爱福丁兼治蚜虫螨类斑潜蝇的药效试验

通过多种药剂试验和对比分析表明,24.5%北农爱福丁乳油是兼治蚜虫、螨类、斑潜蝇的一种安全、经济、高效的无毒生物型杀虫剂.另外,对蚜虫、螨类、斑潜蝇的防治时机、药剂的喷洒浓度也作了进一步探讨.     

Birds as predators of cork and holm oak pests

The recent decline of Mediterranean oak woodlands in SW Iberian Peninsula is related to insect pests which affect both cork oak (Quercus suber) and holm oak (Quercus rotundifolia). We identified twenty-six bird species as potential regular predators of twenty major pests by reviewing the diet of breeding, wintering and resident species in this ecosystem. Foraging guilds are strongly associated with predation at distinct stages of the pests’ life-cycle: ground-foragers prey on overwintering pupae and larvae of seed-borers, tree-foragers prey on eggs, larvae and pupae of defoliating and wood-boring pests, and aerial-sweepers prey on airborne imagines. Bird predation can cover the complete life-cycle of pest species because different species may be complementary due to a dissimilar exploitation of foraging niches and periods. Small generalist tree-foraging passerines are important pest predators given their high densities and widespread distribution in Mediterranean oak woodlands, but management practices can have a significant negative effect in their populations.     

Fruit tree Aphids and their natural enemies in Isparta region,Turkey

Fourteen aphid species belonging to eight genera and three families of the superfamily Aphidoidea were presented from Isparta region in fruit tree orchards. Among these, Dysaphis plantaginea, Aphis pomi and Dysaphis devecta, which cause harm to apples, are the most common species in the area because of the high amount of apple production. In addition, eight species from the family Coccinellidae (Coleoptera), three from Syrphidae (Diptera) and one species from Forficulidae (Dermaptera) were found as predator. Totally, eight species were determined as parasitoids from the families Aphidiidae, Aphelinidae and Pteromalidae (Hymenoptera).     

蚜灰蝶及其他3种捕食性天敌对竹蚜的控制作用

在我国,竹类是一类广为栽植的经济林和用材林树种,同时也发展成为城市园林重要的观赏植物,而竹蚜是竹林的一类重要害虫,常造成竹林生长衰退,进而引发的竹林霉污病可进一步加剧竹林残败,并降低城市园林竹类的观赏价值。据安徽皖东竹林     

Banker plants and landscape composition influence colonisation precocity of tomato greenhouses by mirid predators

Journal of Pest Science - Conservation biological control involves manipulation of the environment to enhance the effectiveness of natural enemies in controlling crop pests. In this study, we...     

Weeds,aphids, and specialist parasitoids and predators benefit differently from organic and conventional cropping of winter cereals

The aphid–natural enemy interaction in winter wheat fields constitutes a complex system that has been frequently studied because of its implication for biological control. However, not all of the aphids living in cereal fields are crop pests, as there are also aphids living on weeds that may serve as alternative hosts or prey for aphid parasitoids or predators. In this context, a concomitant survey of the plant and insect communities was conducted to understand how different plant communities affect the abundance and richness of aphids and the interactions with their natural enemies. The plant community was split into functional groups (grasses, legumes and forbs), and the aphid community was divided into feeding groups according to their host preferences (specialists in grasses or forbs). The grass aphids, which dominated the total aphid catches, responded positively to grass cover, which was particularly enhanced in the conventional fields. Conversely, the forb aphids, which mainly conditioned the total species richness of the aphids, were closely correlated with the local abundance of legumes. The system of cereal aphid-parasitoids was enhanced in the conventional fields, where the abundance of grasses was higher, whereas the legumes of the organic fields indirectly played a key role in enhancing the richness of the parasitoids and the abundance of predators. Our findings indicate that a bottom-up effect exists throughout the plant community, aphids, and aphidophagous insects and that plant community characteristics should be considered to better understand cereal aphid control.     

Dormancy induction in container-grown Abies seedlings: Effects of environmental cues and seedling age

Twelve-week-old container-grown seedlings of noble fir (Abies procera Rehd.) and Shasta red fir (A. magnifica A. Murr. var. shastensis Lemm.), both high-elevation species, were grown under controlled environments in a study of induction of terminal-bud dormancy. Eight treatment combinations of long (15 h) or short (11 h) photoperiods, warm (25°/20°C) or cool (18°/12°C) thermoperiods, and dry (–1.2 MPa) or wet (–0.6 MPa) moisture regimes were imposed upon seedlings for 12 weeks. Treatment factors significantly affecting the induction of dormancy in terminal buds of seedlings were identified over time. The results suggest that seedlings responded dynamically to dormancy cues. The warm/dry and cool/wet combinations induced dormancy in the first 2 weeks in noble fir and in the first week in Shasta red fir. Short-day/warm and long-day/cool combinations enhanced dormancy induction in weeks 3 to 4 in noble fir and in weeks 1 to 7 in Shasta red fir. Short days and cool thermoperiods independently hastened dormancy induction in noble fir in weeks 5 through 12.     

Distribution patterns of acorns after primary dispersion in a fragmented oak forest and their consequences on predators and dispersers

Forest fragmentation affects seed production, but little is known about how seeds are distributed in fragmented forests after primary dispersion and how this affects their interactions with other organisms. This study addressed these issues in a fragmented oak forest of Quercus laeta where four habitat types were recognized: interior and edge of patches, deforested matrix around patches, and an abandoned field. Areas and distances to the abandoned field were measured for 40 patches, and acorns were sampled in all habitats. Only samples from the interior and edge of patches had acorns, which were classified as aborted, viable, and parasitized by insects or fungi. Acorns in all these classes were regressed against patch area and distance to the abandoned field. Field experiments were also conducted to determine whether acorn removal rates varied across habitats. Aborted acorns within patches were not related to area or distance, but they decreased with increasing values of both variables at patch edges. Within patches, viable acorns were positively related to increases in area and distance, while the converse occurred for insect-damaged acorns; fungal-infested acorns were not related to patch variables in this habitat. Complex interactions between area and distance explained how acorns in these classes were distributed across patch edges. Acorn removal was higher within patches and their edges when compared to human-disturbed habitats; both mice and birds were identified as potential acorn dispersers. These results suggest that forest fragmentation affects acorn-mediated processes and that this may influence the recovery of patch connectivity in the landscape.     

Attractiveness of three weed species to polyphagous predators and their influence on aphid populations in adjacent lettuce cultivations

The utilization of olfactory responses of predators and ­parasitoids to the allelochemicals emitted by phytophagous arthropods and their host plants is becoming more important in biological pest control. The effects of three weed ­species, i.?e. wormwood Artemisia vulgaris L., tansy Tanacetum vulgare L. and stinging nettle Urtica dioica L., which were planted as accompanying vegetations into a lettuce field, were examined for the predatory species Coccinella septempunctata L., Adalia bipunctata (L.), Propylea quatuordecimpunctata (L.) (Coleoptera, Coccinellidae) and Chrysoperla carnea (Steph.) (Neuroptera, Chrysopidae), as well as for aphids during the summer of 2000. The presence of weeds significantly increased the density of adults and larvae of the predators on the lettuce plants in relation to the control (lettuce field without weeds). However, the differences remained smaller for eggs and pupae. C. septempunctata tended to be the most abundant species, followed by P. quatuordecimpunctata. Remarkable differences among the attractiveness levels of the weeds in the 3 treatments were not observed. The increased populations of predators were accompanied by significantly reduced infestation rates with aphids in the treatments in relation to the control. Myzus persicae Sulzer was in general the most abundant aphid species followed by Nasonovia ribisnigri Mosley and Macrosiphum euphorbiae Thomas. The results of the present study are discussed with respect to the management of agroecosystems and the use of weeds in biological control.     

Perceptions of “close-to-nature forestry” by German and Japanese groups: inquiry using visual materials of “cut” and “dead” wood

It is generally believed that forests are perceived differently according to the cultural background of the visitor. Different cultural groups tend to have diverse perceptions of tree species, landscapes, or gardens. In this research project, we conducted interviews of German and Japanese groups (each group consisting of three or more people), to identify their perspectives in exploring the theme of “cut” and “dead” wood. For this purpose, we interviewed 20 groups from each cultural background (40 data sets in total). Each group was asked to categorize 36 pictures chosen from photographic contests. The results were examined with PCA and cluster analysis. The quantified results of the two national groups highlighted the dichotomy of the cut and dead wood relationship. The method and materials used gave robust results. Differences between the two groups were identified by their perceptions of cut and dead wood. The results are insightful from a methodological and political rationale. First, new insights were gained by adopting group-based interviews using pictures from photographic contests. Research about public perceptions in forest science is often dominated by a focus on verbal inquiry. This study explored similar questions, using visual materials. The interviews consisted of visual materials to overcome bias in languages or the question order. Second, the results indicated the influence of “close-to-nature forestry” policy on public perceptions. While German society has a wide practice of leaving dead wood in forests based on their close-to-nature forestry policy, there is no equivalent Japanese concept. Although Japan and Germany both face pressures for economic restructuring and public participation, the difference in public perception of forestry can lead to a difference in acceptance for the same policy. If such differences are to exist, we can observe that the legitimacy of forestry in the two countries is reconstructed in different ways.     

国槐转雪花莲凝集素基因及抗蚜性

通过农杆菌介导法将雪花莲外源凝集素基因(gna)导入国槐叶片,获得转基因再生植株,经卡那霉素抗性筛选,PCR和Southern blot检测证实,gna基因已经整合进入国槐基因组中。凝血活性检测表明,大部分转基因植株表现出一定的凝血活性,对照未转化植株的凝血活性很低。室内离体叶片虫试试验进一步证明,转基因植株较非转基因植株有一定的抗蚜虫能力。     

Use of acoustic testing to detect decay and sort western juniper for modulus of elasticity and modulus of rupture

While wood has numerous attributes that make it an excellent material for many uses, its properties can also vary widely according to wood species and even within the same species. Wood used in structural applications is categorized into classes. For many wood products, these classes or grades are based upon visual assessments that account for grain characteristics along with natural defects such as knots or splits. These approaches are simple, but also limit the potential for identifying products based upon actual material properties. One alternative is to use acoustic tests to estimate modulus of elasticity and then correlate these values to actual material properties. The potential for using acoustic tests to estimate wood properties was assessed with a prototype acoustic device (Metriguard Model 242) on western juniper (Juniperus occidentalis) posts that were then tested using a destructive bending test. These tests could allow the identification of decayed areas within a post if they were directly in the tested area, but predicted modulus of elasticity was poorly correlated with actual modulus of rupture (r^2?=?0.23). The correlation was improved by only considering those samples where the acoustic test was made through the same area where the test load was applied, but the relationship was still weak (r^2?=?0.33). Acoustic testing did appear to be able to identify unacceptably weak samples with minimal rejection of acceptable samples, suggesting that acoustic testing might be a useful sorting tool to improve the reliability of timbers.     

Evaluation of promoters and visual markers for transformation of eastern white pine

This report serves to evaluate possible promoters for use in theproduction of transgenic eastern white pine (Pinus strobus L.).Embryogenic cultures of eastern white pine were bombarded with goldparticles coated separately with a variety of gene constructs containingthe UidA -glucuronidase (GUS) or green fluorescentprotein (GFP) reporter gene. Transient expression of the UidAgene, driven by a novel algal virus adenine methyl transferase genepromoter, as well as five other promoters used in angiospermtransformation, were evaluated. The maize alcohol dehydrogenase promoterwas not effective in eastern white pine cultures. The construct with thedoubled Cauliflower Mosaic Virus 35S promoter plus Alfalfa Mosaic Virusenhancer showed the highest levels of expression. GUS expression wasdetected within 24 hours, but decreased after 5 days and was notdetectable 15 days after bombardment. Expression of GUS activity wasrecorded mainly in somatic embryonal heads of various stages ofdevelopment and occasionally in suspensor cells. Similar to GUSexpression, modified green fluorescent protein (GFP) was detected in theembryonal head cells 24 hours after bombardment. GFP-expressingsuspensor cells were both more infrequent and difficult to detect, astheir highly vacuolate nature rendered the GFP presence less visibleagainst the yellow background autofluorescence.     

A metabarcoding tool to detect predation of the honeybee Apis mellifera and other wild insects by the invasive Vespa velutina

The invasive Vespa velutina has been widely referred as an effective predator of honeybees. Despite the potential risk to pollination services provision and honey production, there is no accurate quantification and assessment of its real consequences for honeybees. To date, the identification of the honeybee and other insects in the diet of V. velutina has been investigated by direct observation of adult foraging or examination of food pellets. To overcome these limitations, in this study we used a DNA metabarcoding approach to evaluate the usefulness of different types of sample (jaws and stomachs collected from workers and larval faecal pellets taken from the hornet comb) to investigate the predation of V. velutina upon honeybees, and potentially on other insects. Honeybee DNA was identified in all types of samples, but larval faecal pellets retrieved the higher number of reads of honeybee DNA and the largest diversity at all taxonomic levels. Over all samples we could identify 4 orders, 9 families, 6 genera and 1 species of prey. We estimate that collecting 6 workers is sufficient to identify honeybee predation by a colony using worker’s jaws. Stomachs were the least useful sample type to detect honeybee DNA. The presence of honeybee DNA in all analysed colonies irrespective of collection site, and the variety of insect orders detected in the diet support current concerns over the acknowledged negative impact of V. velutina on managed honeybees and its potential threat to pollination services provision.

     

UPS在DCS系统中的选择及应用

本文从UPS的原理着手,着重讨论为什么使用UPS,如何选择UPS。     

强化工程项目管理,提高资金使用效益--廊坊市三北防护林四期工程推行项目管理有新举措

强化工程项目管理,提高资金使用效益,这是保持三北防护林工程快速、健康、协调、持续发展的关键。河北省廊坊市坚持用科学的发展观指导三北防护林工程项目管理,总结出“科学规划,合理布局;统筹兼顾,突出重点;明晰责任,严明奖惩;健全制度,规范管理”的项目管理经验和做法,值得各地学习和推广。     

Differentiation of poplar and willow clones using RAPD fingerprints

The technique of random amplified polymorphic DNA (RAPD) fingerprinting was used to differentiate species and identify clones of 15 poplar and 15 willow clones (ramets of three poplar clones were also included to verify the stability of the results). Four random DNA primers (Deca-11, Chl-1, Chl-4 and Chl-10) and an M13 universal primer were used to determine DNA polymorphism among the clones. Based on the DNA banding pattern obtained with the four DNA primers by polymerase chain reaction (PCR) amplification we conclude that RAPD fingerprinting with properly selected primers can be used for clonal and species differentiation of poplar and willow. The technique is simple, accurate and inexpensive.     

Evaluation of the visual stress grading standard on French Spruce (Picea excelsa) and Douglas-fir (Pseudotsuga menziesii) sawn timber

? In this paper an evaluation of the visual grading standard for softwood sawn timber was made.

? In order to do so, visual grading according to EN 518 and theoretical grading according to EN 338 and EN 384 (measurements of MOE, MOR and density) were applied to lumber. Two batches of 111 and 102 French boards were graded, respectively, of Spruce (Picea excelsa) and Douglas-fir (Pseudotsuga menziesii). For the visual grading the most discriminant criterion was noted: knots, cracks, wane, etc.

? Finally, the results of the two grading methods were compared, and it was shown that the visual stress grading gave quite low results for our two French species.