الفهرس 
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Abstract
Laboratory studies were conducted to determine the
efficacy of some native and introduced nematode strains
against some larval instars of Agrotis ipsilon. It was
found that the native species were more efficient than
the imported ones. The fourth larval ins tar of A.
ipsilon was found to be more susceptible to all tested
nematode species than the 5th and 6th ins tar larvae.
Susceptibility of A. ipsilon pupal stage to Steinernema
glaseri and Heterorhabditis bacteriophora nematodes was
also studied . H. bacteriophora was more effective
against this stage than S. glaseri.
Susceptibility of three larval instars of
Spodoptera littoralis to infective stages of S. glaseri
nematode was examined. Both 4th and 6th larval instars
were more susceptible than the 5th one.
All the tested inoculum levels of entomopathogenic
nematodes were effective against the larval instars of
both insects and the level of 100 dauer stages/ml
distilled water achieved 100 , mortality of the host.
Malformations as a result of nematode infection in
larval and pupal stages were determined. Results indicated
that decreasing the nematode inoculum levels
caused in an increase in the malformation percentages.
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A study was carried out to determine the efficacy
of two introduced and two native nematode species
against Z. pyrina and Synanthedon myopaeformis. The
native species achieved a higher pest control than the
imported two species. The tested nematode species
proved to be more effective against Z. pyrina than S.
myopaefor.mis. The employed technique is very important
in application of entomopathogenic nematodes. It was
found that inserting of cotton piece soaked in nematode
suspension into insect gallery gave the best larval
mortality followed by injection method. While the spray
of nematode suspensions induced the lowest percentage
of mortality.
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pupation percent and percentages of moth emergence
decreased as the inoculum levels increased.
The nematode recovery of three nematode species
from the tested individual insects was studied. The
resulted dauer stages of all the tested nematodes from
cadavers of the 6th larval instar of A. ipsilon were
the most followed by that of the 5th and 4th larval
instare. The native strain of Heterorhabditis sp.
propagated with numbers of dauer stages from cadaver of
A. ipsilon more than that given by H. bacteriophora or
S. glaseri. Also, the resulted nematodes from pupae or
adult moths of A. ipsilon were recorded. H. bacteriophora
propagated better than S. glaseri and the adult
moths yielded infective stages more than pupae or
larvae.
Field trials to control some fruit trees borers
were conducted. Over 90 \ larval mortality of Zeuzera
pyrina was gained in olive or apple orchards when some
nematode species were either injected or sprayed 5
times in 8 days intervals. Mixing the nematode suspensions
with the recommended dose of B. thuringiensis did
not achieve any increase in the mortality percentages
of z. pyrina in both olive and apple orchards.