الفهرس 
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Abstract
a
iods.
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5. SUKMAR.Y
The objective of this work was to study the efficacy
of phosphine against four species of mites infesting stored
pr ducts in Egypt At the same time the biological
cha acteristics of the survivors of one mite species, namely
Ac rus siro L., exposed to the median lethal dose of
ph sphine, were studied in comparison to that of the
un reated individuals.
Species tested were A. siro L. , Tyrophagus
u rescentiae (Schrank) , Gohieria fusca (Oudemans) and
Ch rto 1 hus arcuatus (Troupeau).
1. Efficacy of phosphine against the tested aites:
Fumigation experiments were performed in the laboratory
at 23±1°C, 6±1°C and 80±5% r.h. Tests were conducted using
fixed concentration of 0.85 mg/L; an increasing
co centration with a maximqm of 5.8 mg/L at varying exposure
:~
alts akove. the follovi~:
i
Phosphine was aore efttcti”e at the higher tea))erature.
eggs were aore to phosphine at both test
t peratures than the stales· of .i tt!!•S The
”ttSpla iae: ~’vas;~,.o.evhilt: siailar
. _.-:.?:,~
s ceptibility of A. ~s~ir~..
t e that ofT~ utresce.iie
-
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Larvae of A. siro and T. putrescentiae were found
at 6±loC more sensitive to phosphine than adult stages.
Long exposure periods, at the two test concentrations,
we e more effective against mite stages than short exposures
at both temperatures.
The CT-product values required to achieve 99.9%
tality at the constant concentration and 23±1°C were
95, 79 and 396 mgh/L for the adul t, nymphal, larval
egg stages of ~ siro respectively; at 6±1°C were 142,
96 and 2556 mgh/L for the adult, nymphal, larval and
egg stages of A. ~ respectively.
The LC.T
99
.
9
-values for T. putrescentiae were at
23±10C: 91, 92, 77 and 328 mgh/L; at 6±loC: 148, 133, 105
and 2730 mgh/L for the adult, nymphal, larval and egg stages
r spectively.
The LC.T99.9 -val ues achieved by using the increasing
c ncentration at 23±1°C were 213, 251, 159 and 1212 mgh/L
f r the adult, nymphal t 1aT’,.1 and egg stages of A. siro
r spec tivel}; at 6±1°C tliese Talues were 1168. 1333, 954
a d 3959 mgh/L for the aduJt. nymphal, larTal and .~gg stages
r spectively.
The correspoD.ial T. p.tresceatiae at 23±I°C
307; 904; 288 aad at 6±1-C were 1407,
-
10 1, 765 and 3898 mgh/L for the adult, nymphal, larval
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an egg stages respectively.
The LC.T99.9 values obtained using the increasing
eo. centration at 23±1 DC for G. fusea were 186, 141 and
22 mgh/L for the adult, nymphal and larval stages
re pectively.
The corresponding values for Ch. arcuatus ”,ere 539,
43 and 385 mgh/L for the adult, nymphal and larval stages
re pectively. It is obvious that Ch. arcuatus was more
to erant to phosphine than G. fusca.
Data indicate also that CT-products required for a
pa y level of mortality by using the increasing
c. of 5.8 mg/L were higher than that achieved by using
fixed concentration of 0.85 mg/L at both test
peratures.
2. Effect of the .edia. let •••l .ose of ,ltos,hi.l!. 0. the
biological. characteristJc8 of tlte sar-oriTors of Acarus
siro L:
Results of biologica ~TesticatioDs carrie~l out in
th laboratory at 26·C r.h. todeteraiDe the
bi locieal
exose4 to the
th ’ follovj~&.,:
••••
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difference was found betlieen the
No significant
su vivors and the untreated stock (parents) in the average
pr -oviposition period, average number of eggs laid per
feale per day. average hatching rate, average incubation
pe iod, average duration of larval and nymphal instars,
la val and nymphal mortalities and total developmental
pe iod. The total developmental period averaged 9.7±O.7
da s for the survivors and 9.8±0.5 days for the untreated
ulation at the above mentioned temperature and relative
idity. The mean number of egg laid daily per female
5.04±O. 78 for the survivors and 5.4±1.4 for the
rea ted stock