严防外来有害生物褐纹甘蔗象入侵海南

【背景】褐纹甘蔗象原产于菲律宾,严重危害椰子等棕榈科植物和甘蔗,目前该虫已传入我国台湾、广东、广西和云南,尚未在海南省发生。【方法】为尽早预防该虫传入,本文简要描述了褐纹甘蔗象的生物生态学特性,并运用有害生物危险性分析(PRA)方法,从国内分布情况、潜在的经济危害性、受害寄主的经济重要性、传播扩散的可能性和危险性管理难度等方面对该虫入侵海南的可能性进行了定性和定量分析。【结果】褐纹甘蔗象在海南省的风险评估值R=2.08,属于高风险的林业有害生物,建议将其列入海南省林业检疫性有害生物名单;同时提出了该虫的综合防治措施和建议。【结论与意义】本研究可为尽早制定褐纹甘蔗象防范措施提供参考。     

褐纹甘蔗象在中国的适生区分析

褐纹甘蔗象Rhabdosceluslineaticollis (Heller)是棕榈科植物和甘蔗的重要害虫。利用CLIMEX气候模型 ,对该虫在我国的适生区进行了分析和预测。结果显示 ,海南省、广东省、广西壮族自治区、福建省、浙江省和云南省南部地区是褐纹甘蔗象在我国大陆的适生区。这些区域正是我国棕榈科植物和甘蔗的主要生产区 ,超前预防该虫入侵是非常必要的。     

褐纹甘蔗象生物学特性及其防治研究进展

本文主要介绍了为害棕榈科植物和甘蔗的危险性害虫-褐纹甘蔗象(Rhabdwscelus lineaticollis Heller)的危害性、生物学特性以及防疫控制技术等,并探讨了这种害虫的未来防治技术.     

褐纹甘蔗象风险分析及其风险管理

通过对褐纹甘蔗象在国内外的分布情况及国内寄主植物分布、适生范围、传播渠道、检疫管理措施等指标的定性和半定量的风险分析,得出其在我国属于中度危险的林业有害生物(其风险评估值为R=1.746),对我国种植面积广泛的棕榈科植物构成了较大的威胁。建议在有其寄主分布的省份将其列入林业检疫性有害生物省级补充名单进行管理,防止其在我国继续扩散危害,并提出了国内检疫管理的措施。     

甘蔗茎尖离体培养褐变影响因素及细胞区室结构分析

该研究通过综合分析对甘蔗(ROC 22)茎尖离体培养褐变不同条件因素的影响以及褐变细胞区室结构的变化,探讨了甘蔗茎尖离体培养褐变的机理机制。结果表明:不同芽位茎尖诱导成活率具有明显差异,随着芽位的增加,诱导成活率不断降低;不同季节取芽对外植体茎尖总酚类物质含量无明显影响;但不同芽位及不同催芽天数,外植体芽的总多酚含量明显不同,随着催芽天数的增加,不同芽位的多酚含量呈现由低升高的趋势;蔗芽在培养4周时多酚含量较低,适宜进行采芽接种培养;从褐变甘蔗茎尖的解剖结构变化分析,褐变甘蔗茎尖细胞离体培养初期细胞核结构出现变形,线粒体有肿胀拉长,部分液泡膜开始分解;中后期质壁分离更为严重,胞质中出现大量溶酶体,线粒体等细胞器全分解,细胞膜、液泡膜、核膜、线粒体膜的双层膜结构出现破损和缺口;而正常发育的茎尖细胞,能基本保持细胞核的形态结构,只有少量的溶酶体出现。因此,可以推测细胞核和线粒体结构变形以及膜系统的大量破损是甘蔗茎尖培养褐变死亡的原因。     

甘蔗害虫优势天敌及其保护利用

本文对7种甘蔗害虫优势天敌的寄生捕食特点及其保护利用进行了探讨和综述.云南蔗区甘蔗害虫种类多,天敌资源十分丰富.全省甘蔗害虫天敌达283种之多,其中,具有保护利用价值和研究意义的优势种主要有:寄生甘蔗螟虫Sesamia inferens Walker的赤眼蜂Thichogramma、螟黄足绒茧蜂Apanteles flavipes(Cameron)和大螟拟丛毛寄蝇Sturmiopsis inferens Townsend;捕食甘蔗绵蚜Ceratovacuna lanigera Zehntner的大突肩瓢虫Synonycha grandis (Thunberg)、双带盘瓢虫Lemnia biplagiata(Swartz)、六斑月瓢虫Chilomenes sexmaculata(Fabricius)和绿线食蚜螟Thiallela sp.;捕食甘蔗粉蚧Saccharicoccus sacchari(Cocherell)、Dysmicoccus boninsis Kuwana和蔗头象虫Trochorhopalus humeralis Chevrolat Diocalandra sp.的黄足肥螋Euborellia pallipes Shiraki等.还有一种寄生菌-白僵菌Beauvria sp.,在自然界中分布十分广泛,可寄生蔗螟、蔗龟Exolontha serrulata(Gyllenhal)Alissonotun impressicolle Arrow、蔗头象虫、蛀茎象虫Otidognathus rubriceps Chevrolat等多种甘蔗害虫,其自然寄生率一般在10%左右,对甘蔗害虫具有一定的自然抑制作用.合理保护利用天敌,充分发挥天敌对害虫的自然调控作用,这对保护生态环境,维护蔗田生态平衡,提高害虫综合治理水平,促进蔗糖业可持续发展均具有重要意义.     

寄主植物对赭色鸟喙象取食、发育和繁殖的影响

本文对甘蔗赭色鸟喙象OtidognathusrubricepsChevrolat在甘蔗、玉米、竹子和类芦上的取食、发育和繁殖作了比较研究。结果表明 :成虫趋向取食甘蔗、在甘蔗上产卵 ;每雌产卵量、产卵历期、成虫寿命和卵孵化率以甘蔗为最高、最长 ,然后依次为类芦、玉米、竹子。甘蔗最有利于该虫的取食、发育和繁殖。     

甘蔗茎尖培养中减轻酚害

甘蔗茎尖组织预先在无菌水中浸泡30 min后,再接种到附加6-BA 2.0 mg·L-1、NAA 0.1 mg·L-1的MS培养基中,可减轻外植体的褐变;茎尖诱导培养基中直接附加适量的活性炭(AC,以0.02%为宜,最高不超过0.05%),减轻茎尖组织酚害的效果最理想.另外,在培养基中附加抗氧化剂(如:聚乙烯吡咯烷酮,PVP),或根据外植体的褐变情况及时转移到新鲜的培养基中,均能减轻甘蔗茎尖组织的酚害.     

甘蔗、斑茅及其杂种的过氧化物酶同工酶

甘蔗属(Saccharum L.)主要包括热带种(S.officinarum L.)、中国种(S.sinensisRoxb)、印度种(S.barberi Jeswiet)、“割手密”种(S.spontaneum L.)和大茎野生种(S.robustum Brandes)。甘蔗属的近缘植物——斑茅(Arundinaceum Retz)应该划归甘蔗属、蔗茅属(Erianthus Michx)或另立一属,意见不一。Dutt 等将斑茅列入蔗茅属,耿以礼等则将其划归甘蔗属。甘蔗糖业栽培的甘蔗(糖蔗)是热带种与割手密种、大     

甘蔗蓟马种群动态及其在不同品种甘蔗上为害情况

【目的】明确甘蔗蓟马Fulmekiola serrata的发生动态及其在不同品种甘蔗上的为害情况,为探讨该虫对不同甘蔗品种的选择性和采取有效的防治措施奠定基础。【方法】田间种群动态调查于2013年4月初到7月末进行,研究了12个品种在新植甘蔗和宿根甘蔗田块遭受甘蔗蓟马为害情况。【结果】甘蔗蓟马种群数量先逐渐上升后又下降,发生高峰期集中在6月中旬到7月上旬。12个甘蔗品种均受到甘蔗蓟马为害,其中,新植甘蔗中云瑞06-189甘蔗蓟马数量最多,平均有25.80头/株,闽糖01-77甘蔗蓟马数量最少,平均有7.80头/株;宿根甘蔗中ROC22甘蔗蓟马数量最多,平均有106.93头/株,云蔗06-80甘蔗蓟马数量最少,平均有33.60头/株。同一田块不同品种甘蔗蓟马若虫和成虫数量不等,同一品种宿根甘蔗蓟马数量多于新植甘蔗,株虫量差异范围为10.10~90.90头/株。【结论】甘蔗品种和植期影响甘蔗蓟马发生,不同品种甘蔗蓟马为害程度和抗性水平存在差异。     

大气环流特征量的水稻白背飞虱发生程度预报模型的研究

根据500hPa大气环流特征量能表征天气形势和控制天气条件的这一特性,利用线性及单调曲线相关与最优化因子相关两种技术对环流特征量因子进行普查、对比分析,发现白背飞虱虫情指标与环流因子之间关系不仅是线性及几种单调曲线的关系,而且还存在非线性、非单调的单峰(谷)型的相关关系,并从中挑选一批与水稻白背飞虱虫情指标相关极其显著、稳定性强、因子间相互独立、可靠的大气环流特征量作为预报因子,在此基础上,建立了江苏省水稻白背飞虱虫情指标预报的环流模型,且还证实了模型中的环流因子与影响白背飞虱迁入、发生发展的气象条件呈显著相关关系,为预报白背飞虱发生程度提供了新的长期因子和新途径。     

毛健夜蛾生物学特性初步研究

毛健夜蛾Brithyscrini(Fabricius)取食多种石蒜科植物,近年来对上海市的葱兰危害尤其严重。文章介绍了该虫的形态特征、年生活史及生活习性。为进一步的害虫治理奠定了基础。     

Insectivorous birds are not effective pest control agents in olive groves

Although avian-mediated pest control is a significant ecosystem service with important economic implications, few experimental studies have ever documented its role in Mediterranean agroforests. Specifically, information on pest control by birds is lacking in certain permanent agroecosystems of worldwide importance such as olive groves.Here, we assess experimentally for the first time the effectiveness of insectivorous birds in controlling the two main olive-tree pests. We also explore the effects of distance to semi-natural habitat patches on avian insectivore abundance and pest control. We combined bird and pest surveys with pest damage monitoring and two field experiments (branch exclusion and plasticine models) at a regional scale.The experiments showed that birds played a negligible role as pest controllers (measured in terms of attack rates on plasticine models and controlled pest damage) in the studied olive groves; overall, pests were abundant and pest damage was high on most farms. In addition, surveys showed that insectivorous birds were more abundant and diverse in patches of semi-natural habitat, compared to the matrix of olive groves, and that proximity to semi-natural patches was not a driver of bird-driven pest control.This study experimentally demonstrates that insectivorous birds are not effective pest controllers in olive groves. The absence of patterns linking insectivorous birds’ availability and observed pest control suggests that birds are unable to exert effective control over the main olive-tree pests. This lack of biocontrol by birds is probably due to low accessibility and/or appetence for the current insectivorous groups. Habitat improvement aimed at encouraging some under-represented forager species could improve the likelihood that birds will provide this ecosystem service.     

A spatial model of the development of pest resistance to a transgenic insecticidal crop: European corn borer on Bt maize

A mathematical model was constructed to describe the evolution of resistance to the Bacillus thuringiensis toxin (Bt) in an insect pest (European corn borer) population on a transgenic crop (Bt corn). The model comprises a set of partial differential equations of the reaction-diffusion type; local interactions of three competing pest genotypes formed by alleles of Bt resistance and susceptibility are described as in the Kostitzin model, and the spread of insects is modeled as diffusion. The model was used to evaluate the influence of pest characteristics on the efficacy of the high-dose/refuge strategy aiming to prevent or delay the spread of Bt resistance in pest populations. It was shown, by contrast, that a model based on Fisher-Haldane-Wright equations and formally incorporating a diffusion term cannot adequately describe the evolution of Bt resistance in a spatially inhomogeneous pest population. Further development of the proposed demo-genetic model is discussed.     

Experimental analysis of the influence of pest management practice on the efficacy of an endemic arthropod natural enemy complex of the diamondback moth

Maximizing the contribution of endemic natural enemies to integrated pest management (IPM), programs requires a detailed knowledge of their interactions with the target pest. This experimental field study evaluated the impact of the endemic natural enemy complex of Plutella xylostella (L.) (Lepidoptera: Yponomeutidae) on pest populations in commercial cabbage crops in southeastern Queensland, Australia. Management data were used to score pest management practices at experimental sites on independent Brassica farms practicing a range of pest management strategies, and mechanical methods of natural enemy exclusion were used to assess the impact of natural enemies on introduced cohorts of P. xylostella at each site. Natural enemy impact was greatest at sites adopting IPM and least at sites practicing conventional pest management strategies. At IPM sites, the contribution of natural enemies to P. xylostella mortality permitted the cultivation of marketable crops with no yield loss but with a substantial reduction in insecticide inputs. Three species of larval parasitoids (Diadegma semiclausum Hellén [Hymenoptera: Ichneumonidae], Apanteles ippeus Nixon [Hymenoptera: Braconidae], and Oomyzus sokolowskii Kurdjumov [Hymenoptera: Eulophidae]) and one species of pupal parasitoid Diadromus collaris Gravenhorst (Hymenoptera: Ichneumonidae) attacked immature P. xylostella. The most abundant groups of predatory arthropods caught in pitfall traps were Araneae (Lycosidae) > Coleoptera (Carabidae, Coccinelidae, Staphylinidae) > Neuroptera (Chrysopidae) > Formicidae, whereas on crop foliage Araneae (Clubionidae, Oxyopidae) > Coleoptera (Coccinelidae) > Neuroptera (Chrysopidae) were most common. The abundance and diversity of natural enemies was greatest at sites that adopted IPM, correlating greater P. xylostella mortality at these sites. The efficacy of the natural enemy complex to pest mortality under different pest management regimes and appropriate strategies to optimize this important natural resource are discussed.     

Exploiting predators for pest management: the need for sound ecological assessment

Most people agree that arthropod natural enemies are good for insect pest management in agriculture. However, the population suppressive effects of predators, which consume their prey and often leave no direct evidence of their activity, are more difficult to study than the effects of parasitoids, which can be sampled from host populations relatively easily. We critically reviewed field studies which investigated the relationship between lepidopteran pests and their associated predatory fauna, published in 11 leading entomology and applied ecology journals between 2003 and 2008. Each study was appraised to determine whether or not it demonstrated that predators had an impact on prey (pest) populations and, if so, whether it was conducted at an ecological scale relevant to pest management. Less than half (43%) of the 54 field studies adopted methodologies that allowed the impact of predators on target pest populations to be measured. Furthermore, 76% of the studies were conducted at the scale of experimental plots rather than at the ecological scale which determines pest and predator population dynamics or at which pest‐management decisions are made. In almost one‐third of the studies, predator abundance and/or diversity was measured, but this metric was not linked with pest suppression or mortality. We conclude that much current research does not provide evidence that predatory arthropods suppress target lepidopteran pest populations and, consequently, that it has little relevance to pest management. Well‐designed ecological experiments combined with recent advances in molecular techniques to identify predator diets and the emergence of organic agriculture provide both the mechanisms and a platform upon which many predator–prey interactions can be investigated at a scale relevant to pest management. However, benefits will only be reaped from this opportunity if current approaches to research are changed and relevant ecological data are collected at appropriate ecological scales.     

Lepidoptera pests collected in Eucalyptus urophylla (Myrtaceae) plantations during five years in Três Marias,State of Minas Gerais,Brazil

Lepidoptera pest species from eucalyptus were collected in Eucalyptus urophylla plantations in the region of Três Marias, State of Minas Gerais, Brazil, every 15 days from June 1989 to June 1994 with five light traps. Twelve primary and 15 secondary pest species were collected in the period with an average of 13,387 and 812 individuals per light trap, respectively. Most collected primary pest species were Stenalcidia grosica (Geometridae), Iridopsis subferaria (Geometridae), Eupseudosoma aberrans (Arctiidae) and Psorocampa denticulata (Notodontidae), totalizing for the study period an average of 5,450, 2,162, 2,436 and 1,458 individuals per light trap, respectively. Idalus admirabilis (Arctiidae) was the most collected secondary pest species, averaging 652 individuals/trap. Most primary pest species were collected during the dry season, from April to July, whereas most secondary pest species were collected during the rainy season, from January to March. These differences on seasonal occurrence between the two groups could be due to the fact that many secondary pest species of Eucalyptus in Brazil pupate in the soil, and they need humidity to complete its pupal stage.     

Non-crop habitats concurrently drive crop colonization by the millet head miner and regulation by natural enemies

Non-crop habitats, depending on their composition, can enhance the abundance and diversity of natural enemies of crop pests, but also at the same time provide resources to pests, thereby reducing the effect on pest incidence and resulting yield losses. The objective of the present study was to test (1) the effect of semi-natural habitats in the landscape on crop colonization by pests and natural regulation, and (2) the relationship between natural regulation and pest incidence. The pearl millet head miner (MHM) was selected as a case study because it is a key pest of millet cultivated in traditional pesticide-free tree-crop agroforestry systems in which its control mostly relies on the action of natural enemies.A set of 24 millet fields were selected in a 20×20 km area in Senegal, from the analysis of high-resolution satellite images (Pléiades), and hypotheses on the relative abundance of semi-natural habitats (here trees and rangelands) in the agricultural landscape. Millet fields were monitored for pest infestation of panicles and pest natural regulation. We used partial least squares structural equation modelling (PLS-PM) to evaluate the relationships between the abundance and diversity of semi-natural habitats at the landscape scale, crop colonization, natural pest regulation, and pest incidence.Panicle colonization by the MHM was generally high (14–92%) and increased with the abundance of trees and to a lesser extent with the rangeland area at a 1000 m-radius around millet fields. However, regulation provided by natural enemies was amplified by the abundance of trees at a local scale (250 m-radius around millet fields). This was particularly true at early crop colonization of the MHM with parasitism and direct predation on eggs and young larvae. This multi-scale effect of semi-natural habitats on crop colonization and natural regulation could explain why no clear relationship between crop colonization and pest incidence, nor natural regulation and pest incidence, was observed. Future studies on the identification of complex species-specific interactions between trees and natural enemies should provide a better understanding of the ecological processes underlying the performance of natural regulation of MHM populations.     

害虫对苏云金杆菌的抗性研究进展

本文主要针对害虫对苏云金芽孢杆菌（Bt）的抗性机理和防治对策方面进行综述.深入研究昆虫对Bt毒素的抗性机理,将有助于建立虫害综合防治体系,实现无公害Bt农药的广泛及持续利用.     

Comparison of α- and β-mannosidase activity in the three cereal pests,Haplothrips tritici Kurdjumov (Thysanoptera: Phlaeothripidae), Rhopalosiphum padi L. (Homoptera: Aphididae) and Eurygaster integriceps Puton (Hemiptera: Scutelleridae)

The Sunn pest, Eurygaster integriceps, the bird cherry-oat aphid, Rhopalosiphum padi, and wheat thrips, Haplothrips tritici are the major pests of wheat and other cereals in a wide area of the world. All these three insect species could produce damage to the wheat to some extent. Therefore, the purpose of the present study was to determine α- and β-mannosidase of the three mentioned insect pests. These insects were collected from the wheat farm and their guts (the Sunn pest and the aphid) and salivary glands of Sunn pest were removed. However, regarding tiny body of thrips, the whole body used in order to extract the enzymes. The enzymes, including α- and β-mannosidase activity, were measured by the hydrolysis of p-nitrophenyl-α-d-mannopyranoside (pNPαGal) and p-nitrophenyl-β-d-mannopyranoside (pNPβGal), respectively, using phosphate citrate buffer (pH 5.0). Mannosidases were not active in all three tested insect species, and also there were significant differences in activities of the two enzymes in three species. The greatest activity of α-mannosidases was observed in the Sunn pest salivary glands, E. integriceps, and the least activity was found in Sunn pest midgut with no activity. However, the activity of β-mannosidase was established in Sunn pest midgut, but there was no activity in the aphid midgut, R. padi. Activities of these two enzymes were modest in the thrips, H. tritici. The greatest amount of β-mannosidases in the Sunn pest midgut makes sense, since the Sunn pest is the main pest in the wheat farm that can feed on wheat grains. In the wheat grains, the highest amount of glycoproteins and glycolipids are present. Thus, it has been known that these enzymes (α- and β-mannosidases) are active on digestion of carbohydrates.