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273 



The Tioig GircVer — Oncideres cinguJatus. 



This beetle has the singular habit of amputating the twigs of the 

 hickory and pear during the latter half of August and early in September. 

 The female which is shown at a, Fig. 1 1 , makes i)erforations in the 

 smaller branches of the tree upon which she lives, and in these deposits 

 her eggs, one of these punctures is shown in the figure at b. She then 

 proceeds to gnaw a groove about a tenth of an inch wide, and 

 about a similar depth all around the branch, as shown in the 

 figure, when the exterior portion dies and the larva, when hatched, 

 feeds upon the dead wood. The girdled twigs sooner or later fall to 

 the ground, and in them the insect completes its transformations, and 

 finally escapes a perfect beetle. The beetle is more than half an inch 

 long, of a brownish grey colour, with dull reddish-yellow dots, and a 

 broad grey band across the middle of the wing cases. The antennae 

 are longer than the body. 



The Hickory and Walnut Borer — Monohammus tigrinus. 



The larva of this insect bores under the bark and into the solid heart wood of these 

 valuable trees, excavating chambers sometimes to the depth of two feet. The hole runs 

 longitudinally upwards, enlarging as the worm increases in size, being in its largest part 

 about half an inch in width, and a little less in depth. At its upper end it suddenly 

 turns outward through the wood to the bark. Having prepared this outlet for the 

 escape of the insect when it is perfected, the larva retires backward a short distance, 

 and stufis this upper extremity with its castings, for the purpose apparently of prevent- 

 ing birds like the woodpecker from detecting the burrow by its hollowness, thus showing 

 astonishing instinctive foresight. This artifice is not always successful, for the acute ear 

 of the woodpecker is not easily deceived, and these birds often detect the boring larvae, 

 drag them out of their retreats and devour them. All the lower portion of the gallery 

 or chamber is filled with the fine powder like castings of the insect which are of a brown- 

 ish colour. The grub when full grown is about an inch and a quarter long, of a whitish- 

 yellow colour, with a faint interrupted dark line down the back ; body smooth, broad on 

 the anterior segments, tapering towards the extremity ; head black. 



Within its mined chamber the larva changes to a chrysalis, and this finally to the 

 beetle, which gnaws its way through the outer bark and escapes. Soon after escaping 

 the beetles pair, and shortly after the female deposits her eggs upon the bark of the 

 trees, and as soon as hatched the young grubs burrow into the wood and begin to destroy 

 it in the manner already described. 



The Woolly Louse of the Pine — Coccus Pinicorticis. 



This shows itself in the form of a white cottony-like substance, growing upon the 

 smooth bark, particularly below the axils, where the limbs spring from the main trunk, and 

 often small white spots of this same substance are scattered irregularly over the whole 

 of the bark of the limbs, particularly upon the north or shaded side. Trees coated with 

 this substance soon become sickly and stunted in their growth. If a portion of the 

 cottony substance be carefully removed there will be found underneath each tuft, a 

 cluster of small lice huddled closely together and fixed to the bark. 



Attacking the Leaves. 



A multitude of insects devour the leaves of forest trees — prominent among these 

 are the following : 



The Forest Tent Caterpillar — Clisiocampa sylvatica. 



This insect much resembles the common tent caterpillar, Clisiocampa americana. 

 18 (F. G.) 



