Pest density – plant damage relationships are essential guides for decision-making in integrated pest management. In this article, we established pest density – leaf damage relationships for the ...beech leaf-mining weevil, Orchestes fagi L. (formerly Rhynchaenus fagi, Coleoptera: Curculionidae), in its invasive range of Nova Scotia, Canada. Outbreaks of O. fagi cause tree-wide leaf necrosis in American beech (Fagus grandifolia Ehrh.), which can eventually result in tree mortality. In 2014 and 2016, we collected weekly samples in stands with American beech and assessed leaves for densities during different life stages (eggs, larvae, and pupae), population proxy measures (adult feeding damage, egg slits, and larval galleries), and percent necrosis. In general, feeding damage and leaf necrosis plateaued soon after the end of budburst, but before the larval mine expanded. This strongly suggested that leaf necrosis may be linked to damage caused by adults or by mine initiation rather than that caused by larval mine expansion and gallery development. The density of O. fagi per leaf for life stages and population proxies all significantly explained ∼42%–81% of the variation in end-of-season percent leaf necrosis. Results from this study provide a variety of relationships that could be used in both short- and long-term monitoring efforts for O. fagi.
We investigated the potential for human-mediated range expansion of an exotic beech leaf-mining weevil, Orchestes fagi (Linnaeus) (Coleoptera: Curculionidae: Curculioninae: Rhamphini) (formerly known ...as Rhynchaenus fagi) on timber or firewood, which for eight to nine months of the year may harbour adults in diapause. In both relatively low-density and high-density populations, adults were found on the base, middle, and upper boles of the primary host, American beech (Fagus grandifolia Ehrhart; Fagaceae), as well as red maple (Acer rubrum Linnaeus; Sapindaceae) and red spruce (Picea rubens Sargent; Pinaceae) in the vicinity. Comparatively few individuals were found on tree branches, or in the moss, duff, or soil collected beneath beech trees. Overwintering adults appeared to favour parts of trees with relatively high bark roughness. Our study suggests that, between the months of July through May, any woody stems near areas having O. fagi outbreaks are likely to harbour adults. Moreover, as all of the trees studied are common sources of timber or firewood, the harvest and transport of wood from these areas may facilitate outbreak spread; this may explain the multiple, distantly distributed populations of O. fagi that have been reported in eastern Nova Scotia, Canada in recent years.
Purpose
The woolly beech aphid thrives on European beech leaves, which has complex direct and indirect impacts on above- and belowground processes. A mechanistic understanding of insect-mediated ...changes in organic carbon (OC) availability for microbial life and its implications for element cycling is still lacking. This study aims at disentangling aphid-induced effects on phyllosphere and rhizosphere bacterial communities, as well as investigating feedbacks to OC transfer from the canopy to the mineral soil.
Methods
Following 2.5 months of infestation, we tracked the fate of OC (
13
CO
2
pulse-labelling) in several compartments of beech sapling – soil mesocosms over 5 days. In ecosystem solutions, water extracts and soil/plant compartments we determined OC and N and solid δ
13
C. Bacterial community structure (16S rRNA gene targeted amplicon sequencing and quantitative PCR) and metabolite profiles (LC-qTOF-MS) were analysed.
Results
We found significantly higher aphid-mediated inputs of OC within throughfall. Honeydew-derived C on infested leaves was inconsequential for total phyllosphere bacterial abundances, but verifiably affected the community structure. In all soil compartments, cold-water extractable OC pools declined significantly by frequent inputs of readily available OC. This pattern might relate to reductions in rhizodepositions and altered microbial processing by accelerated soil C-mineralization. As a result, the abundance of metabolites changed significantly in different ecosystem solutions.
Conclusions
Our findings attest that insect infestations induce distinct direct and indirect effects on plant-insect-microbiome interactions leading to marked alterations in C dynamics. This integrated approach improves our understanding on microbial dynamics and biogeochemistry and evaluates the role of insects for ecosystem processes.
This paper discusses three problems concerning the Woodland Grayling, Hipparchia fagi Scopoli, 1763, with respect to the identity and application of the junior name Papilio hermione Linnaeus, 1764. ...In 1977, the late Otakar Kudrna designated a specimen of the Rock Grayling, Hipparchia alcyone Denis & Schiffermüller, 1775, to become the lectotype of Papilio hermione - as a result of which hermione supplanted alcyone as the senior epithet for this species. Because P. hermione is the nominal type species of Hipparchia Fabricius, 1807, Kudrna's action rendered this a genus based on a misidentified species. Third, while a majority of lepidopterists have ignored Kudrna's action and continue to apply the name H. alcyone to the Rock Grayling, and still regard P. hermione as a junior subjective synonym of H. fagi, the formal nomenclature for the Rock Grayling has become unstable because a large minority have nonetheless accepted Kudrna's lectotype designation and all that follows from it. It is demonstrated here that no syntypes of Papilio hermione (or Papilio fagi) have survived; consequently, Kudrna's lectotype designation for P. hermione is invalid. By designation of a single specimen of the Woodland Grayling as neotype for both P. fagi and P. hermione, the two names are rendered objectively synonymous, thereby restoring stability to the species name for the Rock Grayling (as Hipparchia alcyone), and to the application of Papilio hermione (= Hipparchia fagi) as nominal type species of the generic name Hipparchia.
Mass outbreaks of herbivore insects perturb the functional properties of forests, by substantially altering water and nutrient cycling of infested trees. Less clear is how low to moderate herbivory ...affects the vertical flow of nutrients from trees to the soil. We report on the effects of low to moderate infestation levels of the woolly beech aphid (Phyllaphis fagi L.) on the nutrient dynamics and hydrology of European beech (Fagus sylvatica L.). We traced the vertical dynamics of macro and micronutrients via throughfall (TF), stemflow (SF) and Oa litter leachates from potted saplings underneath infested and uninfested control trees. The low infestation levels were insufficient to significantly alter TF and litter leachate composition, although, on average, the release of K and DOC and the immobilization of N (NH₄–N) in TF solution were more pronounced under aphid infestation. SF chemistry was significantly altered by aphid activity exhibiting intensified fluxes of K (+159 %), Mg (+82 %), Mn (+93 %), S (+86 %), SO₄–S (+62 %), DOS (+137 %), DOC (+51 %) and DON (+62 %), compared to control trees. SF is likely enriched by low and mid-level aphid activity due to its increased residence time in the canopy. It has interaction with large areas of aboveground vegetative surface area representing a cumulative flux of solutes and particulates from both foliar and woody surfaces from above-lying portions of the canopy. Accordingly, SF might be a useful indicator to evaluate the impact of sap- and leaf-feeding herbivores on forest ecosystems.
Bukva predstavlja jednu od najvažnijih vrsta drveća u Bosni i Hercegovini. Stoga, potrebno je praćenje zdravstvenog stanja bukovih sastojina i poduzimanje svih neophodnih preventivnih i represivnih ...mjera kako bi se zdravstveno stanje ovih sastojina unaprijedilo. U okviru istraživanja analiziran je utjecaj bukove skočipipe na površinu oštećenja listova na stabalcima bukve od imaga i ličinke u ovisnosti od lokacije i položaja stabalaca bukve u sastojini (svjetlo/sjena). Lokacije istraživanja su se nalazile unutar kulture smreke, visokih šuma bukve i mješovitih šuma bukve i jele sa smrekom. Bukova skočipipa predstavlja jednog od glavnih defolijatora koji se javljaju na stablima bukve. Uzorak istraživanja čine 15 stabalaca bukve, po 5 stabalaca na tri lokacije. Na svakoj lokaciji odabrana su 3 stabalca čija krošnja je bila na svjetlu i dva stabalca čija krošnja je bila u sjeni (ukupno 9 stabalaca na svjetlu i 6 stabalaca u zasjeni). Na svakom stablu pregledavana su i mjerena oštećenja od imaga i ličinke bukove skočipipe. Ustanovljeno je da prosječna površina oštećenja lista bukve od imaga je varirala od 2-4%, a ličinke od 4-8%. Statističkim analizama je utvrđeno postojanje statistički značajnih razlika u površini oštećenja lista bukve od ličinke u ovisnosti od položaja stabalaca bukve u sastojini.
The impact of beech weevil on the damaged area of beech trees from adult and larvae was analyzed, depending on the location and position of trees of beech in stand (sun/shadow). The research localities were located within the forest plantation of spruce, natural beech forests and mixed beech, fir and spruce forests. Beech weevil represents one of the main defoliators appearing on beech trees. The research sample consists of 15 beech trees, 5 trees per location, on three locations. On each location, were selected 3 trees with the crown in the sun and 2 trees with the crown in the shade (a total of 9 trees in the sun and 6 trees in the shade). On each tree were measured damages from the adult and larvae of beech weevil. It has been found that the average damaged area on beech leaf varied for adult from 2-4%, and larvae 4-8%. Statistical analysis showed a statistically significant differences in damaged areas of beech leaf from larvae, depending on the position of beech trees in the stand.
Venturiales Shen, M.; Zhang, J.Q.; Zhao, L.L. ...
Studies in mycology,
06/2020, Volume:
96, Issue:
1
Journal Article
Peer reviewed
Open access
Members of Venturiales (Dothideomycetes) are widely distributed, and comprise saprobes, as well as plant, human and animal pathogens. In spite of their economic importance, the general lack of ...cultures and DNA data has resulted in taxa being poorly resolved. In the present study five loci, ITS, LSU rDNA, tef1, tub2 and rpb2 are used for analysing 115 venturialean taxa representing 30 genera in three families in the current classification of Venturiales. Based on the multigene phylogenetic analysis, morphological and ecological characteristics, one new family, Cylindrosympodiaceae, and eight new genera are described, namely Bellamyces, Fagicola, Fraxinicola, Fuscohilum,Neofusicladium, Parafusicladium, Pinaceicola and Sterila. In addition, 12 species are described as new to science, and 41 new combinations are proposed. The taxonomic status of 153 species have been re-evaluated with 20 species excluded from Venturiales. Based on this revision of Venturiales, morphological characteristics such as conidial arrangement (solitary or in chains) or conidiogenesis (blastic-solitary, sympodial or annellidic), proved to be significant at generic level. Venturia as currently defined represents a generic complex. Furthermore, plant pathogens appear more terminal in phylogenetic analyses within Venturiaceae and Sympoventuriaceae, suggesting that the ancestral state of Venturiales is most likely saprobic.
Abstract
Orchestes fagi
(Linnaeus) (Coleoptera: Curculionidae) is a pest of beech trees (
Fagus sylvatica
Linnaeus; Fagaceae) in Europe that has recently become established and invasive on American ...beech (
Fagus grandifolia
Ehrhart) in Nova Scotia, Canada. We tested the effects of trap type, trap colour, trap height, and lure on the numbers of
O. fagi
captured per trap with the objective of developing a survey tool to monitor the weevil’s spread. We captured
O. fagi
in significantly greater numbers on yellow, green, or white traps than on light blue, dark blue, or red traps. There were no significant interactions between trap colour and trap design. Sticky triangular prism traps caught significantly more
O. fagi
than did nonsticky intercept traps regardless of colour. No effect of trap height was observed. Mean catch of
O. fagi
was significantly greater on yellow sticky triangular prism traps than on commercially sourced yellow sticky cards. Baiting yellow, green, or white sticky prism traps with the host volatile 9-geranyl-
p
-cymene did not increase catch of
O. fagi
. Our results suggest that yellow, green, or white sticky prism traps are a useful tool for detecting
O. fagi
adults and monitoring the spread of this species in Canada.
We investigated auditory signals and morphology of the stridulatory apparatus of the European beech leaf‐mining weevil, Orchestes fagi L. (Coleoptera: Curculionidae), an invasive herbivore now ...established in Nova Scotia, Canada, to determine their potential for enhancing survey tools to monitor the spread of the species in Canada. We recorded and described sounds produced by adult O. fagi, analyzed the morphology of the stridulatory mechanism for intersexual differences and asymmetry, and examined behavioral responses elicited in conspecifics by playback of stridulation recordings. Adult O. fagi produced sounds under three conditions: male in distress, female in distress, and male in the presence of female. Female distress chirps lasted significantly longer than male distress chirps and male chirps in the presence of females, but peak frequencies and mean number of chirps per s did not differ significantly among the three groups. Morphology of the stridulation structures in male and female O. fagi was compared using scanning electron microscopy. Orchestes fagi have an elytro‐tergal file‐ and scraper‐type sound production apparatus, through which sound is produced upon anterior motion of the abdomen. Female O. fagi have a ‘pars stridens’ that is longer and has more ridges than males. Width and number of ridges per length of pars stridens did not differ between the sexes. Evidence of asymmetry was found in male pars stridens, with the right side being longer than the left. Playback of recorded sounds to adult weevils suggests female O. fagi were repelled by sounds produced by distressed males.
We investigated auditory signals and morphology of the stridulatory apparatus of adult Orchestes fagi (Coleoptera: Curculionidae), an invasive herbivore in Nova Scotia, Canada. We described sounds, and the stridulatory mechanism, and examined behavioral responses by playback of stridulation recordings. Females have a pars stridens that is longer and has more ridges than males, evidence of asymmetry was found in male pars stridens (the right side being longer), and playback of recorded sounds suggests females were repelled by distressed males.
Three species of mononchids belonging to the
Cobb, 1916 genus, one new and two previously known species collected from natural ecosystem of Khorramabad county, Lorestan province, south west of Iran, ...are described.
sp. nov. is morphologically characterized by its 2.1 – 2.2 mm body length, numerous cuticular pores, slightly offset lip region, prominent labial and cephalic papillae, cephalic papillae larger than labial ones, barrel-shaped and spacious (40 – 43 × 22.5 – 24 μm) buccal cavity, weakly rounded tail tip and weakly expressed tail tip´s hyaline. In this study,
and
were also collected and some additional data of these two species are also given.
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