uly 1S91.J 



psyche. 



109 



wings with the anterior margin dull orange. 

 Fringe of both wings brownish. Under side 

 of forewings with the costa lemon-yellow. 

 Length of body 20 mm. Exp. of wings 35 

 mm. 



The moth issues towards the end of 

 May, and fresh pupal skins can be ob- 

 served till towards the close of June. 

 Some trees harbor hundreds of these in- 

 sects, and consequently suffer greatly; 

 the trunk and all the larger limbs are 

 equally infested. In only one instance 

 a pupal case was seen projecting from 

 the trunk of a small burr oak. 



A second and equally injurious borer 

 is destroying our ash-trees in the wind- 

 breaks surrounding farm houses located 

 in the open prairies, and also those 

 planted in the parks or as shade trees 

 along the streets in our villages. As a 

 general rule only the smaller trees are 

 infested, but these to such an extent that 

 they break down entirely. Professors 

 Aldrich and Orcutt have given the life- 

 history of this insect in a late bulletin. 

 But even old and very large trees do not 

 escape entirely, as I have seen trees two 

 feet in diameter, and apparently quite 

 healthy, whose bark was perforated 

 with numerous holes made by this in- 

 sect. In these cases the trees did not 

 suffer to any visible extent, but death is 

 always the consequence in smaller trees 

 where the borer cuts off entirely the 

 circulation of sap, and enters deeper 

 into the solid wood. 



Trochilium fraxini, n. sp. The head is 

 grizzled black above, with the base, palpi and 

 antennae dark orange. Coxae black, tibiae 

 and tarsi orange, the posterior portion of 

 the tibiae broadly banded with black. Thorax 

 with the disk black, with rather long and 



erect black hairs. Collar, patagia, a large 

 spot at the base of each wing, and a narrow 

 streak over the posterior part of scutellum 

 lemon-yellow; all these spots with the excep- 

 tion of those at base of wings are edged in 

 front with dark orange. Abdomen black, 

 banded with yellow at the posterior end of 

 each segment; sides of posterior 5 segments 

 orange, the orange extending almost over 

 the whole surface of the three last ones. 



Forewings covered with scales, except a 

 narrow portion from base to cell, and some 

 very small spaces immediately behind the 

 cell. Costa and internal margin coppery 

 brown. Outer margin broadlj' brown, shaded 

 with purplish copper. Discal mark large, 

 almost rounded. At the base all the veins 

 are stained with bright scarlet orange, and 

 there are some scales of the same color below 

 the costa. Beneath the forewings are lemon- 

 color on the costa, shading into orange to- 

 wards the centre of the wing, and into brown 

 on the outer margin. Discal mark orange. 

 Hind wings with a coppery sheen. Fringes 

 of both wings brown. Length of body 15 

 mm. Exp. of wings 30 mm. 



In pi. 3, fig. 4, this species is shown ; 

 it resembles very strongly a Polistes. 



This species resembles very closely 

 the injurious m >th Podosesia syrhigae 

 (Harr.), but belongs to a different 

 genus. 



Explanation of Plate 3. 



Fig. 1. Prionoxystus querciperda, 

 $ and 9 imago, and empty pupal case ; 

 natural size. 



Fig. 2. The same, larva ; natural 

 size. 



Fig. 3. Trochilium luggeri, im- 

 ago, empty pupal case and hinder ex- 

 tremity ; the last enlarged, the others of 

 natural size. 



Fig. 4. Trochilium fraxini, ima- 

 go ; natural size. 



