New distribution records ofMatsucoccus josephi andPineus pini (Homoptera) on pine trees in parts of the near east

Information is presented on new occurrences of two homopteran pests,Matsucoccus josephi Bodenheimer et Harpaz (Matsucoccidae) andPineus pini (Macquart) (Adelgidae), in Israel, Jordan and southern Lebanon.M. josephi occurs in Israel in almost all natural relicts of Aleppo pine (Pinus halepensis). It infests all plantations of Aleppo pine, brutia pine (Pinus brutia ssp.brutia) and Eldar pine (P. brutia ssp.eldarica) north of 31°12′ lat. N. Heavy damage has been observed in the Judean Foothills, Judean Mts. and northern Samaria.M. josephi and its specific predator,Elatophilus hebraicus Pericart (Hemiptera: Anthocoridae), are recorded for the first time in Jordan and southern Lebanon. The scale was found in all visited Aleppo pine and brutia pine stands in Jordan and in natural and planted brutia pine in southeastern Lebanon. Damage byM. josephi in Jordan was observed only in young plantations of Aleppo pine; in Lebanon no signs of injury were recorded.P. pini was found for the first time in Jordan, where it causes severe damage to young stands of Aleppo pine and stone pine (Pinus pinea). Contribution from the Agricultural Research Organization. No. 1225-E, 1993 series.     

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.     

Occurrence, isolation and biological activity of phytotoxic metabolites produced in vitro by Sphaeropsis sapinea, pathogenic fungus of Pinus radiata

Sphaeropsis sapinea was repeatedly isolated in Sardinia from symptomatic samples of the upper part of declining pine (Pinus radiata) plants. Observed symptoms mainly consisted of foliage chlorosis, drying of needles and cankers on branches. The S. sapinea strains were shown to produce phytotoxic metabolites in culture filtrates. Three metabolites were isolated for the first time from this fungus and identified by their spectroscopic and optical properties as R-(−)-mellein, (3R,4R)-4-hydroxymellein and (3R,4S)-4-hydroxymellein. When assayed for phytotoxic and antifungal activities on host and non-host plants and on some phytopathogenic fungi, the R-(−)-mellein showed significant activity, while the other two 3,4-dihydroisocoumarins showed only a synergic activity in both tests.     

Major pests of man-made forests in israel: origin,biology, damage and control

The important pests of the three main tree genera used in afforestation in Israel are described. The pine pests are the Israeli bast scale,Matsucoccus josephi; the pine processionary caterpillar,Thaumetopoea wilkinsoni; the bark beetlesOrthotomicus erosus, Pityogenes calcaratus andTomicus destruens; and the Mediterranean shoot moth,Rhyacionia buoliana thurificana. The cypress pests are the bark beetlesPhloeosinus armatus andP. aubei. The eucalypt borerPhoracantha semipunctata is the sole significant pest of eucalypts. All of these pests, except for the last, are considered endemic species which maintained themselves in the natural relict stands. Routine chemical control operations are conducted only againstT. wilkinsoni. Natural enemies are capable of keeping the other pest populations under good control if appropriate silvicultural measures and practices are in use.     

The role of the monoterpene composition inPinus spp. needles, in host selection by the pine processionary caterpillar,Thaumetopoea pityocampa

This paper presents preliminary results on attempts to extract and characterize the volatile secondary metabolites contained in needles of differentPinus species and to ascertain the role played by these substances on the behavior ofThaumetopoea pityocampa (Denis et Schiffermüller) females, which show a marked preference, during the oviposition period, for some indigenous and exotic species of host plants existing in mixed formation. Limonene is the most abundant monoterpene extracted fromP. pinea needles, the least favored species of pine processionary caterpillar (PPC) females, although it is present in only very low amounts in otherPinus species. An increase was observed in limonene production byP. pinea at the start of the flight period of the PPC adult, and subsequently at the beginning of the females’ oviposition period. Assays carried out in two pine stands in central Italy showed that limonene, emulsified with water and sprayed on foliage of four different pine species plants,P. sylvestris, P. nigra, P. pinaster andP. radiata, during the PPC oviposition period, provided a satisfactory degree of protection. In fact, the number of egg clusters collected from treated plants was often lower than the number of egg clusters collected from control plants and was comparable to the number of egg clusters laid onP. pinea plants. In particular (R)-(+)-limonene, although not produced in nature by pines, was the most effective deterrent. However, the effect of (S)-(-)-limonene, the enantiomer biosynthesized by pines, was also adequate.     

Further studies on the role of monoterpenes in pine host selection and oviposition ofThaumetopoea pityocampa

In a young mixed pine plantation (Pinus nigra andP. pinea) in central Italy, the influence of the pine needle monoterpenes (R)-(+)-limonene, (S)-(−)-limonene and (1S)-(−)-β-pinene on the oviposition activity of the pine processionary moth,Thaumetopoea pityocampa (Denis et Schiffermüller), was assessed. Two application methods were compared: spraying the trees with the substances emulsified with water, and setting up polyethylene dispensers from which the monoterpenes evaporated. During the moth’s flight period weekly treatments (at 500 mg of monoterpene /l water) were carried out and the evaporation from the polyethylene dispensers (each with 5 g of a single monoterpene) was checked on each occasion by weighing the dispensers. The GLM analysis did not uncover any difference between the methods of application or between the pine species.T. pityocampa laid a significantly (P=0.01) lower number of egg masses on the trees treated with (1S)-(−)-β-pinene than on those treated with the other substances and on the control trees. A ∼45% reduction in egg mass number was obtained on the pines treated with (1S)-(−)-β-pinene, independent of the level of infestation, method of application or pine species. (R)-(+)-limonene and (S)-(−)-limonene were not effective. http://www.phytoparasitica.org posting July 29, 2008.     

Detection of Diplodia sapinea in Corsican pine seeds

Diplodia sapinea is one of the major pathogens of pines worldwide. Despite the putative critical importance of seed infection in the epidemiology of the disease, this aspect of the biology of the fungus is poorly known. Here, biological and molecular methods were developed for the detection of the fungus and applied to assess D. sapinea infection in Corsican pine seeds. A buffered medium containing tannic acid and malt extract as a nutrient base was the most efficient and selective for D. sapinea recovery. A molecular method based on DNA extraction with a commercial kit and specific amplification, including an internal amplification control, was developed. A high percentage of infection (57% positive isolations) was observed in seeds obtained from fallen cones in a Corsican pine stand with no apparent symptoms of D. sapinea. Seeds collected from trees in a seed orchard showing severe symptoms of dieback caused by D. sapinea had comparatively lower infection (38%). Moreover, very low infection levels (1–5%) were observed after the standard treatment used for seed extraction, which included heating at 40°C. Diplodia sapinea was not recovered from seedlings grown from infected seed lots submitted to water stress. Overall, results suggest that the risk of disease transmission by commercial seeds is probably low, but could be further reduced by thermotherapy.     

Suppressive effect of Azotobacter chroococcum on Rhizoctonia solani infestation of potatoes

Isolates ofAzotobacter chroococcum were found to be promising for the control of infestation of potato plants withRhizoctonia solani. Inoculation with an isolate ofVerticillium biguttatum in combination with isolates ofA. chroococcum effectively protected sprouts, stems and stolons against infestation withR. solani. The effect of inoculation varied with soil temperature.No sclerotia were formed on potatoes harvested from soil in pots inoculated with isolates ofA. chroococcum plusV. biguttatum under glasshouse conditions; the yield increased significantly over the control.Samenvatting Enkele isolaten vanAzotobacter chroococcum bleken sterk antagonistisch ten opzichte vanRhizoctonia solani en leken goed bruikbaar voor een biologische bestrijding van deze ziekteverwekker van de aardappel.Beënting van de grond metVerticillium biguttatum enA. chroococcum gaf — in potproeven — een effective bescherming van spruiten, stengels en stolonen tegen aantasting doorR. solani.De vorming van sclerotiën bleef achterwege op knollen die gevormd waren in grond die was beënt metA. chroococcum plusV. biguttatum. De opbrengst uit behandelde grond was hoger dan die uit onbehandelde.De effectiviteit van de behandeling is afhankelijk van de temperatuur.     

Extracts of killedPenicillium chrysogenum Induce resistance against Fusarium wilt of melon

Dry fungal biomass ofPenicillium chrysogenum (dry mycelium), a waste product of the pharmaceutical industry, was extracted with water and applied to the roots of melon plants before or after inoculation withFusarium oxysporum f.sp.melonis (Font). Seedlings (4–6 days after emergence) treated with either acidic dry mycelium extract (DME) or neutralized dry mycelium extract (NDME) were protected against challenge infection withFom. A single drench with 2–5% DME applied 12–72 h before inoculation provided significant control of the disease compared with water-drenched, challenged seedlings. No protection was seen in plants treated 0–6 h before inoculation or 0–48 h after inoculation. Neither DME nor NDME (0.5–5%) had any effect on fungal growthin vitro, which implied that disease controlin vivo was mediated by induced resistance. The resistance induced by DME protected melon plants not only against race 1,2, but also against the three other races of the pathogen, indicating a race-non-specific resistance againstFom. Both DME and NDME significantly increased peroxidase activity and free L-proline content in seedlings 12 h and 48 h after soil drench, respectively. Resistance to Fusarium wilt was significantly associated with elevated levels of peroxidase activity but not with free L-proline content. Thus, peroxidase might be involved in the defense mechanisms activated by DME or NDME. http://www.phytoparasitica.org posting Aug. 31, 2001.     

Relationship between resistance to pine wilt disease and the migration or proliferation of pine wood nematodes

To study the relationship between resistance to pine wilt disease and the migration or proliferation of pine wood nematodes (PWN) (Bursaphelenchus xylophilus), we conducted experiments using clonally-propagated Japanese black pines (Pinus thunbergii) with pre-evaluated individual resistance levels. Bark including the cortical resin canals—one of the main migration pathways of PWN—was removed by girdling, but neither the migration of PWN nor symptom development of pine wilt disease were inhibited by this treatment in non-resistant clones. Histological observations showed no significant differences in the lumen area or the number of cortical- and xylem- axial resin canals between resistant and susceptible clone groups from a half-sib family. A bioassay using methanol extracts from resistant and susceptible clones showed that extracts from both clones showed similar attractant effects to PWN, but neither had repellent effects. The resistant clones were multi-inoculated with PWN into three split points to mimic migration in the stem. The proportion of damaged plants was not significantly different from that in single-inoculated plants (control). In this experiment, the number of PWN detected from partially-damaged plants was much higher than that from non-damaged plants. An inoculation test using stem cuttings showed that the population of PWN increased in susceptible cuttings at 1–20 days after inoculation (dai), while it remained unchanged or gradually decreased in resistant cuttings. These findings suggested that the factors contributing to resistance were associated with inhibiting the proliferation of PWN, rather than inhibiting their migration.     

Induction of systemic resistance byPseudomonas fluorescens Pf1 againstXanthomonas oryzae pv.Oryzae in rice leaves

When lower leaves of rice plants were inoculated with powder formulation of a saprophytic strain ofPseudomonas fluorescens, Pfl, upper leaves, in addition to the inoculated lower leaves, showed resistance to the rice bacterial blight pathogenXanthomonas oryzae pv.oryzae. When the leaves were challenge-inoculated withX. oryzae pv.oryzae 4 days afterP. fluorescens application on lower leaves, the disease intensity in upper leaves decreased from 6.7 to 1.1. When rice seeds were treated with the formulation ofP. fluorescens Pfl and sown, 30-day-old seedlings showed resistance toX. oryzae pv.oryzae and the disease intensity decreased from 6.8 to 1.2. The induced resistance was transient; leaves sprayed withP. fluorescens Pfl at 30 days after treatment and leaves of 60-day-old seedlings fromP. fluorescens-treated seeds did not show resistance to the pathogen. In field trials, seed treatment followed by foliar application of the powder formulation ofP. fluorescens Pfl effectively controlled rice bacterial blight and increased the yield. In the induced resistant leaves a sharp increase in lignification and activities of peroxidase, phenylalanine ammonia-lyase and 4-coumarate: CoA ligase was observed when the leaves were challenge-inoculated withX. oryzae pv.oryzae. An approximately threefold increase in lignin content, peroxidase activity and phenylalanine ammonia-lyase activity and a fivefold increase in 4-coumarate: CoA ligase activity were observed 5 days after challenge inoculation withX. oryzae pv.oryzae in rice leaves pretreated withP. fluorescens for 5 days. A similar increase in defense-related activities was not observed in susceptible interactions or inP. fluorescens-treated plants at later stages of interactions when no resistance to the pathogen was observed.     

Activation of Defense Responses to Fusarium Infection in Asparagus densiflorus

Defense responses to Fusarium oxysporum f. sp. asparagi and F. proliferatum were compared after root inoculation of the asparagus fern, Asparagus densiflorus vars. Myersii and Sprengeri, and cultivated asparagus, A. officinalis cv. Guelph Millennium. Both varieties of A. densiflorus exhibited a hypersensitive response with rapid death of epidermal cells within 8–24 h and restricted the fungal growth. In A. officinalis roots, rapid cell death was not found, and necrotic lesions were observed 8–14 d after fungal inoculation. Peroxidase and phenylalanine ammonia-lyase activities increased significantly in inoculated A. densiflorus but not A. officinalis plants. Local and systemic induction of peroxidase activity was detected after pathogen inoculation in root and spear tissues, respectively, of A. densiflorus. POX activity decreased in roots of inoculated A. officinalis by 8 d post-inoculation. Germination and germ tube growth were inhibited when spores of F. oxysporum f. sp. asparagi were incubated in root exudates and on root segment surfaces of inoculated A. densiflorus plants exhibiting hypersensitive cell death. Spore germination of F. proliferatum and three fungi non-pathogenic to cultivated asparagus was inhibited as well. Rapid induction of hypersensitive cell death in A. densiflorus was associated with restriction of fungal growth, and activation of peroxidase and phenylalanine ammonia-lyase, two defense enzymes thought to be important for plant disease resistance.     

Analysis of nematodes and soil-borne fungi fromAmmophila arenaria (Marram grass) in Dutch coastal foredunes by multivariate techniques

A survey was carried out at nine locations in the Dutch coastal foredunes to identify the species of soil borne fungi and nematodes associated withAmmophila arenaria (Marram grass).Ammophila arenaria is a sand binding grass that is very important for the stabilization of coastal foredunes. Degeneration of the plants occurs at stabilized sites and is supposed to be caused by a combination of soil-borne fungi and nematodes. Canonical correspondence analysis (CCA) and two-way indicator species analysis (TWINSPAN) were used to examine which fungal and nematode species usually coexist in the rhizosphere of vigorous and early declining stands ofA. arenaria. In total, 47 species of fungi and 10 genera of plant-parasitic nematodes were found. According to CCA, the community of soil organisms of stands that were more than 10 years old was significantly different from recently established stands of 3 years old. Also, the community of soil organisms isolated from calcareous locations differed significantly from that of lime-poor locations. No relationship between the vigour of the plants (vigorous vs. early declining) and the soil borne species composition was found, although in roots of vigorous stands, the number of nematodes was higher than that of early declining stands. A relatively large group of soil organisms occurred generally. This group possibly contains an ubiquitous pathocomplex that cause the growth reducing effects of biotic origin which generally occur inA. arenaria. Analysis of this group of nematodes and fungi by TWINSPAN resulted in 9 different combinations of concurring soil organisms of which 5 combinations were present at all investigated locations. Two of the latter combinations contained both nematodes and fungi. The first contained three endoparasitic nematodes (Meloidogyne maritima, Heterodera spp. andPratylenchus sp.) that concurred with the fungusMucor hiemalis. The second group containedHeterodera spp.,Telotylenchus ventralis, Filenchus sp. together with the potentially plant-pathogenic fungiMicrodochium bolleyi and Fusarium culmorum, as well as the fungiMortierella sp. andTrichoderma harzianum, all in relatively high numbers.It is concluded that both CCA and TWINSPAN are valuable exploratory techniques, especially when used in combination, to detect possible combinations of soil organisms which may be involved in the degeneration ofA. arenaria. Further identifications of harmful organisms should be obtained from experiments.     

Incidence and distribution of Heterobasidion and Armillaria and their influence on canopy gap formation in unmanaged mountain pine forests in the Swiss Alps

Various disturbance factors on different spatial scales can lead to the creation of canopy gaps in forest ecosystems. In this study, we investigated the role of root rot fungi in the formation of canopy gaps in the Swiss National Park in the Central Alps. Dying or recently dead mountain pine (Pinus mugo subsp. uncinata trees (n = 172) and saplings (n = 192) from 42 canopy gaps were assessed for Armillaria and Annosum root rot. Heterobasidion annosum s.str. proved to be the dominant pathogen and was isolated from 49% of the trees and 64% of the saplings. Armillaria was found on 13% of the trees and 20% of the saplings. Three Armillaria species, A. borealis, A. cepistipes, and A. ostoyae, were identified. Armillaria ostoyae was the most frequent species, accounting for 72% of all Armillaria isolates. A total of 31 (74%) gaps were associated with H. annosum, and six (14%) with A. ostoyae. The remaining gaps were either associated with both pathogens (7%) or with other, unknown, factors (5%). Our findings suggest that the two pathogenic fungi, H. annosum s.str. and A. ostoyae, are the main reason for the large-scale mortality of mountain pines and the creation of canopy gaps in high elevation forests of the Swiss National Park.     

高效新型杀松材线虫剂的筛选及其林间防效

为筛选出新型的高效松材线虫Bursaphelenchus xylophilus防治药剂,采用浸渍法室内测定了氯氟氰虫酰胺、阿维菌素、甲维盐、灭多威、特丁硫磷、甲基异柳磷和吡虫啉7种药剂对松材线虫的毒杀作用和对其繁殖能力的影响,采用高效液相色谱仪测定氯氟氰虫酰胺在马尾松体内的输导分布,并在林间开展树干注射氯氟氰虫酰胺抗松材线虫病试验。结果表明,7种药剂中氯氟氰虫酰胺对松材线虫的毒力最强,LC_(50)为0.019 mg/L,阿维菌素和甲维盐次之,LC_(50)分别为0.0213 mg/L和0.0214 mg/L。氯氟氰虫酰胺树干注射3个月内能迅速从马尾松基部传导至树梢顶部,树干边材东、南面的药剂含量显著高于西、北面,且树干不同高度的氯氟氰虫酰胺含量均高于其LC50;氯氟氰虫酰胺制剂在林间注干后,对人工接种病原松材线虫松树的防治效果为73.33%,自然感染松材线虫病松树的死亡率降至2.00%,而对照试验中人工接种松材线虫松树和自然感染松材线虫病松树的死亡率分别为93.33%和19.67%。表明氯氟氰虫酰胺制剂能有效预防松树个体的松材线虫病发生与为害,可以推广使用。     

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.     

Comparison of the Susceptibility of Quercus petraea, Q. robur and Q. rubra to Collybia fusipes

Collybia fusipes is the cause of a root rot of Quercus petraea (sessile oak), Q. robur (pedunculate oak) and Q. rubra (red oak). This parasite is often reported to cause problems in stands of red oaks and field evidence suggests that this North American oak species is more susceptible than the two European oak species. Young saplings of the three oak species and of chestnut, Castanea sativa, in the glasshouse, and also mature sessile and red oaks growing in the same stand were inoculated with C. fusipes to compare their susceptibility. Red oak, both as young seedlings and mature trees, was more susceptible to C. fusipes than sessile oak. Chestnut seedlings were as susceptible as sessile oak. Susceptibility of pedunculate oak seedlings was intermediate between red oak and sessile oak. In one experiment this species was significantly less susceptible than red oak, and in the other it was as susceptible.     

Selective accumulation of Trichoderma species in soils suppressive to radish damping-off disease after repeated inoculations with Rhizoctonia solani, binucleate Rhizoctonia and Sclerotium rolfsii

Artificial suppression of radish damping-off disease was induced by repeated soil inoculations with Rhizoctonia solani, binucleate Rhizoctonia (BNR) and Sclerotium rolfsii in pot systems. Soils repeatedly inoculated with R. solani and BNR showed suppressive to disease caused by R. solani and S. rolfsii, while soils repeatedly inoculated with S. rolfsii were suppressive to disease caused by S. rolfsii but not by R. solani. Species of Trichoderma were consistently isolated from soils repeatedly inoculated with R. solani, BNR and S. rolfsii. These Trichoderma spp. accumulated selectively in relation to the fungal species that was repeatedly added to the soils. The ratios of the frequencies of T. viride, T. harzianum and T. hamatum were 5:2:2 and 8:5:2 in soils repeatedly inoculated with R. solani and BNR, respectively. In S. rolfsii- inoculated soils, T. koningii was predominantly isolated. T. viride, T. harzianum and T. hamatum isolates obtained from either R. solani or BNR after repeated additions to the soils suppressed radish damping-off disease caused after challenge inoculations with R. solani or S. rolfsii. Among the Trichoderma species, T. viride consistently yielded high levels of suppression. However, isolates of T. koningii obtained from S. rolfsii-infested soils suppressed disease caused by S. rolfsii but failed to suppress disease caused by R. solani. Generally, the species of Trichoderma accumulated in a selective pattern that was closely related to the species of fungal pathogen used to induce the suppressive soil.     

Pythium rot of figmarigold (<Emphasis Type="Italic">Lampranthus spectabile</Emphasis>) caused by <Emphasis Type="Italic">Pythium aphanidermatum</Emphasis>

A new leaf rot disease was found on the leaves of figmarigold (Lampranthus spectabile). The causal organism, identified as Pythium aphanidermatum was found to cause the same symptoms after artificial inoculation and was then reisolated from the inoculated plants. We propose to name the disease Pythium rot of figmarigold.     

Aleppo pine provenances vary in susceptibility and secondary chemical response to Gremmeniella abietina infection

Aleppo pine is a thermophilic species that has become a popular tree species in plantings even beyond its natural habitat. In 1999 the pathogenic fungus Gremmeniella abietina was isolated for the first time in Aleppo pine plantations in Spain. The main objective of this study was to analyse the variation in susceptibility to G. abietina (European race, biotype A) infections among trees from five Aleppo pine provenances. Artificial inoculations were performed at two different times in January 2012. The susceptibility of the trees was evaluated by recording disease severity and the length of internal stem necrosis produced by the pathogen. In addition, the concentrations of two flavanone compounds were quantified as putative indicators of resistance. Provenances and G. abietina isolates both significantly affected levels of necrosis although the results were dependent on the time of inoculation. There was a relationship between provenance and resistance, with trees of higher elevation provenances being more susceptible to disease than trees of lower elevation provenances. The amount of naringenin flavanone from trees was significantly different between provenances, suggesting that it is a possible indicator value for resistance. Conversely, no differences were found in the concentration of eriodictyol in trees between provenances. The results show that the provenance‐dependent variation in the susceptibility of Aleppo pine to G. abietina should be considered in selection of seed sources for restoration.