1974] 
Smith — Life History of Abedus herberti 
275 
ultimate effect of compacting the mass, enhancing its structural in- 
tegrity and conformity to the male’s back. The resulting gelatinous 
plate with its embedded eggs is strong, flexible and adheres tena- 
ciously to the male’s hemelytra so long as it is kept moist. If exposed 
to air for 60 minutes or longer, the gelatinous pad becomes brittle, 
loses its adhesive properties and on prolonged exposure will eventu- 
ally fall off. 
Eggs increase in size from mature oviducal (3.064 db .022 mm 
by 1.732 ± .017 mm, n = 50) to those containing nymphs ready 
to hatch (4.983 =±= .036 mm by 2.001 d= .017 mm, n = 50). This 
represents a 59 percent mean increase in length and a 15.5 percent 
mean increase in width. The initial swelling of the egg (during the 
first 48 hours) may be due to imbibition of water, however later 
increase in size seems to be due to the development of the embryo. 
Both Hungerford (1925) and Tawfik (1969) noted dramatic in- 
creases in egg size during the development of Lethocerus eggs which 
are laid above the water on emergent vegetation. Cobben (1968) 
provides a synthesis of what is known about belostomatid eggs and 
embryology. 
Mature oviducal and freshly laid eggs are variable in shape, 
usually imperfect oval with one nearly straight side, yellow in color 
and irregularly hexagonal microreticulate. Soon after occlusion, eggs 
darken to tan. The cap (upper 3/3) differentially darkens and re- 
mains several shades darker until just prior to eclosion of the nymph 
at which time it becomes grayish white in color. As development 
proceeds the shape of the egg comes to resemble an elongate “printed 
comma” ; that is broad and rounded at the free end, narrow and 
pointed at the attached end, with one convex and one concave side. 
The concave side seems always to face the posterior of the mass. 
Cobben (1968, Fig. 232) shows the head of the embryo (of Sphae- 
rodema — Diplonychus ) facing the attached end, but embryonic 
rotation must occur prior to hatching. I observed one instance of 
egg failure due to nonrotation of the embryo. 
INCUBATION 
Male brooding of eggs, a complex of behaviors, is necessary for 
achievement of the greater than 95 percent survival observed for 
eggs of field-captured encumbered males. I never observed any type 
of egg parasitism. Egg failure, in every case but the one, seemed due 
to insemination failure; usually a few eggs on each plate did not de- 
velop. Open spaces in the laying pattern in Figure iA are undevel- 
oped eggs. Harvey (1906) reported that infertile eggs of Pedino- 
