棉区豆田主要害虫及其捕食性天敌生态位的研究

1997年调查了鲁西南棉区豆田不同时期内,大豆植株上、中、下3部位上主要害虫及其捕食性天敌的数量。文中分析了物种生态位宽度和各物种间的重叠度指数,探讨了主要害虫间的竞争关系以及棉铃虫与捕食性天敌间的关系。     

我国农作物害虫测报技术规范制定与应用

截止到2012年底,全国农业技术推广服务中心共制定了24个害虫测报技术的国家标准和农业行业标准,涉及水稻、小麦、玉米、棉花、果树、蔬菜等多种主要农作物。同时,一些省级植保部门根据各自的工作要求和业务特长,补充制定了部分害虫的地方性测报技术规范及国家标准。迄今,已对15大类107种(类)害虫制定了测报技术规范,为基层技术人员的害虫监测和预报业务提供了技术方法,促进了测报工作的有效开展。     

华北棉区夏播棉田害虫发生特点分析

分析和比较了华北棉区夏季播种与春季播种的棉田主要害虫（棉铃虫与棉蚜）的发生特点,探讨了它们的管理对策。     

Conventional tillage versus cover crops in relation to carbon fixation in Mediterranean olive cultivation

Background and Aims

For croplands, controversy persists concerning the adequacy of the soil use and the management of environmental problems such as soil erosion and fertility in a context of climate change. In this study, we used the RothC model to evaluate the capacity of carbon fixation by the soil in a Mediterranean olive grove for two different scenarios: the land-use change from native vegetation (NV) to conventional tillage (T) in the olive grove, and for the change in soil management from conventional tillage to cover crop (CC).

Methods

In three experimental olive groves in Andalusia (S Spain) two soil-management systems were sampled: T and CC. Areas of NV adjacent to the grove were also sampled as indicative of the initial state of the soil without olive trees. We measured the aboveground biomass production of the cover and the clay content, bulk density, and soil organic carbon (SOC) for 0–5, 5–15 and 15–30 cm depth.

Results

The removal of NV to implement T resulted in a significantly loss of SOC that depended mainly on the relief of the terrain. However, the use of CC increased the SOC because of greater inputs (above-and belowground plant inputs) to the soil. The final concentration at each location was related to the carbon inputs and the clay content. The CC resulted in carbon storage during the first year of 4.02?±?1.65 Mg C ha^?1, and a total carbon fixation by the soil of 5.91?±?2.06 Mg C ha^?1.

Conclusion

The use of cover crops in Mediterranean olive groves proved to be a suitable strategy to increase the carbon storage into the soil and then to decrease the CO₂ concentration in the atmosphere.     

Assessment of insecticide resistance in five insect pests attacking field and vegetable crops in Nicaragua

Field populations of Hypothenemus hampei (Ferrari), Plutella xylostella (L.), Spodoptera exigua (Hübner), Helicoverpa zea (Boddie) and Bemisia tabaci (Gennadius) were tested for resistance to several insecticides commonly used in Nicariagua. Assays were conducted to estimate the LD50s or LC50s and the corresponding resistance ratios. A diagnostic concentration was used to discriminate between susceptible and resistant strains of H. hampei. The tests with >6,000 H. hampei adults collected from six different sites indicate the absence of resistance to endosulfan. Resistance to cypermethrin, deltamethrin, chlorfluazuron, thiocyclam, and methamidophos was documented in six field populations of P. xylostella. High levels of resistance to cypermethrin and deltamethrin, but moderate levels of resistance to chlorpyriphos and methomyl, were also documented in two field populations of S. exigua. Moderate levels of resistance to cypermethrin, deltamethrin and chlorpyriphos were also documented in three field populations of H. zea. Moderate to high levels of resistance to bifenthrin, methamidophos and endosulfan were documented in four field populations of B. tabaci. The presence of significant correlations between LD50s or LC50s suggests the occurrence of cross-resistance or simultaneous selection for resistance by different insecticides with different modes of action. Our data could not differentiate between these two possibilities. Because insecticides will continue being used in Nicaragua, a resistance management program is urgently needed. The implementation of integrated pest management tactics must be accompanied by specific regulations for pesticide registration. In the future, pesticide registration regulations in Nicaragua should include periodic resistance monitoring. The mechanisms to cover the costs of resistance monitoring and resistance management should also be established.     

Interactions between cover crops and soil microorganisms increase phosphorus availability in conservation agriculture

Plant and Soil - An essential task of agricultural systems is to improve internal phosphorus (P) recycling. Cover crops and tillage reduction can increase sustainability, but it is not known...     

江苏棉区种植转基因抗虫棉GK22对棉田害虫、杂草种群的影响

2001年在江苏选择南京、盐城两地,试验观察转Bt基因抗虫棉GK22的种植,对棉田害虫及杂草种群变动的影响,结果是：咀嚼式口器害虫的棉铃虫（Helicover pa armigera),红铃虫（Pectinophora goosypiella),玉米螟（Ostrinia nubilalis),金刚钻（Earias cupreoviridis),棉不造桥虫（Anomis flava),棉大卷叶虫（Adoxophyes orana)等虫口数量,蕾铃被害均表现出较好的控制效果,处理区咀嚼式口器害虫的幼虫总 量,比对照区分别减少92．51％,78．4％,其中：棉铃虫幼虫数量分别减少88．3％,72．9％,蕾铃被害虫减少87．5％,90．7％,74．11％,55．85％,红铃虫虫花减少74．4％,51．64％,铃内活虫减少90％,100％,玉米螟虫口减少72．7％,100％,金钢钻,造桥虫,卷叶虫虫口减少93％以上,对刺吸式口器盲蝽象（Adelphocoris suturalis),棉蚜（Aphis gossyppii),棉红叶螨（Tetranychus cinnabariuns)等害虫,试验区和对照区种群消长动态趋势基本一致,差异不显,两试对杂草种类及数量调查,抗虫棉区和对照区差异亦不明显。     

Toxicity of seven foliar insecticides to four insect parasitoids attacking citrus and cotton pests

Laboratory studies were carried out to compare the toxicity of seven foliar insecticides to four species of adult beneficial insects representing two families of Hymenoptera: Aphelinidae (Aphytis melinus Debach, Eretmocerus eremicus Rose & Zolnerowich, and Encarsiaformosa Gahan) and Mymaridae (Gonatocerus ashmeadi Girault) that attack California red scale, Aonidiella aurantii (Maskell); sweetpotato whitefly, Bemisia tabaci (Gennadius) (both E. eremicus and E. formosa); and glassy-winged sharpshooter, Homalodisca vitripennis (Germar), respectively. Insecticides from four pesticide classes were evaluated using a petri dish bioassay technique across a range of concentrations to develop dosage-mortality regressions. Insecticides tested included acetamiprid (neonicotinoid); chlorpyrifos (organophosphate); bifenthrin, cyfluthrin, and fenpropathrin (pyrethroids); and buprofezin and pyriproxyfen (insect growth regulators [IGRs]). Chlorpyrifos was consistently the most toxic pesticide to all four species of beneficial insects tested based on LC50 values recorded 24 h posttreatment compared with 48-h LC50 values with the neonicotinoid and pyrethroids or 96 h with the IGRs. Among the three pyrethroids, fenpropathrin was usually less toxic (except similar toxicity to A. melinus) than was cyfluthrin, and it was normally less toxic (except similar toxicity with E. formosa) than was bifenthrin. Acetamiprid was generally less toxic than bifenthrin (except similar toxicity with G. ashmeadi). The IGRs buprofezin and pyriproxyfen were usually less toxic than the contact pesticides, but we did not test for possible impacts on female fecundity. For all seven pesticides tested, A. melinus was the most susceptible parasitoid of the four test species. The data presented here will provide pest managers with specific information on the compatibility of select insecticides with natural enemies attacking citrus and cotton, Gossypium hirsutum L., pests.     

Effects of apricot trees on insect pests and their natural enemies in nearby cotton fields in southern Xinjiang

2008-2011年在新疆莎车县调查研究了杏树对棉田主要害虫及自然天敌种群发生的影响.研究表明杏棉间作田主要害虫及天敌种类与棉单作田一致.杏树间作种植模式对棉田牧草盲蝽Lygus pratensis、棉蓟马Thrips tabaci和棉长管蚜Acyrthosiphon gossyfii的种群发生有一定影响,不利于其在田间发生;对棉蚜Aphis gossyfii、棉叶螨Tetrangchus urtieae影响不大.棉田瓢虫和食虫蝽天敌受间作和棉蚜发生量的双重影响.间作有利于蜘蛛数量的增加.     

Influence of root and leaf traits on the uptake of nutrients in cover crops

Plant and Soil - The objectives of this study were to determine the spatial structure of soil respiration (Rs) in a naturally-regenerated longleaf pine forest and to assess the ecological factors...     

麦套春棉主要害虫和天敌的生态位研究

调查了麦套着棉不同时期内,棉株上、中、下部棉蚜AphisgossypiiGover、棉叶螨TetranychustruncatusEhara、棉铃虫Helicoverpaarmigera（Hubner）和其主要天敌的数量。求得各期害虫与害虫、害虫与天敌、天敌与天敌之间的生态位宽度和重叠指数,并分析了它们彼此在空间上的竞争关系。     

Population dynamics of caterpillars on three cover crops before sowing cotton in Mato Grosso (Brazil)

Direct seeding mulch-based cropping systems under a preliminary cover crop such as millet are common in some areas of Brazil. Lepidopteran pests that damage cotton, soybean and maize crops can proliferate on cover crops, so preventive chemical treatments are necessary. Very little data is available on these pests on cover crops. This paper presents the dynamics of Spodoptera frugiperda, S. eridania, Mocis latipes and Diatraea saccharalis caterpillars monitored at Primavera do Leste, Mato Grosso state (Brazil) during the of 2005/2006 and 2006/2007 cropping seasons on four cover crops, i.e. finger millet (Eleusine coracana), pearl millet (Pennisetum glaucum), sorghum (Sorghum bicolor) and ruzigrass (Brachiaria ruziziensis). The pests were visually counted on plants within a 1 m2 transect (wooden frame). Caterpillars were reared to facilitate identification of collected species and parasitoids. Many S. frugiperda caterpillars were observed on millet in 2005, with a maximum of 37 caterpillars/m2. On sorghum, we found 30 caterpillars/m2, or 0.83 caterpillars/plant. The Diatraea borer attacked sorghum later than the other pests. M. latipes was also observed on millet. The millet cover crop had to be dried for at least 1 month before direct drilling the main cotton crop in order to impede S. frugiperda infestations on cotton plantlets, thus avoiding the need for substantial resowing. The comparative methodological aspects are discussed.     

The relative injuriousness of insect pests of cotton in the Namoi Valley,New South Wales

The sequence and relative injuriousness of insect pests was studied for three successive years in unsprayed cotton of the Namoi Valley. Heliothis punctigera Wallengren, the native budworm, and to a lesser extent H. armigera (Hübner), the cotton bollworm, prevented the setting of full crops by destroying buds and bolls. After setting, high proportions of bolls were injured by Earias huegeli Rogenhofer, the rough bollworm. Incidental damage was caused to seedlings by Thrips imaginis Bagnall, the plague thrips, and lo leaves by Anomis flava Fabricius, the cotton looper, and by Austracris guttulosa (Walker), the spur-throated locust. In commercial crops, pest control must rely on the use of broad-spectrum insecticides: H. armigera is currently resistant to several of these, and has become the principal species in the local population of cotton pests. A number of enviromental features impede the natural control of pests in the southerly areas where cotton is now produced. In comparison to the older dryland cropping practised in central Queensland, a higher yield is necessary to cover the production costs of irrigated cotton; a shorter growing season prevents the plants from compensating effectively for insect damage and the natural enemies of cotton pests are less abundant and less active.     

多样化的棉田生态系统控害保益功能特征研究

应用数量分析与能量测定相结合的方法 ,定量地分析和比较了华北棉区多样化的套间作棉田生态系统与单作棉田生态系统中主要害虫、天敌的种群动态及其天敌对害虫的控制作用 .结果表明 ,多样化的套间作系统中苗蚜与 2代棉铃虫发生轻 ,而伏蚜与 3代棉铃虫发生重 ;套间作系统有利于天敌群落能量的生产 ,尤其是利于捕食性蜘蛛类群的能量生产 ;从棉田生态系统棉株 害虫 天敌相互作用关系来看 ,尽管间套作系统内天敌群落生产力增加 ,保护益虫 (天敌 )作用好 ,同时也增加了害虫群落生产力 ,其控害功能较差 .     

Optimal control of pests in the presence of predators

Optimal control theory is applied to the problem of controlling pests by biological and chemical means simultaneously. The net birth rate of the pests is controlled chemically while at the same time predators are allowed to operate. Several numerical examples are included.     

抗虫和感虫大豆混播对产量及害虫种群发生和昆虫群落多样性影响

[目的]利用大豆高抗虫和高感虫品种混播,明确有效控害保产的最优比例,以实现大豆生产中有效的害虫生态防控和提高大豆产量.[方法]本研究选取高抗(Lamar;R)和与高感(JLNMH;S)斜纹夜蛾Spodoptera litura的大豆品种,进行不同比例的种子混播种植(即R、S单作,90％R和10％S(9R1S)、80％R和20％S(8R2S)、70％R和30％S(7R3S)、50％R和50％S(5R5S)混播),探究对大豆产量和主要害虫种群发生及昆虫群落多样性的影响.[结果]不同比例混播处理间斜纹夜蛾和筛豆龟蝽Megacopta cribraria的百株虫量无显著差异,但均显著低于S单作.混播处理8R2S和9R 1S以及R单作下昆虫群落多样性指数(H)和均匀度指数(E)显著高于其他试验处理,而优势度指数(C)显著低于其他试验处理.此外,昆虫群落丰富度指数(D)随着高感虫大豆混播比例的增加而降低;其中,混播处理8R2S和9R1S,以及R单作都显著高于S单作.对于大豆产量,混播处理显著影响大豆百株籽粒重,但对千粒重的影响不明显.其中,R单作和9R1S混播方式下大豆百株籽粒重最高,且有随着高抗虫品种(R)混播比例的增加而提高的趋势.[结论]高抗虫和高感虫品种混播可有效降低大豆主要害虫发生,且R混播比例≥80％能有效提高昆虫群落多样性、均匀度和丰富度,并对大豆产量提高有利.大豆生产中,建议采用80％以上的高抗虫品种与高感虫品种混播以实现大豆控害保产的生态防控效果.     

Population dynamics,hunting nature on insect pests and existence of symbiotic bacterial microbes among leading transgenic cotton spiders

The genetically modified cotton holding Bt proteins, is noxious to bollworms larvae but very little is known about its impact on population of non-target spiders within the field. Studies conducted with the aim to identify spiders along with their abundance, prevalence pattern, preying habit on insect pests in Bt cotton (L280, Cry2Ab4) and commonness of symbiotic bacteria in these spiders. Spiders collections were made via vial tapping/jarring, from May to end of October (2018). In total, 13,342 spiders were recorded during the entire cropping season. Least relative abundance was in May (0.28%), highest in August (30.39%) while ahead decline was observed, reached to 12% in October. The 27 species were verified, least richness was in May (3 species), high in August (19 species), later in the end, reduced to 7 species. High abundance was of Hylyphantes graminicola (68.56%) and Neoscona theisi (19.98%). Existence of H. graminicola and Pardosa astrigera observed during the whole cropping season. Presence of seven guilds among spiders had a diverse nature of hunting insect pests and on number of species existed in the crop, maximum was from direct hunting habit. Composition and community structure of microbiota varied as of spider species. Proteobacteria was the most abundant bacterial phylum and topmost genus was Wolbachia in observed spiders. Five groups of bacteria distinguished across 4 clusters of spiders depending on core community of symbiotic bacterial genera. This effort is an initial step to get knowhow about spiders in Bt cotton, which will facilitate future research studies concerning spiders.     

The control of vertebrate pests by vertebrate predators

Carnivores can control mammalian pests for long periods, but only after pest numbers have been reduced by other means. In Australia, the cause is prolonged dry weather. The consequent low populations of rabbits can then be regulated by European foxes, feral cats and dingoes. Kangaroos, and probably feral goats and pigs, succumb to dingoes at the same time, as substitute prey for rabbits. In the general case, such regulatory predation may be triggered climatically, by disease or by human intervention. When predators are themselves pests to be controlled, integrated pest management may be required to avoid unwanted resurgences of other pests.