If you want to study this...check out first on how much microbial pesticides have been used for the crop you want to evaluate. The fundamental of resistance developed from microbial pesticides usage might not differ much from conventional chemical pesticides. Define well what you want exactly to study: be more specific.

A well known bio-pesticide is Bt; there is no clear report on resistance gain by any pest on it. thus interesting to assess such possibility. But remember that you are regulated by laws when you go search on such aspect. Repetitive usage of the same pesticides may develop this resistance giving the pest time to adapt to the product generation after generation. It is a long term study for years (5 minimum may be) or more. So depending on the life cycle of the pest you wanna evaluate, that is few factors you have to consider in making selective choice of a specific study. Without that you wont know where to go.

Thank you......

Thank you.....what about resistant enzymes levels....?!!!

You are going into many directions now....solve problems one by one...Have you decided about what is the exact pest and to which crop it is related to yet?

Have you decided yet on this?

The used of microbial biopesticide product is purposely to overcome the issue of resistance raised by chemical insecticide. For me, it should not be the main focus in our subject of study. Anyway, to solve on the potential of less virulency problem by microbial agent; just to reisolate the microbe against the pest (host) and do the subculture technique to get back the pure culture.This technique is just to mantain the virulency of our stock culture for mass propagation program.

Abdo,

You should look up the work of Bruce Tabashnik on Bt resistance which has shown up in only two insects that I am aware of - the diamondback moth (Plutella xylostella) and the cabbage looper (Trichoplusia ni) . When I worked in research and development with a pesticide company we used to look at mixtures of BT with pesticides as a way to overcome resistance to the pesticide in the same way that some fungicides can synergize insecticides by inhibiting enzymatic detoxification systems like mixed-function oxidases (MFOs). In the case of methoxyfenozide and Bt, we thought the Bt toxin might be breaking down the gut wall of the pest and allowing faster movement into the blood stream of the IGR and speeding up mortality. Studying why only two insects have developed resistance to Bt seems like a useful area to me and synergism of mixtures may give you insight into the mode of action of both compounds. The problem with mixtures in resistance management, however, is that you can develop a 'superbug' with resistance to both compounds and it is generally thought to be better to alternate products for each generation. Mixtures may only be a short-term fix to a resistant pest already out of control.

Proc. Natl. Acad. Sci. USA Vol. 94, pp. 1640–1644, March 1997 Agricultural Sciences

One gene in diamondback moth confers resistance to four Bacillus thuringiensis toxins. BRUCE E. TABASHNIK*†, YONG-BIAO LIU*, NAOMI FINSON*, LUKE MASSON‡, AND DAVID G. HECKEL

A. F. Janmaat & J. Myers (2003). "eRapid evolution and the cost of resistance to Bacillus thuringiensis in greenhouse populations of cabbage loopers, Trichoplusia ni". Proceedings of the Royal Society B 270 (1530): 2263–2270. doi:10.1098/rspb.2003.2497.

Jump up ^ P. Wang, J. Z. Zhao, A. Rodrigo-Simon, W. Kain, A. F. Janmaat, A. M. Shelton, J. Ferre & J. Myers (2006). "Mechanism of resistance to Bacillus thuringiensis toxin Cry1Ac in a greenhouse population of cabbage looper, Trichoplusia ni". Applied and Environmental Microbiology 73 (4): 1199. doi:10.1128/AEM.01834-06.

Hope these references help get you started. David

Thank you Dr.David.

my proposal title: Genetic variability of entomopathogenic fungi (Beauveria bassian) and Mechanisms of Insecticide Resistance based on Host-Pathogen interaction.

If you have any modifications on title.

kind regards,

abdo