H.A. BORAEI
Economic Entomology Department
Fac. Agric., Kafr EI-Sheikh, Tanta Univ.

ABSTRACT

Key Words: Microctonus sp., morphology, development, behavior, phenology.

A.M.A. IBRAHIM, S.A. EL-ARNAOUTY AND K.T. AWADALLAH
Biological Control Lab., Fac. Agric., Cairo Univ., Cairo, Egypt

ABSTRACT

The present paper deals with the effect of pruning process on population densities of aphids and mealy-bugs infesting apple trees at the Giza region. The aphid species found were; Myzus persicae (Sulz.), Aphis gossypii (Glov.) and Aphis pomi De Geer, while the mealy- bugs were only represented by Icerya seychelarum species Statistically, the pruning process showed a significant effect, i.e. the counts increased on pruned trees than unpruned.
The secured parasitoids associating with aphids were Diaeretiella rapae Mcintosh, Ephedrus persicae Froggatt, Aphidius matericariae Hal. and Praon volucrea Hal., their counts were calculated with those of aphids. Statistically, pruned showed a significant effect on the counts of parasitoids. For the predators associated with aphids, six groups belonging to the families:
Chrysopidae, Seyrphidae, Coccinellidae, Staphvlinidae, Cecidomyidae and Mantidae were reported. Their counts reached a peak in May and September. The counts of predators in relation to aphids was equivalent in the presence or absence of pruning.

Key Words: Sap-Sucking pests, natural enemies, pruning, apple trees.

M.A.NADA, MONA A.A. HEWADY AND AMIRA M. RASHAD
Plant Prot. Res. Institute. Dokki, Giza , Egypt

ABSTRACT

Under natural conditions, the ectoparasitic mite, Pyemotes herfsi (Oudemans) appeared as an important agent against the diapausmg pink bollworm larvae resting in dry cotton boils in cotton stalk heaps stored on land or on top of farmers' houses. Evaluation of the efficacy of Pyemotes as a controlling agent was carried out at the end of April, May and June, 1993.
According to release of the parasitic mite on the cotton stalk heaps stored on land or on top of houses at El-Ebrahemea region, Sharkia Governorate, reduction rates of healthy diapausing larvae after three weeks in a height of 0.5 to 1.0 meter reached 40 and 66.7%, respectively. The reduction rate reached 68.1 and 85.5% when the parasite was released underneath the heaps on land in a level of 0.5-1.0 m and 1.0-1.5 m, respectively. Meanwhile, the reduction rate reached 88 1% after 3 weeks when it was released underneath the heaps on top of houses at the height of 0.5-1.0 m.
Percentage of parasitism reached 68.0 and 83.3% after 3 weeks from releasing the mite on the height of 0.5-1.0 m of cotton stalk heaps when releasing was on heaps, while it reached the maximum percent after 3 weeks post releasing the parasite underneath the heaps, where it was 85.7 and 95.2% in dry cotton boils in stalks on land or on top of houses, respectively.

AMAL I. AFIFI AND A.M.A. IBRAHIM
Biological Control Lab., Fac. Agric., Cairo Univ.Giza, Egypt

ABSTRACT

The histerid Carcinops 14-striata Steph. was successfully reared in Laboratory at 27±2°C and 70% R.H. on Larvae of Musca domestica L. The total developmental period of this species averaged 48.27±0.1 and 44.13±0.03 days in female and male, respectively. Four larval instars were reported for this species. The various stages of its life cycle were described. Mating, oviposition processes and the egg laying activity were reported.

Key Words: Carcinops 14-striata, Biology. Description.

A.M.A. IBRAIHM
Biological Control Laboratory, Fac. Agric.Cairo University , Cairo , Egypt

ABSTRACT

The relationship between aphid species, Myzus persicae (Sulz.), Aphis gossypii (Glov.) and Aphis pomi De Geer infesting apple trees in Giza and their parasitoids; Ephedrus persicae Frogatt, Aphidius matricariae Hal., Diaeretiella rapae McIntosh and Praon volucre Hal. had been studied during 1993. The aphids first appeared on these trees on the first week of March by 0.8 individuals? leaf. Three aphid peaks of 9.6, 12.6 and 12.2 aphids/leaf were noticed on April 15th, May 27th and July 8th, respectively. Consequently, 12.5, 24.6 and 28.7% parasitism were reported for the parasitoids mentioned above. Both E. persicae and A. matricariae were the dominate and highly effective species against the aphids M. persicae and A. gossypii. 35.9% and 34.1% of the total percentage of parasitism were found to be resulted from them. The other two parasitoids namely D. rapae (15.6%) and P. volucre (14.4%) are less important. During the last week of May and second week of July, the highest density of the aphid parasitoids occurred and this was enough to suppress the population of aphids beyond the economic level. Statistical analysis showed significant correlation between aphid and associating parasitoids.

Key Words: Aphids, Parasitoids, Apple trees.

A.M.A. IBRAHIM AND AMAL I. AFIFI
Biological Control Laboratory, Fac. Agric. Cairo Univ., Giza , Egypt

ABSTRACT

Two aphidiid parasitoids naemly Aphidius colemani Vier and Aphidius picipes (Nees) are secured associated with the aphid, Hyalopterus prunE (Geofftoy). The latter parasitoid was firstly reported in association with the aphid in Egypt . The total numbers of healthy and parasitized alate viviparous (V.L.), apterous viviparous (V.A.) and immatures (N) forms of H. prunE were recorded on peach during the period from December 1992 to November 1993 at Giza governorate. Percentages of parasitism were estimated. Preference of the parasitoids to different forms of the aphid H. pruni was estimated under field conditions during the active season of the parasitoids. The adult aptera was the most preferred form for the two parasitoids A. colemani and A. picipes, and the coefficient preference was O.06PO.94 and O.06PO.5 I in the two pa.rasitoids, respectively.

Key Words: Hyalopterous pruni, Parasitoids, Peach

STUDIES ON SOME FUNGAL NEMATODE ANTAGONISTS IN RELATION TO NEMATODE EGG HATCHING AND REPRODUCTION

A.H.H. ALI
Nematology Research Center , Fac. Agric, Cairo Univ. , Cairo , Egypt

ABSTRACT

Twenty four fungi were isolated from cysts of Heterodera zeae in Egypt . The most frequently occurring species were Paecilomyces lilacinus, Chioridium sp., Trichoderma harzianum, Cheatomium spirales, Acremonium strictum, Pyrenocheata sp., Vetricillium chiamidosporium and Mycolyptodiscus sp. with occurrences of 26.5, 23.0, 22.0, 19.0, 18.8, 18.3, 16.6 and 13.8 percent, respectively. The study of their effect on Meloidogyne incognita egg hatching revealed that P. lilacinus gave an inhibition over 90%. C. spirales gave the least inhibition for egg hatching (58%). Four of these fungi were studied for their effect on Rotylenchulus renzformis reproduction on cotton in a pot experiment. A. strictum at higher inoculum level gave 70% PF reduction which was very close to that of Aldicarb treatment (76.98%). At lower inoculum levels, however, all fungi species were not effective in this respect. Adding the flingal inocula of any of the four species prior to nematode inoculation was significantly effective than post nematode application

Key Words: Fungi. biocontrol. plant parasitic nematodes, antagonism.

A.H.H.ALI AND M.I.E.BARAKAT*
Nematology Research Center . Fac. Agric., Cairo Univ. , Cairo , Egypt .
*Botany Dep., Fac. Agric, Fayoum, Cairo Univ.

ABSTRACT

The effect of culture filtrates (CFs) of Trichoderma harzianum. on juveniles mortality and hatchability of Meloidogyne incognita was studied. Both isolates of I harzianum at all tested concentrations demonstrated toxic effect, specially with the increase of exposure time. Different culturing media also affected the toxicity of isolates. Czapek's medium exerted higher toxicity at all CF concentrations and reached 91% followed by PD medium with 71% after 48 hours. CFs when applied to the soil reduced number of galls on tomato roots as well as population of M. incognita in soil. On the other hand, foliar application did not show any effect. Number of M incognita J2, gall, root galls as well as disease severity of the pathogenic fungi, Fusarium oxysporium F. lycopersici, Alternaria solani and Rhizoctonia solani were greatly suppressed by the addition of the antagonistic fungus T. harzianum to the soil under open field conditions.

Key Words: Biocontrol. Antagonism. Trichoderma harzianum, Meloidogyne incognita.

ABUNDANCE OF APHYTIS LEPIDOSAPHES (COMPER) (HYMENOPTERA : APHELINIDAE) AND ITS HOST THE PURPLE MUSSLE SCALE, LEPIDOSAPHES BECKII (NEWMAN) ON CITRUS

M.M. EL-HUSSEINI, S.M. SWAILEM AND G.S.M. AHMED*
Fac. Agnc., Cairo Univ. , Giza , Egypt
* Ciba Geigy Agrochemical Research Station, Kaha , Egypt

ABSTRACT

Seasonal fluctuations of Aphytis lepidosaphes (Comper) parasitizing Lepidosaphes beckli (Newman) has been studied during two seasons (1985/1987) in citrus plantations that received no chemical applications. The first season was characteristic with relatively higher rate of parasitism (54.4%) than the second season (23.4%). The maximum rate of parasitism (64.4%) occurred in February at 1st season, while it was 38.2% in August of the 2nd season. The minimum rate of parasitism (46.0%) took place in May during the 1st season and in October during the 2nd season (13.8%). Nymphs and females of L. becidi seemed to be more favorable to the parasitoid than their males. The average values of annual fluctuations were 1.404 and 2.768 for 1st and 2nd seasons, respectively.

Key Words: Aphytis lepidosaphes, parasitoids, abundance, citrus.

AMA, ABD EL-HAFEZ, SUZAN H. TAHER AND SAWSAN M. ABDEL -HALIM
Plant Prot. Res. Inst., Dokki. Giza , Egypt

Key Words: Pectinophora gossypiella, Bacillus thuringiensis, survival, malformation, fecundity. fertility.

A.N. HASSAN
Dept. Biological and Natural Sciences, Inst. Environ. Studies & Research.
Ain Shams Univ., Cairo , Egypt .

ABSTRACT

To assess the use of cytoplasm compatibility as a genetic method to control Culex pipiens mosquitoes, bidirectional crosses were made between populations from Egypt (ET) and UK (LN). LN males were crossed to ET females, 79% of produced egg rafts were incompatible, 7% were partially compatible and 14% were compatible. In the reciprocal cross, 65% of the rafts were incompatible, 35% were partially compatible, and no compatible egg rafts were produced. Of larvae hatched from ET and LN eggs, only 3% and 39% survived to the adult stage. Moreover, sex ratios were also disrupted.
These results demonstrate diversity of a maternally inherited characteristics within interbreeding allopatric populations of Cx. pipiens. The observed diversity in cytoplasmotypes between the tested Cx. pipiens populations may allow two-way leakage of genomes during a genetic control program exploiting this characteristic, thus, reducing its efficiency.

Key Words: Cytoplasm incompatibility, Culexpipiens. control.

INTERACTION BETWEEN ENTOMOPATHOGENIC NEMATODES AND BACILLUS THURINGIENSIS: A NEW APPROACH FOR BIOLOGICAL CONTROL OF INSECTS

M.H.EL-BISHRY
Plant Prot Res. Inst. Dokki, Giza , Egypt

ABSTRACT

The interaction between two commonly used insect pathogens, i.e entomopathogenic nematodes (Steinernema carpocapsae and Heterorhabditis bacteriophora) and Bacillus thuringiensis was studied against Agrotis ipsilon. The results revealed that infective juveniles of the two nematode species contaminated with B. t. could provide a pathway for B. t spores to the insect's haemocel specially in case of H. bacteriophora. Higher mortality rates were obtained in this case than those obtained by each pathogen when used as single infection. Antagonistic effect was detected between B.t. and Xenorhabdus spp., the symbiotic bacteria associated with the nematodes. The cause of insect death depended mainly on which bacterium started its action first.

Key Words: Entomopathogenic nematodes, Bacillus thuringiensis, Interaction.

M ALIA ABD EL-HAFEZ
Plant Prot. Res. Inst., Dokki, Giza , Egypt .

ABSTRACT

Laboratory experiments were carried out at 27±1°C and 80±5% R.H. to test the effectiveness of two parasitoids i.e., Trichogramma evanescens and Trichogrammatoidea bactrae in parasitizing Pectinophora gossypiella (Saund.) and Earias insulana (Boisd.) eggs. Parasitic females from pink bollworm eggs were significantly more fecund than those from spiny bollworm eggs, and T. evanescens females produced significantly more progeny than T bactrae females in both host eggs. Both parasitic females significantly preferred oviposition into young than old eggs of the two hosts and preferred pink bollworm eggs than spiny bollworm eggs when offered the choice between the two hosts.

Key Words: Pectinophora gossypiella, Earias insulana, Trichogramma evanescens, Trichogrammatoidea bactrae.

S.A. MANSOUR, S.SH. MESSEHA; M. S. AHMED* AND M. A. SHOUKRY*
National Research Centre, Dokki , Egypt
* Fac. of Science, Am Shams Univ. , Cairo , Egypt

ABSTRACT

In laboratory tests, the potential voracity of the fish, Gambusia affinis (Baird & Girard), upon 3rd instar larvae of Culex pipiens (L.) was determined. On basis of the daily consumed number of the prey, young fish devoured less than the adult. Also, the adult male fish devoured less number than adult female. Concerning quantity of daily consumed prey to the fish body weight, young fish devoured a quantity equal to 29% of its body weight, while this rate for adult female and male fish was equal to 22% and 16%, respectively. Such findings may reflect the potential voracity of Gambusia affinis upon Cx. pipiens larvae as affected by stage and sex of the concerned predatory fish.

Key Words: Potential voracity, Gambusia affinis, Culex pipiens.

AMAL I. AFIFI, K.T. AWADALLAH, M.F.S. TAWFIK AND EMAN I. ELSEBAEY*
Biological Control Lab., Fac. Agric., Cairo Univ. , Giza , Egypt .
* Plant Prot. Res. Inst., Dokki, Giza , Egypt .

ABSTRACT

The reduviid species were surveyed from different localities in Egypt , either by hand or sweeping or by using light traps. The reduviids could be classified into three groups, the first group included the diurnal species, the second group consisted mainly of nocturnal species attracted to light traps and the third group was represented by some reduviids that were found in large numbers during the day time and at the same time in fairly large numbers attracted to artificial lights.

Key Words: Survey, Reduviids, Egypt .

AMAL. I. AFIFI, K.T. AWADALLAH, M.F.S. TAWFIK AND IMAN I. ELSEBAEY*
Laboratory of Biological Control, Fac. Agric., Cairo Univ., Giza, Egypt
*plant Prot. Res. Inst., Dokki, Giza

ABSTRACT

Coranus sp. was first reported from Mersa-Matruh and South Sinai on the host plants Alhagi mourorum Med. (Leguminosae), Morrubium vulgar L. (Labiatae) and some desert shrubs, attacking the lygaeid bug, Spilostethus pandurus Scop.
Durations of various developmental stages, together with the biological processes and the egg laying activity were investigated.

Key Words: Coranus sp., Biology.

F.M. EL-AGAMY; S.M.I. MET WALLY; R EL-SUFTY AND A. YOUSSEF
Econ. Int. Dept., Fac. Agric., Tanta Univ. , Kafr El-Sheikh , Egypt .

ABSTRACT

In the present work, two braconid larval parasitoid species were recorded; Opius nitidulator Nees. from Pegomyla mixta Villuve and Agathis sp. from Scrobipalpa ocellatella Boyd.
In September plantations, the whole season percentage of parasitized larvae and pupae of P. mixta by 0. nitidulator recorded 13.6 and 16.0% in seasons 199 1/92 and 1992/93, respectively. The highest rate of parasitism appeared in April representing 19.8 and 12.1% for the first and second seasons, respectively. In December plantations, it was 18.8 % allover the first season and 21.0% for the second one. The highest percentage of parasitism (27.5%) was recorded in April in the first season and in May (27.9%) of the second one.
Rate of parasitized larvae of S. ocellatella by Agathis sp. allover the season reached 7.5 and 6.9% for the two successive seasons in September plantations. The highest parasitization rates occurred during April reaching 9.8 and 9.9% in the two successive seasons of study. In December plantation, it reached 12.4 and 10% for the first and second seasons, respectively. The highest rate was observed in June represented by 15% in the first and 11.4% in May for the second season.

Key Words: Opius nitidulator, Agathis sp., parasitism, sugar beet, Egypt .

F.M. EL-AGAMY, S.M.I. METWALLY, R. EL-SUFTY AND A. YOUSSEF
Econ. Int. Dept., Fac. Agric., Tanta Univ. , Kafr El-Sheikh , Egypt

ABSTRACT

Two parasitoid speices were recorded for Cassida vittata de Villers in Kafr El-Sheilch governorate, the egg parasitoid, Monothochaeta nigra Blood and Kryger (Hymenoptera:Trichogrammatidae) and the gregarious larval parasitoid; Tetrastichus sp. (Hymenoptera:Eulophidae).
In September plantation, the percentage of parasitized eggs of C. vittata by the parasitoid M nigra reached 10.1 and 15.5% for seasons 1991/92 and 1992/93, respectively. In case of December plantation, the percentages of parasitism were 14.0 and 11.5% for the two consecutive seasons of the study, respectively. The highest percentage of parasitized eggs occurred in April in both September and December plantations in the two seasons of study.
Considering the gregarious larval parasite, Tetrastichus sp. in September plantation, the “whole season percentage” of parasitism was 5.3 and 4.3% in the first and second seasons, respectively. The highest percentage occurred in April in the two seasons of the study. In case of December plantation, the percentages of parasitism were 4.2 and 3.7% for the first and second seasons, respectively. The highest percentage of parasitized larvae and pupae was recorded in May for both seasons.

Key Words: Sugar beet, Cassida vittata, Parasitoids, Egypt

PATHOLOGICAL RESPONSES CAUSED BY A VIRUS INFECTION TO THE PARASITOID MICROPLITIS RUFIVENTRIS KOK. AND ITS HOST SPODOPTERA LITTORALIS (BOISD.)

AHLAM A. ALFAZAIRY, HEDAYA H. KARAM, E.M. HEGAZIE AND LAMYA M. ABO-ABD-ALLAH
Plant Protection Dept., Fac. Agric., Alex. Univ.

ABSTRACT

The histopathological study showed that there is no evidence of a direct effect of the Spodoptera littoralis nuclear polyhedrosis virus (SLNPV) on tissues of the parasitoid Macropilis rufiventris Kok. as a result of developing in infected hosts. There was no indication of polyhedral formation within the parasitoid cells. However, some larval mstars, prepupae, cocoons, or pupae of the parasitoid were abnormal or adversely affected. The symptomatology and histopathology of the SLNPV in S. littoralis larvae were typical of NPV- infection in other insects. Typical hypertrophy in cell nuclei of the fat body, hypodermis, tracheal matrix and haemocytes was observed. Nuclei of such cells were greatly enlarged and completely filled with polyhedra. Also, the results demonstrated that, as the virus concentration applied to host-feeding diet was low, increase in morphological abnormalities (prothetely monsters) was observed among the insects affected by this viral infection.

Key Words: Spodoptera littoralis NPV, Macropilis rufiventris, nuclear polyhedrosis virus, symptomatology, histopathology.

K.S. AHMED
Department of Biological and Geological Sciences.
Fac. Education, Ain Shams Univ., Cairo , Egypt

ABSTRACT

The pteromalid, Anisopteromalus calandrae How. is an ectoparasitoid of Rhyzopertha dominica (Fab.) and other stored product pests. In association with R. dominica , durations of the immature stages, egg laying activity and longevity of A. calandrae were investigated at two constant thermal conditions (26 and 30°C at 60% R.H.). Five coleopteran hosts were checked for parasitoid host preference. The most suitable hygrothermal and tropic condition for rearing this parasitoid were 26°C and 60% R.H. and it preferred parasitizing prepupal stage of R. dominica. The parasitoid was active in the field from February to November; reaching its highest rate of parasitism (5 9.3%) in July.

Key Words: Parasitoid, Anisopteromalus calandrae, Rhyzopertha dominica .

A.A. HAFEZ
Plant Protection Dept., Fac. Agric. Moshtohor, Zagazig Univ. (Benha Branch), Egypt

ABSTRACT

Seasonal abundance of certain biocontrol agents associated with aphids in wheat fields was studied throughout 1992/93 wheat season. Three aphid species were recorded infesting wheat plants during the study. The highest rates of aphid infestation were observed during March and April. Four groups of insect predators were counted. Highest numbers of predators were recorded during the period prolonged from the end of March to the beginning of April. Coccinellids and chrysopids were the most abundant predtory species in wheat fields. The maximum parasitism % was estimated at the end of April. Two hymenopterous parasitoids and one hyperparasitic species were identified. Rates of parasitism were increased by planting flowering plants around wheat plots, and that was associated subsequently with certain decrease in aphid counts and increase in the obtained yield. Calandula was recommended to be cultivated around wheat plants, as in this case higher numbers of aphidophagous insects, lower aphid infestation and higher grain yield were recorded.
Numbers of aphidophagous insects were also counted on 10 different wheat varieties. Data indicated variations in the counted numbers which were highest on Pick variety, followed by Copper and Serren varieties.

Key Words: Biocontrol agents, cereal aphids, wheat.

M.H. EL-BISHRY AND H.K. BEHKEIT
Plant Prot. Res. Institute, Dokki, Giza

ABSTRACT

Mixing infective juveniles of the nematode Steinernema carpocapsae with Bacillus thuringiensis commercial formulation Dipel 2x resulted better mortality rates against larvae of Agrotis Epsilon. The LC50 value was reduced from 56.25 juveniles in case of nematode treatment alone to 10.79 juveniles in combination with B.t.. The cause of death was due to the action of one of the two pathogens only; the one who started its action first in the insects haemocoel. When a fixed number of nematode juveniles (20) was combined with different concentrations of B.t. spores, best results were obtained at the concentration of Vz and 1 g Dipel 2x per 1 liter. Increasing the concentration to 2 glliter or decreasing it to ¼ glliter reduced the mortality rates.

H.K.M. BEKHEIT, M.H. EL-BISHRY AND G.M. MOA WAD
Plant Prot. Res. Institute, Dokki, Giza , Egypt

ABSTRACT

Concentration of coating antigen, pH and some solvents, were studied as factors affecting the sensitivity of the ELISA. Results indicated that the antibody 957 (dilution of 1:500) with the coating antigen P-exotoxin-Gi-BSA at 0.5 gIwell was the most sensitive assay, but decreased at 0.4 and 0.6 JAg/well. The assay sensitivity was greatly affected by PH; the most suitable ranged between pH 7.5 and 8. Acetone and methanol had a very strong positive effect on the assay sensitivity when used as organic solvent, but acetonitril, up to 12.5% did not significantly affect it. With some modifications, the ELISA assay could reach a very high level of sensitivity and provide excellent reproducibility.

Key Words: ELISA, Bacillus thuringiensis, ß-exotoxin, modifications.

YOUSRYA M. ABDEL-HAMID, M. A. KENAWY* AND M. I. MOUSSA**
Res. Inst. of Medical Entomology, Ministry of Health, Dokki
*Entomology Dept., Fac. Science, Ain Shams Univ., Abbassia
• U.S. Naval Medical Res. Unit No.3 (NAMRU-3), Abbassia, Cairo , Egypt .

ABSTRACT

The feeding capacity of Toxorhynchites splendens larvae upon four common mosquito species in Egypt and their development on a non-living diet (Tetramine, a fish food) were investigated at 26±4°C. During the whole larval stage, a single predatory larva could devour significantly more larvae (P<0.O1) of Culex pipiens (152 larvae) than those of Ades caspius (72 larvae), Anopheles pharoansis (49 larvae), or Culiseta longiareolata (38 larvae). There was no significant effect (p<O.05) of the feeding on any of the four prey species upon the duration of the predator immatures nor on the sex ratio of the emerged adults. The predatory larvae maintained on fish food and their pupae developed Ca. 2.5-3.5 times slower than those maintained on Cx. pipiens larvae. Significantly higher mortality rate (P<0.01) was observed during larval development of the predator on fish food (30.30%) than on prey larvae (18%). Results howed that larvae of the predator Tx. splendens could complete their development on a non-prey diet. This is of significance in making the breeding technique much simpler and less expensive.

Key Words: Tx. splendens, mosquito larvae, non-prey diet, survival, Egypt .

V.A. EL-SEBAY AND M.H. EL-BISHRY
Plant Prot. Res. Inst., Dokki, Giza , Egypt

ABSTRACT

The efficacy of the nematodes Steinernema carpocapsae and S. glaseri and a commercial preparation of Bacillus thuringiensis were evaluated against the subterranean termite Anacanthotermes ochraceous under laboratory conditions by subjecting termites to contaminated diet. The results revealed that mortality rates ranged from 58.49 to 100%. S. carpocapsae alone was the most effective bioagent followed by S. glaseri. The Lowest mortality rate was obtained in case of B.t. treatment. Mixing B.t. with S. glaseri enhanced the mortality. The opposite was evident with S. carpocapsae. Coating the diet with agar as a moistening material increased the efficacy of B.t., and S. glaseri, while S. carpocapsae was negatively affected. Nematode development inside dead termites was detected only in case of S. glaseri, while S. carpocapsae failed to complete its life cycle.

I.A. ISMAIL
Pests and Plant Protection Department,
National Research Center , Dokki, Cairo , Egypt

ABSTRACT

Treatment of Heliothis armigera with different concentrations of thymol induced biological activity as growth inhibitor. It caused prolongation of the life span and high percentage of deformed pupae. At 2% concentration, most larvae died when fed on treated castor oil leaves, 1% concentration prevented moth emergence. At 0.5% concentration adult females laid no eggs, while at the lowest two concentrations (0.25 and 0.125%), females produced a very low number of infertile eggs. A negative correlation was found between thymol concentration and larval growth, pupation and moth emergence. Pupal weight decreased and longevity of adults was significantly affected with larvae fed on leaves treated with 0.5 or 0.25% concentrations.

Key Words: Heliothis armigera, thymol, inhibitory effect.

M.M.E. SALEH, A.M. SEMEADA* AND E.A. ELSHAZLY*
Department of Pests and Plant Protection,
National Research Centre, Dokki, Giza , Egypt
* Department of Economic Entomology and Pesticides, Fac. Agric., Cairo Univ.

ABSTRACT

Laboratory tests proved that Heterorhabdias and Steinernema spp. isolated from Egypt were highly virulent against larvae of the apple borer, Zeuzera pyrina. H. bacteriophora HP88 was as virulent as the Egyptian isolates. S. carpocapsae All was less virulent, while S. glaseri NC was the least virulent against the pest larvae. Pupae of the pest were less susceptible than the larvae. Heterorhabditid nematodes developed in the cadavers better than steinernematids. Applying the Egyptian nematode Heterorhabditis sp. (Si) either via spraying or injection in apple branches infested with Z. pyrina larvae and/or pupae achieved 100% control to the insect stages inside the branches within one week.

Key Words: Zeuzera pyrina, Steinernema, Heterorhabditis, virulence.

A.H. EL-HENEIDY
Dept. of Biological Control, Plant Prot. Res. Inst., Giza, Egypt.

ABSTRACT

This study was carried out through the Nile Valley Project for the five successive seasons 1988/89 - 1992/93 to evaluate the efficacy of natural enemies against aphids at wheat fields in Egypt . Sampling of aphids and their natural enemies were taken weekly from experimental fields located at Sohag, Beni-Suef and Sharkia Govemorates. Studies on seasonal abundance of aphids showed that the highest population of the pest was recorded during boating and heading growth stages of wheat plant (mostly in March), the same trend was estimated for parasitism (%), while the highest population of predators was counted few weeks later during ripening stage (around mid-April). Role of the predators and parasitoids seems to be relatively low to meet the rapid increase of aphid population. Harmful effect (was recorded after insecticidal treatments) that caused 71 and 66% decline in the population of predators and percentage of parasitism, respectively. Timing and efficacy of insecticidal applications are very critical fctors concerning resistance building in aphids. Therefore, an integrated pest management program for aphid control is required to minimize dependance on currently used schedules of chemical insecticides in wheat fields in Egypt .

Key Words: Wheat, aphids, aphidophagous insects, insecticides, evaluation.

M.M.E. SALEH AND TAYSEER A.H. EL-KIFL
Pest and Plant Prot. Dept., National Research Centre, Dokki, Giza , Egypt

ABSTRACT

Diapausing larvae of the European corn borer Ostrinia nubilalis Hubner (Lepidoptera: Pyralidae) were exposed under laboratory conditions to inoculum levels of the entomopathogenic nematodes: Steinernema carpocapsae Weiser DD 136, Steinernema glaseri Steiner NC and Heterorhabditis bacteriophora Poinar HP88. S. carpocapsae proved to be the most virulent to the pest larvae followed by H. bacteriophora, while S. glaseri was the least virulent. H. bacteriophora reproduced better and produced more infective juveniles in the larvae than S. carpocapsae did. The infective juveniles of Ii bacteriophora succeeded in invading the pest larvae while being inside the corn stalk. However, the resulted infective juveniles did not migrate out of the cadaver.

Key Words: Virulence, Steinernema, Heterorhabditis, diapasued Ostrinia nubilalis.

M.M. SHAMS ELDEAN; M.M. ABDELGAWAD* AND M.H. ELBISHRY**
Nematology Res. Center , Fac. Agric., Cairo Univ. , Giza , Egypt .
** Nematology Lab., Dept. Plant Path., Nat. Res. Centre, Dokki, Giza , Egypt .
** Plant Prot. Res. Inst., Dokki, Giza , Egypt .

ABSTRACT

Evaluation took place for Egyptian heterorhadbitid nematode isolates in the laboratory to identify' the most efficient ones for biological control of certain insect pests. The nematode isolate EGB 1 showed a wide host range infecting and killing economically important insect pests in Egypt , e.g. the Egyptian cotton leafworm, black cutworm, common mole cricket, spiny bollworm and pink bollworm. Depending on the infected insect species and the development of this nematode, one insect cadaver could produce from ca 10,000 to > 250,000 infective nematode juveniles (IJs). Superior merits were manifested by the nematode isolates EASD9 1, EMSI3, EBNUC and EMS18 for the highest numbers of their emerging 1J5 and the isolates EGB4B, EAS59 and EASD91 for the relatively short span of their Life cycles on both the greater wax moth and the Egyptian cotton leafworm. A 100% mortality of these insects obtained by numerous nematode isolates could possibly be used on field scale.

Key Words: Heterorhabditis, entomopathogenic nematodes, Egyptian isolates, host range, efficacy.