Importance of the Host Phenotype on the Preservation of the Genetic Diversity in Codling Moth Granulovirus.

To test the importance of the host genotype in maintaining virus genetic diversity, five experimental populations were constructed by mixing two granulovirus isolates, the Mexican isolate CpGV-M and the CpGV-R5, in ratios of 99% M + 1% R, 95% M + 5% R, 90% M + 10% R, 50% M + 50% R, and 10% M + 90% R. CpGV-M and CpGV-R5 differ in their ability to replicate in codling moth larvae carrying the type I resistance. This ability is associated with a genetic marker located in the virus gene.

Determination of Formulation Conditions Allowing Double Emulsions Stabilized by PGPR and Sodium Caseinate to Be Used as Capsules.

Water-in-oil-in-water (W/O/W) double emulsions stabilized by polyglycerol polyricinoleate (PGPR), a lipophilic food grade small polymer, and sodium caseinate, a hydrophilic milk protein, were developed to encapsulate vitamin B12, a model hydrophilic substance easy to titrate. Using rheology, sensitive to drop size evolution and water fluxes, static light scattering, and microscopy both giving the evolution of drops' size and vitamin B12 titration assessing the encapsulation, we were able to detect independently the double emulsion drop size, the encapsulation loss, and the flux of water as a function of time. By differentiating the PGPR required to cover the W-droplets' surface from PGPR in excess in the oil phase, we built a PGPR-inner droplet volume fraction diagram highlighting the domains where the double emulsion is stable toward encapsulation and/or water fluxes.

Biological Characteristics of Experimental Genotype Mixtures of Cydia Pomonella Granulovirus (CpGV): Ability to Control Susceptible and Resistant Pest Populations.

The detection of resistance in codling moth (Cydia pomonella) populations against the Mexican isolate of its granulovirus (CpGV-M), raised questions on the sustainability of the use of this biological insecticide. In resistant host cells, CpGV-M is not able to complete its replication cycle because replication is blocked at an early step. Virus isolates able to overcome this resistance have been characterized-among them, the CpGV-R5 isolate.

Water fluxes and encapsulation efficiency in double emulsions: impact of emulsification and osmotic pressure unbalance.

We study the influence of the emulsification process on encapsulation efficiency of drugs in double water-in-oil-in-water emulsions. Two drugs were used, first vitamin B12 which can be considered as a model drug and secondly a suspension of Cydia pomonella Granulovirus (CpGV), a virus used in organic agriculture to protect fruits against the Carpocapse insect. Encapsulation is measured by classical UV-Vis spectroscopy method.

Resistance to bio-insecticides or how to enhance their sustainability: a review.

After more than 70 years of chemical pesticide use, modern agriculture is increasingly using biological control products. Resistances to conventional insecticides are wide spread, while those to bio-insecticides have raised less attention, and resistance management is frequently neglected. However, a good knowledge of the limitations of a new technique often provides greater sustainability.

Progressive adaptation of a CpGV isolate to codling moth populations resistant to CpGV-M.

The NPP-R1 isolate of CpGV is able to replicate on CpGV-M-resistant codling moths. However, its efficacy is not sufficient to provide acceptable levels of control in natural (orchard) conditions. A laboratory colony derived from resistant codling moths was established, which exhibited a homogeneous genetic background and a resistance level more than 7000 fold.