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1.
2.
Ophiostoma species were isolated from bark beetles and Abies mariesii, A. veitchii and A. homolepis attacked by the beetles in Nikko, Tochigi, central Honshu, Japan. One to two Ophiostoma species were frequently isolated from each species of bark beetle. Ophiostoma subalpinum was the most common associate of Cryphalus montanus. Ophiostoma sp. B as well as O. subalpinum was a common fungus associated with Polygraphus proximus. Ophiostoma europhioides was isolated from Dryocoetes hectographus and D. autographus as one of the common associates. Ophiostoma sp. J and Ophiostoma sp. S were frequently isolated from D. autographus and D. striatus, respectively. These fungi seem to have specific relationships with particular bark beetles. Ophiostoma sp. B, Ophiostoma sp. J and Ophiostoma sp. S have unique morphological characteristics and appear to be new species. Five trees of A. veitchii, approximately 43 years old, were inoculated with five Ophiostoma species to assess the relative virulence of the fungi. Ophiostoma subalpinum, Ophiostoma sp. B, and O. europhioides had relatively higher virulence than the other species studied.  相似文献   

3.
Ophiostomatoid fungi are known to be associated with various species of bark beetles. However, information about fungal associates of root‐feeding bark beetles in Europe is still fragmentary. For this reason, the fungal associates of Hylastes ater, H. opacus and Hylurgus ligniperda on Pinus sylvestris were isolated and identified. A total of 743 fungal isolates were collected and separated into 10 morphological groups. Analyses of ITS rDNA and partial β‐tubulin gene sequences confirmed that these groups represented distinct species. The 10 species included a total of 13 associations between fungi and bark beetles that had not been recorded previously. All of the bark beetles examined were frequently associated with ophiostomatoid fungi. The fungal diversity and relative abundance of species were very similar in the three species of root‐feeding bark beetles. The most commonly encountered associates of these beetles were Grosmannia radiaticola, Leptographium lundbergii, L. procerum and L. truncatum. Insect infestation data furthermore suggest that Hylastes spp. and Hg. ligniperda are also important vectors of the fungal pathogen Sphaeropsis sapinea.  相似文献   

4.
The objective of this study was to elaborate a statistical method for estimating the total average density of infestation of silver fir (Abies alba Mill.) windfalls by the bark beetle (Pityokteines curvidens Germ.) that allows calculation of estimation errors and does not require debarking of the whole stem. The study was conducted in near-natural forests with A. alba growing in the Świętokrzyski National Park in Central Poland. In total, 56 windfalls of this species were examined. Two main patterns (A and B) of spatial distribution of P. curvidens egg galleries on stems of A. alba were observed. In pattern A, egg galleries were present in the first 1-m length of stem (measured from the base), and the probability of infestation in the first, second, and third 1-m-long stem section was 100%; it then decreased as the distance from the tree base increased. In pattern B, egg galleries were absent from the first 1-m length, but the probability of infestation in successive 1-m lengths increased (from the second to the ninth sections); then it decreased (from the 10th to the 18th sections). The linear regression equations were calculated for trees with the infested (pattern A) and uninfested (pattern B) first 1-m-long stem section measuring from the tree base. The most significant correlation between the number of P. curvidens egg galleries in individual 1-m-long stem sections and the total infestation density in the case of pattern A was found for the sixth and seventh sections counting from the tree base (coefficients of determination were 0.8551 and 0.8516, respectively, while the mean relative errors of estimation did not exceed 28%), and in the case of pattern B for the tenth section (coefficient of determination was 0.7992, and the mean relative error of estimation was 39.7%). The method presented in this paper facilitated quick estimation of the density of infestation of A. alba stems by P. curvidens. Together with survey sampling, it allows estimation of the P. curvidens numbers in the area investigated, also in stands situated in zones under strict protection in nature reserves and national parks.  相似文献   

5.
Allergic diseases such as bronchial asthma, perennial rhinitis, and atopic dermatitis caused by the house dust mites Dermatophagoides pteronyssinus and Dermatophagoides farinae, which are dominant species in homes, have recently become serious health problems. Reducing the number of and exposure to mites and mite allergens are the most important factors in preventing allergic diseases. Recently, the effects of essential oils of plants on house dust mites have received much attention with a view to producing natural mite-killing agents. Essential oils and their components of wood and their leaves have also received much attention. In this article, we summarize the biology of house dust mites, mite allergens, and their concentration in homes, and discuss the control of house dust mites by using plant and wood extractives, especially in relation to the influence of essential oils and volatiles from wood on house dust mites.  相似文献   

6.
The ambrosia beetle Platypus quercivorus causes mass mortality of Fagaceae trees in Japan, and tree species differ in their susceptibility to P. quercivorus. We hypothesized that interspecific differences in susceptibility are caused by differences in beetle infestation patterns, that is, how many beetles fly to a tree and how many of those arriving bore holes. To examine how tree susceptibility is related to these parameters, two tree species with different degrees of susceptibility were studied (highly susceptible Quercus crispula and less susceptible Q. salicina). Specifically, we measured the number of male beetles per unit area that flew to the host trees (NFM) and the density of holes bored by male beetles (DH). From these two values, we calculated the proportion of male beetles flying to a host tree that bored holes (PBM). These parameters were compared for the two Quercus species. Although the two species did not differ in NFM in 2003, PBM was markedly lower for Q. salicina than for Q. crispula and DH was significantly lower for Q. salicina than for Q. crispula. Thus, the lower susceptibility of Q. salicina is partly explained by its low PBM.  相似文献   

7.
The study of the life history dynamics of the pine sawyer beetle Monochamus galloprovincialis (Olivier) is important because the beetles vector the pinewood nematode. The objectives of this study were to investigate differences in beetle life history parameters between the two common host tree species in Turkey, Pinus sylvestris and Pinus nigra. Relationships between the number of oviposition sites, holding time (time between log cut and oviposition), log moisture content, log volume and area, and adult survivorship were evaluated. No significant differences were found between the two tree species except adult density per m2. The holding time did not influence the number of oviposition sites, larval entry holes or adults for P. sylvestris. There was a negative correlation between the holding time and the number of oviposition sites for P. nigra. The number of adults emerged per log was correlated with the number of larval entry holes only for P. sylvestris. Only 12 and 15% of the initial cohort completed development and emerged as adults for P. sylvestris and P. nigra, respectively. Both tree species are equally suitable hosts for M. galloprovincialis development. We conclude that the high within-log mortality of beetles is a combination of resource quality and quantity factors and intraspecific competition and cannibalism during larval development.  相似文献   

8.
A laboratory study revealed that females of the phytoseiid mite, Amblyseius swirskii Athias-Henriot, fed on protonymphs of their own species or of other predatory mites i.e. Agistemus exsertus Gonzales and Euseius scutalis Athias-Henriot exhibited a marked decline in their fecundity and a shortening in their longevity. Moreover, the rate of predation was also reduced. When A. swirskii females were fed on nymphs of the two-spotted spider mite Tetranychus urticae Koch after having been fed previously on protonymphs of either A. swirskii or A. exsertus increases in the rates of oviposition and consumption were observed, although these rates were lower than those of conspecific females reared continuously on the two-spotted spider mite only.  相似文献   

9.
Two-spotted spider mite (TSSM) and onion thrips are serious pests of potatoes in the Ardabil region (Iran). In the present study, anthocorid species were identified in potato fields of this region during 2006 and 2007. The results of the abundance study indicate that Orius niger (Wolff) and O. minutus (Linnaeus) are major predators of these pests in potato fields. The life table parameters of these predators were compared when they were fed 2nd instar larvae of onion thrips or female TSSM on potato leaves. In these experiments, O. niger had a lower nymphal mortality, longer oviposition period, higher net reproductive rate (R 0), and higher intrinsic rate of natural increase (r m ) when fed thrips instead of mites. O. minutus feeding on mites compare to thrips had a lower nymphal mortality, longer oviposition period, higher net reproductive rate, and higher intrinsic rate of natural increase. Based on these results, it can be concluded that these predators could be useful as biological agents in potato fields.  相似文献   

10.
The effect of volatile matter from various wood chips on house dust mites and their influence on human comfort were measured. To investigate the effect of volatile matter on the mite speciesDermatophagoides pteronyssinus, the activity of the mites was observed after exposure to volatile matter from six species of wood chips. The degree of activity of the mites was classified into two categories: (1) walking or moving and (2) immobilized. To measure their influence on human comfort, the smells of those wood chips were evaluated by the subjects. Among softwoods, volatile matter fromChamaecyparis obtusa andThujopsis dolabrata var.hondai chips suppressed the activity of the mites highly and made the subjects feel refreshed and unexcited.Cryptomeria japonica showed slight suppression of the mites and was considered to be refreshing, natural, and unexciting by the subjects. Among hardwoods,Cinnamomum camphora highly suppressed mites activity and was considered to be non-refreshing and exciting by the subjects. Part of this paper was presented at the 49th Annual Meeting of the Japan Wood Research Society, Tokyo, April 1999  相似文献   

11.
Using allyl-isothiocyanate-baited traps, we recorded six species of flea beetles in cabbage and horseradish crops in the region of Sofia, Bulgaria in 2006 and 2007. The most abundant species in the traps was Ph. cruciferae (92–96%) followed by Ph. vittula, Ph. undulata and Ph. nigripes. The overwintering adults of these species emerge before the beginning of April and are active to the end of May–beginning of June. Catches of adults of the new generation occurred from the end of June–beginning of July to the second half of October–beginning of November. In 2006, air temperature and humidity strongly influenced the catches of the flea beetles. Investigations of the reproductive status of field collected females of Ph. cruciferae showed that this species develops one generation per year in the region. The results of this study can be used in integrated pest management approach to flea beetles control.  相似文献   

12.
Trunk circumferences and canopy diameters of Prosopis glandulosa, P. chilensis and P. alba, and soil nitrogen under and between the trees were measured in a seven-year-old plantation at the University of California, Riverside. P. glandulosa had the smallest biomass of the three species. However, the nitrogen concentration of the soil under P. glandulosa was higher than under the other two species. Presumably more nitrogen is cycled through the leaves of this species rather than invested in wood production, where it would be sequestered. The soil nitrogen accumulation under P. glandulosa was significantly higher (total and subsurface) than that measured in soil taken between trees. The soil nitrogen content under P. chilensis and P. alba was not significantly different than that between the trees. These results indicate that the choice of woody legume in an agroforestry system will depend on its intended use. The most efficient nutrient cycling is not necessarily associated with the best biomass production.  相似文献   

13.
Relationships between tree mortality and bark beetle infestation onAbies veitchii at the wave-regenerated forest in Mt. Asahi, Okuchichibu area were investigated. Most of the firs with green needles and newly developed current year’s shoots in the dieback zone were heavily infested by bark beetles before the death of the trees. After heavy infestation of beetles, about half of the infested firs died within the year, and the other half died in the next year. When the species composition of bark beetles and associated ophiostomatoid fungi were investigated in Mt. Asahi and also at a typical wave-regenerated forest in Mt. Shimagare, Yatsugatake area,Cryphalus montanus andC. piceae were dominant beetle species for Mt. Asahi and Mt. Shimagare, respectively.Ophiostoma subalpinum andO. europhioides were dominant fungal species at both wave-generated forests. BecauseO. subalpinum was detected more frequently from deeper areas of sapwood thanO. europhioides, it was suggested that the fungal species may accelerate the death of stressed firs in wave-regenerated forests. Contribution No. 169, Laboratory of Plant Parasitic Mycology, Institute of Agriculture and Forestry, University of Tsukuba.  相似文献   

14.
In honeybee, Apis mellifera, colonies infested with larval and adult small hive beetles (SHB), hive material, and in particular honey, tends to ferment, probably due to SHB-associated yeasts such as the predominant Kodamaea ohmeri. Here, we test the effects of organic acids on K. ohmeri and on SHB-infested honey/pollen combs. Organic acids were applied at standard concentrations used by beekeepers to control other pests. In laboratory tests, the growth of K. ohmeri was significantly inhibited by lactic, formic and acetic acids. Treatments of SHB-infested honey/pollen combs (N = 18 colonies) with acetic acid significantly increased mortality of adult SHB and treatments with formic acid significantly reduced larval infestation. Our data suggest that treatment of honeybee colonies and storage rooms with organic acids could also help in reducing SHB damage.  相似文献   

15.
A number of various species of blue-stain fungi were isolated fromTomicus piniperda adults at various stages of development, as well as from the galleries, pupal chambers and sapwood underneath galleries on Japanese red pine. This study was an attempt to identify the species, composition of blue-stain fungi associated withT. piniperda, the frequency of occurrence of the fungi, and their role in the sapwood-staining of Japanese red pine in Tsukuba City, central Japan. Among the seven species of blue-stain fungi isolated, an undescribed species ofOphiostoma together withO. minus were the dominant species and closely associated withT. piniperda. These two species occurred on newly emerging adults more frequently than the overwintered adults.Hormonema dematioides was also associated with the beetle, however, its frequency of occurrence from the emerged new adults was very low. Although the two other species,O. ips andGraphium sp. were also isolated from emerged beetles, the frequency of these fungi from gallery systems suggested that they were accidentally carried byT. piniperda. Leptographium wingfieldii, known to be associated with the beetle in Europe, was also isolated at a very low frequency and the fungus seemed not to be closely associated with the beetle.Ophiostoma sp. andO. minus appear to be the most important causes of blue-stain of Japanese red pine sapwood after infestation byT. piniperda.  相似文献   

16.
The response of adult females of Monochamus alternatus to volatiles of non-host plants was evaluated using a Y-tube olfactometer. Eight non-host plant species were tested, namely Broussonetia papyrifera, Cedrus deodara, Firmiana simplex, Metasequoia glyptostroboides, Platycladus orientalis, Populus xiaohei, Salix babylonica and Sophora japonica. The volatiles of all test species, except those of C. deodara, repelled the females in the olfactometer bioassays. Oviposition by adult females on the host plant, Pinus massoniana, was deterred by the volatiles of non-host plants and by some other chemicals. Volatiles of P. orientalis had the strongest oviposition-deterring activity and those of S. japonica the least. Volatiles of C. deodara had no influence on oviposition of the females. Selected chemicals, namely benzaldehyde, citronellal, essential oil of Mentha spicata, eucalyptol, nerolidol, nicotine and salicylaldehyde, strongly deterred the females from oviposition, and nicotine caused maximum decrease in egg-laying and scar-excavation.  相似文献   

17.
Studies on tree crop interaction under rainfed condition in Dehradun valley were conducted for 13 years during 1977 to 1990. Grewia optiva (Bhimal), Morus alba (Mulbery) and Eucalyptus hybrid were tried along with rice (CV: Akashi) — wheat (CV: RR-21) rotation. One-year-old tree seedlings of the above tree species were planted in line, 5 m apart in N-S direction, in July 1977, in the middle of the plot (size 20 m × 20 m). Eucalyptus was first harvested in 1987. Grewia optiva, Morus alba and coppice of Eucalyptus were harvested in 1990. All tree species had depressing effect on crop yields. Eucalyptus had maximum effect in depressing crop yield till the first harvest and had least effect thereafter. From 1987 onwards, Morus alba affected rice most, while wheat was mostly affected by Grewia optiva. The depressing effect on an average varied from 28 to 34% depending upon the species.Distance of tree line from the crop significantly affected the crop yield upto a distance of 5 m and there was 39% decrease in crop yield upto 1 m, 33% from 1–2 m, 25% from 2–3 m and 12% from 3–5 m distance. Annual removal of lops and tops from trees partly compensated the deficit. Grewia optiva could produce 1.08 t ha–1 yr–1 of branches and 0.26 t ha–1 yr–1 of leaves (air dry) and 1.28 t ha–1 yr–1 of branches and 0.28 t ha–1 yr–1 of leaves were obtained from Morus alba. Wood (ADT) produced by the trees was 33.6 t ha–1 from Eucalyptus, 9.5 t ha–1 from Grewia optiva and 11.6 t ha–1 from Morus alba.  相似文献   

18.
Bark beetles (Coleoptera: Curculionidae, Scolytinae) are commonly recognised as important agents of tree mortality in coniferous forests of the Western Carpathians. They, together with weevils, are consistently associated with ophiostomatoid fungi. Information regarding conifer beetle-associated fungi in the Western Carpathians remains incomplete and unreliable, particularly with respect to fir-infesting bark beetles. This study aims to clarify associations between fungi in the genera Graphilbum, Leptographium, Ophiostoma and Sporothrix (Ophiostomatales) and their beetle vectors in Norway spruce (Picea abies), European larch (Larix decidua) and silver fir (Abies alba). Samples associated with 20 bark beetle species and weevils were collected from nine stands in Poland and the Czech Republic. Fungi were isolated from adult beetles and galleries. Isolates were identified based on morphology, DNA sequence comparisons for four gene regions (ITS, LSU, ß-tubulin, TEF 1-α) and phylogenetic analyses. In total, 46 distinct taxa were identified, including 25 known and 21 currently unknown species. Several associations between fungi and subcortical insects were recorded for the first time. In addition, O. borealis and O. quercus were detected from A. alba for the first time. The composition of the fungal communities varied among the studied tree species and to a lesser degree among the beetle species. The spruce-infesting bark beetles were commonly associated with species of Leptographium s. l. and Ophiostoma s. str.; the larch-infesting bark beetles were often associated with Ophiostoma s. str. and Sporothrix, while the fir-infesting bark beetles were commonly associated with Ophiostoma s. str. and Graphilbum. The most commonly encountered fungal associates of the examined insects were (a) Grosmannia cucullata, G. piceiperda, Grosmannia sp. 1, Ophiostoma macroclavatum and O. piceae with the spruce-infesting bark beetles; (b) O. pseudocatenulatum and Sporothrix sp. 1 with the larch-infesting bark beetles; and (c) O. piceae, Ophiostoma sp. 2 and Graphilbum sp. 2 with the fir-infesting bark beetles. The differences in fungal associates among the bark beetle species occurring on P. abies, L. decidua and A. alba could be linked to the different habitats that these beetles occupy.  相似文献   

19.
Laboratory studies were conducted to assess several life-history characteristics of three Trichogramma species—T. cacoeciae, T. evanescens, and T. principium—reared on potato tuber moth eggs. The effects of host age, parasitoid age, and different temperatures on the mean number of parasitized eggs and the percentage of emerged progeny were determined. The age of both Trichogramma and host eggs significantly affected the number of eggs parasitized by the wasps, but did not affect the percentage of parasitoids emerging from parasitized eggs. No intraspecific differences for potato tuber moth eggs were found among the tested Trichogramma species. However, T. principium proved to be more effective than T. cacoeciae and T. evanescens in parasitizing host eggs at high temperatures (>33 °C). Trichogramma significantly decreased the number of potato tuber moth F1 emerged progeny when they were released with moths in small cages either over potatoes or potato seedlings.  相似文献   

20.
Four different pathogen species (Gregarina typographi, Chytridiopsis typographi, Unikaryon montanum and Menzbieria chalcographi) were found in adult Ips typographus from the Forest Demonstration Centre, BOKU University in the course of a 7-year period of investigation (1995–2001). Annual variations were found in both the spectrum and prevalence of pathogen species. Variations were found in the number of infected male and female beetles as well as the infections of beetles with different dates of emergence.  相似文献   

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