94 
abounded six years ago. It is true many of the trees infested 
by them were cut down and burned, yet many more remained. 
What has killed these insects so effectively is not known. 
A description of the moth follows in smaller type, so that the 
readers not interested in such matters may skip it. 
Trochilium luggert H. Edw. Upper side of head black, orbits of eyes 
bright lemon-yellow. Face black. Palpi black at the base, otherwise 
lemon-yellow. Thorax with the disk black, with shorterect downy hairs. 
Collar, patagia, spot at base of the wings, and a broad streak at base of 
the thorax conspicuously lemon-yellow. Antenne chestnut-brown above, 
dull orange beneath. Tibice orange, tarsi somewhat of a darker shade. 
Abdomen black, anal tuft pale orange, with bright yellow band at the 
posterior edge of all segments, those of tne posterior segments much 
widened. Fore wings thinly clothed with scales, the costa narrowly dull 
orange, as is also the oblique rather indistinct discal mark at the end of 
the cell. The space from vein 2 to vein 5 clear of scales behind the cell. 
Hind wings with the anterior margin dull orange. Fringe of both wings 
brownish. Under side of fore wings with the costa lemon-yellow. Length 
of body 20 mm. Expanse of wings 35mm. (Fig. 48). 
THE ASH-TREE BORER, ( Trochilium fraxini Lugger)is another 
borer that is very common in the prairie regions of Minnesota 
and South Dakota. It effects the ash, and is a very serious 
hindrance to the growth of the tree. Wherever this tree is 
utilized for windbreaks or for shade trees, it will soon be 
attacked by these borers. Asa general rule they do not per- 
mit trees to reach much of a size, but 
soon cause them to break down 
entirely. All parts of the trees are 
=, infested, though the borers are most 
usually found just below the surface 
of the soil. Young trees always suc- 
cumb, while larger trees will survive 
many years. The adult of this borer 
is a moth that resembles very closely 
a paper-wasp, as may be seen by 
Fig. 49.—Ash-tree borer. studying its picture, Fig.49. The 
naire moth resembles an eastern species of 
clearwings which also infest the ash. A description of our 
species is given below: 
Trochilium fraxini Lugger. The head is grizzled black above with the 
base, palpi and antennz dark orange. Coxe black, tibiv and tarsi 
orange, the posterior portion of the tibiew broadly banded with black. 
Thorax with the disk black, with: rather long and erect hairs. Collar, 

