was found that the greater portion of the root growth was dead. This accounted 

 for the presence of the Fruit Bark-beetle on this apparently healthy tree. 



Both the Peach Bark-beetle (Plilceotribus liminaris, Harr.) and the Shot-hole 

 Borer (Xyleborus dispar, Fab.) have likewise been wrongly charged with being the 

 cause of fungous diseases, because they have been found abundantly upon trees only 

 showing slight traces, or as yet none at all, of the diseases. The former of these has 

 been thought to be the cause of the ' yellows ' in the peach, and the latter has similarly 

 been written about under the title of the Pear-blight Beetle. 



Mr. G. E. Fisher drew my attention to a characteristic growth easily recognized 

 on peach and other trees badly affected with the San Jose Scale, in which the tree, as 

 an effort to save itself, throws out strong water-shoots at the base of the larger branches. 

 This is so frequent that he has styled it the ' trade mark of the scale.' It was very 

 apparent in one orchard of seriously injured apple trees which we visited together, 

 aear Blenheim. 



THE GRAPE-VINE COLASPIS 



(Colaspis brunnea, Fab.). 



Attach. — Small pale yellowish beetles about one-fifth of an inch long, with de- 

 rated lines on the wing covers, swarming on grape vines in July, August, and Sep- 

 tember, feeding on the foliage, riddling it with small round holes, 

 sometimes leaving little more than the veins of the leaves. 



During the past summer the first recorded occurrence in Can- 

 ada of this insect doing damage was reported as follows : — 

 ' Queenston, Out., July 15. — I send you three small enemies and 

 a grape leaf. For three years I have been troubled with them. 

 They appear in July and are on the increase until early September, 

 when they suddenly disappear. In 1S99 I had three acres of young 

 Fl vine "colasp^— 6 " grapes badly eaten before I noticed them. Spraying with Bor- 

 enlarged and nat- deaux mixture checks them, though does not entirely rid the 

 ural size. vines. As no one here knows the insect nor has had trouble with 



