hungerford: aquatic hemiptera. 95 



the tibia of the foreleg, and the other drawing forth the body juices 

 through the beak inserted just behind one eye. Many a young marsh- 

 treader meets such a fate! Only a few minutes are required to crumple 

 the little body down to a shapeless form. 



Number of Instars. There are five nymphal instars, as has been noted 

 by Martin. These have not heretofore been described, however, and 

 great difficulty and confusion resulted in the writer's first attempts to do 

 so, due to the fact that length within the instars varied so greatly. At 

 last, by the use of limb measurements which are fairly constant, it was 

 possible to make a description that could be applied for the identification 

 of material taken in the field. All the rearings were apterous when 

 mature. 



Maturity. Bueno has given us the time between mating and oviposi- 

 tion, but not the time from emergence to oviposition. He mated a virgin 

 female July 26 and on the 28th or 29th it laid the first egg. The entire 

 period from emergence to egg laying need occupy but two days. 



Fecundity. The peculiar shape of these insects and the relatively large 

 eggs (see pi. XIII, fig. 15) has led to the belief that reproduction is not 

 very rapid. To determine this point the writer carried out numerous 

 isolations. Here is the story of a stender dish containing eight females 

 and one male. The bugs were placed here July 8, and the eggs were 

 counted and removed from time to time. 



July 8, p. m 6 eggs removed. 



July 16, a. m 127 eggs removed. 



July 16, p. m 6 eggs removed. 



July 17, p. m 53 eggs removed. 2 females dead; 6 



females remain. 



July 18, p. m 18 eggs removed. Male escaped. 



July 20, 22 eggs removed. 



July 26, 135 eggs rem.oved. 



July 28, 2 females dead; 4 females 



remain. 

 July 29, 13 eggs removed. 1 female dead; 3 



females i-emain. 



Aug. 2, No eggs removed. 



Aug. 4, 1 female dead ; 2 females 



remain. 



Aug. 5, — — 46 eggs removed. 



Aug. 6, a. m 13 eggs removed. 



Aug. 7, a. m 10 eggs removed. 



Aug. 11, p. m 42 eggs removed. 1 female dead; 1 



female remains. 

 Aug. 31, p. m 30 eggs removed. Drop experiment. 



By keeping in mind the number of females involved during each period 

 we get an average of 3.6 eggs per day laid by each female from July 8 

 to August 31. The first 9 days the 8 females laid 192 eggs, an average of 

 2% plus, each per day. The next day 6 females laid 3 eggs each, and for 

 the 10-day period laid 175 eggs, which was very nearly an average of 3 

 eggs per female each day. August 6, 2 females laid 13 eggs, and the next 

 day, 5 each. This remarkable record was continued for the next five 

 days. The production then declined. In another jar one nymph was 

 placed. This became an adult female August 1. On the 5th there were 



