60 



THE REPORT OF THE 



No. 19 



75. The European Fruit Scale, Aspidiotus ostreaejormis, Curtis. This species also has a 

 wide range of food plants, and among other trees has been found on the basswood. It occurs 

 in several places in western Ontario. 



76. Pxdcinaria tiliae. King & Ckll. This species occurs in western Ontario, but is not 

 a very common insect. 



77. Eulecanium tulipiferw, Cook. This insect is the same as Lecaiiium tiliae. It has been 

 found occasionally on basswood at Ottawa, but not in any numbers. 



BORING INTO THE WOOD. 



The insects which bore into the wood of the linden belong chiefly to the Order Coleoptera, 

 or beetles. They do not as a rule attack healthy trees ; it is when these are weakened in 

 some way that they are attacked by the grubs of boring beetles. The following borers are 

 known to occur in the wood of the basswood. 



Order Coleoptera. 



78. The Linden Borer, Saperda vestita, Say. This is the most destructive borer of the 

 basswood. It is a common species and has a wide distribution. The grubs are white, rather 

 slender, and when mature slightly over an inch in length. The beetles emerge at Ottawa late 

 in May and during the early part of June. On the 4th June 1902, we found mature larvte, and 

 also pupjfe in a tree in the arboretum of the Central Experimental Farm, which had been 

 killed by the attacks of this borer. Beetles which had just emerged were also collected. 



79. The Flat-headed Apple-borer, Chrysobothris femorata, Fab. (Fig. 19.) Although the 

 larva of this insect has been called the JMat-headed Apple-borer, it does not by any means con- 

 fine its attacKs to that tree. ^Larvfe have been found in linden as well as in many other orchard 

 and forest trees. The species is common and widespread. The larvfe are pale jellow, flat- 

 lieaded grubs. The eggs are laid by the female beetle in the cracks and crevices of the bark, 



and the young larva upon hatching eats its way through the bark 

 and feeds on the sap-wood within. As it becomes mature it usually 

 enters the solid wood, and when about to change to a pupa, bores 

 its way back again to the outside but not quite through the bark. 

 The female beetles in Canada resort to the trees for egg laying 

 during the month of June, and at that time the trunks and larger 

 branches of the trees to be protected should be painted with an 

 alkaline wash. Dr. Fletcher recommends : soft soap reduced to 

 the consistency of thick paint by the addition of a strong solution 

 of washing soda in water. If applied with a brush on the morning 

 of a waim day, this will dry in a few hours and form a tenacious 

 coating not easily dissolved by rain. If one pint of crude carbolic 

 acid be added to the gallon of wash it will make it more effective. 



80. The Sugar-maple Borer, Plagionotus speciosus, Say. (Fig. 20 ) 

 The only reference we know of to this borer as a linden insect appears in 

 Country Gentleman for August 8, 1895. In this issue Dr. Lintner spoke 

 of injury to sugar maples and a linden tree as probably having been 

 caused by the larva of this beetle. In his 1885 Report, Dr. Fletcher 

 mentioned that he had received several specimens of this handsome 

 wasp-like beetle, with the statement that it had done considerable dam- 

 age to shade trees. It is not an uncommon species in Ontario, but we 

 do not know of any instances of the larvre having injured basswood 

 in Canada. 



Fiir. 19. Flat-heailed tioier : a, 



iirwh ; b, pupa ; c, head cf 



borer ; d, beetle. 



Fii;. '20. Sugar-maple 

 ))orer. 



