Influences of trees on abundance of natural enemies of insect pests: a review

In this article we review the use of natural enemies in crop pest management and describe research needed to better meet information needs for practical applications. Endemic natural enemies (predators and parasites) offer a potential but understudied approach to controlling insect pests in agricultural systems. With the current high interest in environmental stewardship, such an approach has special appeal as a method to reduce the need for pesticides while maintaining agricultural profitability. Habitat for sustaining populations of natural enemies occurs primarily at field edges where crops and edge vegetation meet. Conservation and enhancement of natural enemies might include manipulation of plant species and plant arrangement, particularly at these edges; and consideration of optimum field sizes, number of edges, and management practices in and near edges. Blending the benefits of agricultural and forestry (windbreak) systems is one promising approach to field edge management that has additional benefits of wind protection and conservation of desirable wildlife species.Journal series 10549 of the Agriculture Research Division, University of Nebraska-Lincoln. This material was prepared with the support of USDA Agreement 91-COOP-1-6592 for the USDA/EPA Program, Agriculture in Concert with the Environment. Any opinions, findings, conclusions or recommendations expressed herein do not necessarily reflect the views of the US Department of Agriculture or the US Environmental Protection Agency.     

Diseases and insect pests of Gmelina arborea: real threats and real opportunities

Gmelina arborea Roxb. (gmelina) is a rapidly growing tree, which due to its drought tolerance and excellent wood properties, is emerging as an important plantation species. Perhaps the greatest threat to plantations of this tree is damage due to pests and diseases. Numerous insect pests and pathogens have been recorded in stands of gmelina in areas where the trees are native. Some fungal pathogens have been introduced into areas where the trees have been established as exotics. Among these, leaf spot caused by Pseudocercospora ranjita is most widespread although it has not caused any substantial damage. A serious vascular wilt disease caused by Ceratocystis fimbriata in Brazil has caused the most significant failure of G. arborea in plantations. In plantations within the natural range of the tree, insects have caused substantial damage. Among these, the defoliator Calopepla leayana (Chrysomelidae) appears to be most important. No serious insect pest problems have been recorded where G. arborea is grown as an exotic. All indications are that pathogens and insect pests will become much more serious impediments to the propagation of gmelina in the future. However, excellent opportunities exist to resolve such problems through biological control of insects and integrated disease and pest management. In addition, gmelina can be vegetatively propagated and thus, breeding and selection for insect and pathogen tolerance will facilitate the propagation of healthy trees. Palabras clave: Control biológico, Cuarentena, Especies exóticas, Implementación operacional de clones Resumen. La Gmelina arborea Roxb. (gmelina) es un árbol de rápido crecimiento, el cual debido a su tolerancia a las sequías y a sus excelentes propiedades de la madera se está convirtiendo en una especie de importancia para las plantaciones forestales. Tal vez, la amenaza más grande para las plantaciones de estos árboles es el daño causado por las plagas y las enfermedades. En las áreas en donde la especie es nativa, se han reportado gran cantidad de plagas de insectos y de patógenos. Algunos hongos patógenos se han introducido dentro de las áreas en donde los árboles han sido establecidos como especies exóticas. Entre estos, las manchas de las hojas ocasionadas por el hongo Pseudocercospora ranjita, es el más extendido aunque no ha causado ningún daño sustancial. Una seria enfermedad de marchitamiento vascular causada por el Ceratocystis fimbriata en el Brasil, ha causado la pérdida más seria en las plantaciones de G. arborea. En las plantaciones dentro del rango natural del árbol, los insectos han causado un daño considerable. Entre estos insectos, el defoliador más importante parece ser el Calopepla leayana (Chrysomelidae). En las áreas en donde la gmelina crece como una especie exótica no se han reportado problemas con las plagas de insectos. Todo parece indicar que en un futuro, los agentes patógenos y las plagas de insectos se convertirán en un impedimento más serio para la progagación de la gmelina. Sin embargo, a través del control biológico de insectos y del manejo integrado de las enfermedades y plagas, existen excelentes oportunidades para resolver este tipo de problemas. Además, la gmelina puede ser propagada vegetativamente y por lo tanto su mejoramiento y selección facilitará la propagación de árboles saludables por su resistenciacia contra los insectos y los patógenos.     

A review of Sorghum insect problems in Australia

The insect pests attacking grain sorghum in Australia are reviewed. For easy handling the insects are grouped according to the stages in plant growth which they attack, e. g. pests of the planting and seedling stages, pests of the vegetative stage, pests of flowering stage and pests of the maturity stage. Reference is made to the importance of storage pests. The adoption of minimum tillage practices in Australian summer cropping areas, the importance of soil insects during establishment stage of the crop is expected to increase. The sorghum midgeContarinia sorghicola (Coquillet) no doubt is the most damaging pest species.Heliothis armigera (Hübner) is second in importance to sorghum midge as a pest of sorghum. Damage and control methods of this and other pests are discussed. Economic injury levels are also discussed.     

A review of ecophysiologically-based seedling specifications for temperate Australian eucalypt plantations

The Australian hardwood plantation estate has significantly expanded in the last decade. Key production issues included: (1) will Eucalyptus nitens Maiden seedlings produced in nurseries on relatively mild sites be susceptible to transplant shock and browsing on cold out-planting sites and can this be managed? And; (2) what specifications should be required of nursery producers for Eucalyptus globulus Labill seedlings for out-planting on mild ex-pasture sites? This review outlines the research conducted in order to address these key questions. Nitrogen deprivation in the nursery induced accumulation of foliar anthocyanin which conferred hardiness to low temperature. Target specifications of 8–10?g/kg foliar nitrogen are recommended. Height of >120?mm, root collar diameter >2.8?mm, seedling container volume of ≥85?cm³, depth of ≥73?mm, density of ≥549?cells/m² and foliar nitrogen concentration of 15–20?g/kg were found to be key specifications for optimal E. globulus growth following planting onto mild ex-pasture sites. Exponential nutrient loading was a useful technique for attaining target foliar N concentrations. Seedling size was found not to affect growth of E. globulus post-planting on mild ex-pasture sites. However, large seedlings were preferentially browsed on high vertebrate-browse-pressure sites in Tasmania (poisons are banned and shooting is not effective on some sites) that did not affect subsequent growth rate but did increase the incidence of double-leaders. The ‘target seedling concept’ is applicable to eucalypts for Australian planting sites: specifications attained in the nursery should be matched to the factors limiting growth on the planting sites.     

A review of tower flux observation sites in Asia

Aggregating and sharing the metadata of flux observation sites results in a strong collaboration among various fields of study. Such data sharing will also be a part of the future design of a tower flux observation network in Asia. The aim of this review is to comprehend the state of tower flux observation sites in Asia. There are 109 tower flux observation sites in Asia including 51 forest sites. There are more new sites under construction in Asia than in America and Europe. These sites range from the taiga in Siberia to the rainforest in Southeast Asia, and from the equatorial to polar Koeppen climate zones. There are many highly humid areas in Asia, not only at low latitudes but also at middle latitudes. This climate condition has developed unique vegetation such as lucidophyllous (evergreen broadleaf) forest, which is distributed in warm areas with high precipitation in the growing season. However, there are only a few observations taking place in lucidophyllous forest. Rice paddy fields are also unique land cover in Asia. It is important to accumulate long-term data for rice fields with their management records, because plant activity depends highly on both climate conditions and land-use management. Flux data, especially net ecosystem exchange and related elements, are used for widespread studies not only within the flux-research community but also in other fields of study, for example remote sensing. At present, however, both the quantity and quality of the data are not sufficient for these studies. Regarding the quantity, there are many recently established sites that have not published data yet; regarding quality, flux data include uncertainties caused by methodological problems. Flux researchers are required not only to obtain flux data but also to improve their quality. Meanwhile, data users must understand there are still uncertainties in flux data. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

土著植物产品对印度森林病虫害防治的生物功效：综述

讨论了苦楝树和其他热带树种天然产品在印度森林病虫害防治中的生物功效。这些树木产品可起到拒食素、防护剂、不育诱导剂、毒素等作用,可以调控害虫生长,具有效力高、价格低廉和对环境无公害的特点。将这些树木产品整合到森林虫害管理策略中,会增强森林的可持续性,防止木材质量衰退。表3参61。     

Predation of lowbush blueberry insect pests by ground beetles (Coleoptera: Carabidae) in the laboratory

Agriculture relies on ecosystem services, such as biological control of pests, for economic success and sustainability. Commercially managed lowbush blueberries are an important crop in eastern North America, but pest control by natural enemies has not been well studied. In this paper we address questions about consumption of two blueberry pests by ground beetles (Carabidae) that are common in blueberry fields. In the first experiment, a Poecilus l. lucublandus, Carabus nemoralis, or Pterostichus mutus beetle was placed with two blueberry spanworm larvae, Itame argillacearia, in a simple (cup only or cup + soil) or more complex (cup + soil + blueberry sprigs) treatment arena. In most cases, probability of spanworm consumption reached 100 % in simple arenas by the end of the experiment (48 h) but was 25–50 % lower in more complex arenas. In a second experiment, a male or female Pterostichus melanarius or Harpalus rufipes beetle was placed in a plastic container with saturated or dry soil into which mature blueberry maggots, Rhagoletis mendax, dropped from blueberries to pupate. Approximately 40–80 and 35 % fewer pupae were recovered when a P. melanarius and H. rufipes beetle was present, respectively, but soil moisture and beetle sex were not significant factors. Our results demonstrate that ground beetles can prey upon important blueberry pests, but suggest that consumption may be influenced by microhabitat structure.     

岳阳市园林植物病虫害发生与防治

园林植物保护是城市绿化养护管理工作的重要环节,是关系城市绿化美化事业能否健康、有序和可持续发展的一项重要的基础性工作。作者从岳阳市园林植物病虫害的现状出发,分析了病虫害发生的原因,针对本市园林植保工作中存在的问题,提出了园林植物病虫害防治对策。     

First discovery of a cave-dwelling Tineid moth （Lepidoptera,Tineidae） from East Asia

In this study, we report Monopis crocicapitella （Clemens, 1859） （Tineidae）, which was collected from bat guano in a cave in the southern region of Korea, for the first time from East Asia. We briefly redescribe and illustrate the external morphology and genital structures of both sexes. Also, we discuss the local habitat characteristics and some of the ecological information that was observed during our field investi-gation.     

Management of pests and diseases of tropical sericultural plants by using plant-derived products:a review

Host plants of domesticated silkworms in tropical countries are attacked by an array of insect pests, disease pathogens and nematodes. In order to reduce resulting plant damage, chemicals have been ext...     

Effect of shelter on temperate crops: a review to define research for Australian conditions

The fact that the shelter created by windbreaks can have a significant, positive effect on crop production is supported by eight decades of research from many countries around the world. Although the concept of planting windbreaks to enhance crop production has general currency in Australia, the practice is not as wide as it could be. This review of the last decade of windbreak literature defines the research needed to encourage wider utilisation of windbreak technology. After outlining the principal mechanisms behind the effect of shelter on temperate crops, the review discusses relevant literature of the past decade especially that from Australia. The main mechanisms discussed are: the protection of crops from physical damage; soil conservation; the direct augmentation of soil moisture; and the alteration of the crop energy balance and plant water relations. Also discussed are the elusiveness of the shelter effect, competition from windbreak trees, and the modelling of windbreak systems. Suggestions for future research in Australia include: quantifying the competition of various windbreak species and the effect of root pruning on both crop and tree; a model of crop energy and water relations at the tree-crop interface; an economic model and a farmer-oriented decision support tool. This revised version was published online in June 2006 with corrections to the Cover Date.     

Genetic consequences of low local tree densities - Implications for the management of naturally rare, insect pollinated species in temperate forests

Early on, researchers of evolutionary biology recognised that heterogeneity in the mating environment is an important source of variation in mating patterns. Focusing on the mating environment, we assessed the effect of conspecific tree density on mating patterns in the naturally scattered forest tree Sorbus domestica L. In an area of more than 100 km², we mapped and genotyped all 189 adult trees and performed a paternity analysis on seeds produced by single mothers. Despite a self-incompatibility system, average selfing rate was 31.9%, but with high variation among mother trees. Over 70% of this variation was explained by local density of conspecifics (i.e. within a radius of 300 m), with isolated trees being more prone to selfing. While we detected high selfing rates in progeny, adult trees showed no signs of inbreeding. As almost all inbreeding in the offspring could be attributed to self-fertilisation, we hypothesise that there is strong selection against selfed individuals. The effective reproductive output of isolated trees, which mainly self, is therefore greatly reduced. These findings have important consequences for the management of naturally scattered, insect-pollinated temperate tree species, often belonging to the family of Rosaceae. For these species, local density of conspecifics should be maintained above a certain threshold (i.e. 0.05 trees/ha in S. domestica), to avoid negative fitness consequences from selfing.     

百合新虫害的发现——地下害虫迟眼蕈蚊

文章论述了迟眼蕈蚊对为害百合鳞茎的为害症状、发生特点、生物学特性以及防治措施。     

Quality assurance (QA) in international forest monitoring programmes: activity, problems and perspectives from East Asia and Europe

? The quality of monitoring is defined by its ability to provide data that (i) allow estimates of the status of the target resource with defined precision level, (ii) permit change detection with defined power, and (iii) are comparable through space and time. To achieve these requirements a Quality Assurance (QA) perspective is essential.

? To what extent QA was considered and data quality achieved in international forest monitoring programmes in East Asia and Europe? What is missing?

? Past and present QA activity in forest monitoring in East Asia and Europe revealed that most attention was given to evaluate and promote comparability of measurements, with special emphasis on analytical chemistry. Much less attention was given to field sampling and to the overall monitoring design. QA approaches were unbalanced among the various investigations, and several problems with data comparability remained over years.

? Despite considerable work on data quality control, parts of the monitoring process are still poorly covered by QA and revealed weaknesses in design and implementation. More comprehensive, formal and stringent QA procedures are necessary in international monitoring initiatives. Steps currently being undertaken for a more comprehensive QA approach are presented.

     

Initial vegetation recovery following a blowdown of a conifer plantation in monsoonal East Asia: Impacts of legacy retention, salvaging, site preparation, and weeding

All or a part of a sequence of forest practices (i.e., salvage logging, site preparation, planting crop trees, and weeding) has been implemented after natural disturbances for the rapid re-establishment of tree cover. Forest policies in Japan have recently changed from monocultural planting of coniferous crop trees to planting native broadleaved trees to restore forests and nurture local biodiversity following large windthrows. However, the effects of this new practice on preserving biodiversity, as well as the effects of legacy retention, have never been verified in Asia. Thus, the objective of our research was to compare the effects of legacy retention with plantation after salvaging on the initial stage of vegetation recovery in a blowdown area, specifically focusing on plant species diversity, the occurrence of alien species, and the composition of plant species. Following the analysis of our results, we finally describe appropriate practices to alter disturbed coniferous plantations to bring the species composition closer to that of the original natural mixed forests.A control (A, legacy retention) and three experimental treatment sites (B, salvage logged, site prepared, and Quercus crispula seedlings planted; C, same as B, but weeded once during the summer; and D, residual rows that emerged after establishing sites for planting) were prepared, and quadrats were set. Eleven indicators of the ground condition and the number of vascular plant species, including ferns, were quantified, and the number and abundance of residual and newly colonized plants of the main woody species were estimated.Our main findings were as follows: (1) in unsalvaged sites and residual rows, the diversity of plant species was poor, but a variety of plant species compositions were observed due to the heterogeneous conditions of the ground and ample residual plants; (2) in the planting site, many species appeared, but little variety of the species composition was observed due to the homogeneous condition of the ground and the destruction of residual plants; (3) a large number of alien species emerged in broad, unvegetated areas; (4) the impact of site preparation overwhelmed the impact of salvage logging on the initial recovery of plant species; and (5) to restore a natural mixed forest, a combination of legacy retention and plantation after salvaging would be the most appropriate.     

Influence of several tree traits on rainfall partitioning in temperate and boreal forests: a review

? In forests, rainfall is partitioned into intercepted water (IW), throughfall (TF) and stemflow (SF). We reviewed the majority of published works comparing water flows among tree species in temperate and boreal forests to test the effect of several tree traits on water flows.

? We hypothesized that water flows differed between evergreen and deciduous species, and according to successional status and bark roughness. We also investigated that water flows would be explained by stand variables such as basal area.

? Linear mixed models fitted on reviewed data showed that evergreens had a lower TF than deciduous trees (decrease of 13.9% of total precipitation year-round and 8.4% over the growing period). Similar results were found for conifers compared to broadleaves. TF also declined with the successional status from pioneer to late-successional tree species. SF decreased with bark roughness from smoother to rougher bark. Evergreens had water flows that were dependent on age of the stand, especially for TF which increased by 15.6% of total precipitation from young to adult forests.

? The large scale of TF differences between tree genera together with specific transpiration amounts and rooting features highlighted in other studies should result in significant differences in soil water content among tree species. This may have consequences on stand fitness and growth, and understory vegetation.

     

Reproductive biology of Cornus capitata Wall. ex Roxb.: a native species in East Asia

The reproductive biology of Cornus capitata was studied in detail from June 2014 to October 2015 in Tehri Garhwal, Uttarakhand, western Himalaya, India and elucidated floral morphology, confirming autogamy, geitonogamy, and xenogamy. A new inflorescence ball formed each year with developing fruits that were initiated the previous year; thus reproduction is a continuous cycle. The total pollen production within a tree ranged between 4.0 × 10~7 and 9.3 × 10~7. Anthesis peaked between 08:00 and 10:00. There was significant effect of micro-environmental condition on anthesis(F = 243.8, p = 3.01). A significant positive relationship between the number of lateral shoots and total inflorescence showed that the inflorescence production in C. capitate depends largely on the number of lateral shoots. Time and concentration of various solutions significantly affected pollen germination(time: F = 5.39, p = 0.002; concentration: F = 1.40,p = 0.234). Anthophora bees and thrips were observed as the main pollinators. There was a significant difference in seed set between natural and obligate self-pollination(t = 11.84, p = 1.99). Significant effect was also observed on fruit size(t = 8.88, p = 2.09) between open and shaded conditions. SEM micrographs of pollen grains showed that the shape of dehydrated pollen grains differed greatly due to variations in the rate of dehydration among pollen grains within the anther. Seed germination was observed only in quality seed derived from open pollination, supporting xenogamy in C. capitata. Findings of the present study will be of immense value in formulating effective conservation measures for the species in wild habitats.     

Responses of small mammals to clear-cutting in temperate and boreal forests of Europe: a meta-analysis and review

We analyzed the responses of small mammals to clear-cutting in temperate and boreal forests in Europe. We conducted a meta-analysis of published research on most often studied small mammal species (the striped field mouse, the yellow-necked mouse, the wood mouse, the field vole, the common vole, the bank vole, the Eurasian harvest mouse, the common shrew and the Eurasian pygmy shrew), comparing their abundance on clear-cuts and in unharvested stands. For four other species (the gray-sided vole, the Siberian flying squirrel, the Eurasian red squirrel and the hazel dormouse), we provide a qualitative review of their responses to forest harvest. Results of the meta-analysis suggest that common species of small mammals usually increase in abundance after clear-cutting or are unaffected by this disturbance. As an exception, the yellow-necked mouse declines after clear-cutting in boreal but not in temperate forest. The qualitative review suggests that the responses of more specialized (e.g., arboreal) species to forest harvest are more varied than the responses of generalist species included in the meta-analysis. For some species of small mammals (e.g., the Siberian flying squirrel), habitat loss resulting from forest harvest is a major threat.