الفهرس 
IntroductionOnly 14 pages are availabe for public view
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Abstract
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This work is a st~dy on the effects of gamma irradiation
uponreproductlon and mating competitiveness of t~t
\:~(.
sugar cane stem borer Sesam1a cretioa and Jl cotton leaf
worm Spodoptera 11ttoralis.Six doses of gamma radiation,
10, 15, 20, 25, 30 and 35 krad were used for -S. cretioa, while three doses 20, 35 and 50 krad were used for .S--•.
littoralis. These studies continued throughout two year
1981 - 198).
The following are the main results obtained;
5-1. Sugar cane stem borer S. cretica I
1) When adult moths, less than 24 ho~s old, were
exposed to 10, 15, 20, 25, 30 and 35 krad, the fecundity
of the females decreased, almost proportionally, with
the increase in the dose.
2) The treatment of the male had 11ttle effeot on
tie fecundity of the female •
) The reduotion in egg viability, of the sugar
cane borer , was highly oorrelated with the given dose.
4) At the same dose irradiated temales laid more
nonviable eggs wben paired with untreated males than wben
untreated females were mated With irradiated males.
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5) Sterilizing dos8 fJr adult females was 30 krad,
while 35 krad was the sterilizing dose tor adult males.
6) There was a significant reduction in the percentages
of egg-hatching within all ratio combinations
including treated males and temales as compared with the
untreated control combinations.
7) Neither theperecentage of mated females, nor
the average nl.1mberof spermatophores per mated female
got affected by irradiating the adult moths with 10, 15,
20 or 25 krad.
8) A:t 30 or 35 krad the percentage of mat.ed
females having sperm in their spermatheoae was significantly
less than 1n those subjected to 10. 15, 20 or 25
krad doses.
9) Gamma rays, till 35 krad had almost no effect
on adl.11tlongevity of both sex.
10) The male competitiveness value was higher
• among-the males or females irradiated With 35 krad.
11) The reduction in egg hatch was signit~cantly
greater at the ratio 5:111 than at 1:1:1. (treated
males: untreated male : Wltreated temale).
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8) Ad~lt males or ad~lt females irradiated with
20t 35 and 50 krad did not affect the ability of sperm
transfer in the spermathecae. However, at 35 krad the
percentage of irradiated· ••ted females having sperms
significantly less than untreated control.
9) Gamma rays lBd al~ost no effect on adult longevity
except females receiving 35 krad which lived significantly
longer period than untreated ones.
10) Increasing the ratios of either irradiated males
or irradiated females to eated population from
1:1:1 to 5:1:1 gave significant1 more reduction in egg
hatch.
11) The competitiveness v lues were significantly
higher for the males or the fe les irradiated with 50
krad.
12) A significant reductio in egg batch occured within
the combinat1onsof native ama1e paired with laboratory
male than native female pa red with native mAle.
13) Irradiation of labors ory maleswlib substeriJ!z1JJgdoses
of 20an4 35kard lead to good co etitivene88 with the native
males, 1n mating With native fa las. In the meantime t the
reduction in egg hatch 1n 1:1 combination was significantly
more than in the
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14~A oomplete sterility we obtained when adult (less
than one day - old) irradiated t 50 krad for females and
males.