Characterization of a carlavirus in elderberry (Sambucus spp.)

A carlavirus was isolated fromSambucus racemosa andS. nigra in the Netherlands. The virus was sap-transmissible and capable of infecting 14 out of 58 plant species and cultivars tested, causing symptoms in five of them. It was also transmitted byMyzus persicae at a low rate. Dilution end-point was 10^–3–10^–4, thermal inactivation at 70–75°C and ageing in vitro 2–4 days. The virus had a sedimentation coefficient of 155 S and molecular weight of capsid protein subunits of 31 000 dalton. The average buoyant density of the four isolates used was 1.315 g/cm³. The virus particles had an average normal length of 678 nm and a width of approximately 12 nm. In ultrathin sections of leaf tissue ofS. racemosa Plumosa Aurea bundles of virus particles were observed in the cytoplasm. Close serological relationship was found to a virus isolated from elderberry in Britain and a distant relationship to carnation latent virus. In its reaction on host plants and its persistence in crude sap it also resembled the former virus, originally code-named elderberry virus A. We propose the name elderberry carlavirus for it.Samenvatting Een carlavirus werd geïsoleerd uitSambucus racemosa enS. nigra in Nederland. Het virus kon met sap worden overgebracht en was in staat 14 van de 58 getoetste plantesoorten en-cultivars te infecteren waarbij op vijf van deze symptomen verschenen. Ook metMyzus persicae vond overdracht plaats, zij het in beperkte mate. De verdunningsgrens was 10^–3–10^–4, de inactiveringstemperatuur 70–75°C en de houdbaarheid in vitro 2–4 dagen. Het virus had een sedimentatiecoëfficiënt van 155 S en het molecuulgewicht van de structuurelementen van het capside-eiwit bedroeg 31 000 dalton. De deeltjes van de vier gebruikte isolaten hadden een gemiddelde zweefdichtheid van 1,315 g/cm³. De gemiddelde normale lengte van de virusdeeltjes bedroeg 678 nm bij een breedte van ongeveer 12 nm. In ultradunne coupes van bladweefsel vanS. racemosa Plumosa Aurea werden bundels draadvormige virusdeeltjes waargenomen in het cytoplasma. Het virus vertoonde een zeer sterke serologische verwantschap met een virus uit vlier geïsoleerd in Groot-Brittannië en een geringe verwantschap met het anjer-latenvirus. In zijn reactie op waardplanten en zijn eigenschappen in ruw sap vertoonde het ook veel gelijkenis met eerstgenoemd virus, in de literatuur vermeld onder de code-naam elderberry virus A. We stellen voor de naam carlavirus van vlier aan dit virus te geven.     

The attraction of cerambycids and other xylophagous beetles, potential vectors of Bursaphelenchus xylophilus, to semio-chemicals in Slovenia

The attractiveness of different semio-chemicals to potential vectors of the phytoparasitic nematode Bursaphelenchus xylophilus was investigated in conifer forests in Slovenia. From 2007 to 2009, the presence of xylophagous beetles in Pinus nigra, P. sylvestris, P. halepensis, Picea abies and Abies alba stands was assessed at eight locations. Insects were collected at 1-month intervals during the growing season using four cross vane traps per location with a collecting container with propylene glycol and attractants (ethanol+??-pinene, Pheroprax? and Gallowit?). The trapped insects represented 24 families of the order Coleoptera, and we identified 94 species. The most numerous group was the weevil subfamily Scolytinae (76.55% of all insects collected), followed by the family Cerambycidae (8.12%), and the weevil subfamily Curculioninae (1.67%). With regard to species number, the most frequent wood-borers were Cerambycidae (24 taxa), Scolytinae (12 species) and Buprestidae (8 species). The most abundant species was Spondylis buprestoides, followed by Arhopalus rusticus, Monochamus galloprovincialis and Arhopalus ferus. At all locations, the largest catch of Cerambycidae occurred in July. The most effective attractant was ethanol+??-pinene, followed by Gallowit?; the least effective attractant was Pheroprax?. Among Monochamus species, M. galloprovincialis represented 17.54%, M. sutor 0.09% and M. sartor 0.04% of the long-horned beetles collected. Monochamus individuals were most numerous in the P. nigra stand and were attracted in the greatest numbers by Gallowit?, followed by ethanol+??-pinene. The cerambycid catch was highly correlated with the catch of non-target bark beetle predators (Cleridae, Staphylinidae, Histeridae, Trogositidae, Nitidulidae, Rhizophagidae) in the traps.     

Relative susceptibilities of eleven potato cultivars and breeders' clones toGlobodera pallida pathotype Pa 3, with a discussion of the interpretation of data from pot experiments

Curves according to the equationPf=M (1-e ^–aPi/M ) fitted well to the relations according to Seinhorst's (1993) modelPf=y _e y _h M(1-e ^–aPi/M ) between initial egg densities of potato cyst nematodes (Globodera rostochiensis, G. pallida)Pi up to 5T _h (T _h =the tolerance limit of haulm weight) andPf at the end of the growing season (a=maximum rate of reproduction,M, M=different theoretical maximum egg densities). Variation of estimates ofM, due to variation of the parameters of the submodelsy _e andy _h for the effect of weight reduction of haulms (and, therefore, of roots) on cyst production and damage to root tissue on egg production, respectively, was small enough to be ignored relative to experimental error. Therefore, ratios of values ofM, determined in simultaneous pot experiments with different potato cultivars, are reliable measures of the relative host status of these cultivars at initial egg densitiesPi of these nematodes up to about 5T _h . Variation between potato cultivars of growth reduction and damage to root tissue by the nematodes reduces the reliability of ratios of rates of relative susceptibility of these cultivars.The ratios between the maximum rates of reproduction ofG. pallida, pathotype Pa 3, on 8 out of 9 cultivars and one breeder's clone of potatoes and this rate on the susceptible cvs Bintje and Irene (relative susceptibilitiesrs _a ) could be considered to be equal to the ratios of maximum population densitiesM on these cultivars (relative susceptibilitiesrs _M ) (relative susceptibilities independent of initial egg density). The latter ratios were 0.59 times the first (relative susceptibilities negatively correlated with initial egg density) in one cultivar and one breeder's clone. Relative susceptibilitiesrs _a andrs _M of the tested cultivars and breeders clones suggest the existence of continuous ranges of both relative susceptibilities between 0.50 and 0.15 with, in a great majority of cases,rs _a =rs _M .     

First report of Eulachnus tuberculostemmatus (Theobald, 1915) on Pinus nigra subsp. mauretanica stands in Algeria

Pinus nigra (black pine) is a Mediterranean taxonomic complex (including different subspecies), with a discontinuous distribution. The southernmost part of its range is in North Africa, in Morocco and Algeria, where it is present as P. nigra subsp. mauretanica. Currently, an extremely limited number of trees of this subspecies still persist within its natural range, giving this taxon an outstanding ecological importance. These residual stands are threatened by many biotic and abiotic factors, putting at risk the survival of this subspecies in its natural habitat. This paper reports for the first time the presence of Eulachnus tuberculostemmatus (Hemiptera: Aphididae: Lachninae) in Algeria, and its infestation on P. nigra subsp. mauretanica. This insect was detected in three sites of the Djurdjura National Park in May 2012 and identified in February 2016. The aphid seems to be responsible for needle discoloration and premature senescence, symptoms observed since spring 2008 on the infested pines. These clusters of P. nigra subsp. mauretanica trees are protected by park regulations, and given their conservation status further investigations into this pest species, and other biotic and abiotic factors that may threaten this important tree, are required.     

De bramestengelboorder,Hartigia nigra (Hymenoptera,Cephidae), in cultuurbramen

The nativeHartigia nigra Harris, has been found recently in cultivated blackberries near Biezelinge (Zeeland), but is not of economic importance.     

Definitive confirmation of establishment of Parasaissetia nigra (Nietner) (Hemiptera,Coccidae) in Sicily (Italy), with notes on its association with a new host,Syzygium myrtifolium Walp.

The nigra scale, Parasaissetia nigra (Hemiptera, Coccidae), has occurred for a long time on many ornamental plants in continental Italy. Records of the presence of this polyphagous scale in the island of Sicily have remained unconfirmed. This study confirms the establishment of this damaging insect in Sicily, where the scale has been found on a new host, Syzygium myrtifolium.     

Phenology and damage of Anarsia lineatella Zell. (Lepidoptera: Gelechiidae) in peach,apricot and nectarine orchards under semi-arid conditions

This study was conducted under semi-arid conditions in ?anl?urfa province (Turkey) in 2010–2011. One orchard each of peach, apricot and nectarine was selected for the study. There was less than one mile distance separating the orchards, and therefore climate, soil and topography were similar. Adult emergence, population peaks, number of generations per year and damage of the peach twig borer [PTB] [Anarsia lineatella Zell. (Lepidoptera: Gelechiidae)] on twigs and fruits were determined. Sex pheromone traps were used to determine moth population dynamics. Fruits and twigs were checked to determine damage rate and host preference of the PTB among peach, apricot and nectarine. This study showed that the first adults of the PTB were detected in early May and pest populations peaked four times during both years. The highest numbers of adults captured by the pheromone traps in peach, apricot and nectarine orchards were 115, 86 and 70 adults/trap, respectively. The PTB damage rates on twigs were 38, 18 and 16% (2010) (P < 0.05) and 30, 22 and 14% (2011) (P < 0.05), while damage rates on fruits were 29, 6 and 6% (2010) (P < 0.05) and 14, 8 and 5% (2011) (P < 0.05) in peach, nectarine and apricot, respectively. The results showed that A. lineatella caused greater damage on peaches than on apricots and nectarines.     

Effects of fertilization with ammonium sulphate and potassium sulphate on the development of Sphaeropsis sapinea in Corsican pine

Potted plants ofPinus nigra subsp.laricio were fertilized with ammonium sulphate (AS) and potassium sulphate (PS) each year during 3 consecutive years. The then 5-year-old plants were artificially inoculated withSphaeropsis sapinea. The fungus caused much bigger bark necroses in plants that had been fertilized with AS, than in plants fertilized with PS. It is concluded thatP. nigra growing in poor sandy soil becomes more susceptible toS. sapinea when fertilized with an excess of AS. This may explain partly the increased incidence ofS. sapinea inP. nigra stands in areas with a high rate of atmospheric NH₄-deposition in the Netherlands.     

Resurgence of Cryptodiaporthe populea in Italy1

Serious resurgence of Cryptodiapor the populea (anamorph Dothichiza populea), with appearance of perithecia, has been reported on poplar in Italy, particularly upon newly commercialized clones. Disease symptoms, incidence of attack and resulting damage have been examined through all phases of poplar cultivation, on various clones and under different environmental conditions. Consideration was also given to predisposing factors such as the water status of the plant, the adaptability to the environment of the clones and its other genetic characteristics. Levels of resistance to D. populea of 131 of the most important European clones are reported for North Italy. Most Populus deltoides and P. trichocarpa clones and their hybrids appeared resistant, while most P. nigra clones were susceptible and P. euramericana clones were partly susceptible and partly resistant. Immediate control strategies, and current genetic improvement programmes in Italy, are discussed.     

Enhancement of dye-sensitized phototoxicity to house fly larvae in vivo by dietary ascorbate,diazabicyclooctane, and other additives

Several reagents reported to be singlet oxygen quenchers and/or radical scavengers and to be protectants against photooxidative damage to isolated systems in vitro were examined, in vivo, for protective effect on the larvae of the house fly (Musca domestica L.; Diptera:Muscidae). A standardized erythrosine-sensitized phototoxic test procedure was used. β-Carotene appeared to show some protective effect. Other dietary additives exhibited no measurable degree of protection to the larvae in vitro; on the contrary, mortality increased in the presence of butylated hydroxytoluene, ascorbate, and diazabicyclooctane.     

Fortuitous parasitoids of the invasive tomato leafminer Tuta absoluta in Tunisia

The South American tomato leafminer, Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae), is a major threat to tomato (Solanum lycopersicum L.) crops. After its first detection in Spain in 2006, it spread rapidly through the Western Palaearctic region, arriving in Tunisia 2 years later. The aim of this research was to assess whether generalist indigenous parasitoids are adapting to this exotic host in Tunisian tomato crops. For this, we conducted a survey in four Tunisian tomato-growing areas by sampling infested leaves of tomato and solanaceous weeds and exposing artificially infested sentinel plants. Two ectoparasitoid species were found attacking and developing on T. absoluta: Bracon sp. (Hymenoptera: Braconidae) and Necremnus sp. nr artynes (Hymenoptera: Eulophidae), whereas no egg or pupal parasitoids were found. The eulophid wasp was the most abundant with a peak of apparent parasitism rate of 25.5%. It emerged from parasitized T. absoluta young larvae in exposed sentinel plants and in sampled infested tomato leaves, both in greenhouse and open field cultivations. Bracon sp. showed a gregarious development on T. absoluta mature larvae and it was collected only on sentinel plants exposed in the Ragueda (Kiarouan) site, with 10.23% of estimated parasitism. Although further research is still needed to assess properly the ecological role of these parasitoids in the biological control of T. absoluta, this study represents the first step toward establishing the scientific basis for including these parasitoids in the Tunisian IPM and biological programs against this pest.     

Comparison of the reproductive potential of <Emphasis Type="Italic">Monochamus galloprovincialis</Emphasis> on two pine species under laboratory conditions

Monochamus galloprovincialis Olivier (Coleoptera: Cerambycidae) is one of the vectors of the pinewood nematode Bursaphelenchus xylophilus (Steiner and Buhrer) Nickle (Nematoda: Parasitaphelenchidae), the causal agent of pine wilt in susceptible pine trees. It is therefore important to study both the biological and ecological characteristics of the beetle. In this study reproductive potentials of female beetles reared on two pine species were investigated under laboratory conditions and compared using fertility tables constructed for beetles reared on each tree species. Beetle population parameters were compared between tree species. The intrinsic rate of increase and associated population parameters of beetles reared on Pinus sylvestris L. were consistently higher than those reared on P. nigra Arnold. This result suggests that P. sylvestris has a significantly greater positive effect on the reproductive potential of M. galloprovincialis populations than does P. nigra.     

First report of Pauesia silana Tremblay, 1969 (Hymenoptera: Aphidiidae), a natural enemy of the aphid Cinara pini L., in Algeria

A survey of aphids and their parasitoids in a garden park located in Algiers from March 2015 to March 2016 detected the presence of Cinara pini Linnaeus, 1758 for the first time in Algiers. This species had previously been reported in one other location in Algeria. This aphid was found on Pinus nigra and Pinus halepensis. Mummies of C. pini were found to be parasitized by Pauesia silana Tremblay, 1969. This paper provides the first report of P. silana in Algeria.     

Molecular cloning and virus-induced gene silencing of MiASB in the southern root-knot nematode, Meloidogyne incognita

Root-knot nematodes (Meloidogyne spp.), cause serious damage to agricultural production worldwide. In this study, we designed special primers based on the predicted Mitochondrial ATP synthase b subunit gene (ASB) sequence to clone the same gene in M. incognita (MiASB). The identity between the cloned MiASB and the predicted MiASB was as high as 100 %. Using the tobacco rattle virus (TRV)-mediated virus-induced gene silencing (VIGS) system, we delivered MiASB RNAi triggers to the M. incognita feeding site on tomato seedlings, resulting in significantly fewer galls on the seedlings. Sixty days after inoculation with M. incognita, the number of root galls induced on the MiASB silence-treated seedlings was reduced by 64.3 % compared to that on the control seedlings, and reduced by 64.1 % compared to that on untreated control seedlings. This study revealed the MiASB silencing had a positive effect on the control of root-knot nematodes, and MiASB may be associated with the formation of galls caused by the nematode.     

First report of flower chafer beetle, Oxycetonia versicolor, on pigeonpea and mungbean from Punjab, India

The occurrence of flower chafer beetle, Oxycetonia versicolor (Fabricius) (Scarabaeidae: Coleoptera) damaging the flowers of important grain legumes such as pigeonpea (Cajanus cajan (L.) Millsp.) and mungbean (Vigna radiata (L.) Wilczek) is reported for the first time from Punjab, India. Heavy infestation of these flower beetles at flowering may cause considerable damage to these crops. A mild to moderate level of infestation of 15?C17 beetles per ten plants was recorded at the time of peak flowering period on both the grain legumes. Adult beetles devour the flowers and buds, thereby greatly reducing the number of pods that are set. Information on important taxonomic characters of the beetle is highlighted in this report. Careful monitoring and timely reporting on this chafer beetle is necessary to avoid any future outbreak.     

Effects of rhizobacteria on parasitism by Meloidogyne ethiopica on grapevines

Meloidogyne ethiopica is one of the most important plant-parasitic nematodes affecting vines in Chile and is very aggressive and difficult to control. This study evaluated 16 strains of rhizobacteria, originally isolated from roots of grapevines, for their effects on parasitism and nematode damage to potted vine plants. The antagonistic effect of rhizobacteria was assessed by treating 2-month-old plants of cv. Chardonnay in 3-l pots with a suspension containing 1?×?10⁶?cfu?ml^?1 of the bacteria and 1,000 nematode eggs. After 6?months of growth, the plants were cut and root and canopy weights, nematode populations and root damage determined. The effect of rhizobacterial culture filtrate on hatching of nematode eggs was also assessed in vitro. Seven strains of rhizobacteria proved effective in inhibiting damage or reproduction of the nematode. These were strains of Serratia marcescens, Comamonas acidovorans, Pantoea agglomerans, Sphingobacterium spiritivorum, Bacillus mycoides, Alcaligenes piechaudii and Serratia plymuthica. A further three strains, of Bacillus megaterium, P. agglomerans and Pseudomonas savastanoi, significantly increased root weight, but did not decrease nematode damage or population density. The supernatant of all strains significantly decreased hatching of juvenile nematodes after 24?h of immersion, with isolates of P. putida and B. megaterium being the most effective.     

Determination of genotoxic effects of chlorfenvinphos and fenbuconazole in Allium cepa root cells by mitotic activity, chromosome aberration, DNA content, and comet assay

Genotoxic effects of Chlorfenvinphos and fenbuconazole were examined by using mitotic index, mitotic phase, chromosomal abnormalities, 2C DNA content and Comet assay on the root meristem cells of Allium cepa. The roots were treated with 10, 20, 40, 60, 80, and 100 ppm concentrations for 24 and 48 h. The results indicated that Chlorfenvinphos and fenbuconazole significantly decreased the mitotic index in all treatments when compared with their controls. The percentages of mitotic phases have changed. Chlorfenvinphos and fenbuconazole significantly increased the abnormal cell frequency at all concentrations and treatment periods when compared with their controls. Different abnormal mitotic figures were observed in all mitotic phases. Among these abnormalities were stickiness, anaphase bridges, c-mitosis, laggards, and micronucleus. These pesticides remarkably depressed the 2C DNA content in the root meristems of A. cepa. The genotoxicity of chlorfenvinphos and fenbuconazole in A. cepa root cells was analyzed using comet assay, which allows the detection of single strand breaks. In all concentrations, chlorfenvinphos and fenbuconazole induced a significant increase in DNA damage. Additionally, it was also researched to determine if there is a relation between the amount of DNA and the DNA damage and a regression analyses was conducted. When the data that was accumulated via comet analysis from A. cepa root tip cells that are treated with type chlorfenvinphos and fenbuconazole, was compared to the data that was acquired as the result of the measurement of 2C DNA amount, a relation with negative correlation was found, (respectively, r = −0.80 and r = −0.82). This relation factor is statistically important and strong (p < 0.05).