INSECT PESTS OF OHIO SHADE AND FOREST TREES 253 



THE VICEEOT 

 (Basilarchia disippus Go dart) 



Description. The viceroy is best known in the adult stage. 

 It is then a beautiful, brown butterfly having much the appearance 

 of the common milkweed or monarch butterfly. Moreover, it mimics 

 the monarch very closely and this fact combined with its close 

 physical resemblance renders it frequently mis-identified. Upon 

 close inspection the viceroy will be found to be smaller than the 

 monarch and the conspicuous black cross-veins of the hind wing are 

 much differently arranged than with the monarch. 



In contrast with the adult form, the larvae of the two hold 

 little resemblance. A glance at Plate XXXVIII, Fig. 1, conveys a 

 better idea of the physical characteristics of the insect than it is 

 possible to do by means of a description. Regarding color, how- 

 ever, it may be stated that in general it is reddish-brown marked 

 with yellow. When full grown it measures nearly 1% inches long. 

 (See Plate XXXVIII, Fig. 1.) 



Life history and habits. The winter is passed in the partly- 

 grown larval stage within the shelter of a rolled up leaf. The cater- 

 pillars are most abundant in September when they may be found 

 feeding singly on the preferred host. 



Nature of work. The harm done by this species is not exten- 

 sive simply because the insect rarely occurs in great numbers. It 

 is a foliage-devouring insect, however, and if it should occur in 

 abundance is capable of considerable harm. 



Food plants. In the main the viceroy feeds upon the leaves 

 of willow and poplar, although it has been reported on the plum. 



Distribution. This species occurs throughout the State. Its 

 general range is given by Holland as "everywhere from southern 

 Canada and British America into the Gulf States." 



Control. Spraying with arsenicals is effective where remedial 

 measures are necessary. Handpicking the feeding larvae likewise 

 is practicable in some instances. 



THE EED-HTJMPED OAK WOEM 



(Symmerista albifrons Abb. & Sm.) 



Description. The larva of the red-humped oak worm merits 

 its common name because of the large red hump on the eighth 

 abdominal-segment, and this, in conjunction with its large red head, 

 renders it a conspicuous caterpillar. (See Plate XXXVIII, Fig. 2.) 

 Five slender black lines on a lilac background extend down the back, 

 of the caterpillar and bordering these on each side in a single broad 

 yellow line. Bordering the yellow lines are three black lines and 

 below these is another yellow line. Except for the enlarged head, 



