@article {11990, title = {Organophosphate resistance in olive fruit fly, Bactrocera oleae, populations in Greece and Cyprus}, journal = {Pest Management SciencePest Management SciencePest Management Science}, volume = {63}, number = {1}, year = {2007}, note = {ISI Document Delivery No.: 126MFTimes Cited: 11Cited Reference Count: 41}, month = {Jan}, pages = {42-48}, type = {Article}, abstract = {The olive fruit fly Bactrocera oleae (Gmelin) (Diptera: Tephritidae) is the most important pest of olives in countries around the Mediterranean basin. Its control has been based mostly on bait sprays with organophosphate insecticides (usually dimethoate or fenthion) for about 40 years. In the present study, the resistance status of olive fruit fly populations to dimethoate was examined in Greece and Cyprus over 2 years. Thirty-one populations from various regions of Greece, nine from Cyprus and one laboratory susceptible strain, which served as a control, were assayed by topical application of dimethoate. Considerable variation in the resistance levels to dimethoate was recorded in the populations of B. oleae, with resistance ratios ranging from 6.3 to 64.4 (ED50 values 12.5-128.7 ng dimethoate per insect). The highest resistance ratios were found in populations from Crete, and the lowest in those from Cyprus. This variation could be attributed to different selection pressures from insecticidal applications among populations from the various regions. Migration of resistant genotypes, either autonomous or via commerce, may also be involved. (c) 2006 Society of Chemical Industry.}, keywords = {Bactrocera oleae, Corfu, DACUS-OLEAE, dimethoate, DROSOPHILA-MELANOGASTER, GMEL DIPTERA, insecticides, INSENSITIVE ACETYLCHOLINESTERASE, MALATHION, olive fruit fly, organophosphates, POINT MUTATIONS, resistance, SIMULANS, Tephritidae}, isbn = {1526-498X}, author = {Skouras, P. J. and Margaritopoulos, J. T. and Seraphides, N. A. and Ioannides, I. M. and Kakani, E. G. and Mathiopoulos, K. D. and Tsitsipis, J. A.} } @article {10625, title = {Morphological separation of host adapted taxa within the Hyalopterus pruni complex (Hemiptera: Aphididae)}, journal = {European Journal of EntomologyEuropean Journal of Entomology}, volume = {104}, number = {2}, year = {2007}, note = {Cited By (since 1996): 5Export Date: 8 November 2011Source: Scopus}, pages = {235-242}, author = {Poulios, K. D. and Margaritopoulos, J. T. and Tsitsipis, J. A.} } @article {9303, title = {Efficacy of the pyrethroid alpha-cypermethrin against Bactrocera oleae populations from Greece, and improved diagnostic for an iAChE mutation}, journal = {Pest Management SciencePest Management SciencePest Management Science}, volume = {64}, number = {9}, year = {2008}, note = {ISI Document Delivery No.: 339FVTimes Cited: 5Cited Reference Count: 30}, month = {Sep}, pages = {900-908}, type = {Article}, abstract = {BACKGROUND: The most important pest of olive orchards worldwide is the olive fruit fly Bactrocera oleae (Gmelin). Its control in Greece has been based on organophosphates (OPs), but their intense use has led to the development of resistance. A test previously developed to monitor the trait may not be as robust as originally thought. The pyrethroid alpha-cypermethrin has recently been registered for bait sprays, as an alternative to OPs. RESULTS: The susceptibility of 20 B. oleae populations to alpha-cypermethrin was examined. Variation was observed in their response, with LD50 ranging from 0.14 to 3.28ng insect(-1) and resistance factors from 2.3 to 54.7. Resistance mechanisms were investigated. Cytochrome P450 monoxygenase activities showed an association with resistance. Sequences in the domain IIS4-IIS6 of the B. oleae para-type sodium channel were also analysed, but no resistance-associated mutations were identified. Finally, a novel diagnostic assay able to reliably monitor the frequency of the iAChE G488S resistance mutation was developed. CONCLUSION: This is the first attempt to evaluate the efficacy of alpha-cypermethrin against B. oleae from Greece. Data showed that it can be used effectively, but also highlighted the importance of continuous monitoring. The IIS4-IIS6 sodium channel region is the default area in which to look for resistance mutations if target-site resistance to pyrethroids arises. The application of the novel iAChE molecular diagnostic may facilitate the introduction of pyrethroids alongside OPs currently in use. (C) 2008 Society of Chemical Industry.}, keywords = {ACETYLCHOLINESTERASE, BEMISIA-TABACI, EXPRESSION, Greece, identification, Insecticide resistance, KNOCKDOWN RESISTANCE KDR, olive fruit fly, OLIVE FRUIT-FLY, ORGANOPHOSPHATE-INSENSITIVE, P450s, POINT MUTATIONS, pyrethroid resistance, sodium channel, SODIUM-CHANNEL GENE, Tephritidae}, isbn = {1526-498X}, author = {Margaritopoulos, J. T. and Skavdis, G. and Kalogiannis, N. and Nikou, D. and Morou, E. and Skouras, P. J. and Tsitsipis, J. A. and Vontas, J.} } @article {9304, title = {Insecticide resistance status of Myzus persicae (Hemiptera : Aphididae) populations from peach and tobacco in mainland Greece}, journal = {Pest Management SciencePest Management SciencePest Management Science}, volume = {63}, number = {8}, year = {2007}, note = {ISI Document Delivery No.: 197ETTimes Cited: 15Cited Reference Count: 36}, month = {Aug}, pages = {821-829}, type = {Article}, abstract = {The susceptibility of 88 and 38 field samples of Myzus persicae (Sulzer) to imidacloprid and deltamethrin respectively was examined using the FAO dip test bioassay. The field samples were collected from tobacco and peach from various regions of Greece in the period from 2004 to 2006. In addition, 497, 349 and 370 clones originating from peach and tobacco were screened for the three known resistance mechanisms, elevated esterases, modified acetylcholinesterase (MACE) and knockdown resistance (kdr) respectively, using biochemical and DNA diagnostics. Most of the samples assayed with imidacloprid showed low resistance factors (P.Fs)-39\% below 5 and 21\% between 5 and 10. However, 9\% of the samples (all from tobacco) showed relatively high RF values (24-73). Differences were found between crops, with higher RF values recorded in samples from tobacco than in those from peach. Bioassays with deltamethrin revealed the development of strong resistance in the populations examined. The RFs were mostly higher than 23, and in 29\% of the samples they were extremely high (152-436). Finally, the three known resistance mechanisms were found in high frequencies in the populations examined, although some differences between crops and years were detected. The implications of the study for management schemes against M. persicae are discussed. (c) 2007 Society of Chemical Industry.}, keywords = {ESTERASE, Homoptera, Insecticide resistance, life-cycle, MECHANISMS, MUTATION, Myzus persicae, neonicotinoids, nicotianae, NICOTINIC ACETYLCHOLINE-RECEPTOR, peach, POTATO APHIDS, SEQUENCES, SULZER, tobacco aphid}, isbn = {1526-498X}, author = {Margaritopoulos, J. T. and Skouras, P. J. and Nikolaidou, P. and Manolikaki, J. and Maritsa, K. and Tsamandani, K. and Kanavaki, O. M. and Bacandritsos, N. and Zarpas, K. D. and Tsitsipis, J. A.} } @article {9306, title = {Biological characteristics of the mirids Macrolophus costalis and Macrolophus pygmaeus preying on the tobacco form of Myzus persicae (Hemiptera: Aphididae)}, journal = {Bulletin of Entomological ResearchBulletin of Entomological Research}, volume = {93}, year = {2003}, pages = {39-45}, keywords = {Homoptera Heteroptera}, author = {Margaritopoulos, J. T. and Tsitsipis, J. A. and Perdikis, D. C.} } @article {9309, title = {Host selection by winged colonisers within the Myzus persicae group: a contribution towards understanding host specialisation}, journal = {Ecological EntomologyEcological Entomology}, volume = {30}, number = {4}, year = {2005}, pages = {406-418}, publisher = {Blackwell Synergy}, keywords = {Homoptera}, author = {Margaritopoulos, J. T. and Tsourapas, C. and Tzortzi, M. and Kanavaki, O. M. and Tsitsipis, J. A.} } @article {9311, title = {Morphological discrimination of Aphis gossypii (Hemiptera: Aphididae) populations feeding on Compositae}, journal = {Bulletin of Entomological ResearchBulletin of Entomological Research}, volume = {96}, year = {2006}, pages = {153-165}, keywords = {Homoptera}, author = {Margaritopoulos, J. T. and Tzortzi, M. and Zarpas, K. D. and Tsitsipis, J. A. and Blackman, R. L.} } @article {9298, title = {Genetic variation among Mediterranean populations of Sesamia nonagrioides (Lepidoptera: Noctuidae) as revealed by RFLP mtDNA analysis}, journal = {Bulletin of Entomological ResearchBulletin of Entomological Research}, volume = {97}, number = {3}, year = {2007}, month = {June}, pages = {299-308}, isbn = {0007-4853}, author = {Margaritopoulos, J. T. and Gotosopoulos, B. and Mamuris, Z. and Skouras, P. J. and Voudouris, K. C. and Bacandritsos, N. and Fantinou, A. A. and Tsitsipis, J. A.} } @article {3653, title = {Distribution of common genotypes of Myzus persicae (Hemiptera : Aphididae) in Greece, in relation to life cycle and host plant}, journal = {Bulletin of Entomological ResearchBulletin of Entomological ResearchBulletin of Entomological Research}, volume = {97}, number = {3}, year = {2007}, note = {ISI Document Delivery No.: 183IGTimes Cited: 7Cited Reference Count: 49}, month = {Jun}, pages = {253-263}, type = {Article}, abstract = {Microsatellite genotyping was used to identify common clones in populations of the Myzus persicae group from various hosts and regions in mainland Greece and southern Italy and to compare their distribution and occurrence on tobacco and other crops. Common clones were defined as genotypes collected at more than one time or in more than one population; and, therefore, unlikely to be participating in the annual sexual phase on peach. Sixteen common genotypes were found, accounting for 49.0\% of the 482 clonal lineages examined. Eight of these genotypes were subjected, in the laboratory, to short days and found to continue parthenogenetic reproduction, i.e. they were anholocyclic. Four of the six commonest genotypes were red, and one of these accounted for 29.6\% of the samples from tobacco and 29.4\% of those from overwintering populations on weeds. All six commonest genotypes were found on weeds and five of them both on tobacco and on other field crops. In mainland Greece, the distribution of common clones corresponded closely with that of anholocyclic lineages reported in a previous study of life cycle variation. Common genotypes were in the minority in the commercial peach-growing areas in the north, except on weeds in winter and in tobacco seedbeds in early spring, but predominated further south, away from peach trees. This contrasts with the situation in southern Italy, reported in a previous paper, where peaches were available for the sexual phase, yet all samples from tobacco were of common genotypes.}, keywords = {aphid, ASEXUAL POPULATIONS, clones, cyclical parthenogenesis, GENETIC-VARIABILITY, INSECTICIDE, life cycle variation, Myzus persicae, NATURAL-POPULATIONS, nicotianae, NICOTIANAE HOMOPTERA, PARTHENOGENETIC SITOBION APHIDS, PEACH-POTATO APHID, PREDOMINANT CLONE, resistance, SULZER HEMIPTERA, Tobacco, tobacco aphid}, isbn = {0007-4853}, author = {Blackman, R. L. and Malarky, G. and Margaritopoulos, J. T. and Tsitsipis, J. A.} }