(33) 



The young Elms only are thus infested. When the 

 trees are about twenty-five feet high the insect ceases to 

 trouble them, and generally the younger the trees the 

 greater number of galls found upon them. 



Eriosoma ulmi. RILEY, OR DOWNY LICE. 

 (HEMIPTERA. APHID^.) 



The bark of the Elm is subject to the attacks of a woolly 

 plant louse, often proving their destruction. The young 

 lice cluster together and cause a knotty, unnatural growth 

 of the wood. They are found in between the crevices 

 formed by these knots, subsisting on the sap which exudes 

 from the holes made by the punctures of their beaks. A 

 downy or woolly matter is secreted from all parts of the 

 body, but mostly from the posterior end. The lice are 

 often imbedded in the substance and hidden from view. 



The matured insect is found on the tree with the larva? 

 and pupae, about the first of July. Prof. Riley has found 

 washing the trunk of the tree with a weak solution of 

 cresylic acid soap will kill them instantly. They are preyed 

 upon by the larvae of a Lacewing fly. (Ckrysopa eriosoma.) 



The Vanessa Antiopa. LINN^US. 

 (LEPIDOPTERA. VANESSA.) 



During the summer of 1875, the leaves of the Elm were 

 very much riddled by the caterpillars of this butterfly. 



The natural history of the insect is as follows : The 

 eggs are deposited in clusters, during the latter part of May 

 or first of June, on the twigs of the Elm, Poplar and Willow. 

 The caterpillars live together, feeding on the under side of 

 the leaves. In about one month they become fully grown ; 

 are black, minutely dotted with white, with a row of eight 

 dark brick-red spots on the top of the back. The head is 

 black, and rough with projecting points ; the spines, of 

 which there are six or seven on each segment except the 

 first, are black, stiff and branched ; the intermediate legs 

 reddish. The insect measures an inch and three-quarters 

 in length. 



