8 
Psyche 
[March-June 
Three to four days after oviposition there appears a diffuse whitish 
line nearly girdling the egg a short distance from its distal pole 
(figure 4). This line circumscribes an arc of 270 degrees and marks 
the line of weakness along which the egg will split as the larva 
emerges; the extent of the weakened area and the positioning of 
each egg at the time of laying assures that the “cap” of each egg 
will remain attached to the main egg body by a “hinge” and will 
flip toward the midline of the egg-mass at the time of hatching. It 
can be seen (figure 4) that the developing embryo conforms to no 
strict rule of position within the egg except to have its head end 
toward the egg’s distal pole. A few days prior to hatching, the 
whitish outline of the embryo disappears and the sides of the egg 
cave in slightly; the egg progressively darkens to a slate-grey color 
and hatches on the fifteenth or sixteenth day after oviposition. 
The repagula of Uliilodes mexicana do not resemble the eggs at 
all. They are rod- or club-shaped structures, reddish-brown and 
shiny in apperance, surrounding the twig bristle-like five to ten 
millimeters below the egg-mass (figure 2). Sometimes they are 
arranged in a series of neat rings but more usually are rather 
irregularly placed. Each repagulum is approximately two-thirds the 
length of a normal egg, measuring 1.2 to 1.4 mm in length and 
0.25 to 0.30 mm at its widest point; it appears to lack any vestige 
of a micropyle, despite its ovariolar origin. It is characterized by a 
small, round, light-colored basal swelling and a larger, oblong, 
darker distal swelling, joined by a thin translucent stem (figure 
5-B). The over-all reddish hue is apparently imparted by the shiny 
fluid coating each repagulum. This non-sticky fluid should not be 
confused with the hard brownish glue that secures both eggs and 
repagula to the stem: it neither hardens upon nor evaporates from 
the repagulum surface for at least three to four weeks after ovi- 
position. Long after the true eggs have hatched, these strange 
barriers gradually collapse, their surfaces choked with debris. 
Apparently the repagula are extruded from the female’s body 
after she has deposited her eggs, since in laboratory situations repagula 
are often found glued randomly to the surfaces of the eggs. Thus 
it would seem that the Ululodes female oviposits progressively from 
the tip of the twig towards its base, with her head oriented down- 
ward; such a view agrees with what we know of the standard rest- 
posture of Ascalaphidae. Typically, four of the twelve ovarioles in 
each of the female’s ovaries are modified for the production of 
repagula (figure 6). However, the insect is nevertheless capable 
