麦红吸浆虫成虫和幼虫滞育过程中蜕皮激素的定量分析

为明确麦红吸浆虫成虫和幼虫滞育过程中体内蜕皮激素的变化规律,采用放射免疫分析法测定了麦红吸浆虫成虫和幼虫滞育过程中的蜕皮激素滴度.结果表明,同一天羽化的成虫,雌虫蜕皮激素滴度为7.43pg/头,显著高于雄虫;滞育前后及滞育期幼虫蜕皮激素滴度存在显著差异,滞育前为5.22pg/头,进入滞育后显著降低;滞育期间,冬季蜕皮激素滴度为6.64～7.10pg/头,显著高于其它季节;滞育解除后蜕皮激素滴度显著降低,之后随着幼虫的生长发育逐渐升高,至化蛹前约1周达到最高,为15.22 pg/头.滞育期间同期裸露幼虫与结茧幼虫,以及不同滞育年限幼虫的蜕皮激素滴度差异均不显著.     

小麦吸浆虫滞育前后和滞育期蛋白质含量及其电泳分析

为弄清小麦吸浆虫滞育与蛋白质的关系,应用考马斯亮蓝G-250染色法、SDS-PAGE及PAGE电泳技术分析小麦吸浆虫滞育前后及滞育期蛋白质含量和组分的变化。结果表明,不同阶段蛋白质含量存在显著差异,老熟幼虫入土前和滞育解除后均高于入土滞育期。入土滞育期间,同期裸露幼虫与结茧幼虫,以及不同滞育年限幼虫的蛋白质含量差异均不显著;滞育年周期中,无论结茧幼虫还是裸露幼虫,蛋白质含量的变化均可划分为两个阶段,第1阶段为当年6月至12月,蛋白质含量较低,平均为19.2269μg/头和19.5734μg/头;第2阶段为翌年2月底至5月中旬,蛋白质含量相对较高,平均为20.9578μg/头和20.7153μg/头。电泳图谱分析发现,SDS-PAGE 18.3kD和32.0kD蛋白带与4条PAGE蛋白带的表达量,以及SDS-PAGE 18.3kD和19.8kD蛋白带的相对表达量在滞育前后及滞育期发生了一定的变化,但在滞育期不同阶段基本无变化。     

温、湿度及处理时间对麦红吸浆虫老熟幼虫脱穗的影响

为研究温、湿度对麦红吸浆虫老熟幼虫脱穗的影响,在室内条件下,以小麦黄熟期麦红吸浆虫老熟幼虫尚未脱穗的被害麦穗为材料,测定不同温、湿度及处理时间对麦红吸浆虫老熟幼虫脱穗的影响,其中湿度通过PE自封袋加水调节。温度为12～16℃时老熟幼虫脱穗率明显高于其它温度处理,14℃达到峰值24.78%。每袋加水2 mL时脱穗率达39.6%,明显高于其它湿度处理。处理12～36h脱穗率明显增加,处理48h时脱穗率与36h差异不显著。表明在14℃、每袋加水2mL、处理时间为36 h时麦红吸浆虫老熟幼虫最易脱穗活动。     

干旱对麦红吸浆虫实验种群的影响

在玻璃棚内人工接虫研究了不同干旱时间不同栽培措施下麦红吸浆虫的实验种群生命表,从中得出干旱一个月和干旱三个月的各区吸浆虫死亡率均比对照各区高33%,而冬季死亡率变动较小,一代吸浆虫的种群数量变动均随时间的增长而变小,不存在多峰现象,且有滞育个体出现。     

呋虫胺防治穗期麦红吸浆虫的田间药效试验

目前在防治麦红吸浆虫的药效试验中,尚缺乏穗期防治的试验方法。本试验采用黄色粘板监测麦红吸浆虫成虫的发生动态,在小麦齐穗期,用不同剂量20%呋虫胺可溶粒剂喷雾对麦红吸浆虫进行防治。结果表明,20%呋虫胺可溶粒剂用量为20、25和30g/667m2时对麦红吸浆虫的防治效果可达90%以上。本试验为今后制定麦红吸浆虫穗期防治的药效试验准则提供了科学依据。     

不同色彩粘板对麦红吸浆虫成虫的诱集效果比较

为了改进麦红吸浆虫成虫的监测方法,提高监测效率,于2009—2011年在河北省保定市徐水县,通过田间试验比较了14种颜色粘板对麦红吸浆虫成虫的诱集效果,并进行了3个高度的紫板和黄板对该成虫的诱集试验。结果显示：在14种颜色粘板中,紫色、桃粉、橙红、橙黄、浅粉的诱集效果较好,其中以紫板最多,其诱集效果显著高于生产上普遍用于监测的黄板,且紫板上诱集到的蝇类数量也明显偏少;下部粘板诱集到的麦红吸浆虫成虫数量最多,与中、上部之间存在极显著差异,且相同高度的紫板上诱集到的麦红吸浆虫成虫数量显著多于黄板。因此,建议用紫板监测麦红吸浆虫成虫发生动态,高度以紫板下缘与地面平齐为宜。     

小麦品种（系）抗麦红吸浆虫鉴定技术研究

小麦抗麦红吸浆虫指标的制定是筛选抗虫品种,对麦红吸浆虫实行综合治理的基础工作。通过分析比较危害指数、粒被害率、估计损失率、抗性指数、相对指数及聚类分析等指标鉴定结果,发现以感虫品种为对照,以穗被害率、粒被害率、估计损失率和单穗虫数等多个指标为依据的聚类分析法的鉴定结果最符合客观实际,建议今后在麦红吸浆虫抗性鉴定中推广应用。     

苹果酸脱氢酶与异柠檬酸脱氢酶在滞育七星瓢虫中的差异表达

为分析七星瓢虫滞育相关蛋白质的类别和功能,在滞育调控及滞育后生物学研究的基础上,应用双向电泳、质谱分析(ESI-QUAD-TOF)、生物信息学等蛋白质组学方法,对表达量存在2倍及以上差异且差异显著的蛋白点进行鉴定。应用Mascot软件进行数据库检索,根据数据的匹配程度鉴定蛋白质。所得蛋白质中,参与三羧酸循环的两种关键酶呈现差异性表达,其中苹果酸脱氢酶(gi|212508346)呈上调表达,异柠檬酸脱氢酶(gi|21392222)则呈下调表达。苹果酸脱氢酶的增加,推测与滞育状态下的生理需求相关:一方面与昆虫对NAD的合成和利用有关,另一方面或是七星瓢虫应对滞育环境条件的一种应激方式,与正常个体的代谢通路相比,滞育个体开启了另外的代谢通路以适应环境条件的改变。异柠檬酸脱氢酶作为三羧酸循环中起关键调节作用的限速酶,在滞育个体中下调表达,或反映了三羧酸循环整体速率的降低,表现在滞育七星瓢虫体内维持了低水平的能量代谢。本文的研究结果,为从蛋白质水平深入揭示七星瓢虫滞育调控及其机理提供一定的参考。     

南阳盆地小麦吸浆虫回升因素浅析

小麦吸浆虫是小麦生产上一种毁灭性害虫。该虫在 4 0年代末期至 50年代初期 ,以及 80年代中、后期曾在南阳市形成 2次为害高峰 ,发生面积均在 3 3万ｈｍ2 以上。 90年代以来 ,吸浆虫发展蔓延更为迅速 ,发生面积不断扩大 ,虫口密度急剧增加 ,为害程度逐年加重 ,已成为影响本市小麦高产、优质、高效的严重障碍。1　回升原因1 .1　生物学因素1 )麦红吸浆虫属长日照滞育型昆虫。在外界条件适宜时可迅速发展 ,条件不适宜时 ,幼虫可在土壤中结茧休眠 1 8ａ,仍保持繁衍能力。该虫虫体小 ,为害具有隐蔽性。 1ａ有 1 1个月生活在土壤中 ,受不利因素影…     

瘿蚊科3种昆虫核糖体DNA的克隆及序列分析

瘿蚊科是双翅目昆虫中的重要类群?本研究对瘿蚊科3种昆虫—麦红吸浆虫?菊花瘿蚊和食蚜瘿蚊的核糖体DNA进行PCR扩增?克隆?测序及序列分析, 并对ITS-1在麦红吸浆虫4个地理种群中的遗传变异情况进行分析?结果表明, 从3种昆虫中获得的核糖体DNA序列包括:部分的18S rDNA(44 bp)?28S rDNA(37 bp), 全部的ITS-1(487~535 bp), 5.8S rDNA(121 bp)及ITS-2(336~352 bp)序列?3种昆虫ITS序列的碱基差异百分比在17.21%~29.59%之间, 共含有206个变异位点?ITS-1序列在麦红吸浆虫4个地理种群中比较保守, 只有4个变异位点, 单倍型多样性为0.311 7~0.796 5, 核苷酸多样性为0.000 6~0.002 2?本研究为今后瘿蚊科昆虫的分类鉴定?系统发育和遗传进化等相关研究提供了基础?     

Effectiveness of Some Insecticides on Wheat Blossom Midges in Winter Wheat

Orange wheat blossom midge damage can impart serious loss of quantity and quality of winter wheat. Wheat midges were evaluated in large scale field in winter wheat in Bad Lausick (Leipzig, Saxsony) central Germany. The present study aimed at studying the activity of wheat blossom midges WBM, Sitodiplosis mosellana (Géhin) and Contarinia tritici (Kirby) using pheromone, sticky traps and two types of water traps. Management of midges with different treatments was studied; Karate (pyrethroid), Biscaya (neonicotinoid) and NeemAzal T/S (botanical insecticide) were sprayed on wheat at heading stage (GS 55). Monitoring was conducted before the treatment and continued for 4 weeks after the treatment. Pheromone traps were used for forecasting midge adult population and determine the control date. Water traps were used to assess midge larvae, while midge adults were surveyed using sticky traps. A strong correlation between midge catches and weather conditions was obtained; as well a coincidence between pheromone catches and wheat midge infestation in the susceptible growth stages (GS 47–65) was recorded. Insecticide applications to fields of midge-infested winter wheat significantly reduced the wheat midge damage. There were significant differences in wheat midge numbers between treated and untreated; wheat midge numbers were lower in the treated than in control. The results proved that both Karate and Biscaya caused more mortality to wheat midges than NeemAzal T/S.     

The citrus blossom midge,Contarinia Citri Barnes (Diptera: Cecidomyiidae), in Israel

The citrus blossom midge,Contarinia citri Barnes, was sampled in two lemon groves. Infestation lasted from December through April. Midge-infested blossoms were seldom concomitantly attacked by the citrus flower moth,Prays citri Mill. Some midge larvae completed their development in the laboratory, their numbers declining and the period required for pupation becoming shorter toward the end of the season. Very few parasitoids were obtained. It is suggested thatC. citri andP. citri may be partially mutually-exclusive in lemon flowers, that the number of annual midge generations depends on the availability of blossoms, and that the midge may undergo a prolonged diapause in the soil.     

Cloning and expression of an atrazine inducible cytochrome P450, CYP4G33, from Chironomus tentans (Diptera: Chironomidae)

Previous studies performed in our laboratory have measured the effect of atrazine exposure on cytochrome P450-dependent monooxygenase activity and have found increased activity in midge larvae (Chironomus tentans) as a result of atrazine exposure (1-10 ppm). Here we report the cloning and expression of a specific C. tentans CYP4 gene that is responsive to atrazine induction with an open reading frame of 1678 bp which encodes a putative protein of 559 amino acid residues. Alignments of deduced amino acid sequences with other insect P450 genes and phylogenetic analysis indicated a high degree of similarity to other insect CYP4 genes. Northern blotting analysis employing a fragment of 1200 bp from the CYP4 gene as a probe indicated that the CYP4 gene was expressed in all developmental stages, but was expressed at highest levels in late instar larvae. Additionally, over-expression of CYP4 in C. tentans exposed to atrazine (10 mg/l) confirms the ability of atrazine to induce specific P450 genes and provides insight into potential consequences of atrazine exposure in aquatic organisms.     

西伯利亚蝗卵发育过程中血蓝蛋白基因Hc1、Hc2表达、差异及其与土壤温度的关系

为明确血蓝蛋白基因在新疆优势害虫西伯利亚蝗Gomphocerus sibiricus卵发育过程中的作用,本研究采用实时荧光定量PCR技术检测血蓝蛋白基因Hc1、Hc2在西伯利亚蝗卵不同发育阶段和1龄蝗蝻中的相对表达量,比较基因Hc1、Hc2相对表达量的差异,并分析这2个基因与土壤温度的相关性。结果表明,血蓝蛋白基因Hc1和Hc2在西伯利亚蝗卵所有发育阶段均有表达,并具有阶段特异性。在蝗卵早期发育阶段,Hc1基因相对表达量较高,Hc2基因相对表达量较低,其中在I阶段,Hc2基因相对表达量最低,为0.05;在滞育阶段,Hc1基因相对表达量降低,且在深度滞育期降至最低,为0.12,Hc2基因相对表达量略有增加;在滞育解除后发育阶段,Hc1基因相对表达量无显著变化,Hc2基因相对表达量在第VIII阶段最高,为17.26;在1龄蝗蝻阶段,Hc1基因相对表达量急剧升高至最大值,为39.43,Hc2基因相对表达量急剧下降。在西伯利亚蝗卵发育过程中,Hc1基因相对表达量平均数为8.83,高于Hc2基因的平均数,且蝗卵早期发育阶段、滞育后发育阶段和1龄蝗蝻阶段的Hc1和Hc2基因相对表达量之间差异显著。土壤温度与西伯利亚蝗卵各发育阶段和1龄蝗蝻阶段中Hc1基因相对表达量正相关,但相关性不显著,与Hc2基因相对表达量无显著相关性。     

Protein metabolism in Spodoptera litura (F.) is influenced by the botanical insecticide azadirachtin

Azadirachtin, as a botanical insecticide, affects a wide variety of biological processes, including reduction of feeding, suspension of molting, death of larvae and pupae, and sterility of emerged adults in a dose-dependent manner. However, the mode of action of this toxin remains obscure. By using proteomic techniques, we analyzed changes in protein metabolism of Spodoptera litura (F.) induced by azadirachtin. Following feeding 4th instar larvae of Spodoptera litura (F.) with an artificial diet containing 1 ppm azadirachtin until pupation, 48 h old pupae were collected and protein samples prepared. Total soluble protein content was measured and the results showed that azadirachtin significantly influenced protein level. Moreover, the proteins were separated by 2-DE (two-dimensional polyacrylamide gel electrophoresis) and 10 proteins were significantly affected by azadirachtin treatment when compared to an untreated control. Six of these proteins were identified with peptide mass fingerprinting using MALDI-TOF-MS after in-gel trypsin digestion. These proteins are involved in various cellular functions. One identified protein may function as an ecdysone receptor, which regulates insect development, and reproduction. It is suggested that the botanical insecticide azadirachtin affects protein expression and the azadirachtin-related proteins would be essential for a better understanding of the mechanisms by which neem toxins exert their effects on insects.     

The nematicidal and proteomic effects of Huanong AVM (analog of avermectin) on the pine-wilt nematode, Bursaphelenchus xylophilus

Huanong AVM is a novel nematicide, which was synthesized from avermectin by selective oxidization of the hydroxyl group at C-4, followed by the reaction with glacial acetic acid. Effects of Huanong AVM on Bursaphelechus xylophilus are reported in this paper. Huanong AVM had strong nematicidal activity against B. xylophilus, with LC₅₀ values of 14.84 μg/mL, 12.49 μg/mL and 11.05 μg/mL, respectively, at 48 h, 72 h and 96 h after treatment. The proteins that responded to Huanong AVM were identified by proteomic analysis. 2-DE analysis revealed eighteen differentially accumulated protein spots. Five spots were successfully identified by MS analysis, and three Huanong AVM induced proteins were annotated in the database as LEVamisole resistant family member (lev-11), ACTin family member (act-4) and Hypothetical protein Y52B11A.10. Two Huanong AVM-up-regulated proteins were assigned as PIP Kinase family member (ppk-3) and Hypothetical protein B0432.6. These proteins are involved in signal transduction, maintaining cytoskeletal structure and LEVamisole resistance. These results point to pathways that are important for the mode of the action of Huanong AVM on B. xylophilus.     

解除生殖滞育的巴氏新小绥螨捕食能力

巴氏新小绥螨Neoseiulus barkeri是极具应用潜力的捕食螨，在农业生产中，广泛应用于防治多种害螨和小型吸汁性害虫。由于活体天敌的特殊性，如何保障储运期间巴氏新小绥螨的存活率和捕食能力的稳定性，是目前捕食螨产品高效安全应用的难题之一，进行诱导生殖滞育，是延长捕食螨货架期的有效途径。本文采用选择系数和Holling圆盘方程测试方法，研究了解除生殖滞育（以下简称滞育）的巴氏新小绥螨的选择取食作用和捕食功能，结果如下：（1）普通品系、滞育解除品系、滞育品系的巴氏新小绥螨对腐食酪螨不同螨态的捕食选择性和被食比例呈现出基本一致的趋势，表现出强烈的选择性；三个品系的巴氏新小绥螨均对猎物幼螨表现出嗜食性，其选择系数从高到低为幼螨，卵，若螨，成螨；但也表现出一定的差异性，普通品系与滞育解除品系对猎物的卵和幼螨均表现为嗜食性，滞育品系的巴氏新小绥螨仅对猎物的幼螨表现为嗜食性。（2）三个品系的捕食功能曲线均符合HollingⅡ型圆盘方程；滞育解除后巴氏新小绥螨能快速恢复生长发育和捕食能力，普通品系、滞育品系、滞育解除品系的巴氏新小绥螨对猎物腐食酪螨的攻击系数a分别为0.6761、0.2731、0.6468；理论日最大捕食量分别为12.8205头、12.0482头、14.4928头，理论日最大捕食量滞育解除品系大于普通品系与滞育品系，滞育品系与普通品系理论日最大捕食量无显著差异；三个品系的处理时间T_h分别为0.0780 d、0.0830 d和0.0690 d。（3）滞育解除品系、普通品系、滞育品系的巴氏新小绥螨对猎物的捕食能力a/T_h由高到低为滞育解除品系，普通品系，滞育品系，分别为9.37、8.67、3.29，表明诱导生殖滞育，对滞育解除后的巴氏新小绥螨捕食能力无不利影响，且有一定程度的增强。     

梨小食心虫滞育过程中几种代谢酶活力的相关变化

梨小食心虫Grapholita molesta是一种重要的蛀果害虫,以老熟幼虫滞育越冬。为明确梨小食心虫滞育幼虫对低温的生理适应性,用3,5-二硝基水杨酸比色法、双试剂法及代谢酶活力测试盒分别测定了梨小食心虫幼虫体内海藻糖酶（trehalase,TRE）、山梨醇脱氢酶（sorbitol dehydrogen-ase,SDH）及己糖激酶（hexokinase,HK）、丙酮酸激酶（pyruvate kinase,PK）和碱性磷酸酶（alkalinephosphatase,ALP）的活力变化。在低温条件下,滞育幼虫体内各酶活力明显不同,TRE活力在滞育初期显著提高,而后随滞育时间的延长而逐渐降低;SDH活力总体变化较为平缓,变化量较小;HK、PK和ALP活力在滞育前期均显著降低,且随后一直保持在较低水平。滞育期间,5种代谢酶的活力均与滞育发育及温度有关;通过相关代谢酶的调节,梨小食心虫的代谢速率维持在较低水平,提高了虫体的耐寒能力,从而顺利完成滞育。     

二化螟滞育生物学特性的研究进展

二化螟是我国水稻上一种重要的钻蛀性害虫,以幼虫滞育越冬.本文总结了二化螟滞育生物学特性的总体研究进展,包括滞育诱导、滞育的维持和解除、滞育后的发育、越冬滞育幼虫的年龄组成、越冬滞育幼虫抗寒性与越冬存活等方面.     

日本平腹小蜂滞育幼虫的重要生化物质变化

日本平腹小蜂是多种果树蝽类害虫的优势寄生蜂, 能以老熟幼虫滞育越冬。本研究分别测定了日本平腹小蜂非滞育老熟幼虫、滞育25、35、45、55 d老熟幼虫和滞育解除老熟幼虫体内的总蛋白、脂类、糖类及醇类等生化物质的含量, 以及海藻糖酶和抗氧化酶(超氧化物歧化酶、过氧化物酶、过氧化氢酶)等关键酶的活性变化, 比较了日本平腹小蜂滞育、非滞育和滞育解除老熟幼虫体内重要生化物质的差异。结果表明:滞育老熟幼虫显著积累脂类、甘油三酯、糖原等能源物质以及山梨醇等低温保护物质, 且滞育个体的抗氧化能力显著增强, 这些变化有助于提高其抗逆性, 满足滞育维持期及滞育解除后恢复发育的能量需求, 保证滞育个体的发育和存活。结果为解析日本平腹小蜂的滞育机制奠定了基础。