74 ENTOMOLOGICAL SOCIETY 



a thick mass of duckweed was floating, extrude the spiracles, 

 and make a soft chirping- noise, not unlike a subdued cricket 

 song. It was some time before I could make out just where 

 the music came from, but I finally succeeded in observing the 

 act, and verified it a number of times. That a song could 

 emanate from so odd a source as the rectal spiracles of a water 

 bug seemed unnatural, but such is the fact. When the bug 

 was engaged in chirping one had to look very closely among 

 the duckweed to discover the spiracles, but, once found, a 

 rhythmical contraction and relaxation could be distinctly ob 

 served with every note of the song, which was produced much 

 more slowly than that of our cricket. 



The breeding season of this water bug at Watsonville, CaL, 

 where it is very abundant, is from April to June, and during 

 this time from two to four sets of eggs are hatched. The eggs 

 are glued tight and fast to the back of the male, and there they 

 stay through the whole period of incubation. Upon the wing 

 sheath of the male is first spread a drop of mucilaginous adhe 

 sive. Into this drop of adhesive are fastened the eggs, one at 

 a time, closely together, at all angles from perpendicular in the 

 center of the clutch to a cant of 45 at the edges of the wing 

 sheaths. From 70 to 175 eggs are deposited upon the back 

 of the male, but not all at one time. Part of them will be 

 deposited one night and the rest the next or succeeding nights. 

 This work is all done in the dark and I was never fortunate 

 enough to observe it. If a spot of two, three, or more eggs 

 is missed, it is filled in afterwards, and should some of the 

 eggs prove to be infertile, these drop off and are replaced by 

 others as late as the sixth or eighth day of incubation. 



Incubation lasts from ten to twelve days, at the end of which 

 time the egg cases and adhesive nidus that holds them are cast 

 off entire, providing there be no late-laid eggs, in which in 

 stance the empty egg cases and nidus remain attached until 

 all are hatched. The cast-off mass of egg cases and nidus 

 resembles a knobbed shield, being oblong-oval, with the con 

 cave side towards the male's back. The eggs are 5 millimeters 

 long by i millimeter thick and are of the same color as the 

 parent. During the period of incubation the male spends much 

 of his time in aerating the eggs. This is accomplished by 

 gently raising and lowering the wings so that the air taken in 

 at the surface and held under the wing cases is moved back and 

 forth beneath the mass of eggs, and taken up a little at a time. 

 If by any chance the male should be removed from the water 

 for a few hours during incubation, the whole mass of eggs 

 nidus and all loosens and comes off. 



At the end of incubation the male comes to the surface and 



