马尾松诱导抗性对马尾松毛虫幼虫生长发育的影响

利用不同受害方式和受害程度的马尾松 (PinusmassonianaLamb.)针饲养马尾松毛DendrolimuspunctarusWalker虫幼虫 ,研究受害松针对幼虫生长发育的影响。结果表明 :马尾松毛虫取食受害松针后 ,幼虫的取食量下降 ,排粪量减少 ,对食物的消耗和利用指数降低 ,幼虫发育速率缓慢 ,死亡率增加 ,从而影响马尾松毛虫的种群动态     

云南主要蔗龟的生物学研究

蔗龟是云南甘蔗上的1种主要地下害虫。经1987～1991年系统研究,大等鳃金龟、暗褐鳃角金龟、突背蔗金龟是云南危害甘蔗的优势种。前两种主要以幼虫为害根部,造成减产,严重的无收;第三种主要以成虫咬食蔗苗基部,造成枯心死亡。3种均1年发生1代。成虫有趋光性,初孵幼虫喜食已腐烂的有机质。在沙壤土、粘土较重土壤虫口较多;宿根年限越长受害愈重。蔗稻轮作;7～8月雨季用水淹灌蔗地;结合松、培土每亩施用3％甲基异柳磷颗粒剂4～5kg,防治效果达90％左右。     

广聚萤叶甲在豚草上的空间分布

广聚萤叶甲Ophraella communa LeSage是恶性入侵杂草豚草Ambrosia artemisiifolia L的一种重要天敌,为了了解广聚萤叶甲卵、幼虫、蛹、成虫在豚草上的分布情况,本文对各虫态广聚萤叶甲在豚草植株上的空间分布进行了调查。调查结果表明,各虫态广聚萤叶甲在豚草上的空间分布均为聚集分布;不同受害程度豚草植株上各虫态广聚萤叶甲主要分布于上部和中部。就不同受害程度豚草植株上同一虫态广聚萤叶甲而言,卵比例随受害程度的加重逐步递减,幼虫和蛹的比例则逐步增加。由此可见,广聚萤叶甲为了确保后代能获得更充足的食物,成虫倾向于在受害程度较轻的植株上产卵。     

受害马尾松针叶营养及次生物质含量与思茅松毛虫种群参数的相关分析

为了揭示受害马尾松Pinus massoniana针叶主要化学物质变化对思茅松毛虫Dendrolimus kikuchii Matsumura种群变动的影响, 本研究以受思茅松毛虫危害程度不同（轻度、 中度和重度）的马尾松针叶喂养思茅松毛虫幼虫, 测定思茅松毛虫饲养种群的特征参数和不同受害程度马尾松针叶营养物质与次生物质含量, 用综合相关系数分析法对试验结果进行分析。结果表明： （1）随植株受害程度加重, 针叶黄酮含量增加, 可溶性糖、 蛋白质、 多糖含量减少, 各龄幼虫平均历期延长、 死亡率升高。单宁和总酚含量的变化与各龄幼虫平均历期、 死亡率之间没有显著的相关性; （2）除6龄幼虫外, 其他各龄幼虫的平均历期、 死亡率均与松针营养物质和次生物质含量有直接的和综合的相关性; （3）随受害程度加重, 7龄幼虫体重、 幼虫平均取食量、 蛹重、 化蛹率、 雌性比、 每雌生殖力减小。单宁、 总酚含量的变化对7龄幼虫体重、 幼虫平均取食量、 蛹重、 幼虫平均死亡率、 化蛹率、 雌性比、 每雌生殖力都没有显著影响。总体上, 松针营养和次生物质含量对思茅松毛虫种群参数有重要影响, 其重要性依次为可溶性糖＞蛋白质＞多糖＞黄酮, 单宁和总酚的作用相对较小。     

Correlative analysis between contents of nutrients and secondary substances in damaged masson pine needles and population parameters of Dendrolimus kikuchii ( Lepidoptera: Lasiocampidae)

为了揭示受害马尾松Pinus massoniana针叶主要化学物质变化对思茅松毛虫Dendrolimus kikuchii Matsumura 种群变动的影响,本研究以受思茅松毛虫危害程度不间(轻度、中度和重度)的马尾松针叶喂养思茅松毛虫幼虫,测定思茅松毛虫饲养种群的特征参数和小同受害程度马尾松针叶营养物质与次生物质含量,用综合相关系数分析法对试验结果进行分析.结果表明:(1)随植株受害程度加重,针叶黄酮含量增加,可溶性糖、蛋白质、多糖含量减少,各龄幼虫平均历期延长、死亡率升高.单宁和总酚含最的变化与各龄幼虫平均历期、死亡率之间没有显著的相关性;(2)除6龄幼虫外,其他各龄幼虫的平均历期、死亡率均与松针营养物质和次生物质含量有直接的和综合的相关性;(3)随受害程度加重,7龄幼虫体重、幼虫平均取食量、蛹重、化蛹率、雌性比、每雌生殖力减小.单宁、总酚含量的变化对7龄幼虫体重、幼虫平均取食量、蛹重、幼虫平均死亡率、化蛹率、雌性比、每雌生殖力都没有显著影响.总体上,松针营养和次生物质含量对思茅松毛虫种群参数有重要影响,其重要性依次为可溶性糖＞蛋白质＞多糖＞黄酮,单宁和总酚的作用相对较小.     

甘蔗细平象的研究

甘蔗细平象Trockorhopalus humeralis Chevrolat是云南甘蔗上的一种毁灭性地下害虫,以幼虫和成虫在地下蔗头内为害,为害期8-10个月。据1989年调查,受害蔗每亩损失500-3000kg,严重的无收。此虫1年发生1代,以成虫在蔗头内越冬,有喜湿性,不能飞翔,主要通过沟河流水传播。在河川坝地,沙壤土中虫口较多;宿根年限越长的甘蔗受害越重。建议蔗稻轮作;缩短甘蔗宿根年限;早春翻挖有虫蔗蔸烧毁;结合新植蔗下种,宿根蔗松蔸培土施用甲基异柳磷或铁灭克等颗粒杀虫剂进行防治。     

甘蔗赭色鸟喙象生物学及防治研究

甘蔗赭色鸟喙象 Otidognathus rubriceps Chevrolat是云南甘蔗上一种新的严重蛀食蔗茎的害虫 ,主要以成虫和幼虫危害蔗茎 ,使蔗株枯死 ,造成减产 ,严重的无收。此虫 1年发生 1代 ,以成虫在土中越冬 ,成虫有假死性 ,会飞翔。 5月底 6月初成虫出土 ,交尾产卵 ,9月下旬终见 ;7～ 9月幼虫危害最盛 ,9月上旬至 11月上旬老熟幼虫入土 8～ 15cm做茧化蛹。在胶泥土中虫口较多 ;宿根年限越长受害越重 ;不同甘蔗品种受害差异大。防治措施蔗稻轮作 ;缩短宿根年限 ;选种抗虫品种 ;人工捕杀 ;10月上中旬用水淹灌蔗地 ;6月中下旬结合培土每公顷用 3%甲拌磷或呋甲颗粒剂 75kg,到 7月上旬末和 8月上旬初再结合其它害虫的防治 ,用 4 0 %水胺硫磷乳油 10 0 0倍稀释液喷雾 ,防治效果达 90 %左右     

甘蔗斑点象生物学及防治的研究

甘蔗斑点象是云南甘蔗上另一种新的严重蛀食地下蔗头的害虫,主要以幼虫在甘蔗地下蔗头内为害,为害期8～9个月,受害蔗每666．7m2减少0．5～0．3t,并缩短了宿根年限。此虫1年发生1代,无越冬现象,有喜湿性,不能飞翔,主要通过沟河流水传播。在河川坝地、沙壤地中虫口较多,宿根年限越长受害越重。蔗稻轮作,缩短宿根年限翻蔸烧蔸,结合松蔸培土每666．7m2用3％米乐尔或3％甲基异柳磷颗粒剂4kg,防治效果达90％左右。     

甘蔗、玉米气味对亚洲玉米螟成虫产卵和幼虫取食的影响

【目的】农作物间套作对害虫的影响很大程度上取决于害虫的行为反应,通过研究玉米/甘蔗套作系统中植物气味对亚洲玉米螟Ostrinia furnacalis(Guenee)行为的影响,将为利用化学生态手段防治套作田中的害虫提供依据。【方法】通过昆虫触角电位实验、成虫产卵和幼虫取食实验,测定了甘蔗、玉米植株及二氯甲烷漂洗物对亚洲玉米螟成虫产卵、幼虫取食的影响。【结果】亚洲玉米螟成虫在甘蔗植株上的落卵量(卵粒数、卵块数)与玉米植株差异不显著,取食甘蔗植株的幼虫数量显著低于玉米植株。亚洲玉米螟对甘蔗、玉米叶片漂洗物均可产生EAG反应,且在同一浓度下的反应值之间无显著差异。成虫产卵量(卵粒数、卵块数)在0.1 gE/mL浓度的甘蔗和玉米漂洗物间差异不显著;幼虫对经甘蔗叶片漂洗物处理过的饲料的相对取食率均低于65.00%,显著低于玉米漂洗物处理的饲料。【结论】甘蔗和玉米气味对亚洲玉米螟产卵的影响没有差异,但甘蔗气味会导致初孵幼虫表现出很强的逃逸行为。     

小麦淹水死亡原因的研究

一.前言在夏秋季节,经常由于降雨量的过分集中而形成不同程度的内涝災害。这时正是植物生长旺盛的时期,许多植物,尤其是农作物遭受着不同程度的危害。受害轻微时,植株的部分组织受害,产量降低。受害严重时,植物全部死亡。因此,水涝災害对农业生产的影响是十分严重的。过去已发表的研究报告和调查报     

Management of feeding damage and survival of southwestern corn borer and sugarcane borer (Lepidoptera: Crambidae) with Bacillus thuringiensis transgenic field corn

The efficacy of transgenic corn hybrids expressing an insecticidal Bacillus thuringiensis (Bt) delta-endotoxin from different transformation events was evaluated in field corn, Zea mays L., against the southwestern corn borer, Diatraea grandiosella Dyar, and sugarcane borer, Diatraea saccharalis (F.). Susceptibilities of neonates and third instars were determined on Bt and non-Bt corn plants (V6 and R1 stages) in field plots and corn leaf tissue feeding exposure in laboratory bioassays. Bt corn hybrids associated with MON810 and CBH351 transformation events sustained significantly less injury by southwestern corn borer and sugarcane borer during mid-whorl stage infestations compared with their respective non-Bt hybrid equivalents. Southwestern corn borer and sugarcane borer feeding injury to ear leaf-sheath and husk tissues during the silking stage of corn was significantly reduced in MON810 and CBH351 Bt corn compared with their respective non-Bt hybrids. However, resistance levels to feeding injury in Bt hybrids associated with the MON810 event were significantly higher than that in the hybrid associated with the CBH351 event. Southwestern corn borer and sugarcane borer caused more feeding injury to husk tissue than to ear leaf-sheath tissue in both Bt and non-Bt hybrids infested during the silking stage. Laboratory performance of the MON810 event against southwestern corn borer and sugarcane borer varied among hybrids associated with the same event. Third instars of southwestern corn borer were highly susceptible to MON810 Bt corn hybrids in leaf tissue experiments. However, sugarcane borer larvae were susceptible to the MON810 event only in one of the Bt hybrids evaluated. Sugarcane borer mortality was significantly lower after 96 h of feeding exposure on CBH351 Bt corn leaf tissue than on MON810 Bt corn leaf tissue. Plant resistance to southwestern corn borer and sugarcane borer increased as plants matured, independent of the presence of a Bt construct. These results are essential to estimate the importance of Bt transgenic corn in areas of southern United States and other areas where mixed populations of southwestern corn borer and sugarcane borer are predominant and cause severe damage to corn production.     

Tolerance and compensatory response of rice to sugarcane borer (Lepidoptera: Crambidae) injury

A 3-yr field experiment was conducted to evaluate the tolerance and compensatory response of rice (Oryza sativa L.) to injury caused by sugarcane borer, Diatraea saccharalis (F.), as affected by cultivar (Cocodrie, Francis, and Jefferson), stage of crop growth during which the injury occurred (third tiller stage, panicle differentiation stage, and heading stage), and sugarcane borer density. The proportion of rice tillers with sugarcane borer injury (leaf and leaf sheath injury and/or stem injury) was lower when injury occurred at the third tiller stage (0.05) than at panicle differentiation (0.19) and heading (0.18). When injury occurred at the two latter stages, both the proportion of tillers with injury and the proportion of tillers with stem injury were negatively correlated with rainfall. Rainfall resulted in dislodgement and mortality of sugarcane borer eggs and larvae before the larvae entered the stems. Rice plant density in this study (111.1 plants/m2) was higher than recorded for previous research on rice compensation using potted rice or conducted in low-density hill production systems (26.7-51.3 plants/m2). Two mechanisms of within-plant tolerance/compensation were observed. Stem injured plants produced approximately 0.69 more tillers than uninjured plants, whereas tillers with leaf and leaf sheath injury produced larger panicles, up to 39.5 and 21.0% heavier than uninjured tillers, when injury occurred at third tiller stage and at panicle differentiation, respectively. Rice yield was not reduced with up to 23% injured tiller and up to 10% injured stems at the third tiller stage, 42% injured tillers and 17% injured stems at panicle differentiation, and 28% injured tillers and 14% injured stems at heading. Significant between-plant compensation was not detected, suggesting competition between adjacent plants is not significantly reduced by injury. Our results suggest that rice can tolerate and/or compensate for a level of stem borer injury previously considered to be economically damaging.     

Evaluation of transgenic Bacillus thuringiensis corn hybrids against Cry1Ab-susceptible and -resistant sugarcane borer (Lepidoptera: Crambidae)

A Louisiana strain of the sugarcane borer, Diatraea saccharalis (F.) (Lepidoptera: Crambidae), was selected for resistance to the CrylAb protein of Bacillus thuringiensis (Bt) by using an F2 screening procedure. Survival of Bt-resistant, -susceptible, and -heterozygous genotypes of sugarcane borer was evaluated on vegetative and reproductive stages of five non-Bt and seven Bt field corn, Zea mays L., hybrids in a greenhouse study. Larval survival was recorded 21 d after infestation of neonates on potted plants. Larval survival across the three sugarcane borer genotypes and five non-Bt corn hybrids after 21 d ranged from 23.6 +/- 5.2% (mean +/- SEM) to 57.5 +/- 5.2%. Mean survival of Cry1Ab-resistant larvae on vegetative and reproductive plant stages was 12 and 21%, respectively. During the vegetative stages, all seven Bt corn hybrids were highly efficacious against Cry1Ab-susceptible and -heterozygous genotypes of sugarcane borer, with a larval survival rate of <2% for the Bt-susceptible genotype and < or =5% for the heterozygotes. However, 8-18% of the heterozygous genotype survived on reproductive stage plants for four of the seven Bt corn hybrids tested. The variation in performance of Bt corn cultivars at vegetative and reproductive growth stages against Cry1Ab resistant sugarcane borer suggests differential seasonal expression that may hasten resistance in the field. Bt corn hybrids expressing a "high dose" for European corn borer, Ostrinia nubilalis (Hübner), may not produce a sufficient high dose for the sugarcane borer.     

Effects of soybean proteinase inhibitor on development, survival and reproductive potential of the sugarcane borer, Diatraea saccharalis

One approach that can be employed in integrated pest management is the use of proteins with antinutritional effects on insect metabolism and development. The antimetabolic properties of soybean proteinase inhibitor (SPI) on growth of neonate larvae of the sugarcane borer, Diatraea saccharalis (Fabricius, 1794) (Lepidoptera: Crambidae) have been evaluated. When incorporated into an artificial diet at 0.5% (w/w), SPI retarded growth rate and development of larvae when compared with larvae fed on artificial diet alone. However, larval survival was not significantly affected. The purpose of our research was to calculate demographic statistics for the sugarcane borer reared on diet either with or without semi-purified extract of SPI. Net reproductive rate (R ₀), instantaneous rate of increase (r _m), combined age-specific survivorship (l _x) and age specific fecundity (m _x) provide information about population growth potential. These parameters were measured in order to determine the effects of the proteinase inhibitor on the insect's population dynamics. The observed differences would potentially translate into large reductions in population growth, indicating a potential value of using SPI for protecting sugarcane plants against damage by the sugarcane borer.     

Genetic transformation and pyramiding of aprotinin-expressing sugarcane with cry1Ab for shoot borer (Chilo infuscatellus) resistance

We evaluated the insecticidal toxicity of Cry1Aa, Cry1Ab and Cry1Ac toxins against neonate larvae of sugarcane shoot borer Chilo infuscatellus Snellen (Lepidoptera: Crambidae) in vitro on diet surface. With the lowest LC₅₀ value, Cry1Ab emerged as the most effective among the three toxins. Sugarcane cultivars Co 86032 and CoJ 64 were transformed with cry1Ab gene driven by maize ubiquitin promoter through particle bombardment and Agrobacterium-mediated transformation systems. Gene pyramiding was also attempted by retransforming sugarcane plants carrying bovine pancreatic trypsin inhibitor (aprotinin) gene, with cry1Ab. Southern analysis confirmed multiple integration of the transgene in case of particle bombardment and single site integration in Agrobacterium-mediated transformants. The expression of cry1Ab was demonstrated through Western analysis and the toxin was quantified using ELISA. The amount of Cry1Ab protein in different events varied from 0.007 to 1.73% of the total soluble leaf protein; the events transformed by Agrobacterium method showed significantly higher values. In in vivo bioassay with neonate larvae of shoot borer, transgenics produced considerably lower percentage of deadhearts despite suffering feeding damage by the borer compared with the untransformed control plants. Expressed Cry1Ab content was negatively related to deadheart damage. Aprotinin-expressing sugarcane pyramided with cry1Ab also showed reduction in damage. The potential of producing sugarcane transgenics with cry1Ab and aprotinin genes resistant to early shoot borer was discussed in the light of the results obtained.     

Transgenic sugarcane plants resistant to stem borer attack

A truncated cryIA(b) gene encoding the active region of the Bacillus thuringiensis -endotoxin was expressed in transgenic sugarcane plants (Saccharum officinarum L.) under the control of the CaMV 35S promoter. Genetic transformation was accomplished by electroporation of intact cells. The levels of recombinant toxin were established and biological activity tests were performed against neonate sugarcane borer (Diatraea saccharalis F.) larvae. Transgenic sugarcane plants showed significant larvicidal activity despite the low expression of CryIA(b).     

Expression of soybean proteinase inhibitors in transgenic sugarcane plants: effects on natural defense against Diatraea saccharalis

The introduction and expression of proteinase inhibitor encoding genes into sugarcane (Saccharum officinarum L.) genome is an interesting strategy for conferring partial resistance to the sugarcane borer Diatraea saccharalis (Lepidoptera: Crambidae), the major insect pest of sugarcane in Brazil. To investigate the role of soybean (Glycine max L.) Kunitz trypsin inhibitor (SKTI) and soybean Bowman–Birk inhibitor (SBBI) in the control of D. saccharalis, the cDNAs encoding these proteinase inhibitors were placed under the control of the maize ubiquitin promoter (Ubi-1), and introduced into sugarcane callus using particle bombardment. Putative transgenic plants were initially identified after regeneration from callus growing in the presence of 30 mg l^–1 geneticin, while molecular characterization of transgenic plants revealed that both genes were incorporated into the sugarcane genome and expressed. We also carried out insect feeding trials using D. saccharalis neonate larvae and leaf tissue excised from propagated transgenic and untransformed plants, and found that the growth of larvae feeding on leaf tissue from transgenic plants containing BBI and Kunitz inhibitors was significantly retarded as compared to larvae fed on leaf tissue from untransformed plants. In greenhouse trials with transgenic sugarcane plants infested with D. saccharalis neonates, we found that these plants still presented the ‘dead heart’ symptom typically observed in susceptible plants in the field, suggesting that the retardation of the growth of D. saccharalis observed in the laboratory-based feeding trials was not sufficient to prevent this type of damage.     

Silicon impedes stalk penetration by the borer Eldana saccharina in sugarcane

Many plants grown in soils amended with silicon (Si) display increased levels of resistance to attack by insect herbivores. This study aimed to determine if Si treatment impeded Eldana saccharina Walker (Lepidoptera: Pyralidae) stalk penetration and subsequent damage, as well as borer mass gain, on the node and internode of a susceptible (N11) and a resistant (N33) sugarcane cultivar. Sugarcane [Saccharum spp. (Poaceae)] cultivars were grown in a pot trial in Si‐deficient river sand, with (Si+) and without (Si–) calcium silicate. Sugarcane was infested with 2‐week‐old E. saccharina larvae and harvested at four times, 24, 48, 72, and 96 h after infestation. Silicon‐treated plants showed significant increases in Si content compared to controls, and the external rind was significantly harder for Si+ cane than Si– cane. Silicon treatment significantly decreased borer penetration, stalk damage, and larval mass gain. The results are consistent with the hypothesis that Si contributes to sugarcane stalk borer resistance by impeding larval penetration. Silicon appears to contribute to the suppression of E. saccharina directly through reduced larval growth and feeding damage to the crop, and indirectly by delaying stalk penetration, resulting most likely in increased exposure time of young larvae to natural enemies, adverse climatic factors, or control measures that target young larvae (e.g., insecticides).     

Influence of plant silicon and sugarcane cultivar on mandibular wear in the stalk borer Eldana saccharina

1 Silicon can increase the resistance of plants to attack by herbivorous insects. The present study aimed to determine the effect of silicon and cultivar on mandibular wear in larvae of the sugarcane stalk borer Eldana saccharina Walker (Lepidoptera: Pyralidae).
2 Four sugarcane cultivars, resistant (N21, N33) and susceptible (N11, N26) to E. saccharina were grown in a pot trial in silicon deficient river sand, with (Si+) and without (Si−) calcium silicate. Individual third-instar larvae were confined on the sugarcane stalk at three known feeding sites (leaf bud, root band and internode) and left to feed for 21 days.
3  Eldana saccharina larval heads were mounted on stubs, with the mandibles oriented horizontally and photographed under a scanning electron microscope. Mandibular wear was measured from the digital images using a quantitative method.
4 Although there was a trend for increased wear in larvae that developed on Si+ cane, no significant effect of silicon, cultivar or site on mandibular wear of E. saccharina was shown.
5 This is the first study to accurately and quantitatively measure the mandibular wear of an insect fed on Si+ plants.