70 Journal New York Entomological Society. [Voi. vii. 



ga/opyge differs from the Anthroceridse and Pyromorphidae only in the 

 addition of the menabranous pads to the ordinary feet. We have only 

 to imaging the loss of the crochets and the extension of the pads till 

 they touch each other, to give essentially the Eucleid structure.* 



NOTE ON TWO HYDRGECIA LARVAE. 



plate ii, figs. 4-6. 



By Harrison G. Dyar. 



Mr. H. Bird has recently presented to the National Museum larvai 

 of Hydnvcia uitela and H. piirpm-ifascia. A remarkable difference is 

 seen between them in the ])osition of one tubercle on the seventh abdom- 

 inal segment. The general rule in the Noctuidseis to have tubercle iv on 

 the seventh segment low down near tubercle v, and this position is seen 

 in H. nitela (Plate II, Fig. 5) In H. purpurijascia, however, this 

 tubercle has been moved upward to the upper corner of the spiracle as 

 on the other segments (Plate II, Fig. 4). The Hydroecia larvae are 

 borers, and it is apparently requisite that such larvae should protect the 

 extremities and surround the spiracles by corneous shields. For this 

 purpose all the tubercles are large and distinct, even the ordinarily ob- 

 scure tubercle iiia is plainly seen before the spiracle (compare the other- 

 wise generalized Hypena hicmuli (Plate II, Fig. 6), which does not 

 show iiia). On most of the segments tubercle iv behind the spiracle, 

 iii above it, iiia before and v below form sufficient protection ; but on 

 the seventh abdominal segment there is a lack of protection behind, ap- 

 parently in a place where it is most needed. It would appear that the 

 two Hydrxcia larvae before me have independently attempted to cor- 

 rect this defect, and owing to some inherent difference of organization, 

 have used different means to this end. H. piirpi/ri/ascia has moved 

 tubercle iv bodily upward into the place of greatest efficiency. H. nitela, 

 on the other hand, has developed an additional small tubercle at the 

 upper corner of the spiracle, which bears no seta. This little shield va- 

 ries in size in different larvae, its character being still not firmly fixed in 

 the species. It would be interesting to examine the other species of 

 Hydroecia in this respect. 



*It is to be noted that there are no feet on the anal segment in the Eucleidse- 

 The suckers are on the first eight abdominal segments, the first and last not so well 

 developed as the others. These (/. e., on abdominal segments I and 8) are in excess 

 of those present in AI'\s;alopyge , but their less degree of development favors the view 

 of their recent acquisition. 



