Background: Various methods have been proposed to assign unknown specimens to known species using... more Background: Various methods have been proposed to assign unknown specimens to known species using their DNA barcodes, while others have focused on using genetic divergence thresholds to estimate "species" diversity for a taxon, without a well-developed taxonomy and/or an extensive reference library of DNA barcodes. The major goals of the present work were to: a) conduct the largest species-level barcoding study of the Muscidae to date and characterize the range of genetic divergence values in the northern Nearctic fauna; b) evaluate the correspondence between morphospecies and barcode groupings defined using both clustering-based and threshold-based approaches; and c) use the reference library produced to address taxonomic issues. Results: Our data set included 1114 individuals and their COI sequences (951 from Churchill, Manitoba), representing 160 morphologically-determined species from 25 genera, covering 89% of the known fauna of Churchill and 23% of the Nearctic fauna. Following an iterative process through which all specimens belonging to taxa with anomalous divergence values and/or monophyly issues were reexamined , identity was modified for 9 taxa, including the reinstatement of Phaonia luteva (Walker) stat. nov. as a species distinct from Phaonia errans (Meigen). In the post-reassessment data set, no distinct gap was found between maximum pairwise intraspecific distances (range 0.00-3.01%) and minimum interspecific distances (range: 0.77-11.33%). Nevertheless, using a clustering-based approach, all individuals within 98% of species grouped with their conspecifics with high (>95%) bootstrap support; in contrast, a maximum species discrimination rate of 90% was obtained at the optimal threshold of 1.2%. DNA barcoding enabled the determination of females from 5 ambiguous species pairs and confirmed that 16 morphospecies were genetically distinct from named taxa. There were morphological differences among all distinct genetic clusters; thus, no cases of cryptic species were detected. Conclusions: Our findings reveal the great utility of building a well-populated, species-level reference barcode database against which to compare unknowns. When such a library is unavailable, it is still possible to obtain a fairly accurate (within~10%) rapid assessment of species richness based upon a barcode divergence threshold alone, but this approach is most accurate when the threshold is tuned to a particular taxon.
Many control methods target agricultural pests’ reproductive traits and so, knowledge of these tr... more Many control methods target agricultural pests’ reproductive traits and so, knowledge of these traits is crucial. The seedcorn maggot, Delia platura (Diptera: Anthomyiidae), is reported as a cosmopolitan polyphagous pest species which can be found in high numbers in numerous crops. Two morphologically identical genetic lines of D. platura (H- and N- lines) with distinct distribution ranges were recently discovered. While many biological traits have been described for D. platura, no study to date has been conducted on the life history strategies and reproductive behaviors of its two lines. Using laboratory-reared colonies originating from the Montérégie region in Québec, this project investigates the effect of group composition (sex-ratio and density) on the mating success and pre-oviposition period of the two D. platura lines. We found a substantial increase in mating success with increasing proportion of males within mating groups for both lines while group density had negligeable ...
SUMMARYWidespread access to the internet is offering new possibilities for data collection in sur... more SUMMARYWidespread access to the internet is offering new possibilities for data collection in surveillance. We explore, in this study, the possibility of using an electronic tool to monitor occurrence of the tick vector of Lyme disease, Ixodes scapularis. The study aimed to compare the capacity for ticks to be identified in web-based submissions of digital images/photographs, to the traditional specimen-based identification method used by the provincial public health laboratory in Quebec, Canada. Forty-one veterinary clinics participated in the study by submitting digital images of ticks collected from pets via a website for image-based identification by an entomologist. The tick specimens were then sent to the provincial public health laboratory to be identified by the ‘gold standard’ method using a microscope. Of the images submitted online, 74·3% (284/382) were considered of high-enough quality to allow identification. The laboratory identified 382 tick specimens from seven diffe...
The large muscid genus Atherigona Rondani (Diptera) includes over 2 0 species, most of which are ... more The large muscid genus Atherigona Rondani (Diptera) includes over 2 0 species, most of which are found in the tropical and subtropical regions of the Old World (Pont and Magpayo 1995). The group is divided into two subgenera: Acritochaeta grimshaw, which contains mostly saprophagous taxa, and Atherigona Rondani, whose phytophagous larvae are shoot-flies that feed on a variety of wild and cultivated grasses (Poaceae) (Pont and Magpayo 1995). Only two species of Atherigona are currently found in North america. The cosmopolitan Atherigona orientalis Schiner (Diptera: Muscidae) has long been known from the southern United States (Malloch 1921; Huckett 19 6) and has not, so far, been recorded in Canada. Atherigona reversura Villeneuve (Diptera: Muscidae), a widespread species in the Oriental, australasian and Palaearctic regions (Pont and Magpayo 1995), is a much more recent introduction: it was documented from the United States less than a decade ago (Hudson 2010) and is recorded here f...
Annals of the Entomological Society of America, 2009
The adult of a new genus and new species of Muscidae, Callainireinwardtia woodi sp. nov, gen. nov... more The adult of a new genus and new species of Muscidae, Callainireinwardtia woodi sp. nov, gen. nov., is described from Costa Rica. This new genus is placed in the tribe Reinwardtiini and can be distinguished from other members of the group as well as other New World Muscidae by the presence of a striking blue to blue-green metallic color combined with a bare anepimeron, setulose metepisternum, a plumose arista, and wings without clouds or spots. Conflicting data on the phylogenetic position of the reinwardtiine genera is summarized and potential avenues for future research are suggested.
FIGURE 5. Piezura pardalina ssp. shanxiensis Xue, Wang & Wu. A. Male genitalia external structure... more FIGURE 5. Piezura pardalina ssp. shanxiensis Xue, Wang & Wu. A. Male genitalia external structures, posterior. B. Male sternite 5, ventral. (adapted from Xue & Wang, 1999).
FIGURE 2. Piezura nearctica Chillcott. A. Male genitalia external structures, posterior. B. Femal... more FIGURE 2. Piezura nearctica Chillcott. A. Male genitalia external structures, posterior. B. Female spermatheca. C. Female genitalia, ventral. D. Male sternite 5, ventral.
A dataset of 3,250,404 measurements, collated from 26,114 sampling locations in 94 countries and ... more A dataset of 3,250,404 measurements, collated from 26,114 sampling locations in 94 countries and representing 47,044 species. The data were collated from 480 existing spatial comparisons of local-scale biodiversity exposed to different intensities and types of anthropogenic pressures, from terrestrial sites around the world. The database was assembled as part of the PREDICTS project - Projecting Responses of Ecological Diversity In Changing Terrestrial Systems; [www.predicts.org.uk](http://www.predicts.org.uk).\r\n\r\nThe taxonomic identifications provided in the original data sets are those determined at the time of the original research, and so will not reflect subsequent taxonomic changes.\r\n\r\nThis dataset is described in [10.1002/ece3.2579](http://dx.doi.org/10.1002/ece3.2579). A description of the way that this dataset was assembled is given in [10.1002/ece3.1303](http://dx.doi.org/10.1002/ece3.1303).\r\n\r\n* `columns.csv`: Description of data extract columns\r\n* `database...
The muscid genus Thricops Rondani comprises forty-four species and two subspecies restricted to t... more The muscid genus Thricops Rondani comprises forty-four species and two subspecies restricted to the northern hemisphere. A species-level phylogenetic analysis of Thricops was conducted using forty-four morphological characters, 426 bp of the nuclear gene white and 523 bp spanning the 5 0 end of the cytochrome c oxidase subunit I (COI), the tRNA leucine gene (L2 region) and the 3 0 end of the cytochrome c oxidase subunit II (COII). Thirty-nine species and two subspecies of Thricops were included in the analysis. Two species of Azelia Robineau-Desvoidy and one species of Hydrotaea Robineau-Desvoidy were used as outgroups. Morphological characters were coded for all included species, the mitochondrial gene fragment (COI þ II) was sequenced for a subset of seventeen species of Thricops and three outgroup species, and white for twelve of those seventeen Thricops species and two outgroup species. Six separate maximum parsimony analyses were performed on three taxon sets of different sizes (n ¼ 14, n ¼ 20, n ¼ 44). Results from the partition homogeneity test indicated no significant incongruence between data partitions, and four combined maximum parsimony analyses were conducted (DNA þ morphology for n ¼ 14; COI þ II þ morphology for n ¼ 20; DNA þ morphology for n ¼ 20; DNA þ morphology for n ¼ 44). The relative contribution of each data partition to individual nodes was assessed using partitioned Bremer support. Strict consensus trees resulting from the unweighted analyses of each dataset are presented. Combination of datasets increased resolution for the small taxon set (n ¼ 14), but not for the larger ones (n ¼ 20, n ¼ 44), most probably due to increasing amounts of missing data in the larger taxon sets. Results from both individual and combined analyses of the smaller taxon sets (n ¼ 14, n ¼ 20) provided support for the monophyly of Thricops and a complete division of the genus into two monophyletic subgroups. The strict consensus cladograms resulting from the analysis of the morphological data alone and the combined data for the large taxa set (n ¼ 44) both supported the monophyly of the genus, but placed the species Thricops foveolatus (Zetterstedt) and Thricops bukowskii (Ringdahl) at the base of the ingroup, in a polytomy with a relatively well-resolved branch comprising all remaining species of the genus. The basal position of these two species, included in the morphological taxon set but absent in the others, illustrates the potential pitfalls of taxon sampling and missing data in phylogenetic analyses. The synonymy of Alloeostylus with Thricops as proposed by previous authors was supported by our results. Relative contributions of different data partitions is discussed, with the mitochondrial sequence generally providing finer resolution and better branch support than white.
The Holarctic genus Cetema Hendel is revised, with special reference to the Nearctic fauna. There... more The Holarctic genus Cetema Hendel is revised, with special reference to the Nearctic fauna. There are four Nearctic species: C. elongata Meigen; C. nigripalpis sp. n., C. procera Loew, and C. subvittata Loew. This is the first record of the Palaearctic species C. elongata in the Nearctic region. All Nearctic species are described and illustrated. The Palaearctic species C. paramyopina Collin is synonymized with C. neglecta Tonnoir and a key to all described species of Cetema is provided. A phylogenetic analysis supports the monophyly of the genus, as well as the monophyly of the subgenera Archecetema Nartshuk and Cetema. The Nearctic species do not form a monophyletic group. Zoogeographic analysis suggests that the genus originated in the eastern Palaearctic and subsequently colonized North America via a Beringian connection, probably in the early to mid-Tertiary. Following speciation in the eastern Nearctic, the more derived lineages of Cetema recolonized the western Palaearctic, p...
Although several studies have examined the influence of landscape structure and agricultural inte... more Although several studies have examined the influence of landscape structure and agricultural intensification on species abundance and diversity, few have addressed how these impact populations across multiple trophic levels. We investigated the effects of landscape structure on the tri-trophic interactions between a bird host (the Tree Swallow Tachycineta bicolor (Vieillot)), its blowfly ectoparasites (Protocalliphora Hough), and their parasitoid wasps (Nasonia Ashmead) across 13 spatial scales, along a gradient of agricultural intensification covering 10,200 km 2 in southern Québec, Canada. We showed that the three taxa responded to landscape structure at distinctive spatial scales that are relative to their size rather than their trophic rank. This response, however, differed according to habitat type. The three organisms responded to the amount of intensive cultures (maize, soybean and other cereals) at smaller spatial scales than to the amount of extensive cultures (hayfields and pastures). Although the number of Tree Swallow fledglings, the number of Protocalliphora sialia Shannon & Dobroscky pupae and the number of P. sialia pupae parasitized by Nasonia sp. per nest were negatively affected by agricultural intensification, our data do not support the prediction that organisms at the higher trophic levels are more susceptible to habitat degradation. Here, ectoparasites at the second trophic level were disproportionally affected by agricultural intensification; the abundance of P. sialia decreased by 80% along the gradient of agricultural intensification compared to a 20% and 35% reduction in the number of Tree Swallow fledglings and in the level of parasitism by Nasonia sp., respectively. Our work highlights the importance of designing protocols that take spatial aspects of trophic interactions into account when studying the impact of habitat loss and fragmentation on populations and communities, as these interactions dictate local biodiversity and community function. Furthermore, our results highlight the importance of considering multiple landscape parameters when identifying the functional spatial scales of an organism, as a failure to do so could lead to an underestimation of the area it uses.
Annals of the Entomological Society of America, 2012
We described the community composition of the ectoparasitic flies Protocalliphora Hough (Diptera:... more We described the community composition of the ectoparasitic flies Protocalliphora Hough (Diptera: Calliphoridae) and their Nasonia (Ashmead) (Hymenoptera: Pteromalidae) parasitoids collected from tree swallow, Tachycineta bicolor (Vieillot), nests in southern Québec, Canada, in 2008 and 2009. The prevalence of nest infestation by Protocalliphora was 70.8% in 2008 and 34.6% in 2009. The average parasitic burden of Protocalliphora spp. was estimated at 5.53 (±5.61 SD) pupae per nestling for 2008 and 4.66 (±9.31 SD) pupae per nestling for 2009. The percentage of nests containing Protocalliphora pupae parasitized by Nasonia spp. was of 85.3% in 2008 and 67.2% in 2009. Three species of Protocalliphora were collected—Protocalliphora sialia Shannon & Dobroscky, Protocalliphora bennetti Whitworth, and Protocalliphora metallica (Townsend)—and two species of Nasonia, Nasonia vitripennis (Walker) and Nasonia giraulti Darling. This is the first record of P. bennetti and N. giraulti in the provi...
The world fauna of the genus Piezura Rondani is revised in order to resolve a series of long stan... more The world fauna of the genus Piezura Rondani is revised in order to resolve a series of long standing taxonomic errors. All species are redescribed, and species concepts and distribution ranges of most species have been modified. The genitalia of all species are illustrated and keys to each sex are provided. The female of P. nearctica Chillcott is described for the first time. Piezura pardalina shanxiensis Wang et al, 1992 is treated as an unavailable name, and P. pardalina shanxiensis Xue et al, 1999 is accepted as the valid name for this taxon.
Neorthacheta dissimilis Malloch (Diptera: Scathophagidae) is a poorly known scathophagid fly that... more Neorthacheta dissimilis Malloch (Diptera: Scathophagidae) is a poorly known scathophagid fly that feeds and develops on iris (Iridaceae). A survey of its occurrence was performed at the Montréal Botanical Garden (Montréal, Québec, Canada) in 2018, 2019, and 2020. Iris species and cultivars from two subgenera, Iris and Limniris, were evaluated for larval infestation. When pooled for subgenera and years, data from 18 Iris classes revealed high levels of infestation per flower stalk, ranging from 34% to 100%. When analysed per bud or flower, levels of infestation remained high, ranging from 19% to 100%, but generally was lower than for flower stalks as the unit of replication. The mean number of N. dissimilis larvae per infested flower or bud was higher for the subgenus Limniris (1.13) than for the subgenus Iris (1.03), with a maximum of four N. dissimilis larvae per flower being observed. These figures are worrying for horticulturalists because the insect is prevalent and causes eithe...
Soil pests of cruciferous crops in Mexico have been gaining importance in recent years; such is t... more Soil pests of cruciferous crops in Mexico have been gaining importance in recent years; such is the case of Delia spp. (Robineau-Desvoidy) (Diptera, Anthomyiidae), of which, to date, there are no studies on the correct identification of associated species, as well as the range of hosts. In an integrated pest management program, it is essential to know this information to design and implement adequate phytosanitary measures. Plants infested by Delia spp. were collected in the states of Guanajuato, Puebla, and Mexico from June to November 2017 and March to December 2018 in commercial plantations of cruciferous crops (Brassica oleracea L. var. italica, botrytis and capitata), B. napus L., and Raphanus sativus L.) as well as some cruciferous weeds (R. raphanistrum L., Sisymbrium irio L., B. campestris L., Capsella bursa-pastoris L., and Lepidium virginicum L.) in the edges of these crops. The two species found in this study, Delia planipalpis (Stein) and Delia platura (Meigen), identifi...
Background: Various methods have been proposed to assign unknown specimens to known species using... more Background: Various methods have been proposed to assign unknown specimens to known species using their DNA barcodes, while others have focused on using genetic divergence thresholds to estimate "species" diversity for a taxon, without a well-developed taxonomy and/or an extensive reference library of DNA barcodes. The major goals of the present work were to: a) conduct the largest species-level barcoding study of the Muscidae to date and characterize the range of genetic divergence values in the northern Nearctic fauna; b) evaluate the correspondence between morphospecies and barcode groupings defined using both clustering-based and threshold-based approaches; and c) use the reference library produced to address taxonomic issues. Results: Our data set included 1114 individuals and their COI sequences (951 from Churchill, Manitoba), representing 160 morphologically-determined species from 25 genera, covering 89% of the known fauna of Churchill and 23% of the Nearctic fauna. Following an iterative process through which all specimens belonging to taxa with anomalous divergence values and/or monophyly issues were reexamined , identity was modified for 9 taxa, including the reinstatement of Phaonia luteva (Walker) stat. nov. as a species distinct from Phaonia errans (Meigen). In the post-reassessment data set, no distinct gap was found between maximum pairwise intraspecific distances (range 0.00-3.01%) and minimum interspecific distances (range: 0.77-11.33%). Nevertheless, using a clustering-based approach, all individuals within 98% of species grouped with their conspecifics with high (>95%) bootstrap support; in contrast, a maximum species discrimination rate of 90% was obtained at the optimal threshold of 1.2%. DNA barcoding enabled the determination of females from 5 ambiguous species pairs and confirmed that 16 morphospecies were genetically distinct from named taxa. There were morphological differences among all distinct genetic clusters; thus, no cases of cryptic species were detected. Conclusions: Our findings reveal the great utility of building a well-populated, species-level reference barcode database against which to compare unknowns. When such a library is unavailable, it is still possible to obtain a fairly accurate (within~10%) rapid assessment of species richness based upon a barcode divergence threshold alone, but this approach is most accurate when the threshold is tuned to a particular taxon.
Many control methods target agricultural pests’ reproductive traits and so, knowledge of these tr... more Many control methods target agricultural pests’ reproductive traits and so, knowledge of these traits is crucial. The seedcorn maggot, Delia platura (Diptera: Anthomyiidae), is reported as a cosmopolitan polyphagous pest species which can be found in high numbers in numerous crops. Two morphologically identical genetic lines of D. platura (H- and N- lines) with distinct distribution ranges were recently discovered. While many biological traits have been described for D. platura, no study to date has been conducted on the life history strategies and reproductive behaviors of its two lines. Using laboratory-reared colonies originating from the Montérégie region in Québec, this project investigates the effect of group composition (sex-ratio and density) on the mating success and pre-oviposition period of the two D. platura lines. We found a substantial increase in mating success with increasing proportion of males within mating groups for both lines while group density had negligeable ...
SUMMARYWidespread access to the internet is offering new possibilities for data collection in sur... more SUMMARYWidespread access to the internet is offering new possibilities for data collection in surveillance. We explore, in this study, the possibility of using an electronic tool to monitor occurrence of the tick vector of Lyme disease, Ixodes scapularis. The study aimed to compare the capacity for ticks to be identified in web-based submissions of digital images/photographs, to the traditional specimen-based identification method used by the provincial public health laboratory in Quebec, Canada. Forty-one veterinary clinics participated in the study by submitting digital images of ticks collected from pets via a website for image-based identification by an entomologist. The tick specimens were then sent to the provincial public health laboratory to be identified by the ‘gold standard’ method using a microscope. Of the images submitted online, 74·3% (284/382) were considered of high-enough quality to allow identification. The laboratory identified 382 tick specimens from seven diffe...
The large muscid genus Atherigona Rondani (Diptera) includes over 2 0 species, most of which are ... more The large muscid genus Atherigona Rondani (Diptera) includes over 2 0 species, most of which are found in the tropical and subtropical regions of the Old World (Pont and Magpayo 1995). The group is divided into two subgenera: Acritochaeta grimshaw, which contains mostly saprophagous taxa, and Atherigona Rondani, whose phytophagous larvae are shoot-flies that feed on a variety of wild and cultivated grasses (Poaceae) (Pont and Magpayo 1995). Only two species of Atherigona are currently found in North america. The cosmopolitan Atherigona orientalis Schiner (Diptera: Muscidae) has long been known from the southern United States (Malloch 1921; Huckett 19 6) and has not, so far, been recorded in Canada. Atherigona reversura Villeneuve (Diptera: Muscidae), a widespread species in the Oriental, australasian and Palaearctic regions (Pont and Magpayo 1995), is a much more recent introduction: it was documented from the United States less than a decade ago (Hudson 2010) and is recorded here f...
Annals of the Entomological Society of America, 2009
The adult of a new genus and new species of Muscidae, Callainireinwardtia woodi sp. nov, gen. nov... more The adult of a new genus and new species of Muscidae, Callainireinwardtia woodi sp. nov, gen. nov., is described from Costa Rica. This new genus is placed in the tribe Reinwardtiini and can be distinguished from other members of the group as well as other New World Muscidae by the presence of a striking blue to blue-green metallic color combined with a bare anepimeron, setulose metepisternum, a plumose arista, and wings without clouds or spots. Conflicting data on the phylogenetic position of the reinwardtiine genera is summarized and potential avenues for future research are suggested.
FIGURE 5. Piezura pardalina ssp. shanxiensis Xue, Wang & Wu. A. Male genitalia external structure... more FIGURE 5. Piezura pardalina ssp. shanxiensis Xue, Wang & Wu. A. Male genitalia external structures, posterior. B. Male sternite 5, ventral. (adapted from Xue & Wang, 1999).
FIGURE 2. Piezura nearctica Chillcott. A. Male genitalia external structures, posterior. B. Femal... more FIGURE 2. Piezura nearctica Chillcott. A. Male genitalia external structures, posterior. B. Female spermatheca. C. Female genitalia, ventral. D. Male sternite 5, ventral.
A dataset of 3,250,404 measurements, collated from 26,114 sampling locations in 94 countries and ... more A dataset of 3,250,404 measurements, collated from 26,114 sampling locations in 94 countries and representing 47,044 species. The data were collated from 480 existing spatial comparisons of local-scale biodiversity exposed to different intensities and types of anthropogenic pressures, from terrestrial sites around the world. The database was assembled as part of the PREDICTS project - Projecting Responses of Ecological Diversity In Changing Terrestrial Systems; [www.predicts.org.uk](http://www.predicts.org.uk).\r\n\r\nThe taxonomic identifications provided in the original data sets are those determined at the time of the original research, and so will not reflect subsequent taxonomic changes.\r\n\r\nThis dataset is described in [10.1002/ece3.2579](http://dx.doi.org/10.1002/ece3.2579). A description of the way that this dataset was assembled is given in [10.1002/ece3.1303](http://dx.doi.org/10.1002/ece3.1303).\r\n\r\n* `columns.csv`: Description of data extract columns\r\n* `database...
The muscid genus Thricops Rondani comprises forty-four species and two subspecies restricted to t... more The muscid genus Thricops Rondani comprises forty-four species and two subspecies restricted to the northern hemisphere. A species-level phylogenetic analysis of Thricops was conducted using forty-four morphological characters, 426 bp of the nuclear gene white and 523 bp spanning the 5 0 end of the cytochrome c oxidase subunit I (COI), the tRNA leucine gene (L2 region) and the 3 0 end of the cytochrome c oxidase subunit II (COII). Thirty-nine species and two subspecies of Thricops were included in the analysis. Two species of Azelia Robineau-Desvoidy and one species of Hydrotaea Robineau-Desvoidy were used as outgroups. Morphological characters were coded for all included species, the mitochondrial gene fragment (COI þ II) was sequenced for a subset of seventeen species of Thricops and three outgroup species, and white for twelve of those seventeen Thricops species and two outgroup species. Six separate maximum parsimony analyses were performed on three taxon sets of different sizes (n ¼ 14, n ¼ 20, n ¼ 44). Results from the partition homogeneity test indicated no significant incongruence between data partitions, and four combined maximum parsimony analyses were conducted (DNA þ morphology for n ¼ 14; COI þ II þ morphology for n ¼ 20; DNA þ morphology for n ¼ 20; DNA þ morphology for n ¼ 44). The relative contribution of each data partition to individual nodes was assessed using partitioned Bremer support. Strict consensus trees resulting from the unweighted analyses of each dataset are presented. Combination of datasets increased resolution for the small taxon set (n ¼ 14), but not for the larger ones (n ¼ 20, n ¼ 44), most probably due to increasing amounts of missing data in the larger taxon sets. Results from both individual and combined analyses of the smaller taxon sets (n ¼ 14, n ¼ 20) provided support for the monophyly of Thricops and a complete division of the genus into two monophyletic subgroups. The strict consensus cladograms resulting from the analysis of the morphological data alone and the combined data for the large taxa set (n ¼ 44) both supported the monophyly of the genus, but placed the species Thricops foveolatus (Zetterstedt) and Thricops bukowskii (Ringdahl) at the base of the ingroup, in a polytomy with a relatively well-resolved branch comprising all remaining species of the genus. The basal position of these two species, included in the morphological taxon set but absent in the others, illustrates the potential pitfalls of taxon sampling and missing data in phylogenetic analyses. The synonymy of Alloeostylus with Thricops as proposed by previous authors was supported by our results. Relative contributions of different data partitions is discussed, with the mitochondrial sequence generally providing finer resolution and better branch support than white.
The Holarctic genus Cetema Hendel is revised, with special reference to the Nearctic fauna. There... more The Holarctic genus Cetema Hendel is revised, with special reference to the Nearctic fauna. There are four Nearctic species: C. elongata Meigen; C. nigripalpis sp. n., C. procera Loew, and C. subvittata Loew. This is the first record of the Palaearctic species C. elongata in the Nearctic region. All Nearctic species are described and illustrated. The Palaearctic species C. paramyopina Collin is synonymized with C. neglecta Tonnoir and a key to all described species of Cetema is provided. A phylogenetic analysis supports the monophyly of the genus, as well as the monophyly of the subgenera Archecetema Nartshuk and Cetema. The Nearctic species do not form a monophyletic group. Zoogeographic analysis suggests that the genus originated in the eastern Palaearctic and subsequently colonized North America via a Beringian connection, probably in the early to mid-Tertiary. Following speciation in the eastern Nearctic, the more derived lineages of Cetema recolonized the western Palaearctic, p...
Although several studies have examined the influence of landscape structure and agricultural inte... more Although several studies have examined the influence of landscape structure and agricultural intensification on species abundance and diversity, few have addressed how these impact populations across multiple trophic levels. We investigated the effects of landscape structure on the tri-trophic interactions between a bird host (the Tree Swallow Tachycineta bicolor (Vieillot)), its blowfly ectoparasites (Protocalliphora Hough), and their parasitoid wasps (Nasonia Ashmead) across 13 spatial scales, along a gradient of agricultural intensification covering 10,200 km 2 in southern Québec, Canada. We showed that the three taxa responded to landscape structure at distinctive spatial scales that are relative to their size rather than their trophic rank. This response, however, differed according to habitat type. The three organisms responded to the amount of intensive cultures (maize, soybean and other cereals) at smaller spatial scales than to the amount of extensive cultures (hayfields and pastures). Although the number of Tree Swallow fledglings, the number of Protocalliphora sialia Shannon & Dobroscky pupae and the number of P. sialia pupae parasitized by Nasonia sp. per nest were negatively affected by agricultural intensification, our data do not support the prediction that organisms at the higher trophic levels are more susceptible to habitat degradation. Here, ectoparasites at the second trophic level were disproportionally affected by agricultural intensification; the abundance of P. sialia decreased by 80% along the gradient of agricultural intensification compared to a 20% and 35% reduction in the number of Tree Swallow fledglings and in the level of parasitism by Nasonia sp., respectively. Our work highlights the importance of designing protocols that take spatial aspects of trophic interactions into account when studying the impact of habitat loss and fragmentation on populations and communities, as these interactions dictate local biodiversity and community function. Furthermore, our results highlight the importance of considering multiple landscape parameters when identifying the functional spatial scales of an organism, as a failure to do so could lead to an underestimation of the area it uses.
Annals of the Entomological Society of America, 2012
We described the community composition of the ectoparasitic flies Protocalliphora Hough (Diptera:... more We described the community composition of the ectoparasitic flies Protocalliphora Hough (Diptera: Calliphoridae) and their Nasonia (Ashmead) (Hymenoptera: Pteromalidae) parasitoids collected from tree swallow, Tachycineta bicolor (Vieillot), nests in southern Québec, Canada, in 2008 and 2009. The prevalence of nest infestation by Protocalliphora was 70.8% in 2008 and 34.6% in 2009. The average parasitic burden of Protocalliphora spp. was estimated at 5.53 (±5.61 SD) pupae per nestling for 2008 and 4.66 (±9.31 SD) pupae per nestling for 2009. The percentage of nests containing Protocalliphora pupae parasitized by Nasonia spp. was of 85.3% in 2008 and 67.2% in 2009. Three species of Protocalliphora were collected—Protocalliphora sialia Shannon & Dobroscky, Protocalliphora bennetti Whitworth, and Protocalliphora metallica (Townsend)—and two species of Nasonia, Nasonia vitripennis (Walker) and Nasonia giraulti Darling. This is the first record of P. bennetti and N. giraulti in the provi...
The world fauna of the genus Piezura Rondani is revised in order to resolve a series of long stan... more The world fauna of the genus Piezura Rondani is revised in order to resolve a series of long standing taxonomic errors. All species are redescribed, and species concepts and distribution ranges of most species have been modified. The genitalia of all species are illustrated and keys to each sex are provided. The female of P. nearctica Chillcott is described for the first time. Piezura pardalina shanxiensis Wang et al, 1992 is treated as an unavailable name, and P. pardalina shanxiensis Xue et al, 1999 is accepted as the valid name for this taxon.
Neorthacheta dissimilis Malloch (Diptera: Scathophagidae) is a poorly known scathophagid fly that... more Neorthacheta dissimilis Malloch (Diptera: Scathophagidae) is a poorly known scathophagid fly that feeds and develops on iris (Iridaceae). A survey of its occurrence was performed at the Montréal Botanical Garden (Montréal, Québec, Canada) in 2018, 2019, and 2020. Iris species and cultivars from two subgenera, Iris and Limniris, were evaluated for larval infestation. When pooled for subgenera and years, data from 18 Iris classes revealed high levels of infestation per flower stalk, ranging from 34% to 100%. When analysed per bud or flower, levels of infestation remained high, ranging from 19% to 100%, but generally was lower than for flower stalks as the unit of replication. The mean number of N. dissimilis larvae per infested flower or bud was higher for the subgenus Limniris (1.13) than for the subgenus Iris (1.03), with a maximum of four N. dissimilis larvae per flower being observed. These figures are worrying for horticulturalists because the insect is prevalent and causes eithe...
Soil pests of cruciferous crops in Mexico have been gaining importance in recent years; such is t... more Soil pests of cruciferous crops in Mexico have been gaining importance in recent years; such is the case of Delia spp. (Robineau-Desvoidy) (Diptera, Anthomyiidae), of which, to date, there are no studies on the correct identification of associated species, as well as the range of hosts. In an integrated pest management program, it is essential to know this information to design and implement adequate phytosanitary measures. Plants infested by Delia spp. were collected in the states of Guanajuato, Puebla, and Mexico from June to November 2017 and March to December 2018 in commercial plantations of cruciferous crops (Brassica oleracea L. var. italica, botrytis and capitata), B. napus L., and Raphanus sativus L.) as well as some cruciferous weeds (R. raphanistrum L., Sisymbrium irio L., B. campestris L., Capsella bursa-pastoris L., and Lepidium virginicum L.) in the edges of these crops. The two species found in this study, Delia planipalpis (Stein) and Delia platura (Meigen), identifi...
Uploads
Papers by Jade Savage