Dy BULLETIN 13824, U. S. DEPARTMENT OF AGRICULTURE 
understanding. Many of these records are found in the extensive 
life-history lterature of entomology under titles which conceal their 
presence. Tor this reason, some important contributions have prob- 
ably been overlooked and, although a sincere effort has been made to 
cover the ground, completeness is not claimed. 
‘The stimuli which determine when and where an insect will ovi- 
posit begin to operate far back in her life and may continue to affect 
her till the eggs are extruded. These influences are of two kinds, the | 
internal and the external, and for convenience they will be taken up 
below in this order. 
INTERNAL PHYSIOLOGICAL CONDITIONS AFFECTING OVIPOSITION 
NUTRITION 
There is evidence to show that the amount and character of the 
food of an insect affect the production of eggs. An adequate treat- 
ment of this subject would necessarily involve a discussion of nutri- 
tion and would lead beyond the limits of the present problem. It 
is sufficient to say here that numerous authors, including Kellogg and 
Bell (44),1 Baumberger (6), Glaser (26), and Kopeé (AT) have in- 
dicated that subnormal nutrition, whether due to the quantity or 
quality of the food, may have a decided effect on oviposition. 
AGE 
Among the groups of insects which possess mature eggs upon 
reaching the adult stage, some species, under favorable conditions, 
lay their eggs soon alter emerging, whereas others retain them for 
a more or less extended period of time. The state of nutrition and 
weather conditions modify greatly the extent of this period (26, 40). 
No particular attempt has been made to assemble the literature 
on this subject and only two references are given here. Breit (10) 
states that bombycid and noctuid moths lay eggs soon after mating, 
while most diurnal Lepidoptera fly around a few days before ovi- 
positing. Age has no influence upon the oviposition of Drosophila 
melanogaster Meig., provided sexual maturity has been reached 
( Adolph, 7). 
FERTILITY 
Horitiny appears to be a stimulus for oviposition in some species, 
influencing not only the time of egg laying but also the number of 
eggs deposited. Normal oviposition of the cotton boll weevil (An- 
thonomus grandis Boh.) apparently will not take place till fertili- 
zation has been accomplished, but it usually begins soon after that 
(41). Mating accelerates the oviposition of Heliothis obsoleta Fab. 
(62). ‘The fertile potato tuber moth (PAthormaea operculella 
Zell.), according to Graf (29), oviposits within 24 to 48 hours after 
emergence and most of the eggs are laid within 4 days. The number 
varies from 38 to 290 eggs, the average, from 114 to 209 eggs, depend- 
ing upon the nutrition of the female. Contrary to this, virgin 
females oviposit in from 1 to 7 days after emergence, the average. time 
being 4.4 days. The number of eggs ranges from 1 to 51, with only 
92.6 as an average. Unpublished: observations of the ‘writer on 
1 Reference is made by number (italic) in parentheses to ‘“ Literature cited,” p. 15. 
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