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Stephen D. Gaimari - One of the best experts on this subject based on the ideXlab platform.
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Two new genera of Nearctic Chamaemyiidae (Diptera: Lauxanioidea) associated with Cinara aphids (Hemiptera: Aphididae) on Pinus
Zootaxa, 2020Co-Authors: Stephen D. GaimariAbstract:Two new genera of Chamaemyiidae (Diptera: Lauxanioidea) are described and illustrated, including: Chamaethrix gen. nov. (type species Chamaethrix necopina sp. nov.), possibly a predator of Cinara ponderosae (Williams) on Pinus ponderosa in the southwestern United States; and Vitaleucopis gen. nov. (type species Vitaleucopis nidolkah sp. nov.; other included species Vitaleucopis astonea (McAlpine), comb. nov., and Vitaleucopis scopulus sp. nov.), predators of Cinara aphids and possibly adelgids on Pinaceae in western North America. Immature stages are discussed or described and illustrated for some taxa, including the eggs of Chamaethrix necopina and Vitaleucopis nidolkah; and the third instars and puparia of Vitaleucopis nidolkah.
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leucopis glyphinivora tanasijtshuk diptera Chamaemyiidae a new aphidophagous biocontrol agent development survival and comparison with aphidoletes aphidimyza rondani diptera cecidomyiidae
Bulletin of Entomological Research, 2019Co-Authors: Stephane Barriault, António O. Soares, Stephen D. Gaimari, Eric LucasAbstract:The silver fly Leucopis glyphinivora Tanasijtshuk (Diptera: Chamaemyiidae) is an aphidophagous predator during its larval stage. Our study describes the life cycle of L. glyphinivora and evaluates its potential as a biocontrol agent. The development, survival and longevity of L. glyphinivora were observed and compared with those of the aphid gall midge Aphidoletes aphidimyza Rondani (Diptera: Cecidomyiidae). Tests were conducted under laboratory conditions in Petri dishes with the green peach aphid Myzus persicae Sulzer (Hemiptera: Aphididae) on potato leaves. Leucopis glyphinivora has a 42% longer life cycle than A. aphidimyza . Larval development was 27% longer in L. glyphinivora than in A. aphidimyza . Egg hatch rate and pupal emergence rate were similar in both species, but larval survival was 20% lower for L. glyphinivora than for A. aphidimyza . Sex ratio was approximately 50% in both species. A longer development time for L. glyphinivora in the larval stage could be an advantage for biocontrol by providing more time to exert predation pressure against aphids. However, this may be offset by the lower survival rate found in the silver fly larvae.
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Cryptic east-west divergence and molecular diagnostics for two species of silver flies (Diptera: Chamaemyiidae: Leucopis ) from North America being evaluated for biological control of hemlock woolly adelgid
Biological Control, 2018Co-Authors: Nathan P. Havill, Stephen D. Gaimari, Adalgisa CacconeAbstract:Abstract Exploring genetic diversity within species of biological control agents can expose previously overlooked beneficial genotypes. This may be the case for two species of silver flies, Leucopis argenticollis and L. piniperda, predators of the hemlock woolly adelgid (Adelges tsugae) in the Pacific Northwest of North America. The same Leucopis species occur in eastern North America, where they feed on other adelgid species, but not on hemlock woolly adelgid, which became a pest in the region after its introduction from Japan earlier this century. We collected DNA sequence data from one mitochondrial and two nuclear genes for 606 Leucopis individuals to examine variation correlated with geographic origin and prey association. Specimens of L. argenticollis and L. piniperda collected from adelgids on hemlock and spruce in the West are phylogenetically divergent from conspecifics collected from adelgids on pine and spruce in the East. These results suggest that within each species, there are distinct lineages that specialize on different adelgid prey on different hosts in western versus eastern North America. The western lineages appear to be strong candidates for enhancing biological control of Japanese hemlock woolly adelgid in the eastern United States, given their widespread occurrence on western hemlock woolly adelgid in the Pacific Northwest, and the absence of these genotypes in the East. We also developed a PCR-RFLP assay based on the mitochondrial COI gene as an inexpensive and reliable way to distinguish the four genetic groups to document establishment and impact following release.
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Predators of Marchalina hellenica (Hemiptera: Marchalinidae) on pine forests in Turkey
Phytoparasitica, 2013Co-Authors: Selma Ulgenturk, H. Civelek, Nesrin Uygun, Meral Fent, Stephen D. Gaimari, Ferenc Szentkiralyi, Belma AyhanAbstract:The honeydew of Marchalina hellenica is collected by honeybees for pine honey production, which is of great economic importance in Turkey. During 2009–2011 we investigated the predators of M. hellenica, which is distributed mainly in the areas with a Mediterranean climate – in the Aegean, Marmara and Mediterranean regions of Turkey. The findings showed that M. hellenica has many predators in the studied areas and that these play an important role in the forest ecosystem. These predators are: Anystis baccarum (L.) (Acarina: Anystidae); Allothrombium triticium Zhang and Allothrombium pulvinum Ewing (Acarina: Trombidiidae); Neoleucopis kartliana (Tanasijtshuk) (Diptera: Chamaemyiidae); Myrrha octodecimguttata (L.), Rodolia cardinalis Mulstant, Scymnus subvillosus (Goeze) (Coleoptera: Coccinellidae), Dichochrysa genei (Rambur), Dichochrysa prasina (Burmeister) and Chrysoperla lucasina (Lacroix) (Neuroptera: Chrysopidae); Wesmaelius subnebulosus (Stephens) (Neuroptera: Hemerobiidae), Cardiastethus nazarenus Reuter and Elatophilus pachycnemis Horváth (Hemiptera: Anthocoridae). The most efficient and common predator was N. kartliana , here recorded for the first time from Turkey.
Kimberly F Wallin - One of the best experts on this subject based on the ideXlab platform.
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Coexistence of three specialist predators of the hemlock woolly adelgid in the Pacific Northwest USA.
Bulletin of entomological research, 2019Co-Authors: Alexander Rose, Nathan P. Havill, Darrell W Ross, Kyle Motley, Kimberly F WallinAbstract:The hemlock woolly adelgid (Hemiptera: Adelgidae: Adelges tsugae Annand) is an invasive insect, introduced from Japan to eastern North America, where it causes decline and death of hemlock trees. There is a closely related lineage of A. tsugae native to western North America. To inform classical biological control of A. tsugae in the eastern USA, the density and phenology of three native western adelgid specialist predators, Leucopis argenticollis (Zetterstedt), Le. piniperda (Malloch) (Diptera: Chamaemyiidae), and Laricobius nigrinus Fender (Coleoptera: Derodontidae), were quantified in the Pacific Northwest. Infested branches were collected from western hemlock (Pinaceae: Tsuga heterophylla (Raf.) Sarg.) at four sites around the Puget Sound, Washington and three sites in Oregon. Immature Leucopis were identified to species using DNA barcodes. Leucopis argenticollis was roughly twice as abundant as Le. piniperda. Laricobius nigrinus larvae were more abundant than the two species of Leucopis during the egg stage of the first adelgid generation, but Leucopis were present as feeding larvae during the second adelgid generation when La. nigrinus was aestivating in the soil, resulting in Leucopis being more abundant than La. nigrinus across the entire sampling period. Adelges tsugae and La. nigrinus densities were not correlated, while A. tsugae and Leucopis spp. densities were positively correlated. Leucopis spp. and La. nigrinus densities were negatively correlated. These results support the complementary use of La. nigrinus and the two Leucopis species for biological control of A. tsugae in the eastern USA, and point to the need for further investigation of spatial and temporal niche partitioning among the three predator species.
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Seasonal phenology and abundance of Leucopis argenticollis, Leucopis piniperda (Diptera: Chamaemyiidae), Laricobius nigrinus (Coleoptera: Deridontidae) and Adelges tsugae (Hemiptera: Adelgidae) in the Pacific Northwest USA
Bulletin of entomological research, 2016Co-Authors: G R Kohler, Kimberly F Wallin, Darrell W RossAbstract:Adelges tsugae infested western hemlock trees were sampled periodically for 1 year at two locations in Oregon and Washington to compare the phenology and abundance of three associated predators (Leucopis argenticollis, Leucopis piniperda, and Laricobius nigrinus) and their host. On each sample date, two 3-10 cm long terminal twigs were collected from each tree and brought to the laboratory to count all life stages of A. tsugae and the three predators. Peak larval abundance of Leucopis spp. and La. nigrinus coincided with the presence of A. tsugae adults and eggs. Leucopis spp. larvae were present for a much longer period of time than were La. nigrinus larvae. Furthermore, Leucopis spp. larvae were present during both the progrediens and sistens egg stages, while La. nigrinus larvae were only present during the progrediens egg stage. Overall, we collected 2.3-3.5 times more Leucopis spp. of all life stages than La. nigrinus. These results support the continued study of Leucopis spp. from the Pacific Northwest as biological control agents for A. tsugae in the Eastern USA.
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prey suitability and phenology of leucopis spp diptera Chamaemyiidae associated with hemlock woolly adelgid hemiptera adelgidae in the pacific northwest
Environmental Entomology, 2011Co-Authors: Sarah M Grubin, Kimberly F Wallin, Darrell W RossAbstract:Leucopis spp. (Diptera: Chamaemyiidae) from the Pacific Northwest previously were identified as potential biological control agents for the hemlock woolly adelgid, Adelges tsugae Annand (Hemiptera: Adelgidae), in the eastern United States. We collected Leucopis spp. larvae from A. tsugae infested western hemlocks in Oregon and Washington and reared them on an unidentified Pineus spp., Pineus strobi (Hartig), Adelges cooleyi (Gillette), Adelges piceae (Ratzeburg), and A. tsugae in three no-choice tests. Leucopis spp. survival on A. tsugae was significantly higher than on A. piceae during the 2010 progrediens generation test and significantly higher than on P. strobi and A. cooleyi during the 2010 sistens generation test. However, across all three tests, some larvae completed development to adult on all four of the alternative adelgid species. Larvae that survived to the adult stage were identified as Leucopis argenticollis Zetterstedt and Leucopis piniperda Malloch. These results suggest that populations of L. argenticollis and L. piniperda in the Pacific Northwest may not be specific to A. tsugae. We also studied the phenology of Leucopis spp. on fourteen A. tsugae infested western hemlock trees in Oregon and Washington over a period of 14 mo. Leucopis spp. larvae were collected year-round, but highest densities coincided with the presence of progrediens and sistens eggs and adults of A. tsugae. There was a positive correlation between Leucopis spp. and A. tsugae abundance.
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predators associated with the hemlock woolly adelgid hemiptera adelgidae in the pacific northwest
Environmental Entomology, 2008Co-Authors: G R Kohler, V L Stiefel, Kimberly F Wallin, Darrell W RossAbstract:The hemlock woolly adelgid, Adelges tsugae Annand (Hemiptera: Adelgidae), is causing widespread mortality of eastern hemlock, Tsuga canadensis L. Carriere, in the eastern United States. In western North America, feeding by A. tsugae results in negligible damage to western hemlock, Tsuga heterophylla (Raf.) Sargent. Host tolerance and presence of endemic predators may be contributing to the relatively low levels of injury to T. heterophylla caused by A. tsugae. Field surveys of the predator community associated with A. tsugae infestations on 116 T. heterophylla at 16 sites in Oregon and Washington were conducted every 4-6 wk from March 2005 through November 2006. Fourteen uninfested T. heterophylla were also surveyed across 5 of the 16 sites. Each sample tree was assigned an A. tsugae population score ranging from 0 to 3. Predators collected from A. tsugae-infested T. heterophylla represent 55 species in 14 families, listed in order of abundance: Derodontidae, Chamaemyiidae, Hemerobiidae, Coccinellidae, Cantharidae, Reduviidae, Miridae, Syrphidae, Chrysopidae, Coniopterygidae, Staphylinidae, Anthocoridae, Nabidae, and Raphidiidae. Laricobius nigrinus Fender (Coleoptera: Derodontidae), Leucopis argenticollis Zetterstedt (Diptera: Chamaemyiidae), and Leucopis atrifacies (Aldrich) (Chamaemyiidae) were the most abundant predators; together comprising 59% of predator specimens recovered. Relationships among predators and A. tsugae were determined through community structure analysis. The abundances of Laricobius spp. larvae, L. nigrinus adults, Leucopis spp. larvae, and L. argenticollis adults were found to be positively correlated to A. tsugae population score. Predators were most abundant when the two generations of A. tsugae eggs were present. L. argenticollis and L. atrifacies were reared on A. tsugae in the laboratory, and host records show them to feed exclusively on Adelgidae.
Darrell W Ross - One of the best experts on this subject based on the ideXlab platform.
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Temporal Asynchrony of Adult Emergence Between Leucopis argenticollis and Leucopis piniperda (Diptera: Chamaemyiidae), Predators of the Hemlock Woolly Adelgid (Hemiptera: Adelgidae), with Implications for Biological Control.
Environmental entomology, 2020Co-Authors: Alex N. Neidermeier, Nathan P. Havill, Darrell W Ross, Kimberly WallinAbstract:Two species of silver fly, Leucopis argenticollis (Zetterstedt) and Leucopis piniperda (Malloch) (Diptera: Chamaemyiidae), from the Pacific Northwest region of North America have been identified as potential biological control agents of hemlock woolly adelgid (Hemiptera: Adelgidae: Adelges tsugae Annand) in eastern North America. The two predators are collectively synchronized with A. tsugae development. To determine whether adult emergence of the two species of silver fly are also synchronized with one another, we collected adult Leucopis which emerged from A. tsugae-infested western hemlock [Pinaceae: Tsuga heterophylla (Raf.) Sarg.] from four sites in the Pacific Northwest over a 29-d period. Specimens were collected twice daily in the laboratory and identified to species using DNA barcoding. The study found that more adult Leucopis were collected in the evening than the morning. Additionally, the daily emergences of adults over the 29-d sampling period exhibited sinusoidal-like fluctuations of peak abundance of each species, lending evidence to a pattern of temporal partitioning. This pattern could have logistical implications for their use as biological control agents in eastern North America, namely the need to release both species for maximum efficacy in decreasing A. tsugae populations.
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Coexistence of three specialist predators of the hemlock woolly adelgid in the Pacific Northwest USA.
Bulletin of entomological research, 2019Co-Authors: Alexander Rose, Nathan P. Havill, Darrell W Ross, Kyle Motley, Kimberly F WallinAbstract:The hemlock woolly adelgid (Hemiptera: Adelgidae: Adelges tsugae Annand) is an invasive insect, introduced from Japan to eastern North America, where it causes decline and death of hemlock trees. There is a closely related lineage of A. tsugae native to western North America. To inform classical biological control of A. tsugae in the eastern USA, the density and phenology of three native western adelgid specialist predators, Leucopis argenticollis (Zetterstedt), Le. piniperda (Malloch) (Diptera: Chamaemyiidae), and Laricobius nigrinus Fender (Coleoptera: Derodontidae), were quantified in the Pacific Northwest. Infested branches were collected from western hemlock (Pinaceae: Tsuga heterophylla (Raf.) Sarg.) at four sites around the Puget Sound, Washington and three sites in Oregon. Immature Leucopis were identified to species using DNA barcodes. Leucopis argenticollis was roughly twice as abundant as Le. piniperda. Laricobius nigrinus larvae were more abundant than the two species of Leucopis during the egg stage of the first adelgid generation, but Leucopis were present as feeding larvae during the second adelgid generation when La. nigrinus was aestivating in the soil, resulting in Leucopis being more abundant than La. nigrinus across the entire sampling period. Adelges tsugae and La. nigrinus densities were not correlated, while A. tsugae and Leucopis spp. densities were positively correlated. Leucopis spp. and La. nigrinus densities were negatively correlated. These results support the complementary use of La. nigrinus and the two Leucopis species for biological control of A. tsugae in the eastern USA, and point to the need for further investigation of spatial and temporal niche partitioning among the three predator species.
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Seasonal phenology and abundance of Leucopis argenticollis, Leucopis piniperda (Diptera: Chamaemyiidae), Laricobius nigrinus (Coleoptera: Deridontidae) and Adelges tsugae (Hemiptera: Adelgidae) in the Pacific Northwest USA
Bulletin of entomological research, 2016Co-Authors: G R Kohler, Kimberly F Wallin, Darrell W RossAbstract:Adelges tsugae infested western hemlock trees were sampled periodically for 1 year at two locations in Oregon and Washington to compare the phenology and abundance of three associated predators (Leucopis argenticollis, Leucopis piniperda, and Laricobius nigrinus) and their host. On each sample date, two 3-10 cm long terminal twigs were collected from each tree and brought to the laboratory to count all life stages of A. tsugae and the three predators. Peak larval abundance of Leucopis spp. and La. nigrinus coincided with the presence of A. tsugae adults and eggs. Leucopis spp. larvae were present for a much longer period of time than were La. nigrinus larvae. Furthermore, Leucopis spp. larvae were present during both the progrediens and sistens egg stages, while La. nigrinus larvae were only present during the progrediens egg stage. Overall, we collected 2.3-3.5 times more Leucopis spp. of all life stages than La. nigrinus. These results support the continued study of Leucopis spp. from the Pacific Northwest as biological control agents for A. tsugae in the Eastern USA.
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prey suitability and phenology of leucopis spp diptera Chamaemyiidae associated with hemlock woolly adelgid hemiptera adelgidae in the pacific northwest
Environmental Entomology, 2011Co-Authors: Sarah M Grubin, Kimberly F Wallin, Darrell W RossAbstract:Leucopis spp. (Diptera: Chamaemyiidae) from the Pacific Northwest previously were identified as potential biological control agents for the hemlock woolly adelgid, Adelges tsugae Annand (Hemiptera: Adelgidae), in the eastern United States. We collected Leucopis spp. larvae from A. tsugae infested western hemlocks in Oregon and Washington and reared them on an unidentified Pineus spp., Pineus strobi (Hartig), Adelges cooleyi (Gillette), Adelges piceae (Ratzeburg), and A. tsugae in three no-choice tests. Leucopis spp. survival on A. tsugae was significantly higher than on A. piceae during the 2010 progrediens generation test and significantly higher than on P. strobi and A. cooleyi during the 2010 sistens generation test. However, across all three tests, some larvae completed development to adult on all four of the alternative adelgid species. Larvae that survived to the adult stage were identified as Leucopis argenticollis Zetterstedt and Leucopis piniperda Malloch. These results suggest that populations of L. argenticollis and L. piniperda in the Pacific Northwest may not be specific to A. tsugae. We also studied the phenology of Leucopis spp. on fourteen A. tsugae infested western hemlock trees in Oregon and Washington over a period of 14 mo. Leucopis spp. larvae were collected year-round, but highest densities coincided with the presence of progrediens and sistens eggs and adults of A. tsugae. There was a positive correlation between Leucopis spp. and A. tsugae abundance.
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predators associated with the hemlock woolly adelgid hemiptera adelgidae in the pacific northwest
Environmental Entomology, 2008Co-Authors: G R Kohler, V L Stiefel, Kimberly F Wallin, Darrell W RossAbstract:The hemlock woolly adelgid, Adelges tsugae Annand (Hemiptera: Adelgidae), is causing widespread mortality of eastern hemlock, Tsuga canadensis L. Carriere, in the eastern United States. In western North America, feeding by A. tsugae results in negligible damage to western hemlock, Tsuga heterophylla (Raf.) Sargent. Host tolerance and presence of endemic predators may be contributing to the relatively low levels of injury to T. heterophylla caused by A. tsugae. Field surveys of the predator community associated with A. tsugae infestations on 116 T. heterophylla at 16 sites in Oregon and Washington were conducted every 4-6 wk from March 2005 through November 2006. Fourteen uninfested T. heterophylla were also surveyed across 5 of the 16 sites. Each sample tree was assigned an A. tsugae population score ranging from 0 to 3. Predators collected from A. tsugae-infested T. heterophylla represent 55 species in 14 families, listed in order of abundance: Derodontidae, Chamaemyiidae, Hemerobiidae, Coccinellidae, Cantharidae, Reduviidae, Miridae, Syrphidae, Chrysopidae, Coniopterygidae, Staphylinidae, Anthocoridae, Nabidae, and Raphidiidae. Laricobius nigrinus Fender (Coleoptera: Derodontidae), Leucopis argenticollis Zetterstedt (Diptera: Chamaemyiidae), and Leucopis atrifacies (Aldrich) (Chamaemyiidae) were the most abundant predators; together comprising 59% of predator specimens recovered. Relationships among predators and A. tsugae were determined through community structure analysis. The abundances of Laricobius spp. larvae, L. nigrinus adults, Leucopis spp. larvae, and L. argenticollis adults were found to be positively correlated to A. tsugae population score. Predators were most abundant when the two generations of A. tsugae eggs were present. L. argenticollis and L. atrifacies were reared on A. tsugae in the laboratory, and host records show them to feed exclusively on Adelgidae.
Vitali N. Tanasijtshuk - One of the best experts on this subject based on the ideXlab platform.
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A new leucopine genus (Diptera: Chamaemyiidae) with species attacking Ceroplastes wax scales (Hemiptera: Coccidae) in South America.
Systematic Entomology, 2001Co-Authors: Stephen D. Gaimari, Vitali N. TanasijtshukAbstract:. A new genus, Echinoleucopis, is proposed within Chamaemyiidae (Diptera). This leucopine genus clearly differs from other Chamaemyiidae in the high lunule, reduction and fusion of spermathecae in females and rounded form of puparia. Within Echinoleucopis, five new species (bennetti, grioti, iota, macula and nigrolinea) are described, in addition to lectotype designation, redescription and recombination for the type species of the genus, Leucopina ceroplastophaga Blanchard. Phylogenetic relationships among the included taxa are hypothesized. All known species of the genus are from South America and are predators on eggs within an ovisac of wax scales in genus Ceroplastes Gray (Hemiptera: Coccidae).
Nathan P. Havill - One of the best experts on this subject based on the ideXlab platform.
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Temporal Asynchrony of Adult Emergence Between Leucopis argenticollis and Leucopis piniperda (Diptera: Chamaemyiidae), Predators of the Hemlock Woolly Adelgid (Hemiptera: Adelgidae), with Implications for Biological Control.
Environmental entomology, 2020Co-Authors: Alex N. Neidermeier, Nathan P. Havill, Darrell W Ross, Kimberly WallinAbstract:Two species of silver fly, Leucopis argenticollis (Zetterstedt) and Leucopis piniperda (Malloch) (Diptera: Chamaemyiidae), from the Pacific Northwest region of North America have been identified as potential biological control agents of hemlock woolly adelgid (Hemiptera: Adelgidae: Adelges tsugae Annand) in eastern North America. The two predators are collectively synchronized with A. tsugae development. To determine whether adult emergence of the two species of silver fly are also synchronized with one another, we collected adult Leucopis which emerged from A. tsugae-infested western hemlock [Pinaceae: Tsuga heterophylla (Raf.) Sarg.] from four sites in the Pacific Northwest over a 29-d period. Specimens were collected twice daily in the laboratory and identified to species using DNA barcoding. The study found that more adult Leucopis were collected in the evening than the morning. Additionally, the daily emergences of adults over the 29-d sampling period exhibited sinusoidal-like fluctuations of peak abundance of each species, lending evidence to a pattern of temporal partitioning. This pattern could have logistical implications for their use as biological control agents in eastern North America, namely the need to release both species for maximum efficacy in decreasing A. tsugae populations.
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Coexistence of three specialist predators of the hemlock woolly adelgid in the Pacific Northwest USA.
Bulletin of entomological research, 2019Co-Authors: Alexander Rose, Nathan P. Havill, Darrell W Ross, Kyle Motley, Kimberly F WallinAbstract:The hemlock woolly adelgid (Hemiptera: Adelgidae: Adelges tsugae Annand) is an invasive insect, introduced from Japan to eastern North America, where it causes decline and death of hemlock trees. There is a closely related lineage of A. tsugae native to western North America. To inform classical biological control of A. tsugae in the eastern USA, the density and phenology of three native western adelgid specialist predators, Leucopis argenticollis (Zetterstedt), Le. piniperda (Malloch) (Diptera: Chamaemyiidae), and Laricobius nigrinus Fender (Coleoptera: Derodontidae), were quantified in the Pacific Northwest. Infested branches were collected from western hemlock (Pinaceae: Tsuga heterophylla (Raf.) Sarg.) at four sites around the Puget Sound, Washington and three sites in Oregon. Immature Leucopis were identified to species using DNA barcodes. Leucopis argenticollis was roughly twice as abundant as Le. piniperda. Laricobius nigrinus larvae were more abundant than the two species of Leucopis during the egg stage of the first adelgid generation, but Leucopis were present as feeding larvae during the second adelgid generation when La. nigrinus was aestivating in the soil, resulting in Leucopis being more abundant than La. nigrinus across the entire sampling period. Adelges tsugae and La. nigrinus densities were not correlated, while A. tsugae and Leucopis spp. densities were positively correlated. Leucopis spp. and La. nigrinus densities were negatively correlated. These results support the complementary use of La. nigrinus and the two Leucopis species for biological control of A. tsugae in the eastern USA, and point to the need for further investigation of spatial and temporal niche partitioning among the three predator species.
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Predators associated with the pine bark adelgid (Hemiptera: Adelgidae), a native insect in Appalachian forests, United States of America, in its southern range
The Canadian Entomologist, 2018Co-Authors: Holly A. Wantuch, Nathan P. Havill, E. Richard Hoebeke, Thomas P. Kuhar, Scott M. SalomAbstract:The pine bark adelgid, Pineus strobi (Hartig) (Hemiptera: Adelgidae), is an herbivore native to eastern North America that specialises on eastern white pine, Pinus strobus Linnaeus (Pinaceae). Little is known about P. strobi , especially in its southern range in the Appalachian Mountains, United States of America, and the composition of its predator complex has not yet been documented in this region. The current study identifies arthropod predators associated with P. strobi in Appalachian forests of Virginia based on a two-year survey. Predators were identified using morphology and DNA barcoding. Predator species include: Laricobius rubidus LeConte (Coleoptera: Derodontidae), Leucopis piniperda Malloch (Diptera: Chamaemyiidae), and Leucopis argenticollis Zetterstedt (Diptera: Chamaemyiidae), that are known adelgid specialists. Also found were predators from the families Cecidomyiidae (Diptera), Coccinellidae (Coleoptera), Chrysopidae (Neuroptera), Hemerobiidae (Neuroptera), and Syrphidae (Diptera). The Cecidomyiidae were especially diverse, with 14 different species inferred from their DNA barcodes. Knowledge of this predator complex is particularly valuable for anticipation and detection of potential interactions between native predator species and those that are being considered for the introduction for biological control of invasive adelgid pests within the southern Appalachian ecosystem.
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Cryptic east-west divergence and molecular diagnostics for two species of silver flies (Diptera: Chamaemyiidae: Leucopis ) from North America being evaluated for biological control of hemlock woolly adelgid
Biological Control, 2018Co-Authors: Nathan P. Havill, Stephen D. Gaimari, Adalgisa CacconeAbstract:Abstract Exploring genetic diversity within species of biological control agents can expose previously overlooked beneficial genotypes. This may be the case for two species of silver flies, Leucopis argenticollis and L. piniperda, predators of the hemlock woolly adelgid (Adelges tsugae) in the Pacific Northwest of North America. The same Leucopis species occur in eastern North America, where they feed on other adelgid species, but not on hemlock woolly adelgid, which became a pest in the region after its introduction from Japan earlier this century. We collected DNA sequence data from one mitochondrial and two nuclear genes for 606 Leucopis individuals to examine variation correlated with geographic origin and prey association. Specimens of L. argenticollis and L. piniperda collected from adelgids on hemlock and spruce in the West are phylogenetically divergent from conspecifics collected from adelgids on pine and spruce in the East. These results suggest that within each species, there are distinct lineages that specialize on different adelgid prey on different hosts in western versus eastern North America. The western lineages appear to be strong candidates for enhancing biological control of Japanese hemlock woolly adelgid in the eastern United States, given their widespread occurrence on western hemlock woolly adelgid in the Pacific Northwest, and the absence of these genotypes in the East. We also developed a PCR-RFLP assay based on the mitochondrial COI gene as an inexpensive and reliable way to distinguish the four genetic groups to document establishment and impact following release.