CLEAR-WINGED MOTHS. 53 
eral, bright yellow bands, When disturbed it makes a 
creaking noise by rubbing together the joints of the fore- 
part of the body. It enters the earth to transform into a 
pupa. 
This insect is very uncommon in Minnesota, but has 
been found as far north as Duluth, though none of its food 
plants, viz., walnut and hickory, grow in that region, which 
indicates that its caterpillar must also be able to subsist 
upon other food. If ever it should become numerous in 
nurseries and wind-breaks, or wherever walnuts or hickories 
are grown, it can readily be kept in check. 
FAMILY SESIID4t OR CLEAR-WINGED MOTHS. 
There is, perhaps, no other family of moths so well sep- 
arated from all other tamilies as that of the Sesiidea. They 
are all small, with slender bodies; they fly only by day, and 
frequently in the brightest sunshine. Their larvee are borers; 
the caudal horn is absent, and in consequence of their min- 
ing habits their colors are uniformly yellowish-white, and 
only head and legs are darker. Many of the species of 
moths belonging here are very beautiful, and most of them 
are remarkable on account of the protective mimicry exhib- 
ited by them. This close resemblance to insects of different 
orders was observed long before the significance of protect- 
ive mimicry was understood. The majority of the Sesiidz 
m mic bees, wasps and flies. We all know from experience 
that bees and wasps can advance some very pointed argu- 
ments to be left alone, and any other insect that closely 
mimics such well armed warriors is very apt to be left un- 
molested. This mimicry is not simply a superficial one, 
since even their motions, if captured or disturbed, are like 
those of the insects imitated. Their attitude when resting, 
the sounds they produce, their hyaline wings, their ringed 
body, even the odor they give off, all are apt to warn us and 
