Frequency and fitness cost of resistance to Bacillus thuringiensis in Chrysomela tremulae (Coleoptera: Chrysomelidae)

Article Abstract:

Pest adaptation to transgenic plants producing 'Bacillus thuringiensis' (Bt) toxins can be delayed or prevented by the 'high dose-refuge' (HDR) strategy whose efficacy depends primarily on the initial frequency of Bt resistance alleles and on the fitness costs associated with these alleles. A study has concluded that resistance to Bt plants may be present at detectable frequencies in pest populations before selection resulting from pest management by humans.

Genetically modified plants, Bacillus thuringiensis, Allelomorphism, Alleles

Genetic isolation between two sympatric host plant races of the European corn borer, Ostrinia nubilalis Hubner. II: Assortative mating and host-plant preferences for oviposition

Article Abstract:

The genetic isolation of races of European corn borer (ECB), Ostrinia nubilalis Hubner is examined with the help of strains from the maize (Z strain) and mugwort (E strain) races. No evidence for crosses between Z females and E males were observed and mating between individuals of the same strain occurred more frequently than mating between males and females of the E and Z strains.

Pheromones, European corn borer

Genetic recombination and adaptation to fluctuating environments: selection for geotaxis in Drosophila melanogaster

Article Abstract:

Research has been conducted on adaptive evolution.The authors have investigated different types of Drosophila melanogaster lines varying in their level of genetic recombination, and the results demonstrate that recombination has not accelerated adaptation during fluctuating or directional selection for geotaxis.

Canada, Analysis, Physiological aspects, Adaptation (Biology), Evolutionary adaptation, Genetic recombination, Drosophila, Heredity, X chromosome