REPORT OF THE STATE ENTOMOLOGIST 1907 215 
flies (Hydroptilidae) and a few larger caddis flies of the genus 
Hydropsyche. 
Males are more in evidence, but probably not more abundant 
in fact. The females come out from their resting places only 
to lay their eggs, and are only to be seen when busily engaged 
in the performance of this task. They stand on tiptoe, with 
the long ovipositor held in vertical position at the tip of the 
deflexed abdomen, and they swing the body up and down in 
rapid shuttlelike vibration, freely rising and falling on the long 
and widely outspread legs. Thus the point of the ovipositor 
is driven against the wet surface of the plank, thrusting almost 
as rapidly as the needlebar of a sewing machine: it is moved 
about over the surface, as if searching for soft spots in the 
wood, and occasionally it makes a deeper thrust when a suitable 
place is found, and an egg is deposited. 
The egg-laying process is often interrupted and is continu- 
ally interfered with by the too importunate males. When a 
male in running about on the plank comes upon a female 
Ovipositing, he stands directly above her at the full upward 
stretch of his legs, while she goes right along with her work; 
but the instant she ceases her vibrating and lifts her ovipositor, 
he is ready with his forceps, upturned and outspread at the 
Hip MO MISGectinveds abdomen, to seize, wer Wsually she does 
not want to be interrupted and moves away, while he tries to 
run parallel and maintain all the while his position of vantage 
above her. Often other males are encountered, and then the 
males engage in a rough and tumble fight. They push and 
shove each other in a most ludicrous manner, reminding one 
of pigs fighting, and often an encounter of this sort enables 
the female to escape and to go on quietly with her work. 
The males have well developed eyes, but their sight must be very 
poor; for, while always searching for females, they seem quite 
unable to find them by sight, often passing females at work within 
a distance of a few centimeters. But their tactile sense seems 
more acute. When a male in running to and fro had passed several 
times within 6 centimeters of a female without noticing her, was 
deflected from his course toward her by an obstruction I purposely 
placed in his way, he instantly sprang toward her upon the slightest 
contact, even of tips of tarsi, but was quite unheeding until this 
contact occurred. If it did not occur he would pass on, even by 
the narrowest margin. 
