Einfuhr und Ansiedlung der Blutlauszehrwespe,Aphelinus mali (Hald.) (Hym., Chalcidoidea) in Saudi Arabien

A report is given on the introduction and establishment of the ChalcididAphelinus mali in the Wadi Lia, Taif region, in Saudi Arabia in 1976, for the purpose of controlling the woolly apple aphid,Eriosoma lanigerum.     

The potential of the predatorOrius albidepennis onAgrotis ypsilon as affected byBacillus thuringiensis

The relation between the pathogenBacillus thuringiensis and the predatorOrius albidepennis (Hem.: Anthocoridae) associated with the greasy cutwormAgrotis ypsilon (Lep.) has been investigated. The biology of the predator showed to be affected in terms of nymphal duration, rate of food consumption and egg production when the predator larvae were fed on treated eggs or neonate larvae of the host (A. ypsilon). The effect of B-exotoxin (thuringiensin) on the predator has been also demonstrated.     

Protective efficacy of H5 inactivated vaccines in meat turkey poults after challenge with Egyptian variant highly pathogenic avian influenza H5N1 virus

In contrast to chickens, there is a paucity of information on the potency of H5 vaccines to protect turkeys against the highly pathogenic avian influenza (HPAI) H5N1 virus infections. In this study, 4 groups, 10 turkey poults each, were vaccinated at seven days old with one of H5N2 or H5N1 commercial vaccines or one of two prepared H5N1 vaccines from a local Egyptian variant HPAI H5N1 (EGYvar/H5N1) strain. At 35 days age, all vaccinated and 10 non vaccinated birds were challenged intranasal with 10(6) EID(50)/0.1 ml of EGYvar/H5N1. All vaccines used in this study were immunogenic in turkeys. There was no cross reaction between the commercial vaccines and the Egyptian variant H5N1 antigen as obtained by the hemagglutination inhibition test. Birds vaccinated with H5N2 vaccine were died, while other H5N1 vaccinated groups have had 20-40% mortality. The highest virus excretion was found in non-vaccinated infected and H5N2 vaccinated birds. Eleven peculiar amino acid substitutions in H5 protein of the variant strain were existed neither in the vaccine strains nor in the earliest H5N1 virus introduced into Egypt in 2006. In conclusion, single vaccination at seven days old is inadequate for protection of meat turkeys against variant HPAI H5N1 challenge and multi-dose vaccination at older age is recommended. For the foreseeable future, continuous evaluation of the current vaccines in H5N1 endemic countries in the face of virus evolution is a paramount challenge to mitigate the socio-economic impact of the virus.     

Lesion nematode suppression with the butte potato and relationships to verticillium wilt

Field studies conducted over a 5 yr period to compare the effect of continuous cropping of several potato clones (Butte, Russet Burbank, Targhee, A66107-51, and A68113-4) showed Butte to be highly resistant toPratylenchus neglectus while being highly susceptible toVerticillium dahliae. This was further evidenced during the 6th yr when Russet Burbank was cropped over all plot-locations. Populations ofP. neglectus were shown to be significantly less (0.05 P) in both soil and roots when Russet Burbank was grown over sites previously cropped with the Butte potato than over site-locations cropped by either Russet Burbank, Targhee, A66107–51, or A68113–4. Additional field and greenhouse studies corroborated the high degree of resistance of Butte toPratylenchus spp. In addition toP. neglectus resistance, a greenhouse investigation also showed resistance to P. penetrans. A field study designed to compare the effects of Butte with nematicides showed that Butte reducedP. neglectus populations in both soil and roots when compared with Russet Burbank. This degree of reduction was equivalent to the effects of either of two systemic nematicides (aldicarb and isofenphos) at 3.4 to 4.0 kg a.i./ha, respectively. Results demonstrate biological control with the Butte potato clone forP. neglectus suppression. Although populations ofP. neglectus were reduced by either nematicides or Butte, wilt severity was higher with Butte than Russet Burbank. Results showed wilt suppression andP. neglectus reduction with treatments of either nematicide, while having no significant effect on the colonization of potato stems byV. dahliae.     

A sustained controlled release formulation of soil nitrogen based on nitrate-layered double hydroxide nanoparticle material

Purpose

Nitrate-layered double hydroxide material (nitrate-LDH) matrix can be considered as a potential formulation of delivering nitrogen into soil in a sustained manner.

Materials and methods

The nitrate-LDH matrix was formulated by a co-precipitation technique and subsequently characterized by scanning electron microscopy, X-ray analysis, and infrared spectroscopy. The release of nitrate was monitored in different buffer mediums: buffer A as a simulated acidic soil solution and buffer B as a simulated neutral soil solution.

Results and discussion

The stability of nitrate-LDH against thermal decomposition was evaluated by thermal gravimetric analysis. The nitrate-LDH supported a sustained controlled release process of nitrate during 16 days into acidic soil at 15 °C, while the release was continued to 20 days into neutral soil at the same temperature. The increase of soil temperature slightly enhanced the release of nitrate.

Conclusions

We offered a potential management strategy of soil nitrogen leaching process. The nitrate form of layered double hydroxide material was used as a nitrogen fertilizer in order to monitor the release of nitrate anion into soil at different conditions.     

Biological effects of the entomopathogenic fungus,Beauveria bassiana on the potato tuber mothPhthorimaea operculella (Seller)

A series of investigations have been carried out on the effect of the entomopathogenic fungusBeauveria bassiana on the various developmental stages ofPhthorimaea operculella. Both first and second insatar larvae were more susceptible than the third or fourth instars. The infected prepupae and pupae resulted in marked decrease in the emergence, longevity of moths, deposited eggs and their egg hatchability. An obvious increase in the pupal duration was observed and the resulting malformed adults were also recorded. The latent effects were markedly obvious, specially in high doses ofBeauveria bassiana.     

Antigenic types of bluetongue virus prevalent in Egypt

Summary In an attempt to identify the antigenic types of bluetongue (BT) virus prevalent in Egypt 31 selected sheep sera from different parts of Egypt which had been screened by gel precipitation tests were examined by a plaque reduction test using 16 types of BT virus. Dilutions 1:5 of those screened sera reduced more than 50% of plaques of at least 1 of 16 types of BT virus. Two sera completely inhibited plaque formation with type 4 virus, 1 with type 13, another serum with type 15 and 2 other sera with type 16 virus. The significance of the above serological findings is discussed.

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Tipos Antigenicos Del Virus De Lengua Azul En Egipto

Resumen Se examinaron 31 sueros seleccionados de ovejas de diferentes partes de Egipto. La prueba utilizada fué la de reducción de placas usando 16 tipos de virus de lengua azul. Los sueros habían sido examinados previamente mediante la prueba de precipitación en agar. Las diluciones 1:5 de los sueros examinados previamente, redujeron más del 50% de placas de por lo menos 1 de 16 tipos de virus de lengua azul. Dos de los sueros inhibieron completamente la formación de placas con el virus tipo 4, 1 con el tipo 13, otro suero con el tipo 15 y dos más con el tipo 16. Se discute el resultado de las pruebas serológicas.

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Types D'Antigenes Du Virus De La Blue Tongue Existant En Egypte

Résumé Pour identifier les types antigéniques du virus de la Blue Tongue existant en Egypte, 31 sérums de mouton provenant de diverses régions du pays, préalablement examinés par immunoprécipitation en milieu gélifié, ont été soumis à un test de réduction des plages avec 16 sérotypes du virus. Les dilutions au 1/5 de ces sérums ont réduit les plages de plus de 50 p. 100 pour au moins un des 16 sérotypes.Deux sérums ont complétement inhibé la formation des plages avec le type 14, avec le type 13, un autre avec le type 15 et deux enfin avec le type 16.La signification de ces résultats sérologiques est discutée.