Nov., 1908.] The Broken Hemelytra in certain Halobatinae. 389 



THE BROKEN HEMELYTRA IN CERTAIN HALOBATINAE. 



J. R. DE LA Torre Bueno. 



In his description of Telmatometra* Dr. Bergroth notes that 

 the membrane of the hemelytra being broken off near its basal 

 margin, a description of its veins was not possible. At first I 

 attached no significance to this and assumed that the membrane, 

 being delicate, had been lost in some way. However, a short time 

 after the appearance of the paper cited, a possible explanation 

 presented itself. To me, it clears up the question completely 

 and exhibits a very remarkable habit in certain Halobatines. 



A¥hile out rowing on St. Mary's Lake, in the vicinity of White 

 Plains, N. Y., on July 4, I noted close to the shore in a little cove 

 made by some rocks, quite a colony of Trepobates pictus H. S., 

 adults and nymphs. A scoop of the net yielded a goodly catch, 

 among them one winged individual. In another similar cove, 

 two more were secured from among a large number of the 

 apterous form. These, being of opposite sexes, were preserved 

 alive and set apart for breeding. On the 6th I was obliged to 

 kill them, owing to the remarkable antics of the male. At first, 

 he was noticed fussing with his wings, passing his hind legs under 

 them repeatedly. Very soon he had one hemelytron so bent 

 that the end (the membrane) stood straight up from the body. 

 He continued these passes, so I imagined, to straighten the wing, 

 but finally he succeeded in breaking off first the membrane of one 

 hemelytron and then of the other, leaving the hemelytra in the 

 condition Dr. Bergroth notes in Telmatofnetra. Vv^hen the 

 females began similar tactics, both were put in the cyanide 

 bottle, because the winged form of Trepobates is so rare in these 

 northern latitudes, that until I caught these three, I had taken 

 only one other macropterous individual in eight years' collecting. 



At the same time I also secured one 9 Rheuntatobates 

 rileyi, fully winged, the only one I have ever seen. This com- 

 menced a, like de-alating operation, and she, too, was promptly 

 despatched. 



A week later I captured no less than seven Trepobates with 

 wings similarly broken off, (but only partlv so in one individual), 

 three of them being males and the remaining four females. Four 

 Rheumatobates were secured at the same time and place, three 

 females and one male, with hemelvtra and wings broken off as in 

 Trepobates. At a later date one more truncate winged Trepobates 

 was found. A.11 these occurred on a pond about a mile and a 

 half from St. Mary's Lake, in which there had been neither 

 Trepobates nor Rheumatobates earlier in the summer. 



*01iio Nat., 1908, Vol. VIII : 375. 



