The natural presence of entomopathogenic nematodes (EPNs) has been investigated in the Piedmont region (Northern Italy) in areas infested by the Japanese beetle Popillia japonica. Thirty-nine out of ...155 soil samples (25.2%) were positive for EPNs. Most of the samples contained only steinermatids (92.3%), 5.1% contained heterorhabditids, and one sample (2.6%) contained both genera. All the recovered isolates were identified at species level both morphologically and molecularly. Steinernema carpocapsae was the most abundant and it was mainly distributed in open habitats, such as perennial meadows, uncultivated soils, and cropland, characterized by sandy loam soil texture and acidic pH. Steinernema feltiae has been found associated mainly with closed habitats such as coniferous and deciduous woodland, characterized by sandy loam-texture and extremely acidic soil. The three isolates of Heterorhabditis bacteriophora were collected only in open habitats (perennial meadows and uncultivated fields) characterized by strongly acidic soils with sandy loam texture. The virulence of all EPN natural strains was evaluated by laboratory assays against P. japonica third-instar larvae collected during two different periods of the year (spring, autumn). The results showed that larval mortality was higher for pre-wintering larvae than post-wintering ones. The five more promising EPN isolates were tested in the semi-field assay in which H. bacteriophora natural strains have been shown to be more efficient in controlling P. japonica grubs. All of these results are finally discussed considering the use of these natural EPNs as biological control agents against P. japonica, within an eco-friendly perspective of management.
Abstract
Rhynchophorus ferrugineus is considered the worst pest of palm species, and few natural enemies are reported for this parasite in its area of origin. Here, we report the first recovery of ...the entomopathogenic fungus Metarhizium pingshaense associated with R. ferrugineus from Vietnam. The morphological, biochemical, and toxicological features of this strain were studied and compared with those of another Metarhizium strain associated with this weevil in Sicily (Italy), an area of recent introduction. The potential use of these fungi as biocontrol agents was tested against adult insects in laboratory trials and a similar mortality rate was found. Both strains were able to produce toxins and cuticle-degrading proteases, but they showed dissimilar enzymatic and toxicological profiles, suggesting a different virulence activity.
First discovery of the entomopathogenic fungus Metarhizium pingshaense associated to Red Palm Weevil in the native area.
A new species of mermithid nematode,
Hexamermis popilliae
n. sp. (Nematoda: Mermithidae) is described from the Japanese beetle
Popillia japonica
Newman in Italy, an area of new introduction for this ...invasive pest. The combination of the following characters separates
H. popilliae
from other members of the genus
Hexamermis
Steiner, 1924: adult head obtuse; amphidial pouches slightly posterior to lateral head papillae in female but adjacent to lateral head papillae in males; amphidial openings large, well developed; amphidial pouches elliptical in females and oblong in males; cuticular vulvar cone well developed, vulvar lips greatly reduced or lacking, vagina curved at tip where meeting uteri, without reverse bend (not S-shaped), spicules slightly curved, with a slight bend in the basal portion, approximately equal to body width at cloaca. This is the first record of a species of
Hexamermis
parasitizing the Japanese beetle
Popillia japonica
. The only previous mention of mermithid nematodes from
P. japonica
was an undescribed species of
Psammomermis
in North America.
Hexamermis popilliae
will be evaluated as a potential biological control agent in an integrated control program of the Japanese beetle in Italy.
The jasmine lacebug Corythauma ayyari is a pest of cultivated and ornamental plants mainly associated to Jasminum spp. This invasive insect is native to Asia, and it has been recently introduced in ...several countries, mainly within the Mediterranean basin. Here, we updated the known distribution of this species, including five new Italian regions (Liguria, Tuscany, Latium, Apulia, and Calabria); Salamis Island in Greece, and the Occitanie region in France. Citizen-science data have significantly contributed to the knowledge on species distribution, and the online platform for sharing biodiversity information can represent an effective tool for the early detection. Molecular analyses revealed that the specimens collected in Peninsular Italy and Sicily belong to a unique clade, suggesting the possibility of a single introduction, whereas those from Menton (France) and Calabria (Southern Italy) are separated from the others and probably originate from separated introductions.
A new phoretic association between Bursaphelenchus minutus and the bark beetle Orthotomicus erosus collected on Pinus pinea is described for the first time. Nematode identification was based on ...morphological observation and biometric measurements of males and females. Moreover, B. minutus was characterized by ITS sequences and RFLP profile.
Developing a technique for the cryopreservation of Bombyx mori L. germplasm may provide significant benefits for supplying good strains to farmers and facilitate the conservation of living material ...in genetic banks. Producing species-specific protocols for the selection of the most apt embryonic stage, dechorionation/permeabilization of eggshells, and the acclimation at low temperature before the treatment of eggs at cryogenic temperature is a prerequisite for cryopreservation of B. mori embryos. In this research, non-diapausing eggs of B. mori Nistari strain were used to study cold hardiness; the final aim was to select the most apt embryonic development stages, and in addition, reliable permeabilization, and vitrification treatments. Polyhybrid B. mori eggs of a diapausing strain were also used for comparison in experiments of embryogenesis, permeability, and acclimation under low temperature before cryopreservation. The Nistari eggs in the stage of 24 hours post-oviposition (h PO) showed a scarce survival rate (0.1%) after their submersion in liquid nitrogen (LN), while the highest survival in loading and dehydration with cryoprotective agents was assessed in 40h PO eggs. Overwintering diapausing eggs preserved for three months at 5 °C and then treated with various vitrification solutions gave rise to good hatching rates. The achieved results show that it is possible to improve the method of cryopreservation of B. mori eggs by obtaining a good permeability with cryoprotectants at loading/dehydration steps and by decreasing the toxicity, reducing the treatment time.
Citizen science, the engagement of people in a research project, has grown rapidly in recent years, also for mapping of species of conservation interest. The Life Project "Monitoring Insects with ...Public Participation" (MIPP) actively promoted collaboration amongst scientists, public administrations and citizens in the collection of occurrence data of nine insect species listed in the Habitats Directive: Lucanus cervus , Osmoderma eremita , Cerambyx cerdo , Rosalia alpina , Morimus asper/funereus , Lopinga achine , Parnassius apollo , Zerynthia cassandra /polyxena and Saga pedo . These species were selected because they share two main characteristics: (i) they are listed in Annexes II and IV of the Habitats Directive and (ii) they are large and relatively easy to identify. From 2014 to 2016, many different strategies were applied to contact and engage the public and approximately 14,000 citizens were reached directly. Additionally, printed and online material informed the public about this project. Citizens could transmit data on the target species, accompanied by a photograph, via the web-site of the project or through a dedicated application (app) for smartphones and tablets. All records were validated by experts based on the photographs sent by citizens. A total number of 2,308 records were transmitted and 1,691 (73.2%) of these were confirmed. Most of the reports were submitted via the website, although the submission via the app increased over time. The species most commonly recorded was L. cervus , followed by M. asper/funereus and R. alpina . Data collected by citizen scientists allowed a detailed analysis to be made on altitudinal distribution and phenology of the species and the results obtained were compared with literature data on altitudinal distribution and phenology. For example, for L. cervus , 67% of the records collected were from the altitudinal range 0-400 m a.s.l. Interestingly, the data showed that the phenology of this species changed with altitude. Keywords: Citizen Science, Habitats Directive, Phenology, Altitudinal distribution
Morimus asper is a morphologically variable longhorn beetle that occurs in large parts of southern and central Europe. Although this saproxylic beetle is widespread in old-growth forests or ...well-structured woodlands, its populations are currently threatened by forest practices, such as the removal of wood (branches and logs). Morimus funereus is considered a valid species by some authors and is included in Annex II of the Habitats Directive. However, a recent molecular study found that all European and Turkish populations should be referred to a single species, M. asper . In this paper, the monitoring methods proposed for M. asper (sensu lato ) in the various European countries are reviewed and the research carried out in Italy, which was aimed at developing guidelines for its monitoring, is presented. The experiments conducted, mainly with log piles built from freshly cut wood, investigated, amongst other things, the importance of wood type, diameter of logs and age of wood for the number of individuals observed. Based on these results and on a literature review, a detailed monitoring method for M. asper is proposed here, together with a discussion on its constraints, spatial validity and possible interferences. In order to facilitate the assessment of the conservation status of populations of M. asper and to allow for comparisons between populations and over time, a method for the calculation of a reference value, based on the monitoring method, is also presented. Keywords: Habitats Directive, saproxylic beetles, Coleoptera, Cerambycidae, monitoring methods, forest biodiversity
The stereoselective synthesis of both enantiomers of trifluoro frontalin (−)-(1S,5R)- and (+)-(1R,5S)-8, as well as of diastereomeric monofluoro frontalines (−)-(1R,2R,5R)-18 and (−)-(1R,2S,5R)-20, ...analogues of the bioactive component of the aggregation pheromone of the Scolytidae insect family, has been accomplished starting from (−)-(1R)- and (+)-(1S)-menthyl (S)-toluene-4-sulfinate as a source of chirality and methyl trifluoroacetate or fluoroacetate, respectively, as sources of fluorine. The C-1 stereocenters were installed via stereoselective epoxidation of β-sulfinyl ketones 2 and 13 with diazomethane. The bicyclic core was obtained by totally stereocontrolled and chemoselective tandem Wacker oxidation/intramolecular ketalization of the intermediate unsatured sulfinyl diols 5, 15, and 19. Axially fluorinated (−)-20 elicited a strong electroantennographic response in laboratory tests on females of Dendroctonus micans, whereas equatorially fluorinated (−)-18 and the trifluoroanalogue (−)-8 showed modest responses. Field trials using (−)-20 were not indicative owing to the locally scarce population of D. micans, but it showed some attractiveness for other Coleoptera families.
Biological invasions are a global threat to biodiversity. Since the spread of invasive alien plants may have many impacts, an integrated approach, assessing effects across various ecosystem ...components, is needed for a correct understanding of the invasion process and its consequences. The nitrogen-fixing tree Robinia pseudoacacia (black locust) is a major invasive species worldwide and is used in forestry production. While its effects on plant communities and soils are well known, there have been few studies on soil fauna and microbes.
We investigated the impacts of the tree on several ecosystem components, using a multi-trophic approach to combine evidence of soil chemical properties and soil microbial, nematode, microarthropod and plant communities. We sampled soil and vegetation in managed forests, comparing those dominated by black locust with native deciduous oak stands.
We found qualitative and quantitative changes in all components analysed, such as the well-known soil nitrification and acidification in stands invaded by black locust. Bacterial richness was the only component favoured by the invasion. On the contrary, abundance and richness of microarthropods, richness of nematodes, and richness and diversity of plant communities decreased significantly in invaded stands. The invasion process caused a compositional shift in all studied biotic communities and in relationships between the different ecosystem components.
We obtained clear insights into the effects of invasion of managed native forests by black locust. Our data confirms that the alien species transforms several ecosystem components, modifying the plant-soil community and affecting biodiversity at different levels. Correct management of this aggressive invader in temperate forests is urgently required.
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•We analysed the impacts of Robinia pseudoacacia invasion.•We analysed impacts on soil chemical properties, plant and soil biotic communities.•We found qualitative and quantitative changes in all components analysed.•We detected soil nitrification and acidification in stands invaded by black locust.•Changes (mostly biodiversity reduction) were observed in biotic communities.
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