First evidence of the effectiveness of a field application of RNAi technology in reducing infestation of the mite Varroa destructor in the western honey bee (Apis mellifera).

Background: The mite Varroa destructor is the most serious pest of the western honey bee (Apis mellifera) and a major factor in the global decline of colonies. Traditional control methods, such as chemical pesticides, although quick and temporarily effective, leave residues in hive products, harming bees and operators' health, while promoting pathogen resistance and spread. As a sustainable alternative, RNA interference (RNAi) technology has shown great potential for honey bee pest control in laboratory assays, but evidence of effectiveness in the field has been lacking.

Growth Regulation in the Larvae of the Lepidopteran : A Field Study.

Size and shape are important determinants of fitness in most living beings. Accordingly, the capacity of the organism to regulate size and shape during growth, containing the effects of developmental disturbances of different origin, is considered a key feature of the developmental system. In a recent study, through a geometric morphometric analysis on a laboratory-reared sample of the lepidopteran , we found evidence of regulatory mechanisms able to restrain size and shape variation, including bilateral fluctuating asymmetry, during larval development.

Size and shape regulation during larval growth in the lepidopteran Pieris brassicae.

By adopting a longitudinal study design and through geometric morphometrics methods, we investigated size and shape regulation in the head capsule during the larval development of the cabbage butterfly Pieris brassicae under laboratory conditions. We found evidence of size regulation by compensatory growth, although not equally effective in all larval stages. Size compensation is not attained through the regulation of developmental timing, but rather through the modulation of per-time growth rate.

A heuristic model of the effects of phenotypic robustness in adaptive evolution.

A recent theoretical, deterministic model of the effects of phenotypic robustness on adaptive evolutionary dynamics showed that a certain level of phenotypic robustness (critical robustness) is a required condition for adaptation to occur and to be maintained during evolution in most real organismal systems. We built an individual-based heuristic model to verify the soundness of these theoretical results through computer simulation, testing expectations under a range of scenarios for the relevant parameters of the evolutionary dynamics. These include the mutation probability, the presence of stochastic effects, the introduction of environmental influences and the possibility for some features of the population (like selection coefficients and phenotypic robustness) to change themselves during adaptation.

Enhancing effect of phenotype mutational robustness on adaptation in Escherichia coli.

Theoretical and computational studies predict a positive role for widespread phenotype resistance to genetic mutation, or "phenotype mutational robustness," in enhancing adaptation to novel environments through the accumulation of cryptic genetic variation. However, this has not been verified through experimental evolution in biological systems at the level of whole organisms. In a short-term evolution experiment of about 250 generations, we studied the adaptive performances of independently evolving populations of the bacterium Escherichia coli in two new nutritional environments, represented by minimal media with either lactate or glycerol as the sole carbon source.