274 FAMILY VI. ACRIDID.E. THE LOCUSTS. 



tion with its large wing expanse its flight is powerful and erratic, 

 and in hot August afternoons it may often be seen hovering mo- 

 tionless in the air or dancing up and down above a particular 

 spot and stridulating, an act which is doubtless to be considered 

 as a sort of courtship. It is an alert species, well able to take care 

 of itself, and on warm days rather difficult to capture." 



In Indiana I have often observed this curious a3rial hovering, 

 not only by the black-winged locust, but by Spharagemon bolli 

 and other Oedipods. Townsend (1891, 44) has written of it as 

 follows: 



"On August 24 I noted an individual of D. Carolina perform three times 

 in succession, and then another alighted on the ground by its side. They 

 ran by each other several times, apparently clasping, probably in conflict, 

 for I am quite sure they were both males. At last one of them flew away 

 and the other soon after renewed the performance. In going through with 

 it they rise at first about three or four feet, making a light purring or 

 beating sound, and then rising higher, change the motion of the wings, 

 when a curious sharp, see-sawing sound is produced. Some rise even 

 higher than six feet in the last act, others only two or three feet. Many 

 do not remain in just the same place while hovering, but vary, falling or 

 jerking about while endeavoring to keep the same point in the air. Of 

 course some excel others in the beauty and ease with which they accomplish 

 the feat and I am of the opinion that the females are sensitive to the grace 

 with which it is performed." 



Somes (1914, 53) says: 



"From a distance this performance of D. Carolina resembles the hover- 

 ing of the 'Mourning Cloak' butterfly, Euvanessa antiopa, more than the 

 actions of a grasshopper. This habit is occasionally seen in a few other 

 related insects, such as some of the Arphias, Camnula pellucida, and Circo- 

 tettix verruculatus. It has been thought by some to be in some way at- 

 tractive to the opposite sex, but as Hancosk (1911, 342) has noted, we often 

 find this demonstration occurring only when males are near, and on the 

 whole it appears more likely a form of play, possibly akin to the jumping 

 contests of small boys. The insect is very social in its habits and individ- 

 uals meeting will sometimes pause and wave the antennae with every ap- 

 pearance of an informal conversation. The males are very ardent in their 

 courtship, and on one occasion we found four unsuccessful males clinging 

 to a mating pair so closely as to form a compact mass of locusts, not even 

 releasing their hold when we rolled them gently down an incline." 



McNeill (1887, 58) has shown that while the length of body 

 is greater in D. longipennis Thos. than in D. Carolina, the tegmina 

 are proportionally longer in both sexes of Carolina and absolutely 

 longer in the male of that species, so that the latter, in spite of 

 the names, is the long-winged form. However, D. longipennis, 

 which ranges from "Idaho and Montana to New Mexico and Tex- 

 as," has other characters sufficiently defining it as a valid 

 species. 



