Orius albidipennis (Rueter) as an effective biocontrol agent against Tetranychus urticae Koch on pepper crops in greenhouse in Egypt

Abstract The present study was carried out in greenhouses, on sweet pepper crops, during the winter plantations 2015–2016 and 2016–2017 in a commercial farm located at Berkash district, Giza, Egypt. During the first season, three acariphagous biocontrol agent species, the predatory mite, Amblyseius swirskii Athias-Henriot (Acari: Phytoseiidae) (at a rate of 2 individuals/m2), and two of predatory insect, Macrolophus caliginosus Wagner (at a rate of 1 individual/m2) and Orius albidipennis (Reuter) (at a rate of 1/2 individual adults/m2), were applied to control Tetranychus urticae. The obtained results showed that T. urticae was controlled successfully using A. swirskii and O. albidipennis. Releasing of A. swirskii and O. albidipennis caused 26 and 24% yield increases, respectively, as compared to control treatment. During the second season of 2016–2017, the efficiency of O. albidipennis at a rate of 1/2 per m2 was compared to three recommended pesticides, for controlling T. urticae. The obtained results revealed that applying O. albidipennis proved to be the most efficient control method against T. urticae on sweet pepper, with the lowest remaining pest density of T. urticae (2.9 mites/leaf); while with chemical control, the remaining density of T. urticae reached 20.13 mites/leaf at the end of the season. Thus, results demonstrated that the released insect predator, O. albidipennis, was the most effective method to control T. urticae under greenhouse conditions for two reasons. On the one hand, it resulted in a 31.36% yield increase, and on the other hand, it could reduce the chemical application, to improve food safety and environmental pollution reduction

Dispersal and maintenance of Neoseiulus cucumeris and Amblyseius swirskii (Acari: Phytoseiidae) to control thrips in greenhouse crops as influenced by micro habitat environment

Conference: 4th International Conference for Applied Biological Control (ESBCP)Location: Cairo, EGYPTDate: OCT 19-22, 2015The present study aimed to investigate the effect of microclimate parameters within the plant cover as well as their effects on dispersal of the bioagents Neoseiulus cucumeris Oudemans and Amblyseius swirskii Athias-Henriot (Acari: Phytoseiidae) at the plant level. It was a preliminary step to microclimate control in order to increase the bioagent efficacy. Effect of humidity was studied in priority, as it seems to have a preponderant role. It consisted in monitoring the dispersal of bioagents in parallel with microclimatic heterogeneity characterization at the plant level. The results highlighted that (i) the climatic parameters varied spatially within the plant according to the level: (ii) At high relative humidity, one week after release, both predators; A. swirskii and N. cucumeris showed a density increase on the plant, while under dry conditions the contrary occurred, and (iii) High humidity was suitable for both predators

Consumo de Uroleucon ambrosiae (Thomas, 1878) (Hemiptera: Aphididae) por larvas de Chrysoperla externa (Hagen, 1861) (Neuroptera: Chrysopidae) em casa-de-vegetação Consumption of Uroleucon ambrosiae (Thomas, 1878) (Hemiptera: Aphididae) BY Chrysoperla externa (Hagen, 1861) (Neuroptera: Chrysopidae) larvae in greenhouse

Com esta pesquisa objetivou-se verificar o consumo de Uroleucon ambrosiae em diferentes densidades, por larvas de Chrysoperla externa provenientes de diferentes regimes alimentares, em casa-de-vegetação. Ninfas de 3º e 4º ínstares do afídeo foram separadas nas densidades 30, 40 e 50, e colocadas nas plantas de alface (35 dias de idade), as quais, foram envolvidas por gaiola de armação de ferro de 27x27x26 cm cobertas com tecido “voil” e acoplada nos tubos de PVC do cultivo hidropônico. Quatro horas após, uma larva de C. externa, de diferentes ínstares e previamente alimentadas com U. ambrosiae ou ovos de Sitotroga cerealella (Olivier, 1819), foi liberada próximo à colônia de afídeos, sendo a gaiola fechada imediatamente; o mesmo procedimento foi adotado sem que a larva fosse confinada. Após quarenta e oito horas, realizou-se a contagem do número de afídeos consumidos em cada densidade de presa disponível. A eficiência do predador, confinado em gaiola, foi de 12,46%, 13,63% e 25,76% para larvas de 1º, 2º e 3º ínstares previamente alimentadas com ovos de S. cerealella; 9,59% e 17,63% para aquelas de 2º e 3º ínstares alimentadas anteriormente com ninfas de U. ambrosiae, respectivamente e de 18,62% para larvas de 3º ínstar previamente alimentadas com ovos do lepidóptero no 1º ínstar e ninfas dos afídeos no 2º instar; no entanto, para larvas não confinadas, não foram verificadas diferenças significativas na eficiência. Nas densidades de 40 e 50 afídeos, as porcentagens de predação (18,30 e 18,72, respectivamente) foram significativamente superiores quando comparada à densidade 30 (11,79); para testes sem confinamento, não houve influência da densidade da presa na resposta do predador. Assim, o alimento fornecido às larvas de C. externa antes de serem liberadas em casa-de-vegetação, o confinamento das mesmas e a densidade de U. ambrosiae disponível influenciaram o potencial de consumo do predador.<br>The objective of this research was to evaluate the consumption of Uroleucon ambrosiae in different densities by Chrysoperla externa larvae derived from different alimentary regimes, in greenhouse conditions. The 3rd and 4th instars nymphs of the aphid were separated in the densities 30, 40, 50 and put on the lettuce plants (35 days old) which were kepted in a voil cage of 27x27x26 cm connected to the PVC tube used for hydroponic cultivation. After four hours, one larva of C. externa previously fed with U. ambrosiae or eggs of Sitotroga cerealella (Olivier, 1819) was released near the aphid colony, with the lettuce plant being immediately covered. The same procedure was adopted without confinement of the larvae. The different instars of C. externa were evaluated, through counting of the aphids after forty eight hours. The efficiencies of the predator, confined in a cage, were 12.46, 13.63 and 25.76% for 1st, 2nd and 3th instars which were previously fed with eggs of S. cerealella. For 2nd and 3rd instar larvae fed with aphids, the efficiencies were 9.59 and 17.63%, respectively. Efficiency was 18.62% for 3th instar larvae fed previously with eggs of the lepidopterous in the 1st instar and with nymphs of aphids in the 2nd ínstar.However, for larvae without confinement, there were no differences among the instars or alimentary regimes. In the densities of 40 and 50 aphids, the percentages of predation (18.3 and 18.72, respectively) were significantly superior as compared with density 30 (11.79). There was no influence of density of prey in response to predator in the experiments without confinement. Thus, the food provided to C. externa larvae before releasing into a greenhouse, their confinement and available density of U. ambrosiae influenced the potential of consumption of the predator