2l6 



SECOND REPORT OF THE STATE ENTOMOLOGIST. 



This useful armature in tlie Cossincr, and in such of the j^geriida as I 

 have had the opportunity of examining, consists of two rows of spines 

 upon most of the abdominal segments, dividing them, when seen in ex- 

 tension, in three nearly equal parts. In Cossus robinicE, the species of the 

 Cossina: with which we are probably the most familiar, these rows occur 

 on the fifth (the first stigmatal segment posterior to the wing-cases) and 

 the following segments. 



In Cossus querciperda alone of the species known to me, they commence 

 in a single row of minute dentations on the fourth segment. The princi- 

 pal features of this armature are the following : It is always the stronger 

 in the male sex — conspicuously so in C. robinicE, but less so in C. Ceniercn- 

 sis: the teeth increase in size from the fifth to the tenth segment : the ante- 

 rior row is always the stronger in each sex ; upon the fifth and sixth seg- 

 ments, it does not, in its lateral extension, reach below the stigma,^^ while 

 upon the following segments it passes in front of the stigma and quite a 

 distance beneath it ; the posterior row is discontinued before reaching the 

 line of the stigmata ; the teeth show irregularity in form and size, particu- 

 larly those of the posterior row. 



The sexual distinction above referred to, presented in this armature, is 

 this : in the male pupae two rows of teeth occur on segments five to ten 

 inclusive ; in the female, two rows on five to nine inclusive. In other 

 words, the tnale pupa shows two roius of teeth on segment ten, where the 



female shows but ONE [as il- 

 lustrated in Fig. 67, of a 

 pupa-case of C. Ce?iterensis, 

 from which the moth had 

 emerged]. In each sex, the 

 eleventh and twelfth have 

 but a single row. Disre- 

 garding, as I think we 

 should in ordinary usage, the subdivision of what is usually known as the 

 terminal segment, into demi-segments, or a segment and a subsegment, 

 and that still further refinement which would make of the extreme por- 

 tion an additional segment with full numerical designation, then it will 

 serve to prevent misapprehension of the particular section showing the 

 sexual feature, if we indicate it as the antepenultimate segment. It would 

 be the eleventh, if we commence enumeration, as some of our entomolo- 

 gists do, with the head, but the tenth, if, as seems to me more proper, we 

 begin with the first thoracic ring. 



Besides the Cossina, this same sexual feature occurs in the .-Egeriidce. I 

 am not able to say if it extends throughout the entire famil}'. At the 

 time of this present writing, I have at my command only the pupse of 

 J£geria exitiosa and A. tipidiformis, and it exists in each. It probably oc- 

 curs in the pupae of Zeuzera (one North American species described), in 

 which the two rows of teeth are found on several of the segments, and per- 



FiG. 67.— Pupa-case of Cossns Centerexsis, male (the moth 

 emerged), with tenth segment of a female pupa-case — enlarged. 



* In C. Centerensis it reaches below the stigma on the sixth segment. 



