Encapsulation rates of the parasitoid <Emphasis Type="BoldItalic">Anagyrus</Emphasis> sp. nr. <Emphasis Type="BoldItalic">pseudococci</Emphasis>, by three mealybug species (Hemiptera: Pseudococcidae)

Laboratory studies assessing the degree of suitability of the mealybugs Planococcus ficus (Signoret), Planococcus citri (Risso) and Pseudococcus calceolariae (Maskell), towards the Sicilian ecotype of the encyrtid parasitoid Anagyrus sp. nr. pseudococci were carried out. All three species of mealybugs were shown to encapsulate the eggs of the encyrtid; however, significant differences were revealed among them in rates of encapsulation and/or superparasitism. The level of aggregate encapsulation and effective encapsulation of the parasitoid eggs by P. citri (74.95 ± 0.87 and 60.19 ± 1.70, respectively) was significantly higher than that recorded for P. ficus (aggregate encapsulation = 58.43 ± 0.83 and effective encapsulation = 31.31 ± 1.55) and significantly lower than the values found in Ps. calceolariae (93.99 ± 0.97 and 88.61 ± 2.03, respectively). As such, rates of parasitism were significantly lower for P. ficus compared with both P. citri and Ps. calceolariae. The two latter species of mealybugs showed similar rates of parasitism by A. sp. nr. pseudococci. Moreover, a significantly higher rate of superparasitism was found for Ps. calceolariae compared with both P. citri and P. ficus, whereas no significant differences were found between the two species of Planococcus for this parameter.     

<Emphasis Type="BoldItalic">Didymella glomerata</Emphasis><Emphasis Type="Bold">causing leaf blight on pistachio</Emphasis>

During 2015 and 2016, we detected blighted leaves of pistachio (Pistacia vera) trees in different orchards in Arizona (USA). A Phoma-like species was isolated from pycnidia that appeared embedded in the leaf tissue. The pathogen was identified by means of morphological characteristics and DNA analysis (by sequencing of the ITS, BT, and EF regions) as Didymella glomerata. The optimum temperature for mycelial growth of the pathogen was around 25 °C. Inoculation tests were conducted on healthy and wounded pistachio leaves, fruits, and shoots of the cv. Kerman (female) and the cv. Peters (male). Overall, the pathogen was highly virulent on leaves of both pistachio cultivars and did not need injuries for infection. Conversely, the pathogen did not cause any macroscopic symptoms on the inoculated fruits and shoots but showed a certain endophytic behavior in the shoots. Also, data on the ability of different fungicides to inhibit the in vitro mycelial growth of the pathogen are presented.     

Insect growth-regulating effects of <Emphasis Type="BoldItalic">Withania somnifera</Emphasis> in a polyphagous pest, <Emphasis Type="BoldItalic">Spodoptera litura</Emphasis>

Treatment of sixth instar larvae and pupae of the polyphagous pest Spodoptera litura Fabr. (Lepidoptera: Noctuidae) with an acetone extract of leaves of Ashwagandha, Withania somnifera L. (Solanaceae), caused toxicity, molt disturbances, formation of larval–pupal, pupal–adult intermediates and adultoids. Our results suggest that W. somnifera acts as an insect growth regulator causing disruption of the endocrine mechanism regulating molting and metamorphosis.     

Comparative biology and life tables of <Emphasis Type="BoldItalic">Trichogramma aurosum</Emphasis> on <Emphasis Type="BoldItalic">Cydia pomonella</Emphasis> at constant temperatures

The influence of constant temperatures on biological parameters of German strains of Trichogramma aurosum Sugonjaev & Sorokina (Hymenoptera: Trichogrammatidae) was evaluated in the laboratory on eggs of Cydia pomonella L. (Lepidoptera: Tortricidae). Development time and longevity of all strains were decreased as temperature increased. Development time of the strains differed significantly only when exposed to 15°, 20°, and 25°C. Cumulative fertility and longevity differed significantly at 15° and 20°C. Realized fertility differed significantly at all constant temperatures. Emergence rates of all strains were less than 65% and were decreased even further as temperature increased. Female-biased sex ratio ranged from 65% to 100% at all constant temperatures. The low temperature threshold for T. aurosum was 10°C and the mean number of degree-days at 15°, 20°, 25° and 30°C was 175, 183, 173 and 185, respectively. The Bavarian strain tolerated high temperatures and had the highest parasitization capability, while the Hessian strain had the lowest parasitization at all temperatures. Fertility life table analysis revealed a major effect of temperature on the population growth parameters. Net reproductive rate was highest at intermediate constant temperatures in all strains, with the highest rate recorded for the Bavarian strains at all constant temperatures. Mean cohort generation time, and population doubling time decreased as temperature increased. The daily intrinsic rate of increase and finite rate of increase were positively correlated with temperature. The relevance of our results is discussed in the context of climatic adaptation, intraspecific variability and biological control.     

Calcium fertilizers induce soil suppressiveness to <Emphasis Type="BoldItalic">Phytophthora cinnamomi</Emphasis> root rot of <Emphasis Type="BoldItalic">Quercus ilex</Emphasis>

Based on the observation that the root disease caused by P. cinnamomi on Q. ilex has a low incidence and severity in soils with medium-high Ca²⁺ content, we studied the ability of Ca²⁺ fertilizers to induce soil suppressiveness to the pathogen. Studies on cultures of P. cinnamomi exposed to different Ca²⁺ fertilizers in vitro showed significant inhibition of sporangial, chlamydospore and zoospore production at millimolar concentrations while mycelial growth was mainly unaffected. Experiments performed with artificially infested soil showed that some Ca²⁺ fertilizers induce a significant decrease on chlamydospore viability. Additionally, greenhouse experiments using artificially infested soils showed a significant reduction of foliar and root symptom severities in Holm oak seedlings growing in soils amended with Ca²⁺ fertilizers. We suggest that limestone amendments in oak rangelands could enhance the suppressiveness of soils to P. cinnamomi, and it is likely that the inhibition of sporangial production was the main mechanism involved.     

<Emphasis Type="Italic">Mycosphaerella</Emphasis> species occurring on <Emphasis Type="Italic">Eucalyptus globulus</Emphasis> in Portugal

Mycosphaerella leaf disease (MLD) is caused by species of Mycosphaerella and several anamorphic form genera that have been connected to Mycosphaerella. Until recently, MLD of eucalypts was largely ignored in Portugal. However, serious damage to Eucalyptus globulus has been reported since 1999 when frequent and severe defoliation of young trees was observed. The severity of this disease prompted a preliminary study of the Mycosphaerella species associated with major symptoms of a leaf blotch disease in commercial plantations of E. globulus in Portugal, which is presented here. The species were identified by molecular methods based on the ITS1-5.8S-ITS2 cluster, together with morphological characters. In addition to confirming the species previously recorded, Mycosphaerella vespa is reported for the first time from Portugal, while the status of Mycosphaerella grandis remains to be resolved.     

Influence of plant stage and organ age on the receptivity of <Emphasis Type="BoldItalic">Pisum sativum</Emphasis> to <Emphasis Type="BoldItalic">Mycosphaerella pinodes</Emphasis>

On spring pea, ascochyta blight (Mycosphaerella pinodes) frequently appears at the plant base on yellowing stipules and disease scores are higher on basal parts of the plants than on the uppermost parts. In order to investigate the relationship between pea plant growth stage and/or organ age, and ascochyta blight on whole plants and detached stipules and pods, two experiments were conducted in 2009 and 2010 under controlled conditions. This study showed that plant stage does not influence receptivity to ascochyta blight before the appearance of the first visual signs of senescence (beginning of yellowing). When stipules were green, regardless of the plant stage, no differences of receptivity was observed (except for the youngest stipule(s) at the top of the plant). Plant stage only had an effect on receptivity by the way of the importance of the visual senescence of the organs and visual senescence has a more predominant effect on plant receptivity than the plant stage considered alone. An effect of the nodal position, linked with the stipule age, was observed on whole plant inoculation, with a decreasing disease severity gradient from the base to the top of the plant which was explained by a greater receptivity for the basal/older stipules which had begun yellowing. On detached stipules, a higher receptivity was observed as soon as visual senescence had been observed. On pods, during their filling, few symptoms appeared and severity was important as soon as they began to yellow. The effect of ascochyta blight on induced senescence of the infected stipules was also observed.     

<Emphasis Type="Italic">Corythucha ciliata</Emphasis>, a new <Emphasis Type="Italic">Platanus</Emphasis> pest in Turkey

An invasive Tingidae, the platanus lace bug Corythucha ciliata (Say, 1832) (Hemiptera: Tingidae), which specializes on Platanus spp., was found for the first time in Turkey in 2007; it was recorded from a 120 km² area in the northwestern part of the country. Infestations occurred in an area between Taşkesti and Abant in Bolu Province, which is located near major cities and two main motorways. The pest species is newly spreading in Turkey, causing noticeable damage to Platanus orientalis trees.     

Evaluation of the <Emphasis Type="BoldItalic">Sss</Emphasis> AgriStrip rapid diagnostic test for the detection of <Emphasis Type="BoldItalic">Spongospora subterranea</Emphasis> on potato tubers

Spongospora subterranea, f.sp. subterranea (Sss), which causes powdery scab, is mainly spread through infected seed tubers and survives in contaminated soil for many years. The visual assessment of tuber lots by inspectors carries the risk of misidentification due to the difficulty of distinguishing lesions caused by either Sss or Streptomyces spp.. To avoid this, the “Sss AgriStrip”, a rapid and lab-independent test tool based on a lateral flow immunoassay has been developed, and we assessed its accuracy and sensitivity for detecting Sss. The Sss AgriStrip performed as well as other lab-based identification methods. The Sss AgriStrip, microscopy, ELISA, PCR, and real-time PCR techniques identified infection with S. subterranea in all tubers with typical powdery scab lesions. When lots with tubers showing a mixture of typical and atypical (suspicious) symptoms were tested, the presence of S. subterranea was confirmed in all lesions by all methods. The DNA content was generally lower in atypical than in typical lesions. Diverse and suspicious symptoms, which were difficult to assign to either powdery or common scab, tested negative with Sss AgriStrip and the other methods. This was despite microscopic observation of sporosori-like structures in some samples. Isolation and molecular identification confirmed that these lesions were mostly caused by Streptomyces spp. The Sss AgriStrip is as sensitive as DAS-ELISA with a detection limit between 1 and 10 sporosori per ml buffer. It is ideal for rapid and selective detection of Sss on farms and border inspection points to prevent spread of the pathogen.     

Predators of <Emphasis Type="Italic">Marchalina hellenica</Emphasis> (Hemiptera: Marchalinidae) on pine forests in Turkey

The honeydew of Marchalina hellenica is collected by honeybees for pine honey production, which is of great economic importance in Turkey. During 2009–2011 we investigated the predators of M. hellenica, which is distributed mainly in the areas with a Mediterranean climate – in the Aegean, Marmara and Mediterranean regions of Turkey. The findings showed that M. hellenica has many predators in the studied areas and that these play an important role in the forest ecosystem. These predators are: Anystis baccarum (L.) (Acarina: Anystidae); Allothrombium triticium Zhang and Allothrombium pulvinum Ewing (Acarina: Trombidiidae); Neoleucopis kartliana (Tanasijtshuk) (Diptera: Chamaemyiidae); Myrrha octodecimguttata (L.), Rodolia cardinalis Mulstant, Scymnus subvillosus (Goeze) (Coleoptera: Coccinellidae), Dichochrysa genei (Rambur), Dichochrysa prasina (Burmeister) and Chrysoperla lucasina (Lacroix) (Neuroptera: Chrysopidae); Wesmaelius subnebulosus (Stephens) (Neuroptera: Hemerobiidae), Cardiastethus nazarenus Reuter and Elatophilus pachycnemis Horváth (Hemiptera: Anthocoridae). The most efficient and common predator was N. kartliana, here recorded for the first time from Turkey.     

Parasitoid complex of <Emphasis Type="Italic">Planococcus ficus</Emphasis> (Signoret) (Hemiptera: Pseudococcidae) in Turkey

In this study a survey for determining the parasitoid complex of Planococcus ficus (Signoret) (Hemiptera: Coccomorpha: Pseudococcidae) was conducted in Adana and Mersin Provinces, Turkey. Five primary, two primary/secondary, two secondary parasitoid species associated with P. ficus, were found. Clausenia josefi Rosen and Chartocerus kurdjumovi (Nikol’skaya) are new records for Turkish fauna.     

Diversity of <Emphasis Type="Italic">Colletotrichum</Emphasis> species in coffee (<Emphasis Type="Italic">Coffea arabica</Emphasis>) plantations in Mexico

The aim of this study was to identify the Colletotrichum species associated with anthracnose symptoms in coffee (Coffea arabica L.) plantations in northern Puebla, Mexico. In 2013, five surveys were conducted in different production areas and at different altitudes. Symptomatic leaves, shoots, and ripe and unripe fruits of the coffee variety Red Caturra were collected. Isolates were obtained and the Colletotrichum species were identified morphologically and characterized by multilocus sequence analyses of the ACT, CAL, GAPDH, and TUB2 genes and the rDNA region. Additionally, pathogenicity tests were conducted using six isolates. We identified C. gigasporum, C. gloeosporioides, C. karstii (two isolates), C. siamense, and C. theobromicola. This is the first report of these five species infecting leaves of coffee. The symptoms caused by these species were characterized, but the species causing Coffee Berry Disease was not found. This is the first report of a complex of species affecting coffee plants in the same geographical area in Mexico, and suggests that other complexes of species may be important pathogens in coffee-producing areas elsewhere.     

First report of blueberry red ringspot disease caused by <Emphasis Type="Italic">Blueberry</Emphasis><Emphasis Type="Italic">red</Emphasis><Emphasis Type="Italic">ringspot</Emphasis><Emphasis Type="Italic">virus</Emphasis> in Japan

Virus-like symptoms—red ringspots on stems and leaves, circular blotches or pale spots on fruit—were found on commercial highbush blueberry (Vaccinium corymbosum) cultivars Blueray, Weymouth, Duke and Sierra in Japan. In PCR testing, single DNA fragments were amplified from total nucleic acid samples of the diseased blueberry bushes using primers specific to Blueberry red ringspot virus (BRRV). Sequencing analysis of the amplified products revealed 95.7–97.7% nucleotide sequence identity with the BRRV genome. This paper is the first report of blueberry red ringspot disease caused by BRRV in Japan. The nucleotide sequence data reported in this paper are available in the GenBank/EMBL/DDBJ database as accessions AB469884 to AB469893 for BRRV isolates from Japan.     

Nonhost resistance of <Emphasis Type="Italic">Arabidopsis thaliana</Emphasis> against <Emphasis Type="Italic">Colletotrichum</Emphasis> species

Arabidopsis thaliana exhibits a durable resistance called nonhost resistance against nonadapted fungal pathogens. A. thaliana activates preinvasive resistance and terminates entry attempts by nonadapted fungi belonging to the genus Colletotrichum, which cause anthracnose disease in many plants. In the interaction between A. thaliana and nonadapted C. tropicale, the preinvasive resistance involves the PENETRATION 2-related antifungal secondary metabolite pathway and the ENHANCED DISEASE RESISTANCE 1-dependent antifungal peptide pathway. The development of invasive hyphae by C. tropicale owing to the reduction of preinvasive resistance then triggers the blockage of further hyphal expansion via the activation of the second layer of resistance, i.e., postinvasive resistance, which guarantees the robustness of the nonhost resistance of A. thaliana against Colletotrichum pathogens. Both the tryptophan-derived metabolic pathway and glutathione synthesis play critical roles in the postinvasive resistance against C. tropicale, although the molecular mechanism of postinvasive resistance remains to be elucidated. In this review, we describe the current understanding of the molecular background of the Arabidopsis nonhost resistance against Colletotrichum fungi and discuss perspectives for future research on this durable resistance.     

Identity and pathogenicity of <Emphasis Type="Italic">Fusarium</Emphasis> species associated with crown rot on wheat (<Emphasis Type="Italic">Triticum</Emphasis> spp.) in Turkey

An extensive survey was carried out to collect Fusarium species colonizing the lower stems (crowns) of bread wheat (Triticum aestivum L.) and durum wheat (T. durum Desf.) from different wheat growing regions of Turkey in summer 2013. Samples were collected from 200 fields representing the major wheat cultivation areas in Turkey, and fungi were isolated from symptomatic crowns. The isolates were identified to species level by sequencing the translation elongation factor 1-alpha (TEF1-α) gene region using primers ef1 and ef2. A total of 339 isolates representing 17 Fusarium species were isolated. The isolates were identified as F. culmorum, F. pseudograminearum, F. graminearum, F. equiseti, F. acuminatum, F. brachygibbosum, F. hostae, F. redolens, F. avenaceum, F. oxysporum, F. torulosum, F. proliferatum, F. flocciferum, F. solani, F. incarnatum, F. tricinctum and F. reticulatum. Fusarium equiseti was the most commonly isolated species, accounting for 36% of the total Fusarium species isolated. Among the damaging species, F. culmorum was the predominant species being isolated from 13.6% of sites surveyed while F. pseudograminearum and F. graminearum were isolated only from 1% and 0.5% of surveyed sites, respectively. Six out of the 17 Fusarium species tested for pathogenicity caused crown rot with different levels of severity. Fusarium culmorum, F. pseudograminearum and F. graminearum caused severe crown rot disease on durum wheat. Fusarium avenaceum and F. hostae were weakly to moderately virulent. Fusarium redolens was weakly virulent. However, F. oxysporum, F. equiseti, F. solani, F. incarnatum, F. reticulatum, F. flocciferum, F. tricinctum, F. brachygibbosum, F. torulosum, F. acuminatum and F. proliferatum were non-pathogenic. The result of this study reveal the existence of a wide range of Fusarium species associated with crown rot of wheat in Turkey.     

Characterization of <Emphasis Type="Italic">Inago1</Emphasis> and <Emphasis Type="Italic">Inago2</Emphasis> retrotransposons in <Emphasis Type="Italic">Magnaporthe oryzae</Emphasis>

From the genome of a Japanese field isolate of the rice blast fungus, Magnaporthe oryzae, we newly identified Inago1 and Inago2 LTR retrotransposons. Both elements were found to be Ty3/gypsy-like elements whose copies were dispersed within the genome of Magnaporthe spp. isolates infecting rice and other monocot plants. Southern hybridization patterns of nine re-isolates derived from conidia of the strain Ina168 produced after a methyl viologen treatment were not changed, indicating that the insertion pattern of Inago elements is relatively stable.     

Identification and characterization of <Emphasis Type="Italic">Alternaria alternata</Emphasis> (Fr.) Keissler causing <Emphasis Type="Italic">Ceratonia</Emphasis> Blight disease of carob (<Emphasis Type="Italic">Ceratonia siliqua</Emphasis> L.) in Turkey

A new dagger nematode, Xiphinema tica n. sp., is described and illustrated from several populations extracted from soil associated with several crops and wild plants in Costa Rica. The new dagger nematode is characterised by a moderate body size (3276–4240 μm), a rounded lip region, ca 13.5 μm wide, separated from body contour by a shallow depression, amphidial fovea large, stirrup-shaped, a moderately long odontostyle ca 135 μm long, stylet guiding ring located at ca 122 μm from anterior end, vulva almost equatorial (50–54%), well-developed Z-organ, with heavy muscularised wall containing in the most of specimens observed two moderately refractive inclusions variable in shape (from round to star-shaped), with uterine spines and crystalloid bodies; female tail short, dorsally convex-conoid, with rounded end and a small peg, with a c’ ratio ca 0.8, bearing two or three pairs of caudal pores and male absent. The unique and novel uterine differentiation based on the coexistence of a well-developed Z-organ mixed with uterine spines and crystalloid bodies in Xiphinema prompted us to update and include this combination of characters in the polytomous key of Loof and Luc (1990). Integrative diagnosis was completed with molecular data obtained, using D2-D3 expansion segments of 28S rDNA, ITS1-rDNA, partial 18S–rDNA and the partial mitochondrial gene cytochrome c oxidase subunit 1 (coxI). The phylogenetic relationships of this species with other Xiphinema spp. indicated that X. tica n. sp. was monophyletic to the other species from the morphospecies Group 4, Xiphinema oleae.     

Advanced lentil lines screened for resistance to <Emphasis Type="BoldItalic">Fusarium oxysporum</Emphasis> f. sp. <Emphasis Type="BoldItalic">lentis</Emphasis> under greenhouse and field conditions

Fusarium oxysporum f. sp. lentis is the most important pathogen of lentil plants, and most areas under lentil cultivation are reported to have a fusarium wilt disease background. The plants are infected in the seedling stage and later stages of their development. Fusarium wilt disease, which has appeared at high incidence rates during recent years, has caused sharp drops in the yield, especially in Moghan, in the northwest of Iran. Forty-five isolates of the pathogen were collected from different regions of the country with two isolates from ICARDA in the summer of 2008 and identified using Nelson’s key. The pathogenicity of the collected isolates was studied on a sensitive line (ILL 4605) under greenhouse conditions and significant differences in pathogenicity were found among them. The most pathogenic isolates from three provinces, East Azerbaijan (EA 30), Ardebil (Ar 3) and Khorasan (Kh 45), were selected and used in screening of 55 developed lines under greenhouse and field conditions. In the greenhouse, test plants were inoculated by immersing root tips in spore suspension and sowing seeds in pre-infested pot soil. Field tests were carried out in a naturally highly infested farm. At all stages, the plant response to the disease was based on the percentage of dead plants. Cluster analyses of the greenhouse and field data led to the selection of three lines (81S15, FLIP2007-42 L and FLIP2009-18 L) that were resistant under greenhouse and field conditions.