hungerford: aquatic hemiptera. 183 



tive creature. The other nymphs were still slow and inactive. On May 

 24, at five p. m., two were still alive, though their guard hairs were non- 

 functional. This tardy coming to the surface seems to be a feature in 

 the behavior of the newly hatched of this bug. The habits of the adult 

 and the needs of the larvas appear to be different from the others studied. 

 The last adult of the overwintering generation was taken early in 

 July. The species was too rare to accord satisfactory study in nature. 

 Here follows a description of the egg and young nymph: 



The Egg. 

 Size. Length, 2.21 mm.; height, viewed laterally, .78 mm.; width 

 viewed from above, .754 mm. 



Color White, with surface quite strongly reticulate so that surface 

 is rough. The chorion is quite tough. 



Shape. Elongate oval, micropylar end somewhat truncate; caudal end 

 more pointed. 



- As with other Notonectid eggs the micropyle is a curved truncate 

 cylindrical peg. 



The egg is attached to the plant stem or other support by a trans- 

 parent pad of mucilaginous material. This egg is proportionately quite 

 large. See the drawings on plate XIX. They are drawn to the same 

 scale and show how much larger this egg is than that of Noto^iecta ir- 

 rorata, a bug of nearly the same size. 



First Instar. 



Size. Length, 2.73 mm.; width of both, 1.248 mm.; width of head, 

 1.092 mm.; width of front of head between the eyes, .546 mm.; distance 

 between the eyes, .442 mm. 



Color. Body white and abdomen and limbs of newly hatched trans- 

 parent, the hairs smoky, eyes red and prominent, antennae and beak dark. 

 The limbs are also sometimes dark in the older nymphs. 



Structural Characters. The antennae are directed downward, 3-seg- 

 mented, basal segment very short. The tarsi are 1-segmented and end in 

 two claws each. The claws of the hind tarsi are not conspicuous. The 

 middle femora have, on their posterior margin, at least 2 spine-bearing 

 tubercles. The posterior femora have 10 or 11 stout spines (on posterior 

 margin) plus 2 longer ones at distal end. 



Notonecta irrorata. 



Habitat. This is a handsome bug of velvety brick red and black, and 

 one of the largest species of back-swimmers. Bueno tells us that it likes 

 the shadows of the bank, of overhanging limb, or of aquatic vegetation. 

 Surely its mottled pattern of dark colors would serve it well in such 

 haunts. We have found it very abundant at the field station and in the 

 Meadow pool at Ringwood Hollow, Ithaca, N. Y. 



Hibernation. It spends the winter months in the deeper ponds and 

 spring-fed open pools, flying from these quarters to shallower waters for 

 breeding. At Ringwood Hollow this bug was present in considerable 

 numbers in the rather deep leaf-strewn pool just west of Winterberry 



