1<4 Bulletin 176. 



body like a pencil, but capable of being expanded at the will of the 

 insect. Giving this the usual interpretation we may take it to be a 

 scent organ. The virgin female soon after emergence from the 

 pupa fixes herself at rest, elevates the abdomen, projects the ovipos- 

 itor with the genital organs directed downw^ard, the tufts expanded, 

 and awaits the male. The antennae show considerable differences 

 betw^een the sexes. In the female the joints are not furnished with 

 tufts of hair on the inner side as is the case of the male. At the 

 base of the antenna the differences between the male and female 

 are yet more marked, and yet here the greatest modification is 

 found in the female.'' On the basal segment of the antenna occurs 

 a sensory fovea *' in the form of a considerable opening covered by 

 a tight, drum-like disc. A series of sensory punctures is found at 

 the base of the second segment, and just above the sensory fovea 

 there is an excavation which leaves that structure entirely free. In 

 the male the large sensory fovea is present, but hardly as well devel- 

 oped as in the female, and there are no sensory punctures on the 

 second segment. It is probable that this fovea is auditory in func- 

 tion. The maxillse of the mouth-parts differ quite strongly in the 

 sexes at the base." 



Mr. Beutenmiiller writes us that only two other species of these 

 clear-winged moths might be easily mistaken for the moths of the 

 peach-tree borer. Both the males and females of Sesia ■pictipes'^ 

 look much like the males of the peach-tree borer, but are readily 

 distinguished by the presence of a narrow yellow band across the 

 venter of the fourth abdominal segment, which is not present in the 

 peach-tree borer. Both sexes of Sannina ^iroceriforinis^ the per- 

 simmon-root borer, resemble the female peach-tree borer, but the 

 hind wings of the forni^,r are entirely opaque, except a small trans- 

 parent area at the extreme base. 



FoOD-Pl>ANTS. 



The peach-tree borer apparently has a decided preference for the 

 peach tree, as no other plant is so often and so destructively attacked. 

 The borer does not seem to discriminate in f^vor of any particular 



* Its larva lives under the bark of plmn, wild cherry, June berry, and beaeh 

 plum. We have also bred it from peach trees. 



