4 o6 
Journal of Agricultural Research 
Vol. XXIV, No. 5 
THE EGG 
DESCRIPTION 
Elliptical in outline, bluntly rounded at the ends, one of which is very slightly 
more obtuse than the other. Length, 0.494 to 0.441 millimeter, average, 0.479 milli¬ 
meter; width, 0.318 to 0.265 millimeter (average, 0.306 millimeter). The chorion is 
ornamented with prominent acute longitudinal ridges, usually 17 in number but 
vaiying from 16 to 20. These ribs become obsolete at the ends of the egg, where the 
polar disks are only slightly tuberculate; in the intervals between the ribs are much 
smaller cross striae, about 30 in the leng^ of the egg (PI. i, C). 
The eggs laid by one female are very constant in size and shape, but there is enough 
variation between those from different moths to make the measmements of little 
value for specific determination. 
The eggs are very pale cream, almost white when laid, but they soon deepen in 
color, reaching a pale salmon yellow in about three days, after which, until maturity, 
the color remains tmehanged. After the third day the minute dark eye spot is visible 
within the egg. A few hours before hatching the darkening of the head and thoracic 
plate gives a purjplish tinge to the whole mass of eggs. The egg is cut slightly to one 
side of the larger end and the larva escapes through a more or less ragged opening, 
leaving the parchmentlike shell nearly transparent. 
NOTES 
In summer the eggs hatch in from five to seven days, the variation 
evidently depending on the temperature. When fully developed the 
larva leaves the egg regardless of outside conditions and does not remain 
quiescent as do some oSiers of this group. The eggs are perfectly dry and 
nonadhesive when laid, and fall down among the grass stems as they are 
dropped by the moths either in flight or at rest. Their small size and 
lack of definite location make them hard to discover ; and to find one a 
prolonged search is necessary even when they are known to be abundant. 
Dissection of two freshly emerged moths showed, respectively, 560 
and 1,120 eggs and egg cells in the ovaries. In the latter case the abdo¬ 
men also contained a large amount of fat in the form of small bodies 
about the size of the matured eggs, but whiter and more irregular in 
shape. The first moth showed a much smaller quantity of this reserve 
supply, which is probably accounted for by less favorable feeding con¬ 
ditions during the latter part of the larval life.* This partial starvation 
of the larva seems to affect directly and very decidedly the fecundity of 
the moths. 
So far as the writer has been able to determine from many experiments 
with this and other species of Crambus, the females do not require food 
other than water for the development of the immature ova in the ovaries 
at emergence. Spent moths show an entire absence of fat bodies and 
immature ova, the youngest of these having evidently broken down and 
been used for the nutrition of the larger eggs. So while there were 1,120 
eggs and egg cells in the more fecund of the two moths mentioned above, 
the actual number of eggs which she would have matured would have 
been much less than that, perhaps 700, and not over 350 for the other. 
The largest number of eggs produced by a single moth of this species, of 
which the writer has record, is 753 eggs, and very few attained 500. 
The average number produced by mo^s taken in the field and at light 
was 170, but many of these had doubtless laid part or all of their supply 
before capture. 
