الفهرس 
Material and methodsOnly 14 pages are availabe for public view
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Abstract
SUMMARY
Laboratory studies were conducted to find out the efficacy of Delfin (a
hioinsecticide derived [Tom Bacillus thuringiensi« var. kurstaki) on
the first instar larvae of Sesamia cretlca and the second instar larvae of
Ostrinia nubilalls, and also the inspect. ofConsuJt (an1.G.R.) on the
first instal latvae of S. cretlca. Laboratory studies were also oriented to
Conomorium sp., which was first recorded in Egypt as pupal
endoparasitoid on S. eretica. On the other hand, field included survey
of paJasitoids on immature stage of S. cretica and O. nubilalis and the
percentages of parasitism on pests infesting summer and 1 ili
plantations in addition to assaying different control methods against the
two mentioned pests. The obtained results may be summarized as
follows:
Laboratory studies:
1-1- Effect of bioinsecticide (Delfin) on Ostrinia nubllalls and
Sesamia cretica.
The efficacy of Delfin (a commercial product of Bacillus
thuringiensis) on the 2nd instar larvae of O. nubilalis and 15t instar
lai ae of S. eretiea were studied. After 48 hours [rom treatment, the
LC5
0 values were 10 104 S.U. on O. nubilalls and 5.2 x 104 S.U. on S.
cretlca. A negative relationship was determined bet een the applied
concentration of Del fin and LTso’ value i.e. the LT5G was shortened bJ
the increase of Delfin concentration in both of O. nubllalis and •\.’.
cretica. In addition these values were shorter in case of I~1instar larvae
of S. cretica than those of the 2nd instar larvae of o. nubilalis at the
same concentration of Delfin.
SUlllmarv
- IM,-
1-2- ElTect or I.G.R. (Consult) on S. cretica
The lsf instar larvae S. cretica were fed on fresh succulent rolled
leaves of maize plants dipped in different concentrations of Consult.
The Leso value was 72 p.p.m., 24 hours after treatment. The LT50 was
shortened by increase in Consult concentration.
1-3- Morphological studies on Conomorium sp,
This study included the first record of Conomorium sp. on S. cretica
pupae. This parasitoid was identified by Dr. Hannes Baur, staff
member Natural History Museum (Bern, Switzerland).
1-3-a-The different immature stages of Conomorium sp, (egg, 4 larval
instars, prepupa and pupa) were briefly described.
Egg of hymenopterous type, on deposition it measures 0.7-mm. long
and 0.28 mm. at its widest part. The size of egg increased as
development proceeds to reach 1.31-mm in length and 0.437 mm in
width, just before hatching. The larva could be easily discerned through
the transparent chorion. The larva molts three times during its
development, i.e. it develops through four larval instars.
The 151 instar larva is 1.4 mm long and 0.525 mm wide, the body 13
segmented. The head capsule measured 0.21O-mm length and its width
0.210-mm. Each of the mandibles of 0.14 nun length and 0.070 mm
width. The 2nd instar measures 2.625-mm in length and 0.7 mm in
width. Head length and width measured 0.245 and 0.42 mm.
Mandibles are O.175-mm long and 0.1OS-mm width. The 3rd instar
measures 4.2-mm long and 0.875-mm wide. The head capsule is 0.21
mm long and 0.315 nun wide. The mandibles are larger in size and
lIIHl1l:Jrv
more pigmented than in the preceding stage. Each mandible has brood
rounded base and tapers to a sharp end. It measures 0.21mm in length
and O.14mm at its base. The 4th larval instar measures 3.325mm long
and 0.857 mm wide. The head capsule is 0.179 mm in length and 0.208
mm at its widest part.
Prepupal stage is formed inside the host pupa and measured 2.9-mm
in length and 1.0 rum width. The posterior parts of prepupa lacks
segmentation. Prepupa transfers to a free type pupa.”which is about 3-
nun long and 2.2-mm wide. At the beginning of this stage, the pupa is
creamy in colour, the compound eyes and ocelli appear red. As
development proceeds, the body darkens gradually starting with the
head and thorax, which become black. Legs appear brown with yellow
in some parts.
1-3-b- The average duration’s of the egg, the four larval instars, the
prepupa and pupa occupied 1.75 ± 0.25,2.25 ± 0.25,3.5 ± 0.09 3.75 ±
0.20 4 ±O.18, 1.13 ± 0.12 and 8.5 ± 0.23 days respectively at 25°C
and 65 ± 5 % R.H. The total larval period occupied 13.5 ± 0.72 days
and the total developmental period was 24.88 ± 1.32 days.
1-3-c- Emergence of parasitoid adults occurs from one or two holes of
a circular shape and 1- 1.5-null diameter. Emergencies is finished
within few hours.
1-3-d- Sexes could be easily differentiated by the close e amination of
antenna and genitalia. The antenna is of geniculate type and consists of
long scape, a shorter pedical and a 7-segmented flagellum in both
sexes. The flagella are longer in male (1.22mm) than female (1.05mm).
Male has also a pale yellow ring, on the ventral side of abdomen, which
is not present in female.
Summar”
- I (,X -
1-3-e- .hlling occurs immediately just after emergence. Males were
able to male al any lime <luling their whole life and the mating be
repealed several limes within a <lay. Females accepted to mate more
than once.
1-3-f- Oviposition processes is described.
f-3-g- Host range: under laboratory condition Conomorium sp. was
successfully reared on A. lpsilon; S. cretica and S. llttoralls but it failed
complete parasitism on Ostrinia nubilalls; Chilo agamemnon; Earias
insulana; Pectinophora gossypiella and Anagasta kuehnlella.
1-3-h- Effects of different temperature conditions (15, 25 and 35 DC) on
oviposition. period, longevity of adult female, total developmental
period, number of adults in progeny per female and sex ratio were
determined. Data indicated that, 25 DC was the most favorable for the
egg laying acti vity of Conomorium sp. At this temperature, the female
lived for a mean period of 27 day, The total developmental periods
cr 25.9 (24-30) day’, An adult female produced (72- 375) adults
with a sex ratio of lmale: 12.95 females.
1-3-1- Effect of copulation on sex-ratio, ovipositional activities rate of
oviposition and life-span in Conomorlum sp.
Data indicated that copulation is 110t the factor that stimulates
oviposition. Urunated females deposit eggs as well as mated ones, but
the progeny obtained ill the former case are males. The number of
produced adults was nearly the same in both cases. It was also found
that mating did not affect the ovipositional activities, life-span of adult
female and the number of eggs deposited female during its life-span.
SIJ IIImmy
1-3-j- Effect of rearing the parasitoid all different host species on the
number of progeny, sex-ratio and life-cycle:
In association with pupae of two host species, .\.’.. cretica and A.
o
ipsilon, and rearing the parasitoid at 30 ± 2 C & 70 ± 5 % R.H., the
life-cycle average (16.8] ± 0.] 4 and 17.44 ± 0.22) days, respectively,
indicating shorter life-cycle by rearing on S. cretica. Insih’1lificaJll
differences were found between rearing on both species ill the numbers
of adults in progeny and the numbers offemale resulted. Sex-ratio was
in favor to rearing of the parasitoid 011 S. cretica (1: 7.9) opposed to 1:
4.67 in case of rearing the parasitoid onA. ipsilon.
1-3-k- 1 umber of generations of Conomorium sp. per year III the
laborarory:
It was found that the parasitoids have 13 generation per year under
laboratory condition,
1-3-1- Effect of suppiementary food on the longevity of Conomorium
adults:
Longevities of adult male and female parasitoids were considerably
short under the state of starvation and when water only was supplied. In
the case of male feeding on bee honey with 20 ~o-d.ried ~ea tresulted
the longest. life-span. In case of females, the lange t life-span (12.7 ±
0.77days) was obser ed when fed on 50 % sucro e solution.
1-4- Storage of Conomorium sp. adults
In four laboratories experiments carried out at 10 ’c, the effect of
low lemperature storage on adults of Conomorium sp. adults was
measured.
1-4-a-EITect of torage on mortality rates among Conomorium
adults:
A number of 50 females and that of 50 males were stored at 10 ’c for
different periods (20, 30 40, 50 60, 70, 80, 90 and 100 days). After
such periods the mortalities among females were 10 26, 46, 60,62 68,
74, 78 and 82%, respectively. While in case of males those were 8, 28,
52, 68, 72, 78, 86 90 and 92 % respectively. These data indicated that
females more tolerant to cold storage than males.
1-4-b- Effect of storage at 10 DC for different periods on mated
females of Conomorium sp.:
The experimented mated females lived for 36 38, 36.1 and 25.2
days, respectively. The mean number of adults re ulted per female
during life- span after such periods of storage were 101.3, 83, 75.1 and
72.2, respectively. Number of adult females resulted per female were
91.6, 74.5,67.1 and 36.7 respectively, while those of males in progeny
were 9.7, 8.5, 8 and 8.5,respective1y. It could be concluded that, the
storaze of the adults mated female for a maximum of 90 davs is the ~ J
favorable one. By storage for 90 days, the longevity of adults females
was not affected significantly from those recorded for storage [or 30 or
60 days.
J-.t-c- Effect of storage for different periods on Conomorium sp,
virgin females:
The experimented virgin females’ len to male with freshly emerged
males before introduction to parasites. Females lived for 38.1,42.4,
37.3 and 27 days. The mean number of adults resulted per female
during life-span after such storage periods were 102.5, 86, 80 and69.7,
S1I1ll1ll<l rv
respectively. umber, of adults female resulted per female was 94.2,
78.4, 73 and 63.5 respectively. The average numbers of male among
the progeny were 8.3, 7.9, 7.1 and 6.2 in association with the
aforementioned periods of storage.
1-4-d- E’ITecL of storage of males for different periods on (he
fertilitv: ’”
Storage of males at lOCo for 25, 35 or 45 daJ s induced adverse
effects upon males. The maximum suitable period for storage adult
males of Conomorium sp. was 25 daJ s. At such period of storage,
males were able to gi e after mating a progeny of males and females
with sex ratio of lmale: 7.3 females.
II-Field studies
The present study was carried out during maize summer and Nili
plantations at vloshtohor during 1998 and 1999. Summer plantation
was sown on April zo” 1998 and April 28th. 1999. While, the lili
plantation was sown on July io” of each year’ The study aimed to find
th r 11 . out e touowing:
II-I-Survey of the parasitoids and percentages of parasitism:
lI-l-l-Egg parasitoids
A-Platylelenomu.. hylas ixon (Hymenoptera: Scelionidae)
This parasitoid emerged [rom S. cretica eggs collected throughout
both summer and 1 ili plantation of the two J ears, the parasitoid
showed lWO periods of activity that coincidence with the period of
presence of S. cretica eggs in the field. During summer plantation, the
first period of activity extended from the second week of May to the
uITImary
end or this month (2.17- 15 %) while the second period was detected
from Ihe til ird wee k of J une to the begi nning 0I .Iuly (3 1. 16- 4 I .66 ~~l
parasitism).
In the two ili plantations, the first period occurred from the Iir .t to the
third week of, August (25- 54.28 % parasitism). While, the second
period was from the second to the 4th week of September showing
highest rate of parasitism (88.88 - 100 %) 011 S. cretica eggs.
B- Trichogramma evanescens West, (Hymenoptera:
Trichogrammatidae)
The percentages of parasi tism by T. evanescens were estimated in O.
nubilali eggs infesting maize plants of -lili plantations of the two
years of study. These percentages started low and increased as the
eason advanced. TIle highest percentages of parasitism were (60 %
on September 19th 1998 and 61.22 % on September 24th 1999.
II-1-2-Larval parasitolds:
A-ApanleLes sp. (Hymenoptera: Braconidae)
It is a gregarious endoparasitoid on S. cretica larvae detected during
summer plantation of the two year . In 1998, the percentages of
parasitism ranged from 1.14 % on May so” to 9.09 % on June 201.’;. in
the subsequent year, those ranged from 1.11 % on . lay, 3 l st to 8 % on
June 21st.
B- Bracon brevicornis Wesm, (Hymenoptera: Braconidae)
1- On S. cretica larvae
This gregarious ectoparasitoid was detected late in the summer
plantation and ili seasons. In summer plantation, percentages of
parasitism ranged from 3.13 % on June 6th to 3.84 % on June 13th in
1998, and from 1.8S % on June ih to 4.41 % on June 13th in 1999. In
Nih season, the percentages of parasitism ranged from 2.44 %) on
September 24th to 3.70 % on October ih 1995, and 2.56 % on
September, n” to 5 % on September 2ih 1999.
2- On O. l1ubilalis larvae
The parasitoid was detected in the Nih plantation parasiusmg O.
nubilalis larvae. In 1998, the percentages of parasitism ranged from
1.77 % October 1st to 3.33 % on September 24th
. Ln 1999 lili
plantation, percentages of parasitism ranged from 2.4 7 % on October,
1~1to 2.54 % on October 8th
.
c- Meteorus rubens Nees (Hymenoptera: Braconldae)
M. rubens i a gregarious endoparasitoid, which was secured from
larvae of S. cretica infesting maize plants of the summer plantation.
The percentages of parasitism ranged from 2.08 on June 6th to 3.84 %
on June is” 1998 and from 1.11 % on May 31st to 3.7 % on June 13til
1999.
D-Tachina larvarum (L.) (Diptera: Tachinldae)
This dipterous parasitoid parasitised S. cretica larvae. In ili plantation
of 1998, the rate of parasitism ranged from 2 % on September io” to
2.44 % on September 24th. In the subsequent lili plantation 1999,
percentages of parasitism ranged from 1.33 % on August 23rd to 2.22 %
·th on August 16 .
11-1-3-Pupal parasitoid
Conomorium sp. (Hymenoptera: Pteromalidae) is a parasruc wasp,
nev ly recorded as endoparasitoid on the pupae of L\: cretica during
summer plantation of the t\ 0 years. In 1998 season summer plantation
the percentages of parasitism ranged from 10% on July 4th to 16.67 %
on June zo”. In 1999, the percentages of parasitism were 7.(1) % all
June 211 to ~O%on July s”
11-2-I-Methotl for S. ere/lea control:
A bacterial bioinsecticide (Delfin) Delfin + I %NaCI, and an insect
growth regulator (Consult) were assayed for the efficacy in controlling
S. creticu infesting maize plants culti vated in (U] area of about hal [a
feddan divided into 16 equal plots. Every 4 plots received a treatment
and the remaining 4 plots were left as control. All plots were
distributed in randomized block design. According to the obtained
data, the applied materials could be divided as follows:
1- Highf efficient, including Delfin + I % NaCl hich caused
66.51 and 38.84 % reductions in the numbers of perforated leaves
due to S. cretica larval feeding opposed to 37.88 and 20.38 leaves
in the control plants of the 1998 and 1999, respectively. This
treatment reduced the mean larval counts 110 infested plants and
caused % reduction than control by 47.39 and 27.01 %in 1998 and
1999, respectively.
2- Intermediately efficient, in luding Delfin treatment as this
preparation caused 64.74 and 26.85 %reduction in the perforated
leaf number than control plants, respecti vely. As to % reduction
than control for the larval COWltSper / 10 infested plants, those were
40.62 and 20.11 % in the two years, respectivelj .
3- Least efficient, represented by the Consult treatment which
caused 42.59 and 28.51 % reductions, respectively in the number of
leaves perforated by,S. cretica larvae than control. The reduction
percentages in larval counts 10 infested plants were 21.88 in 1998
and 13.79 % in 1999.
SlIlllmarv
1I-2-2-ElTect of different treatments on the percentages of
parasitism:
a- Egg parasitold:
The natural role of parasitism by P. hylas in eggs of S. cretlca was
not affected when maize plant.’ were sprayed with Delfin or Delfin +
1% NaCl. Spraying maize plants by Consult cau ed sib’Tlificant
reduction in the 0 erall percentages of parasitism.
b- Larval parasitoids:
The collected larvae of S. cretica were found to be parasitised by
Apanteles sp., Bracon brevicornis and Meteorus rubens. The
obtained data indicated that the spraying of maize b”, Delfin or Delfin
+ 1 0-10 Tad did not affect on the occurrence of the three larval
parasitoids. On the contrary, no parasitised S. cretica larva was
detected in the Consult treatment.
II-3- Evaluation of Triclwgramma evanescens and Bacillus
thurtngiensts in control management of 0. nubilalis.
A biological control program was planned for controlling the
European com borer, O. nubilalis using Trichogramma evanescens
and Bacillus thuringiensis. An area of half a feddan was elivided to
16 equal plots, which received 3 treatments and control in maize
plants cultivated i11 1998 and 1999. Releases were carried out twice at
7 day intervals at a release level of about 33 000 wasps for each one.
One B. thuringiensis spray wa applied against host larvae that
escaped T. evanescence parasitism. Data indicated the following:
1-1n 1998, infestation to maize plants by E.C.B. egg masses of began
on August 15th and reached to the peak on September 5lh.In the
SUl1l1n;)I”\’
- 17(, -
subsequent year first detection of egg masses occurred on August 191h
and the peak was on September Ialt!.
2- The release rate of 66,000 wasps I Ieddan induced rate or
parasiusm In Trichogramma and Trichogrumma + B.
thuringiensis plots by 69.87 and 70.69 % in 1998 and by 75.12 and
73.76 %, respectively in 1999.
3- 1l could be stated that the combined treatment (Trichogramma +
B. lit uringlensisy is the best treatment. In such treatment, the
percentages of reduction in the mean number larvae O. nubilalls at
harvest were 20 and 13.33 % in 1998 and 1999, respectively and
induced a reduction in the infestation to ears than control by 66.67
and 73.33 %, respectively in the two years of study.
4- One B. thuringiensis treatment is not sufficient to prevent the
larval attack to maize plants. This treatment caused 30.29 %and
34.09 % reduction in the mean numbers oflarvae per 10 plants than
control in the two year of study. This treatment resulted 53.33 %
and 46.67 %infestations to ears, thus indicated lowest reduction in
the infestation rate than control by 11.11 in 1998 and 6.67 % in
1999.