160 THE UNIVERSITY SCIENCE BULLETIN. 
Oviposition. Wessenberg-Lund says that with Ranatras the eggs are 
laid in early morning. Fred Enoch, 1909, gives the most complete ac- 
count we have. His observations were upon R. liniaris: 
“Last week I had the pleasure of observing the female engaged in ovi- 
positing on a floating leaf of Alisma, the edges of which were tightly 
grasped by the second and third legs, while the first were held close to- 
gether, high up on a line with the body, which slanted down from the 
head at about an angle of 30 degrees, the head being an inch above the 
leaf. The ovipositor was extruded, and the tip pressed by a downward 
and forward movement into the leaf, until forced through, when it was 
partially withdrawn, opened, and an egg placed in the hole. The long 
lateral filaments sprung open as the ovipositor was withdrawn. She 
moved along a quarter of an.inch, and the process of boring the hole 
repeated; the long respiratory tubes resting on the fork of the last laid, 
which was pressed home until the tip of the egg was just level with the 
surface of the leaf. The eggs’ are also laid in half decayed stems of 
Alisma, and sometimes, though not so frequently, in healthy green stems. 
I have several times bred Prestwichia aquatica Lubbock from eggs of 
Ranatra.” 
The writer has not seen the process, though he has watched for it a 
number of times. He disturbed one in the act at Beebe Lake, July 11. 
Eggs were laid in large numbers in a pool on Six Mile Creek, near 
Ithaca, N. Y., during June. A visit to this pool June 4 found Ranatra 
eges abundant on top of floating dead Typha, some of them showing the 
red eye spots. The photographs on plate VII are of some of these. 
Pettit, 1902, gave some very good drawings of Ranatra eggs which he 
described. 
Incubation. Latreille said, “Ils restent quinze jours au fond de l’eau.” 
Kulgatz says R. linearis is in egg stage two weeks. Bueno gives two or 
three weeks for the incubation period. In one aquarium the writer found 
eggs deposited on May 11 hatched June 14. This was at Ithaca, N. Y. 
Hatching. Bueno says the young emerge through a round cap at the 
top, which bears the filaments. Brocher gives a similar brief account. In 
hatching the nymph casts a clear membrane, post-natal molt, which it 
leaves as a diaphanous mantle, crumpled into a shapeless mass, and 
clinging at its caudal end in the fissure of the shell. See plate XVIII. No 
hatching “burster” is discernible under high power binoculars. Holmes 
1907, says ““‘When one sees a Ranatra on emergence from the egg he can- 
not but be surprised that the young insect should have been inclosed in so 
small a receptacle. The body of the nymph is as broad as the egg and 
over twice as long.” 
Number of Instars. There are five nymphal instars. Bueno reared 
one to the adult stage and found that the first instar lasted 8 to 14 days; 
the second 9 days; the third instar 7 days; the fourth instar 8 days; the 
fifth instar 8 days. “A total of 61 days from egg to adult.” 
Fecundity. The writer believes that these bugs produce many eggs, 
because in one restricted pool where there were few Ranatra the eggs 
were very abundant. 
Food Habits. Here there is a long list of references dating to an early 
time. The food of the young, says Holmes, “consists chiefly of small 
Sa 
ao ee oe 
