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Owen Olfert - One of the best experts on this subject based on the ideXlab platform.
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Seasonal emergence patterns of Sitodiplosis mosellana (Diptera: Cecidomyiidae) in the Peace River region, Alberta, Canada
The Canadian Entomologist, 2021Co-Authors: Amanda Jorgensen, Owen Olfert, Maya L. Evenden, Jennifer OtaniAbstract:Abstract Wheat midge, Sitodiplosis mosellana Géhin (Diptera: Cecidomyiidae), is an invasive pest of wheat, Triticum spp. (Poaceae), in North America and is found in all wheat-growing regions of the world. Wheat midge biology, particularly post-diapause emergence of adults, varies with geographic region. The biology of wheat midge has not previously been examined in the northernmost area of its range in Canada – the Peace River region of Alberta. Wheat midge adult emergence was compared in situ to two phenological models of wheat midge emergence developed in other geographic regions. In-field adult emergence did not match the published phenological models. In the Peace River region, adults emerged later than are predicted by both models and precision for both models was low. With the Saskatchewan model, accumulated rainfall that was more than 110 mm in May and early June delayed emergence, whereas accumulated rainfall that was less than 43 mm during that period caused earlier than predicted emergence. Multiple peaks of wheat midge emergence, up to 20 days apart, were observed at some sites, supporting the Jacquemin model depicting “waves” of emergence. Including differences in soil temperature accumulation related to precipitation and optimising the model temperature thresholds would improve accuracy of the current Canadian phenological model in the Peace River region.
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Non-native insects in agriculture: strategies to manage the economic and environmental impact of wheat midge, Sitodiplosis mosellana , in Saskatchewan
Biological Invasions, 2008Co-Authors: Owen Olfert, R. H. Elliott, S. HartleyAbstract:Wheat midge, Sitodiplosis mosellana (Gehin) (Diptera: Cecidomyiidae), was first detected as early as 1901 in western Canada. The first major outbreak in Saskatchewan was recorded in 1983. Today wheat midge infests much of the wheat-growing area of Manitoba, Saskatchewan and North Dakota (USA), and is beginning to invade Alberta and Montana (USA). In 1984, Saskatchewan wheat midge populations were found to be parasitized by the egg-larval parasitoid, Macroglenes penetrans (Kirby) (Hymenoptera). Through the successful implementation of conservation techniques, this parasitoid now controls an average of 31.5% of the wheat midge across Saskatchewan. Estimated value of the parasitoid, due to reduction in insecticide costs in Saskatchewan alone, was estimated to be in excess of $248.3 million in the 1990s. The environmental benefits of not having to apply this amount of chemical insecticide are a bonus. To minimize the economic and ecological impact of S. mosellana today, wheat producers in western Canada have access to one of the most comprehensive management programs of any insect pest of field crops. Forecasts and risk warnings, monitoring tools, cultural control, agronomic practices, chemical control, biological control and plant resistance are all available for producers to manage wheat midge.
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Establishment of Platygaster tuberosula , an introduced parasitoid of the wheat midge, Sitodiplosis mosellana
The Canadian Entomologist, 2003Co-Authors: Owen Olfert, J.f. Doane, M.p. BraunAbstract:Wheat midge, Sitodiplosis mosellana (Gehin) (Diptera: Cecidomyiidae), was first detected as early as 1901 in Western Canada. The first major outbreak in Saskatchewan was recorded in 1983. In 1984, Saskatchewan wheat midge populations were found to be parasitized by the egg parasitoid Macroglenes penetrans (Kirby). Parasitism levels vary from year to year but, on average, 33% of wheat midge populations are parasitized by M. penetrans . In 1993 and 1994, Agriculture Canada and the International Institute of Biological Control in Delemont, Switzerland, collaborated to release Platygaster tuberosula Kieffer into Saskatchewan to augment biological control of wheat midge. Platygaster tuberosula individuals were recovered at low numbers in follow-up monitoring programs in each of the last 5 years. In 2001, the parasitoid population density increased fivefold at the release site and showed signs of migrating into the surrounding area.
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Inheritance of resistance to wheat midge, Sitodiplosis mosellana, in spring wheat
Plant Breeding, 2002Co-Authors: R.i.h. Mckenzie, I L Wise, Robert J. Lamb, T. Aung, P.s. Barker, Owen OlfertAbstract:Inheritance of resistance to a wheat midge, Sitodiplosis mosellana (Gehin), was investigated in spring wheats derived from nine resistant winter wheat cultivars. F 1 hybrids were obtained from crosses between resistant winter wheats and susceptible spring wheats, and used to generate doubled haploid populations. These populations segregated in a ratio of 1 : 1 resistant to susceptible, indicating that a single gene confers the resistance. The F 2 progeny from an intercross among spring wheats derived from the nine resistance sources did not segregate for resistance. Therefore, the same gene confers resistance in all nine sources of resistance, although other genes probably affect expression because the level of resistance varied among lines. Heterozygous plants from five crosses between diverse susceptible and resistant spring wheat parents all showed intermediate levels of response, indicating that resistance is partly dominant. Susceptible plants were reliably discriminated from heterozygous or homozygous resistant ones in laboratory tests, based on the survival and development of wheat midge larvae on one or two spikes. This powerful resistance gene, designated Sm1, is simply inherited and can be incorporated readily into breeding programmes for spring or winter wheat. However, the use of this gene by itself may lead to the evolution of a virulent population, once a resistant cultivar is widely grown.
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Oviposition deterrence against Sitodiplosis mosellana (Diptera: Cecidomyiidae) in spring wheat (Gramineae)
The Canadian Entomologist, 2002Co-Authors: Robert J. Lamb, I L Wise, M.a.h. Smith, R.i.h. Mckenzie, J. Thomas, Owen OlfertAbstract:Du ble de printemps, Triticum aestivum L., prealablement reconnu comme porteur de legeres infestations d'oeufs et de larves de la Cecidomyiie du ble, Sitodiplosis mosellana (Gehin), a ete teste dans le but de determiner si la reduction des infestations peut etre attribuable a une inhibition de la ponte. Le nombre d'oeufs pondus sur une variete de ble par rapport au nombre trouve sur une variete temoin a servi de mesure de l'inhibition de la ponte. La densite des oeufs sur certaine de ces varietes equivalait a 10 % ou moins de celle sur le cultivar commercial sensible « Roblin » au cours de tests de choix et a 20 % ou moins de celle enregistree au cours de tests sans choix en laboratoire. Ces varietes inhibent egalement la ponte en nature et reduisent la densite des oeufs d'au moins 50 % dans les champs a rangees simples et a rangees multiples. D'autres varietes experimentales avaient des taux d'inhibition de la ponte intermediaires entre les varietes les plus inhibitrices et le cultivar « Roblin ». L'un des 12 cultivars commerciaux utilises le cultivar « AC Superb » a egalement donne lieu a des densites d'oeufs faibles en laboratoire et lors des tests en rangees simples en nature, mais cette inhibition ne s'est pas manifestee de facon constante dans les grandes parcelles ou dans les champs commerciaux. Les varietes experimentales les plus inhibitrices ont des taux d'inhibition de la ponte qui pourraient s'averer utiles en agriculture et meme souhaitables lorsque combines a une resistance aux antibiotiques decrite precedemment.
Robert J. Lamb - One of the best experts on this subject based on the ideXlab platform.
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Volatile compounds from non-preferred wheat spikes reduce oviposition by Sitodiplosis mosellana
The Canadian Entomologist, 2011Co-Authors: Ali Hosseini Gharalari, M.a.h. Smith, Stephen Fox, Robert J. LambAbstract:Abstract Female wheat midges, Sitodiplosis mosellana (Gehin) (Diptera: Cecidomyiidae), were provided with wheat spikes, Triticum aestivum L. (Poaceae), for oviposition while being exposed to air that had passed over wheat spikes of contrasting genotype or growth stage. Spikes of postanthesis ‘Roblin’ and preanthesis ‘Key 10’ are known to deter oviposition. Volatiles emitted by these spikes suppressed oviposition on preanthesis ‘Roblin’, which is preferred for oviposition. Volatiles emitted by spikes of preanthesis ‘Roblin’ did not increase oviposition on preanthesis ‘Key 10’. Reduced oviposition on a resistant genotype and on a deterrent growth stage of wheat is consistent with production of deterrent volatiles rather than a lack of stimulatory volatiles.
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Behaviour of Sitodiplosis mosellana (Diptera: Cecidomyiidae) on spring wheat spikes with and without oviposition deterrence
The Canadian Entomologist, 2010Co-Authors: Ali Hosseini Gharalari, M.a.h. Smith, Stephen Fox, Robert J. LambAbstract:Abstract Wheat, Triticum L. (Poaceae), varieties with deterrence to oviposition by the wheat midge, Sitodiplosis mosellana (Gehin) (Diptera: Cecidomyiidae), can be useful in reducing seed damage. The behaviour of ovipositing females on spring wheat, T. aestivum L., with and without oviposition deterrence was investigated to account for observed differences in oviposition on deterrent and nondeterrent hosts. On deterrent wheat, 34% of females landing oviposited compared with 100% of females landing on nondeterrent wheat. The sequence of female behaviours just prior to egg-laying on deterrent spikes was similar to that on nondeterrent spikes. The length of time required to lay an egg and mean egg-batch size were similar on deterrent and nondeterrent wheat, but females spent nearly twice as long on the latter. After landing on deterrent wheat, females took longer to begin ovipositing and longer to leave after the last oviposition event than did females on nondeterrent wheat, which further reduced the time av...
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Survival of Sitodiplosis mosellana (Diptera: Cecidomyiidae) on wheat (Poaceae) with antibiosis resistance: implication for the evolution of virulence
The Canadian Entomologist, 2007Co-Authors: M.a.h. Smith, I L Wise, Robert J. LambAbstract:Small numbers of larval wheat midge, Sitodiplosis mosellana Gehin, survived and matured in each of five field seasons in a plot of spring wheat carrying the Sm1 gene for antibiosis resistance against this insect. Wheat midge developing on resistant wheat had higher survival in the laboratory than in the field, but survival was always very low compared with that of larvae developing on susceptible wheat. The mass of these larvae and their survival during diapause were approximately half those of larvae developing on susceptible wheat in both the laboratory and the field. The survival of some wheat midge larvae on resistant wheat, and their reduced mass, is consistent with the hypothesis that a virulence allele allowing adaptation to Sm1 is present in the population. Assuming this to be the case, the frequency of the allele in the population was estimated to be between 0.8 × 10−4 and 1.6 × 10−2, if surviving larvae are heterozygous for the allele. Although rare, a virulence allele occurring at this frequenc...
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Sex ratios of Sitodiplosis mosellana (Diptera: Cecidomyiidae): implications for pest management in wheat (Poaceae).
Bulletin of entomological research, 2004Co-Authors: M.a.h. Smith, I L Wise, Robert J. LambAbstract:Sex ratios of populations of the wheat midge Sitodiplosis mosellana Gehin, developing on wheat Triticum aestivum L., were determined at reproduction, adult emergence, and dispersal. The patterns of sex ratio through the life cycle of S. mosellana result from: (i) a genetic mechanism that causes all or nearly all of the progeny of individual females to be a single sex, with an overall sex ratio that is slightly biased at 54-57% females; (ii) a differential mortality during diapause that increases the sex ratio to 60-65% females; (iii) mating which occurs near the emergence site followed by female dispersal which causes the post-dispersal sex ratio to rise to nearly 100% females; and (iv) oviposition which spreads eggs among different plants and assures that the next generation has a local sex ratio close to the population average. These changes in sex ratio through the life cycle have implications for using crop resistance or pheromones to manage S. mosellana, because mating takes place quickly near emergence sites, and because mated females but not males disperse from emergence sites to oviposition sites. Crop refuges used to protect resistance genes against the evolution of virulence by S. mosellana must be interspersed to prevent assortative mating that would occur in separate blocks of resistant and susceptible plants. Monitoring or mating disruption using a pheromone would be ineffective when wheat is grown in rotation with a non-host crop.
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Inheritance of resistance to wheat midge, Sitodiplosis mosellana, in spring wheat
Plant Breeding, 2002Co-Authors: R.i.h. Mckenzie, I L Wise, Robert J. Lamb, T. Aung, P.s. Barker, Owen OlfertAbstract:Inheritance of resistance to a wheat midge, Sitodiplosis mosellana (Gehin), was investigated in spring wheats derived from nine resistant winter wheat cultivars. F 1 hybrids were obtained from crosses between resistant winter wheats and susceptible spring wheats, and used to generate doubled haploid populations. These populations segregated in a ratio of 1 : 1 resistant to susceptible, indicating that a single gene confers the resistance. The F 2 progeny from an intercross among spring wheats derived from the nine resistance sources did not segregate for resistance. Therefore, the same gene confers resistance in all nine sources of resistance, although other genes probably affect expression because the level of resistance varied among lines. Heterozygous plants from five crosses between diverse susceptible and resistant spring wheat parents all showed intermediate levels of response, indicating that resistance is partly dominant. Susceptible plants were reliably discriminated from heterozygous or homozygous resistant ones in laboratory tests, based on the survival and development of wheat midge larvae on one or two spikes. This powerful resistance gene, designated Sm1, is simply inherited and can be incorporated readily into breeding programmes for spring or winter wheat. However, the use of this gene by itself may lead to the evolution of a virulent population, once a resistant cultivar is widely grown.
De Proft Michel - One of the best experts on this subject based on the ideXlab platform.
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Assessing cultivar resistance to Sitodiplosis mosellana (Géhin) (Diptera: Cecidomyiidae) using a phenotyping method under semi-field conditions
2017Co-Authors: Chavalle Sandrine, Jacquemin Guillaume, De Proft MichelAbstract:The orange wheat blossom midge, Sitodiplosis mosellana (Géhin), can significantly reduce wheat yield. Growing resistant wheat cultivars is an effective way of managing this pest. The assessment of cultivar resistance in field trials is difficult because of unequal pressure of S. mosellana caused by differences in cultivar heading dates relative to the flight period of S. mosellana adult females and huge variations of egg laying conditions from 1 day to another. To overcome these hurdles and to expose all cultivars homogeneously to the pest, an assessment method of cultivar resistance was developed under semi-field conditions. In 2015, the resistance of 64 winter wheat cultivars to S. mosellana was assessed. Few or no larvae developed in the ears of resistant cultivars, but in susceptible cultivars, large numbers of larvae developed. Seventeen cultivars proved to be resistant, whereas 47 were susceptible. The identification of new resistant cultivars offers more opportunities to manage S. mosellana. The phenotyping method is easy, cheap, efficient and reliable. It can be used to guide the breeding of new resistant wheat cultivars. Using specific midge populations, this method could also be used in research on new resistance mechanisms in winter wheat or in other cereal species.Peer reviewe
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Assessing cultivar resistance to Sitodiplosis mosellana (Géhin) (Diptera: Cecidomyiidae) using a phenotyping method under semi-field conditions
'Wiley', 2017Co-Authors: Chavalle Sandrine, Jacquemin Guillaume, De Proft MichelAbstract:peer reviewedaudience: researcher, professional, studentThe orange wheat blossom midge, Sitodiplosis mosellana (Géhin), can significantly reduce wheat yield. Growing resistant wheat cultivars is an effective way of managing this pest. The assessment of cultivar resistance in field trials is difficult because of unequal pressure of S. mosellana caused by differences in cultivar heading dates relative to the flight period of S. mosellana adult females and huge variations of egg laying conditions from 1 day to another. To overcome these hurdles and to expose all cultivars homogeneously to the pest, an assessment method of cultivar resistance was developed under semi-field conditions. In 2015, the resistance of 64 winter wheat cultivars to S. mosellana was assessed. Few or no larvae developed in the ears of resistant cultivars, but in susceptible cultivars, large numbers of larvae developed. Seventeen cultivars proved to be resistant, whereas 47 were susceptible. The identification of new resistant cultivars offers more opportunities to manage S. mosellana. The phenotyping method is easy, cheap, efficient and reliable. It can be used to guide the breeding of new resistant wheat cultivars. Using specific midge populations, this method could also be used in research on new resistance mechanisms in winter wheat or in other cereal species
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Protection of winter wheat against orange wheat blossom midge, Sitodiplosis mosellana (Géhin) (Diptera: Cecidomyiidae): efficacy of insecticides and cultivar resistance
'Wiley', 2015Co-Authors: Chavalle Sandrine, Censier Florence, De Proft MichelAbstract:peer reviewedaudience: researcher, professional, studentBACKGROUND: In 2012 and 2013, Sitodiplosis mosellana (Géhin) flights occurred during the susceptible phase of wheat development in Belgium. The protection against this midge afforded by various insecticides was assessed in infested fields on four winter wheat cultivars (susceptible or resistant, and early or late heading). RESULTS: The insecticides sprayed at the right time reduced the number of larvae in the ears by 44-96%, depending on the product. For Julius, the cultivar (cv.) most exposed to S. mosellana in 2013, the mean yield gain resulting from insecticide use was 1,558 kg ha-1 (18%). In the same year, insecticide use resulted in a yield gain of 780 kg ha-1 (8%) for the cv. Lear, despite its resistance to this pest. The link between yield and number of larvae counted in the ears was a logarithmic relationship, suggesting an important reduction in yield caused either by the damage inflicted by young larvae which died at the start of their development or by the activation of costly reactions in plants. CONCLUSION: The study showed that, in cases of severe attack, the timely application of insecticide treatments can protect wheat against S. mosellana and that even resistant cultivars can benefit from these treatments.La cécidomyie orange du blé, Sitodiplosis mosellana, et ses parasitoïdes : un modèle biologique pour l'étude d'autres cécidomyies nuisibles
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Toxicity of several fungicides for orange wheat blossom midge, Sitodiplosis mosellana (Géhin) (Diptera: Cecidomyiidae)
2015Co-Authors: Chavalle Sandrine, Jansen Jean-pierre, San Martin Gomez Y Gilles, De Proft MichelAbstract:audience: researcher, professional, studentThe orange wheat blossom midge, Sitodiplosis mosellana (Géhin) (Diptera: Cecidomyiidae), can cause severe losses in wheat grain yield and quality. This pest is known to be susceptible to many insecticides, but various field observations have suggested that some fungicides could also significantly affect S. mosellana. In order to confirm these field observations, the effect on adult midges of several fungicides commonly applied to wheat crops was investigated in the laboratory and in small plots in the field. In each experiment, the fungicides were compared with a positive (insecticide) and a negative control (water). Four fungicides were assessed in the laboratory, each with five doses based on basis of a tenfold dilution starting at the field-recommended dose. The mortality rate was evaluated after 24 hours and the lethal dose 50% (LD50) was determined for each product. In the field, six fungicides were tested at the recommended dose. The effect of each product was compared on the basis of the number of S. mosellana adults caught alive with an insect vacuum sampler (Vortis®) on the morning after the treatments. Both experiments showed a significant effect of several fungicides tested on S. mosellana adults. Chlorothalonil was not toxic for S. mosellana, but tebuconazole, fluxapyroxad and azoxystrobin all induced significant mortality rates
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Toxicity of several fungicides for orange wheat blossom midge, Sitodiplosis mosellana (Géhin) (Diptera: Cecidomyiidae)
2015Co-Authors: Chavalle Sandrine, Jansen Jean-pierre, San Martin Gomez Y Gilles, De Proft MichelAbstract:The orange wheat blossom midge, Sitodiplosis mosellana (Géhin) (Diptera: Cecidomyiidae), can cause severe losses in wheat grain yield and quality. This pest is known to be susceptible to many insecticides, but various field observations have suggested that some fungicides could also significantly affect S. mosellana. In order to confirm these field observations, the effect on adult midges of several fungicides commonly applied to wheat crops was investigated in the laboratory and in small plots in the field. In each experiment, the fungicides were compared with a positive (insecticide) and a negative control (water). Four fungicides were assessed in the laboratory, each with five doses based on basis of a tenfold dilution starting at the field-recommended dose. The mortality rate was evaluated after 24 hours and the lethal dose 50% (LD50) was determined for each product. In the field, six fungicides were tested at the recommended dose. The effect of each product was compared on the basis of the number of S. mosellana adults caught alive with an insect vacuum sampler (Vortis®) on the morning after the treatments. Both experiments showed a significant effect of several fungicides tested on S. mosellana adults. Chlorothalonil was not toxic for S. mosellana, but tebuconazole, fluxapyroxad and azoxystrobin all induced significant mortality rates
M.a.h. Smith - One of the best experts on this subject based on the ideXlab platform.
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Seed damage by Sitodiplosis mosellana (Diptera: Cecidomyiidae) to spring wheat cultivars with the Sm1 gene
The Canadian Entomologist, 2015Co-Authors: Ian L. Wise, Stephen L. Fox, M.a.h. SmithAbstract:Six resistant spring wheat cultivars with the Sm1 gene were assessed for seed damage by the orange wheat blossom midge ( Sitodiplosis mosellana (Gehin) (Diptera: Cecidomyiidae)) in laboratory and field tests. All resistant cultivars deterred larvae from developing on the seed and had significantly less yield losses than susceptible wheat cultivars. Vesper was the first cultivar with Sm1 that also deterred oviposition by the wheat midge. Seed damage to all resistant cultivars decreased the later plants were exposed to adult midge from the time spikes emerged from the boot until anthesis. Spikes of susceptible wheat cultivars had lower yield losses when exposed two or more days after emergence than spikes exposed at the time of emergence. Seed damage to resistant wheat caused dorsal and lateral distortions of the seed and often altered seed colour and shape. The pedigree of the resistant cultivars had no effect on the extent of seed damage. Shaw wheat had the least amount of seed damage and no third instars on the seed in both field and laboratory tests. All other cultivars had a few small third instars and similar levels of seed damage in laboratory tests, with Fieldstar being the least effective. In at least one mean site-year Shaw had significantly less yield losses than the other resistant cultivars. It is recommended that Shaw be used as the standard for the selection of future spring wheat cultivars with Sm1 .
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Volatile compounds from non-preferred wheat spikes reduce oviposition by Sitodiplosis mosellana
The Canadian Entomologist, 2011Co-Authors: Ali Hosseini Gharalari, M.a.h. Smith, Stephen Fox, Robert J. LambAbstract:Abstract Female wheat midges, Sitodiplosis mosellana (Gehin) (Diptera: Cecidomyiidae), were provided with wheat spikes, Triticum aestivum L. (Poaceae), for oviposition while being exposed to air that had passed over wheat spikes of contrasting genotype or growth stage. Spikes of postanthesis ‘Roblin’ and preanthesis ‘Key 10’ are known to deter oviposition. Volatiles emitted by these spikes suppressed oviposition on preanthesis ‘Roblin’, which is preferred for oviposition. Volatiles emitted by spikes of preanthesis ‘Roblin’ did not increase oviposition on preanthesis ‘Key 10’. Reduced oviposition on a resistant genotype and on a deterrent growth stage of wheat is consistent with production of deterrent volatiles rather than a lack of stimulatory volatiles.
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Behaviour of Sitodiplosis mosellana (Diptera: Cecidomyiidae) on spring wheat spikes with and without oviposition deterrence
The Canadian Entomologist, 2010Co-Authors: Ali Hosseini Gharalari, M.a.h. Smith, Stephen Fox, Robert J. LambAbstract:Abstract Wheat, Triticum L. (Poaceae), varieties with deterrence to oviposition by the wheat midge, Sitodiplosis mosellana (Gehin) (Diptera: Cecidomyiidae), can be useful in reducing seed damage. The behaviour of ovipositing females on spring wheat, T. aestivum L., with and without oviposition deterrence was investigated to account for observed differences in oviposition on deterrent and nondeterrent hosts. On deterrent wheat, 34% of females landing oviposited compared with 100% of females landing on nondeterrent wheat. The sequence of female behaviours just prior to egg-laying on deterrent spikes was similar to that on nondeterrent spikes. The length of time required to lay an egg and mean egg-batch size were similar on deterrent and nondeterrent wheat, but females spent nearly twice as long on the latter. After landing on deterrent wheat, females took longer to begin ovipositing and longer to leave after the last oviposition event than did females on nondeterrent wheat, which further reduced the time av...
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Survival of Sitodiplosis mosellana (Diptera: Cecidomyiidae) on wheat (Poaceae) with antibiosis resistance: implication for the evolution of virulence
The Canadian Entomologist, 2007Co-Authors: M.a.h. Smith, I L Wise, Robert J. LambAbstract:Small numbers of larval wheat midge, Sitodiplosis mosellana Gehin, survived and matured in each of five field seasons in a plot of spring wheat carrying the Sm1 gene for antibiosis resistance against this insect. Wheat midge developing on resistant wheat had higher survival in the laboratory than in the field, but survival was always very low compared with that of larvae developing on susceptible wheat. The mass of these larvae and their survival during diapause were approximately half those of larvae developing on susceptible wheat in both the laboratory and the field. The survival of some wheat midge larvae on resistant wheat, and their reduced mass, is consistent with the hypothesis that a virulence allele allowing adaptation to Sm1 is present in the population. Assuming this to be the case, the frequency of the allele in the population was estimated to be between 0.8 × 10−4 and 1.6 × 10−2, if surviving larvae are heterozygous for the allele. Although rare, a virulence allele occurring at this frequenc...
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Sex ratios of Sitodiplosis mosellana (Diptera: Cecidomyiidae): implications for pest management in wheat (Poaceae).
Bulletin of entomological research, 2004Co-Authors: M.a.h. Smith, I L Wise, Robert J. LambAbstract:Sex ratios of populations of the wheat midge Sitodiplosis mosellana Gehin, developing on wheat Triticum aestivum L., were determined at reproduction, adult emergence, and dispersal. The patterns of sex ratio through the life cycle of S. mosellana result from: (i) a genetic mechanism that causes all or nearly all of the progeny of individual females to be a single sex, with an overall sex ratio that is slightly biased at 54-57% females; (ii) a differential mortality during diapause that increases the sex ratio to 60-65% females; (iii) mating which occurs near the emergence site followed by female dispersal which causes the post-dispersal sex ratio to rise to nearly 100% females; and (iv) oviposition which spreads eggs among different plants and assures that the next generation has a local sex ratio close to the population average. These changes in sex ratio through the life cycle have implications for using crop resistance or pheromones to manage S. mosellana, because mating takes place quickly near emergence sites, and because mated females but not males disperse from emergence sites to oviposition sites. Crop refuges used to protect resistance genes against the evolution of virulence by S. mosellana must be interspersed to prevent assortative mating that would occur in separate blocks of resistant and susceptible plants. Monitoring or mating disruption using a pheromone would be ineffective when wheat is grown in rotation with a non-host crop.
Yun Duan - One of the best experts on this subject based on the ideXlab platform.
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Climate factors associated with the population dynamics of Sitodiplosis mosellana (Diptera: Cecidomyiidae) in central China
Scientific reports, 2019Co-Authors: Jin Miao, Wu Yuqing, Gong Zhongjun, Li Tong, Yun Duan, Jianrong Huang, Guoyan Zhang, Yue-li JiangAbstract:Understanding the impacts of climate on insect pest population dynamics is crucial in forecasting pest outbreaks and developing a sustainable pest management strategy. The orange wheat blossom midge, Sitodiplosis mosellana (Gehin), is a chronic winter wheat (Triticum aestivum L.) pest in China, and its population density can strongly fluctuate. We analyzed climate factors (temperature and precipitation) associated with population dynamics of S. mosellana in a large-scale field trial in central China from 1984 to 2013 using Generalized linear mixed effects models. We found total precipitation during January-March was significantly positively correlated with population density of S. mosellana, whereas temperature parameters were not correlated with the population levels. Moreover, S. mosellana population size was significantly negative effected by interaction between temperature and precipitation, which showed that high precipitation with low temperature in spring also reduced the population density. This suggests that annual population size of S. mosellana in Central China is determined by soil moisture in early spring. These results provide basic information that will help in forecasting population levels and in developing a sound pest management strategy for S. mosellana.
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Identification and expression profile analysis of putative odorant-binding proteins in Sitodiplosis mosellana (Gehin) (Diptera: Cecidomyiidae).
Biochemical and biophysical research communications, 2014Co-Authors: Gong Zhongjun, Li Tong, Jin Miao, Yue-li Jiang, Yun Duan, Wu YuqingAbstract:Abstract Odorant binding proteins (OBPs) contribute to the remarkable sensitivity of the insect’s olfactory system and play important roles in the olfactory recognition. The orange blossom midge, Sitodiplosis mosellana is a cereal specialist, and utilizes pheromone and host odorant as a cue for its mating and oviposition. However, OBP genes have not been largely identified in S. mosellana. Based on the sequenced transcriptome database, twenty-six OBP genes were identified in S. mosellana for the first time. Phylogenetic analysis revealed that S. mosellana OBP genes are more closely related to Mayetiola destructor OBP genes than to Aedes aegypti OBP genes. Most OBP genes seemed to be antenna-specific, but differentially expressed in male and female antennae. Three OBP genes (OBP9, OBP19 and OBP23) are leg-specific. And also, most OBP genes have higher expression levels in adults. Only one OBP gene (OBP10) has higher expression levels in larval stages. These findings serve as an important basis for understanding the molecular mechanisms of chemosensory perception.
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Genetic diversity and population structure of Sitodiplosis mosellana in Northern China.
PloS one, 2013Co-Authors: Yun Duan, Wu Yuqing, Gong Zhongjun, Jin Miao, Yue-li Jiang, Li-zhi Luo, Li TongAbstract:The wheat midge, Sitodiplosis mosellana, is an important pest in Northern China. We tested the hypothesis that the population structure of this species arises during a range expansion over the past 30 years. This study used microsatellite and mitochondrial loci to conduct population genetic analysis of S. mosellana across its distribution range in China. We found strong genetic structure among the 16 studied populations, including two genetically distinct groups (the eastern and western groups), broadly consistent with the geography and habitat fragmentation. These results underline the importance of natural barriers in impeding dispersal and gene flow of S. mosellana populations. Low to moderate genetic diversity among the populations and moderate genetic differentiation (F ST = 0.117) between the two groups were also found. The populations in the western group had lower genetic diversity, higher genetic differentiation and lower gene flow (F ST = 0.116, Nm = 1.89) than those in the eastern group (F ST = 0.049, Nm = 4.91). Genetic distance between populations was positively and significantly correlated with geographic distance (r = 0.56, P
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genetic diversity and population structure of Sitodiplosis mosellana in northern china
PLOS ONE, 2013Co-Authors: Yun Duan, Jin Miao, Li-zhi Luo, Zhongjun Gong, Yue-li JiangAbstract:The wheat midge, Sitodiplosis mosellana, is an important pest in Northern China. We tested the hypothesis that the population structure of this species arises during a range expansion over the past 30 years. This study used microsatellite and mitochondrial loci to conduct population genetic analysis of S. mosellana across its distribution range in China. We found strong genetic structure among the 16 studied populations, including two genetically distinct groups (the eastern and western groups), broadly consistent with the geography and habitat fragmentation. These results underline the importance of natural barriers in impeding dispersal and gene flow of S. mosellana populations. Low to moderate genetic diversity among the populations and moderate genetic differentiation (F ST = 0.117) between the two groups were also found. The populations in the western group had lower genetic diversity, higher genetic differentiation and lower gene flow (F ST = 0.116, Nm = 1.89) than those in the eastern group (F ST = 0.049, Nm = 4.91). Genetic distance between populations was positively and significantly correlated with geographic distance (r = 0.56, P<0.001). The population history of this species provided no evidence for population expansion or bottlenecks in any of these populations. Our data suggest that the distribution of genetic diversity, genetic differentiation and population structure of S. mosellana have resulted from a historical event, reflecting its adaptation to diverse habitats and forming two different gene pools. These results may be the outcome of a combination of restricted gene flow due to geographical and environmental factors, population history, random processes of genetic drift and individual dispersal patterns. Given the current risk status of this species in China, this study can offer useful information for forecasting outbreaks and designing effective pest management programs.
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Global Transcriptome Analysis of Orange Wheat Blossom Midge, Sitodiplosis mosellana (Gehin) (Diptera: Cecidomyiidae) to Identify Candidate Transcripts Regulating Diapause
PloS one, 2013Co-Authors: Gong Zhongjun, Wu Yuqing, Jin Miao, Yue-li Jiang, Yun Duan, Li TongAbstract:Background Many insects enter a developmental arrest (diapause) that allows them to survive harsh seasonal conditions. Despite the well-established ecological significance of diapause, the molecular basis of this crucial adaptation remains largely unresolved. Sitodiplosis mosellana (Gehin), the orange wheat blossom midge (OWBM), causes serious damage to wheat throughout the northern hemisphere, and sporadic outbreaks occur in the world. Traits related to diapause appear to be important factors contributing to their rapid spread and outbreak. To better understand the diapause mechanisms of OWBM, we sequenced the transcriptome and determined the gene expression profile of this species.