-
[show abstract]
[hide abstract]
ABSTRACT: Codling moth Cydia pomonella L. (Lepidoptera: Tortricidae) is the most important insect pest of apple production in Europe. Despite the economic importance of this pest, there is not information about the genetic structure of its population in Greece and the patterns of gene-flow which might affect the success of control programs. In this study, we analysed nine samples from apple, pear and walnut from various regions of mainland Greece using 11 microsatellite loci. Six samples from the aforementioned hosts from southern France were also examined for comparison. Bayesian clustering and genetic distance analyses separated the codling moth samples in two genetic clusters. The first cluster consisted mainly of the individuals from Greece, and the second of those from France, although admixture and miss-classified individuals were also observed. The low genetic differentiation among samples within each country was also revealed by F(ST) statistics (0.009 among Greek samples and 0.0150 among French samples compared to 0.050 global value among all samples and 0.032 the mean of the pair-wise values between the two countries). These F(ST) values suggest little structuring at large geographical scales in agreement with previous published studies. The host species and local factors (climatic conditions, topography, pest control programs) did not affect the genetic structure of codling moth populations within each country. The results are discussed in relation to human-made activities that promote gene-flow even at large geographic distances. Possible factors for the genetic differentiation between the two genetic clusters are also discussed.
Bulletin of entomological research 04/2012; 102(2):185-98. · 1.58 Impact Factor
-
Agricultural and Forest Entomology 01/2012; 14(4):399-407. · 1.60 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Codling moth Cydia pomonella L. (Lepidoptera: Tortricidae) is the most important
insect pest of apple production in Europe. Despite the economic importance of this
pest, there is not information about the genetic structure of its population in Greece
and the patterns of gene-flow which might affect the success of control programs. In
this study, we analysed nine samples from apple, pear and walnut from various
regions of mainland Greece using 11 microsatellite loci. Six samples from the
aforementioned hosts from southern France were also examined for comparison.
Bayesian clustering and genetic distance analyses separated the codling moth
samples in two genetic clusters. The first cluster consisted mainly of the individuals
from Greece, and the second of those from France, although admixture and missclassified
individuals were also observed. The low genetic differentiation among
samples within each country was also revealed by FST statistics (0.009 among Greek
samples and 0.0150 among French samples compared to 0.050 global value among all
samples and 0.032 the mean of the pair-wise values between the two countries).
These FST values suggest little structuring at large geographical scales in agreement
with previous published studies. The host species and local factors (climatic
conditions, topography, pest control programs) did not affect the genetic structure of
codling moth populations within each country. The results are discussed in relation
to human-made activities that promote gene-floweven at large geographic distances.
Possible factors for the genetic differentiation between the two genetic clusters are
also discussed
Bulletin of Entomological Research 01/2012; 102(2):185-198. · 1.88 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: The codling moth Cydia pomonella L. is controlled mostly with chemical insecticides in Greece and control
failures have been reported. However, there are no insecticide resistance studies in the country as yet. We
examined the insecticide resistance status of 33 and 38 populations of fifth-instar non-diapausing and
diapausing larvae, respectively by applying bioassays, biochemical and DNA diagnostics. Diagnostic concentrations
of azinphos-methyl, phosalone, deltamethrin, thiacloprid, fenoxycarb, tebufenozide, methoxyfenozide
and diflubenzuron were used in bioassays. Almost all populations showed reduced
susceptibility to at least one insecticide and approximately half of them to all insecticides examined compared
to a laboratory susceptible strain used as reference. However, only one out of six populations tested
showed reduced susceptibility in ovicidal tests with fenoxycarb. Cross-resistances were observed among
most insecticides, except from the pairs fenoxycarb–phosalone and thiacloprid–phosalone, in non-diapausing
larvae. The more obvious biochemical marker associated with the reduced susceptibility observed
in both larval instars was elevated cytochrome P450 polysubstrate monooxygenases activity, followed by
elevated glutathione-S-transferase activity and reduced carboxylesterases activity. Neither sodium channel
nor AChE known resistance mutations were found in any of the approximately 1000 individuals of
each larval instar screened with diagnostic PCR. Actions for Integrated Resistance Management and application
of alternative control methods are discussed.
Pesticide Biochemistry and Physiology 01/2011; 100:229-238. · 1.71 Impact Factor
