PSYCHE. 



A NEW STRUCTURAL CHARACTER IN INSECTS. 



BV R. A. COOI.EY B. S., AMHERST, MASS. 



While studving the wings of the Gvp- 

 sy Moth for aiich'oconia I observed a 

 peculiar structure which I have ne\er 

 seen definitely described. This struc- 

 ture is a small oval patch of short, sharp 

 spines on the under side of the fore 

 wing, near the base of the hind margin. 

 A short notice of this, with illustrations, 

 appears in Part II of Prof. C. H. Fer- 

 nald's Repoit on the Gypsy Moth, just 

 published. The spinv area was also 

 found in Crambiis laqiieatelliis Clem., 

 and is described in Prof. Fernald's Mon- 

 ograph of the Cranibidae. recentlv pub- 

 lished in the Thirty-third Annual Re- 

 port of the iSIassachusetts Agricidtural 

 College. Further investigation has 

 revealed the fact that the structure is 

 not confined to Portlictria dispar 

 (Linn.), and Crambus laqneatellus 

 Clem., but is present in very many of 

 the Heterocera, and that whenever this 

 occurs, there is always a corresponding 

 patch on the thorax, at the place where 

 the spines rest when the wings are in 

 repose. 



The only previous mention of any- 

 thing of the kind, so far as known to 

 me, is by Dr. W. Donitz, who in an 

 article entitled "A Singing Lepidop- 

 teron," published in 1SS7 in the Berliner 

 entomologische Zeitschrift, Vol. 31, 



states that while holding a male of 

 Dionvchopus uivens Men. between his 

 fingers it made a chirping noise. D. 

 nivalis is found in Japan and Siberia 

 and is related to our Spilosoma. He 

 states that the sound is produced bv the 

 rubbing together of brushes of sharp 

 chitinized spines, one on the luider side 

 of the fore wings near the base, and one 

 on the upper side of the hind wing. He 

 expressed the opinion that the sound is 

 produced for sexual attraction, but he 

 was hardly justifletl in this conclusion 

 since he had only males for examina- 

 ti(jn. Though I have studied many 

 species I have never found an\thing 

 like what Dr. Donitz describes on the 

 hind wing, but as previously stated, the 

 second area is alwa\s found on the 

 thorax. May it not be that he was 

 mistaken in his observations.'' 



The following descriptions were made 

 from Catocala conc/itnbens Walk., an 

 insect which shows the structures dis- 

 tinctly, and which may he considered 

 as typical. Figs, i, 2, 3, and 4 of Plate 

 9, were drawn from this insect. On the 

 fore wing the area Fig. i, s. is more or 

 less oval in form with its longest axis 

 nearly parallel to the hind margin of 

 the wing and it is without scales. It 

 has a definite boundarv at which the 



