Showing papers in "Canadian Entomologist in 2021"
TL;DR: Overall, maintaining host vigour and minimising stress-induced ethanol are keys for managing these insects, particularly X. crassiusculus and X. germanus.
Abstract: Exotic ambrosia beetles (Curculionidae: Scolytinae) in the tribe Xyleborini include destructive pests of trees growing in horticultural cropping systems. Three species are especially problematic: Xylosandrus compactus (Eichhoff), Xylosandrus crassiusculus (Motschulsky), and Xylosandrus germanus (Blandford). Due to similarities in their host tree interactions, this mini-review focuses on these three species with the goal of describing their host-selection behaviour, characterising associated semiochemicals, and assessing how these interactions relate to their management. All three of these Xylosandrus spp. attack a broad range of trees and shrubs. Physiologically stressed trees are preferentially attacked by X. crassiusculus and X. germanus, but the influence of stress on host selection by X. compactus is less clear. Ethanol is emitted from weakened trees in response to a variety of stressors, and it represents an important attractant for all three species. Other host-derived compounds tested are inconsistent or inactive. Verbenone inhibits attraction to ethanol, but the effect is inconsistent and does not prevent attacks. Integrating repellents and attractants into a push–pull management strategy has been ineffective for reducing attacks but could be optimised further. Overall, maintaining host vigour and minimising stress-induced ethanol are keys for managing these insects, particularly X. crassiusculus and X. germanus.
33 citations
TL;DR: An assessment of the state of knowledge and development of semiochemical methods for control of bark beetles in western North America and as a roadmap for future research and development in this field is intended.
Abstract: This paper is intended as an assessment of the state of knowledge and development of semiochemical methods for control of bark beetles (Coleoptera: Curculionidae) in western North America and as a roadmap for future research and development in this field. It is based on a keynote presentation given at the symposium Managing Bark and Ambrosia Beetles with Semiochemicals, held in 2018 in Vancouver, British Columbia, Canada, at the Joint Meeting of the Entomological Society of America, the Entomological Society of Canada, and the Entomological Society of British Columbia. We describe currently available active ingredients, formulations, and release devices. Furthermore, we describe the most urgently needed new products and techniques, and constraints to their further development. Finally, we speculate about opportunities afforded by new advances in microbial synthesis of semiochemicals, streamlining of regulatory processing, and aerial application using unmanned aerial vehicles.
16 citations
TL;DR: Some supporting, original experimental data are reported indicating that a verbenone device can inhibit the beetle’s response to sources of attractant in a radius of at least several metres, and that pheromone background can cause conflicting results in semiochemical field tests.
Abstract: The southern pine beetle, Dendroctonus frontalis Zimmermann (Coleoptera: Curculionidae: Scolytinae), is among the most destructive bark beetle pests of pines (Pinaceae) of the southeast and mid-Atlantic United States of America, Mexico, and Central America. Numerous volatile compounds can stimulate or reduce attraction of the beetle, but efforts to incorporate these into effective, practical technologies for pest management have yielded mixed results. Attractants have been incorporated into lures used in monitoring traps that are employed operationally to forecast outbreaks and detect emerging populations. The attraction inhibitor, verbenone, shows efficacy for suppressing southern pine beetle infestations but has not yet been adopted operationally. No effective semiochemical tree protectant has been developed for the beetle. We discuss complexities in the chemical ecology of the beetle that likely have impeded research and development of semiochemical management tools, and we describe basic science gaps that may hinder further progress if not addressed. We also report some supporting, original experimental data indicating (1) that a verbenone device can inhibit the beetle’s response to sources of attractant in a radius of at least several metres, (2) similar olfactory responses by the beetle to both enantiomers of verbenone, and (3) that pheromone background can cause conflicting results in semiochemical field tests.
10 citations
TL;DR: This work disclosed a suite of antennally and behaviourally active nonhost volatiles, which are detected in common across a range of coniferophagous bark beetles, and established the fact that dispersing bark and ambrosia beetles detect nonhost signals while in flight and avoid nonhost trees without necessarily landing on them.
Abstract: Although the use of nonhost plants intercropped among host crops has been a standard agricultural practice for reducing insect herbivory for millennia, the use of nonhost signals to deter forest pests is much more recent, having been developed over the past several decades. Early exploratory studies with synthetic nonhost volatile semiochemicals led to targeted electrophysiological and trapping experiments on a variety of bark and ambrosia beetles (Coleoptera: Curculionidae: Scolytinae) across three continents. This work disclosed a suite of antennally and behaviourally active nonhost volatiles, which are detected in common across a range of coniferophagous bark beetles. It also established the fact that dispersing bark and ambrosia beetles detect nonhost signals while in flight and avoid nonhost trees without necessarily landing on them. Later work showed that groups of synthetic nonhost volatiles, sometimes combined with insect-derived antiaggregants, are effective in protecting individual trees and forest stands. Further work in this system may lead to the development of a variety of new and useful tactics for use in various integrated pest management strategies.
10 citations
TL;DR: In this article, the distribution of syrphid species from a previously understudied and undeveloped part of northern Ontario that is a large part of the third largest wetland in the world is reported.
Abstract: Syrphids (Diptera: Syrphidae) are a diverse and widespread family of pollinating flies. Their diverse life history traits not only allow them to thrive in a wide range of habitats but also make them potential bioindicators of environmental change. Here, we report on their distributions from a previously understudied and undeveloped part of northern Ontario that is a large part of the third-largest wetland in the world. Samples were collected from across the region between 2009 and 2016, using numerous sampling methods. Of the 122 species identified from 1514 specimens, six are new provincial records to Ontario. Five species were collected over 800 km from their previously known ranges, some of which were west of the Rocky Mountains. Of all the trapping methods employed in the study, Malaise traps were found to be the most effective at catching syrphid species. This work updates known range and provincial records for more than 100 species of syrphids, bringing into clearer focus their distribution throughout this region.
8 citations
TL;DR: Diamondback moth, Plutella xylostella, was first recorded in North America from Europe about 150 years ago and can be a significant pest of canola in Western Canada, so the introduction of one or more additional exotic parasitoids from Europe is being considered to increase the suppression of P. xylstella populations.
Abstract: Diamondback moth, Plutella xylostella (Linnaeus) (Lepidoptera: Plutellidae), was first recorded in North America from Europe about 150 years ago and can be a significant pest of canola in Western Canada. Because parasitism of P. xylostella in Canada is generally low, the introduction of one or more additional exotic parasitoids from Europe is being considered to increase the suppression of P. xylostella populations. Life table studies to determine the impact of parasitoids on diamondback moth populations in Europe were conducted in northwestern Switzerland in 2014–2016. Net reproductive rates were found to be less than one in seven out of eight life tables, suggesting that P. xylostella populations in Switzerland are mostly driven by immigration and recolonisation. In total, seven primary parasitoid species and one hyperparasitoid were associated with diamondback moth. Pupal parasitism by D. collaris reached up to 30%, but because generational mortality was mainly driven by abiotic mortality factors and predation of larvae, the overall contribution of pupal parasitism was low (< 6%). In regions of Canada, where P. xylostella may have increasing populations and low larval mortality, the addition of D. collaris may be a promising approach. Life table studies across Canada are necessary to determine the need for such intervention.
7 citations
TL;DR: The elm zigzag sawfly is more widely distributed than first expected and that the invasion is not localised to a small area, suggesting a possible European origin of the Canadian population.
Abstract: Abstract The elm zigzag sawfly, Aproceros leucopoda Takeuchi (Hymenoptera: Argidae), was reported for the first time in North America during the summer of 2020. Characteristic zigzag defoliation was reported in the province of Québec, Canada, on the community science website, iNaturalist. Field trips conducted to the site resulted in the collection of live specimens (a few larvae and a cocoon from which an adult emerged) and onsite observation of diagnostic defoliation and empty cocoons, confirming the presence of this exotic species in Canada. Subsequent inspection of elm trees by naturalists and scientists in the south of the province led to the conclusion that the species is more widely distributed than first expected and that the invasion is not localised to a small area. Preliminary genetic data pointed to a possible European origin of the Canadian population, but conclusive assignment to source will require examination of more specimens and the collection of reference sequences from different European and Asian populations. This is a good example of the importance of community science in the detection of new invasive species.
7 citations
TL;DR: The successful development of antiaggregation pheromone-based treatments for the Douglas-fir beetle is discussed in relation to efforts to develop similar treatments for other bark beetle species.
Abstract: This paper reviews the literature on the identification of 3-methylcyclohex-2-en-1-one (MCH) as the antiaggregation pheromone of the Douglas-fir beetle (Dendroctonus pseudotsugae Hopkins) (Coleoptera: Curculionidae) and the development of successful management applications using the pheromone. Previously unpublished data from two studies on novel uses of MCH are included. The successful development of antiaggregation pheromone-based treatments for the Douglas-fir beetle is discussed in relation to efforts to develop similar treatments for other bark beetle species, and opportunities for future research on MCH and the Douglas-fir beetle are suggested.
6 citations
6 citations
TL;DR: The species are redescribed, diagnostic characters are provided, and DNA barcodes have been used for the first time in family Mordellidae to examine the divergences between the species and to interpret the morphological variability observed in M. pseudorhenana.
Abstract: The current interpretation of two common European species, Mordellistena minima Costa, 1854 and M. pseudorhenana Ermisch, 1977, is based on misidentification. The confusion regarding the identity of the species is fixed based on the revised type material. Here, the species are redescribed, and diagnostic characters are provided. Mordellistena pseudorhenana is revalidated. Mordellistena emeryi Schilsky, 1895 is recognised as a new synonym of M. minima. Mordellistena sajoi Ermisch, 1977 is recognised as a new synonym of M. pseudorhenana. Lectotype and paralectotypes of M. emeryi are designated. Mordellistena pseudorhenana is reported for the first time from Bosnia and Herzegovina, Slovenia, and Switzerland. Two morphotypes of M. pseudorhenana differing in size and shape of the parameres are recognised. Morphological differences are quantified and displayed using principal component analysis. In addition, DNA barcodes have been used for the first time in family Mordellidae to examine the divergences between the species and to interpret the morphological variability observed in M. pseudorhenana. Low genetic divergences did not provide the evidence for considering the morphotypes as separate species. The discrepancy between the morphological and molecular evidence raises questions about the efficiency of the CO1 gene for Mordellidae identification and the stability of morphological traits conventionally used for species separation.
5 citations
TL;DR: The discovery of new repellents of multicoloured Asian lady beetle provides an opportunity to improve management of the pest in vineyards and to reduce risk of wine taint without using broad-spectrum insecticides.
Abstract: The multicoloured Asian lady beetle, Harmonia axyridis (Pallas) (Coleoptera: Coccinellidae), has become a pest in North American vineyards during harvest due to its adverse effects on wine quality. This study evaluated alternative products that may be suitable for use in vineyards as repellents to the beetle. Products were screened as repellent for multicoloured Asian lady beetle in short-term laboratory trials. Thirteen products significantly reduced the number of beetles on grapes, Vitis vinifera (Vitaceae). Products that showed a 50% or greater repellency were evaluated for residual repellency 24, 48, and 72 hours after application. In these trials, pine oil was highly repellent at each testing period, whereas the repellency of most other products decreased over time. Eight repellent compounds were evaluated in field trials in commercial vineyards that had high multicoloured Asian lady beetle populations. The number of beetles on vines was counted 2–6 and 24–28 hours after application. In the field, the most effective repellents overall were Biobenton and Buran, which reduced the number of multicoloured Asian lady beetles by 39 and 34%, respectively. The discovery of new repellents of multicoloured Asian lady beetle provides an opportunity to improve management of the pest in vineyards and to reduce risk of wine taint without using broad-spectrum insecticides.
TL;DR: When I accepted the invitation to serve as the lead-off speaker for the symposium Managing Bark and Ambrosia Beetles with Semiochemicals on which this special issue is based, I noted that everything one needed to know was published in Seybold et al. (2018), so I took another course.
Abstract: When I accepted the invitation to serve as the lead-off speaker for the symposium Managing Bark and Ambrosia Beetles with Semiochemicals on which this special issue is based, I noted that everything one needed to know was published in Seybold et al. (2018), a really good review of the subject. So, I took another course. About 25 years ago, I gave an oral presentation in the form of a letter to an imaginary graduate student. It seemed to go over well, so I decided to do it again. Here is a version of that letter to Sarah, the latest prospective graduate student conjured up by my imagination.
TL;DR: In this paper, the authors evaluated the efficacy of Bacillus pumilus Meyer and Gottheil PTB180 and Bacillus subtilis (Ehrenberg) Cohn PTB185, used alone and together, to control these two aphids both in the laboratory and in greenhouse on tomato, Solanum lycopersicum Linnaeus (Solanaceae), and cucumber, Cucumis sativus Linneaeus (Cucurbitaceae), plants.
Abstract: The foxglove aphid, Aulacorthum solani (Kaltenbach) (Hemiptera: Aphididae), and the melon aphid, Aphis gossypii Glover (Hemiptera: Aphididae), are among the serious insect pests found in greenhouses. The efficacy of microbial control against these insects has been demonstrated and can be enhanced by the combination of different microbial agents. This study evaluated the efficacy of Bacillus pumilus Meyer and Gottheil PTB180 and Bacillus subtilis (Ehrenberg) Cohn PTB185, used alone and together, to control these two aphids both in the laboratory and in greenhouse on tomato, Solanum lycopersicum Linnaeus (Solanaceae), and cucumber, Cucumis sativus Linnaeus (Cucurbitaceae), plants. The results from the laboratory tests showed an increase in mortality induced by all biological treatments. In the greenhouse, all treatments induced mortality rates significantly higher than that of the control for A. solani. Similarly, all treatments performed better than the control against A. gossypii, significantly reducing its reproduction. Furthermore, we found no additive effects when mixing products nor negative interactions affecting survival for the bacteria investigated. These microorganisms therefore have potential for use in biological control.
TL;DR: This review gathers the most relevant literature regarding new advances about the role of CB2R in a variety of neuropsychiatric conditions, with special emphasis on its potential as a new therapeutic target for the treatment of different psychiatric disorders.
Abstract: Since the identification and cloning of the cannabinoid receptor 2 (CB2R), several studies focused on the characterization of its physiological and pathological role. Initially, CB2R was considered as the peripheral cannabinoid receptor due to its detection in the rat spleen and leukocyte subpopulation in humans. Later, CB2R was identified in different brain regions significantly modifying the landscape and pointing out its role in a wide variety of central physiological functions and pathological conditions. Additional research also detected the expression of CB2R in neurons, microglia, and astroglia in different brain regions. Indeed, the findings collected to date support a significant function of CB2R in anxiety, depression, schizophrenia, and additional neuropsychiatric disorders. This review gathers the most relevant literature regarding new advances about the role of CB2R in a variety of neuropsychiatric conditions, with special emphasis on its potential as a new therapeutic target for the treatment of different psychiatric disorders.
TL;DR: It is demonstrated that, although C. cyanellus occurs across a wide range of habitats, forest habitats might host sexually mature individuals, which translates into more effective individual dispersion and potential reproduction.
Abstract: High-quality habitats presumably have the resources required to sustain relatively high rates of survival and reproduction. We assessed how habitat type and local environmental conditions determine the distribution of individuals of Canthon cyanellus (Coleoptera: Scarabaeidae), an eurytopic dung beetle, according to age category and sexual gonadic maturity. Beetles were surveyed in forest fragments, live fences, and pastures in Mexico. Individuals were categorised into six age categories according to the glandular volumes in males and oocyte number and length in females. Mature females in forest fragments were the most abundant females found among the habitats. Air humidity and soil hardness were positively and negatively related to mature female abundance, respectively. Mature beetles were the most abundant among males, and higher abundance of males occurred in forest fragments than in live fences and pastures. Light quantity was negatively related to the abundance of young males. Compared to forest fragments, females in pastures had larger oocytes. However, sites with higher soil hardness and air humidity had females with lower numbers of oocytes. Our results demonstrate that, although C. cyanellus occurs across a wide range of habitats, forest habitats might host sexually mature individuals, which translates into more effective individual dispersion and potential reproduction.
TL;DR: The genesis of the symposium Managing bark and ambrosia beetles with semiochemicals, and this special issue, was a synthesis published in the Annual Review of Entomology developed by a group of United States Department of Agriculture Forest Service research and development scientists from the western United America.
Abstract: On 14 November 2018, a symposium Managing bark and ambrosia beetles with semiochemicals was held in Vancouver, British Columbia, Canada, at the Joint Meeting of the Entomological Society of America, the Entomological Society of Canada, and the Entomological Society of British Columbia. The focus was on the application of behavioural chemicals for management of bark and ambrosia beetles (Coleoptera: Curculionidae: Scolytinae) in conifers and hardwoods in North America and Europe. Contributors included nine invited speakers from Canada, Slovakia, and the United States of America who summarised the current state of knowledge and latest technologies and shared career-long experiences and insights. This special issue features publications derived from those presentations.
TL;DR: Using natural history collection specimens, in-field observations, and molecular analysis to generate new locale records and natural history data for seven insect species associated with barnacles along the Pacific coast of Canada, America, or Japan.
Abstract: Insects are usually considered to be excluded from the marine environment. A small number of species, however, are considered to be marine, due to spending some portion of their life cycle in salt water. We use natural history collection specimens, in-field observations, and molecular analysis to generate new locale records and natural history data for seven insect species. All seven species are associated with barnacles (Balanomorpha: Balanidae, Chthamalidae) along the Pacific coast of Canada, the United States of America, or Japan. Use of DNA barcode analysis confirms the monophyly of three species of Oedoparena (Diptera: Dryomyzidae). Natural history collection specimens expand the geographical range and illuminate the phenology of Oedoparena spp. In-field observations record direct associations between three species of Thalassosmittia (Diptera: Chironomidae), Diaulota densissima (Casey) (Coleoptera: Staphylinidae), and intertidal barnacles from various locations in British Columbia, Canada. Barnacle host associations and microhabitat preferences are proposed for all species. A new definition of what constitutes a marine insect is offered.
TL;DR: Five new spruce budworm colonies are established from across its range to explore regional adaptations among spruce Budworm populations within common garden experiments and describe the process of flushing, rearing, and disease screening used on new populations to produce healthy disease-free laboratory stocks.
Abstract: Spruce budworm, Choristoneura fumiferana (Clemens) (Lepidoptera: Tortricidae), is a destructive defoliator found throughout the Nearctic boreal forest. This pest has a broad geographic range and shows regional variation in key life history traits. These population differences may represent important adaptations to local environmental conditions and reflect underlying genetic diversity. Existing laboratory colonies of spruce budworm do not capture this regional variation, so we established five new spruce budworm colonies from across its range to explore regional adaptations among spruce budworm populations within common garden experiments. We present methods for establishing new spruce budworm laboratory colonies from wild populations. We describe the process of flushing, rearing, and disease screening used on these new populations to produce healthy disease-free laboratory stocks.
TL;DR: The results indicate that the stimulus of mating per se is enough to induce oviposition and increase egg laying in females even if ejaculate is not received, whereas receiving only accessory gland secretions does not increase ovarian development and is notenough to induce Oviposition or increase egg production.
Abstract: Mating and receiving ejaculate can alter female insect physiology and postcopulatory behaviour. During mating, females receive both internal and external stimuli and different components in the ejaculate. In insects, these components consist mostly of sperm and male accessory gland secretions. Some of the most important changes associated with receiving male accessory gland secretions are a reduction in female sexual receptivity and an increase in oviposition. However, a clear function for these molecules has not been found in the Mexican fruit fly Anastrepha ludens (Loew) (Diptera: Tephritidae). Here, we tested how the stimulus of mating, receiving a full ejaculate, or only receiving accessory gland secretions can influence ovarian development and oviposition. Our results indicate that the stimulus of mating per se is enough to induce oviposition and increase egg laying in females even if ejaculate is not received, whereas receiving only accessory gland secretions does not increase ovarian development and is not enough to induce oviposition or increase egg production. Further research on the internal and external copulatory courtship of A. ludens will increase our understanding of the role of these secretions in stimulating oviposition independent of ejaculate effects. A biological function for male accessory gland secretions on female behaviour for A. ludens still needs to be found.
TL;DR: Mechanisms by which HIV directly or indirectly impairs the central nervous system are discussed, as well as other factors influencing or contributing to the impairment, and the animal models currently used to perform research on the topic are discussed.
Abstract: Early in the course of infection, human immunodeficiency virus (HIV) is able to enter the central nervous system where it stablishes a permanent reservoir. Current antiretroviral therapies do not efficiently cross the blood-brain barrier and therefore do not reach the HIV located in the central nervous system. Consequently, HIV infection can often be associated with neurocognitive impairment and HIV-associated dementia. The purpose of this review is to brief the reader into the world of neurological complications arising from HIV infection. Mechanisms by which HIV directly or indirectly impairs the central nervous system are discussed, as well as other factors influencing or contributing to the impairment, and the animal models currently used to perform research on the topic.
TL;DR: A number of experimental immunotherapies that aim to strengthen the Treg response or to dampen the inflammatory T-cell response as a therapeutic approach in animal models of Parkinson’s disease are summarized.
Abstract: Current evidence indicates that neurodegeneration of dopaminergic neurons of the substantia nigra associated to Parkinson’s disease is a consequence of a neuroinflammatory process in which microglial cells play a central role. The initial activation of microglial cells is triggered by pathogenic protein inclusions, which are mainly composed by α-synuclein. Importantly, these pathogenic forms of α-synuclein subsequently induce a T-cell-mediated autoimmune response to dopaminergic neurons. Depending on their functional phenotype, these autoreactive T-cells might shape the functional features of activated microglia. T-cells bearing pro-inflammatory phenotypes such as T-helper (Th)1 or Th17 promote a chronic inflammatory behaviour on microglia, whilst anti-inflammatory T-cells, such as regulatory T-cells (Treg) favour the acquisition of neuroprotective features by microglia. Thus, T-cells play a fundamental role in the development of neuroinflammation and neurodegeneration involved in Parkinson’s disease. This review summarizes the evidence indicating that not only CD4+ T-cells, but also CD8+ T-cells play an important role in the physiopathology of Parkinson’s disease. Next, this review analyses the different T-cell epitopes derived from the pathogenic forms of α-synuclein involved in the autoimmune response associated to Parkinson’s disease in animal models and humans. It also summarizes the requirement of specific alleles of major histocompatibility complexes (MHC) class I and class II necessaries for the presentation of CD8+ and CD4+ T-cell epitopes from the pathogenic forms of α-synuclein in both humans and animal models. Finally, this work summarizes and discusses a number of experimental immunotherapies that aim to strengthen the Treg response or to dampen the inflammatory T-cell response as a therapeutic approach in animal models of Parkinson’s disease.
TL;DR: The results show the efficacy of adopting integrated pest management and biological control for pest population suppression in greenhouse cucumber production under Mediterranean environmental conditions.
Abstract: The greenhouse cucumber pests, Bemisia tabaci (Hemiptera: Aleyrodidae), Frankliniella occidentalis (Thysanoptera: Thripidae), and Tetranychus urticae (Acari: Tetranychidae), are major threats to the production of greenhouse cucumbers (Cucurbitaceae) in Lebanon. The development of insecticide resistance by these pests has prompted the use of alternative and sustainable pest management strategies. In this study, we used integrated pest management strategies, including the release of the biological control agents, Amblyseius swirskii Athias-Henriot (Mesostigmata: Phytoseiidae) and Phytoseiulus persimilis Athias-Henriot (Mesostigmata: Phytoseiidae), to control whitefly, thrips, and two-spotted spider mite populations on greenhouse cucumber plants in two commercial production sites (sites A and B). We also compared the efficacy of pest population suppression using the integrated pest management strategy with that of chemical pest control. Our results show that biological control effectively maintains the cucumber pest populations below the economic threshold when coupled with additional integrated pest management measures. In addition, we show that biological control agents were equally or more effective in pest population suppression compared to eight and 12 insecticidal and acaricidal sprays performed in the control greenhouses at sites A and B, respectively. Altogether, our results show the efficacy of adopting integrated pest management and biological control for pest population suppression in greenhouse cucumber production under Mediterranean environmental conditions.
TL;DR: The northern population cluster that entered Alberta near Grande Prairie was the source of the most eastern established population near Lac La Biche, and the range expansion to this leading-edge population has been too rapid to establish evidence of population structure.
Abstract: The mountain pine beetle (Dendroctonus ponderosae Hopkins) (Coleoptera: Curculionidae) is a significant destructive force in the pine forests of western Canada and has the capacity to spread east into a novel host tree species, jack pine (Pinaceae). New populations have been documented in central Alberta, Canada, but the source populations for these outbreaks have yet to be identified. In this study, we use genetic data to identify parent populations for recent outbreak sites near Slave Lake, Lac La Biche, and Hinton, Alberta. We found the northern population cluster that entered Alberta near Grande Prairie was the source of the most eastern established population near Lac La Biche, and the range expansion to this leading-edge population has been too rapid to establish evidence of population structure. However, some dispersal from a population in the Jasper and Hinton area has been detected as far north and east as Slave Lake, Alberta. We also identified two potential source populations for the current outbreak in Hinton: most beetles appear to be from Jasper National Park, Alberta, but some also originated from the northern population cluster. These findings demonstrate the dynamic dispersal capabilities of mountain pine beetle across the Alberta landscape and the potential hazard of increased dispersal to newly established leading-edge populations.
TL;DR: It is suggested that to increase the effectiveness of biological control, the environmental conditions and risk of interspecific competition should be considered when selecting parasitoid species for release.
Abstract: In nature, competing species often achieve coexistence through niche differentiation. We examined this phenomenon for Pachycrepoideus vindemmiae and Spalangia endius (Hymenoptera: Pteromalidae), two species of pupal parasitoids that are considered biological control agents of house fly, Musca domestica (Diptera: Muscidae). We examined the ability of each species, alone and in combination, to locate host pupae buried at different depths (0, 1, 2, 4, and 6 cm) in three types of substrate (sand, dry wheat bran, and spent fly diet). We then evaluated the competitiveness of each species by allowing first one species, then the other species, to parasitise host individuals within time periods ranging from less than 2 hours to 96 hours of each other. Spalangia endius exhibited greater ability than did P. vindemmiae to locate host pupae buried at depths below one centimetre. Conversely, P. vindemmiae exhibited a greater competitive ability, being more likely to emerge from pupae co-parasitised by S. endius, regardless of oviposition interval or sequence. Our findings suggest that these two parasitoid species coexist through niche differentiation. Our findings also indicate that to increase the effectiveness of biological control, the environmental conditions and risk of interspecific competition should be considered when selecting parasitoid species for release.
TL;DR: The results contribute important baseline data on the diversity and behaviour of insect communities in orchid habitats of Vancouver Island and on the use of pan traps to characterise insect communities.
Abstract: The role of insects as pollinators within plant communities is well established, yet our knowledge of insect biodiversity in many habitats is lacking. Given the growing concern that insect biodiversity is declining, it is increasingly important to document insect assemblages from a wide range of geographic locations and habitats. Pan trapping is a common means of sampling local insect diversity. Many studies have found different insects associated with different-coloured pan traps. Here, eight different-coloured pan traps were used to sample local insect diversity in habitats supporting Platanthera (bog and rein) orchids on Vancouver Island, British Columbia, Canada. A total of 16 sites supporting seven orchid species resulted in 435 insects from 53 families being caught over 64.9 hours of pan trapping. Both Shannon and Simpson diversity index values were low despite sampling in markedly different habitats. Yellow traps caught higher numbers of insects, but no statistical difference was found among colours overall. No activity indicating pollination was recorded from a total of 254 insect observations over 21.5 hours. Our results contribute important baseline data on the diversity and behaviour of insect communities in orchid habitats of Vancouver Island and on the use of pan traps to characterise insect communities.
TL;DR: T Trap catches were synergistically increased when the pheromone was combined with both the host volatile ethanol and with conophthorin, which was found in female beetles as well as host volatiles.
Abstract: Porapak Q-captured volatiles from both sexes of Trypodendron betulae Swaine (Coleoptera: Curculionidae: Scolytinae) excised from newly attacked logs of paper birch, Betula papyrifera Marshall (Betulaceae), as well as volatiles from unattacked birch logs, were analysed by coupled gas chromatographic electroantennographic detection analysis. Active compounds were identified by gas chromatographic mass spectroscopy. The enantiomeric ratio of 6-ethenyl-2,2,6-trimethyloxan-3-ol (linalool oxide pyranoid) was determined using a Cyclodex B column. Field-trapping experiments disclosed that the female-produced aggregation pheromone of T. betulae is a blend of the (3S,6R)-trans- and (3R,6R)-cis-linalool oxide pyranoid. Trap catches were synergistically increased when the pheromone was combined with both the host volatile ethanol and with conophthorin, which was found in female beetles as well as host volatiles. Use of linalool oxide pyranoid reproductively isolates T. betulae from sympatric Trypodendron Stephens species for which only (+)-lineatin has been identified as an aggregation pheromone.
TL;DR: These findings identify parasitism as an important factor that is suppressing populations of wheat midge in the Peace River region, provide the first report of Inostemma walkeri for North America, and provide theFirst report of this species as a parasitoid of S. mosellana.
Abstract: Wheat midge, Sitodiplosis mosellana (Gehin) (Diptera: Cecidomyiidae), is a major pest of wheat (Poaceae) that was first reported in the Peace River region of northwestern Alberta, Canada in 2011. Although parasitism is an important factor of mortality in wheat midge elsewhere, little is known about the prevalence, species, or distribution of wheat midge parasitoids in the Peace River region. To address this knowledge gap, we conducted a survey of wheat midge parasitoids in commercial wheat fields across the region in 2016 and 2017. For a given field, parasitism of wheat midge larvae ranged from 36 to 71%. All but one parasitoid (n = 2167) were identified as Macroglenes penetrans (Kirby) (Hymenoptera: Pteromalidae). The exception was a specimen in the genus Inostemma tentatively identified as I. walkeri Kieffer (Hymenoptera: Platygasteridae). These findings identify parasitism as an important factor that is suppressing populations of wheat midge in the Peace River region, provide the first report of Inostemma walkeri for North America, and provide the first report of this species as a parasitoid of S. mosellana.
TL;DR: This work aims to provide answers to many of the diseases that currently do not have an effective therapy to treat of slow down disease progression by demonstrating in humans the efficacy of any neuroprotective therapy.
Abstract: Introduction The main challenge in neuroprotection is to demonstrate in humans the efficacy of any neuroprotective therapy. Exploration of Neuroprotective Therapy (ENT) highlights interest in the classical pharmacology, in sophisticated techniques such as deep brain stimulation and in traditional medicine tools (herbal medication, meditation...), etc. While Alzheimer’s disease (AD) and Parkinson’s disease (PD) require neuroprotective interventions to reduce neuronal death whereas amyotrophic lateral sclerosis, spinal cord injuries, autism, etc. may require restoration or both protection and restoration. The challenges are manifold and the 21st century should be able to provide answers to many of the diseases that currently do not have an effective therapy to treat of slow down disease progression.
TL;DR: The relationship between the detection of adelgid wool using this technique and the incidence of A. tsugae-infested twigs by sampling lower-crown branch tips of the same trees was examined and found that the probability of detecting wool with ball sampling increased with number of ball samples per tree, withNumber of trees per simulated stand, and with increasing incidence of ovisacs in the lower crown.
Abstract: Adelges tsugae Annand (Hemiptera: Adelgidae), a nonindigenous insect pest of hemlock (Tsuga spp.) (Pinaceae) in eastern North America, spends most of its life cycle within an ovisac, which resembles a woolly white mass on twigs. We evaluated the probability of detecting adelgid wool with Velcro®-covered balls when taking an increasing number of samples per tree (field sampling) and number of trees per simulated stand. We examined the relationship between the detection of adelgid wool using this technique and the incidence of A. tsugae-infested twigs by sampling lower-crown branch tips of the same trees. We found that the probability of detecting wool with ball sampling increased with number of ball samples per tree, with number of trees per simulated stand, and with increasing incidence of ovisacs in the lower crown. When sampling an individual tree, we found that 20 ball samples per tree achieved a targeted precision level of 0.75, but when sampling a stand, we found that 10 ball samples per tree took the least time for the range of simulated A. tsugae infestations we tested. These sample sizes are recommended for detection of A. tsugae infestations on an individual tree and in a hemlock stand.