2o8 ENTOMOLOGICAIv NEWS [May, '17 



Fourth Instar. The greater part of the characteristics of the nymph 

 are as in the preceding instar. The antennal joints show the greatest 

 change. Joints i and 4 are equal and longest; joint 2 continues the 

 shortest, half as long as i and two-thirds as long as 3. The hind and 

 middle femora show dark spots from each of which springs a long hair 

 or seta. Scattered thorns are also seen on them. 



Fifth Instar. This cannot be described, as the only specimen brought 

 to maturity died while molting and the cast skin was not available. 

 The excessive heat and moisture of the aquarium apparently weakened 

 it. 



Burmeister states that the nymphs of Gcrris may be distinguished 

 from the adult by having single-jointed tarsi. This is the case with 

 G. rcniigis, which shows no sign of two tarsal joints in the fourth in- 

 star, but has them in the adult. 



Tabic of development of Gcrris rcmigis Say. 



Oviposited April 6; May 31; Aug. 3 "1 j^ j^j^g 



Emerged April 19; June 12; Aug. 15 I " 



• Molt I April 26; June 16, 17, 18; Aug. 21 6 " 



Molt II June 20, 21, 22, 24; Aug. 27 6 " 



Molt III June 25. 30; Sept. i 5 " 



MoU IV July 5, 6: Sept. 8 7 " 



Molt V Sept. 18 10 " 



Total days — 37 (four molts) 46 (Complete cycle) 



From the above it is seen that the embryonal and four 

 nymphal stages took thirty-seven days, from the end of May 

 to early July ; the complete cycle, from oviposition to the adult, 

 took in August and September, forty-six days, vv^hich, assum- 

 ing a period of ten days for the last nymph, would make the 

 time nearly equal. These are aquarium results, and this con- 

 dition makes for stability, in that the moisture, heat and food 

 are all there, and that there are not the fluctuations there would 

 be in the open, with cool June days and a precarious food sup- 

 ply. In nature, I would look for decided variations in the 

 period, depending on the temperature largely. The embryonal 

 period ranged from ten to twelve days; the first nymph from 

 four to seven ; the second, four to six ; the third, from five to 

 ten; the fourth, from five to ten, and the fifth (one example), 

 was ten days. Mr. C. E. Olsen, working independently, found 

 the fifth instar fifteen days long, in late June. 



In conclusion I urge the complete and detailed study of the 

 life history of this bug, which, it is evident from this rough 

 preliminary sketch, presents many interesting problems. 



