芜菁夜蛾线虫对沟眶象和臭椿沟眶象侵染力的研究

室内应用斯氏线虫３个种的５个品系，对越冬沟眶象幼虫进行侵染力比较，结果表明，施线虫后８天，芜菁夜蛾线虫Ａ２４品系和Ｂｅｉｊｉｎｇ品系，可使在土壤内的幼虫死亡率分别达１００％和９０％，１４天后Ｂｅｉｊｉｎｇ品系的致死率亦达１００％，其它３个品系均达９０％左右；在土壤含水量为１０－２０％范围内，幼虫死亡率随土壤含水量的增加而递增，施线虫后５天，含水量２０％的处理，幼虫死亡率达７０％，而１０－１５％含水     

检疫性枝干害虫臭椿沟眶象

臭椿沟眶象是专门为害臭椿的一种枝干害虫,在2005年全国林业有害生物普查中,青海省将该虫定为省内补充检疫对象;随着外省（区）苗木的大量调入,其已传入民和县,对臭椿的生长影响很大.为了便于检疫和开展防治,本文对该虫的生物学特性及检疫、防治方法进行介绍.     

磷化氢对小麦中玉米象致死效果的研究

玉米象Sitophilus zeamais(Motschulsky)的卵、幼虫以及蛹在粮食籽粒内部生活与发育,粮粒结构会影响熏蒸气体的渗透以及对隐蔽虫态的杀虫效果,了解粮粒内卵、幼虫、蛹以及成虫对磷化氢耐受能力的差异,有助于科学有效杀虫。本文测定了3个玉米象品系对磷化氢的抗药性,及在100、200、300、400和500mL/m3的磷化氢浓度下玉米象成虫及其隐蔽虫态卵、幼虫和蛹在不同熏蒸时间的死亡率。主要结果为:3个品系的玉米象对磷化氢均未产生抗性。在各磷化氢浓度下,经6h熏蒸后100mL/m3浓度下成虫的死亡率近59%,而500mL/m3浓度下死亡率在91%以上;经12h熏蒸后各品系成虫的死亡率均达100%,而其卵、幼虫和蛹死亡率均小于100%;经24h熏蒸后,各品系的卵、幼虫和蛹死亡率达100%的磷化氢浓度需要在400mL/m3及以上;经36h熏蒸后,100mL/m3浓度可完全致死玉米象BJXNSz品系的卵、幼虫和蛹,但对另外两个品系的卵、幼虫和蛹的致死率小于100%;磷化氢熏蒸48h以上的各浓度均可完全致死受试害虫。结果表明,100mL/m3以上的磷化氢浓度均可在不同时间致死玉米象各虫态,但完全致死玉米象各虫态的时间在100mL/m3浓度下需要48h,在500mL/m3浓度下需要24h,浓度升高完全致死害虫的时间缩短。玉米象卵、幼虫和蛹对磷化氢耐受力相接近且远大于成虫。     

萧氏松茎象幼虫方位与虫道注药致死率的关系

幼虫的死亡率与注射点的方位关系密切。当幼虫位于注射点的正下方时,死亡率最高,高效氯氰菊酯和吡虫啉对第1代幼虫的致死率高达75.61%和67.27%,对第2代幼虫的致死率高达89.47%和95.24%。当幼虫位于注射点的上、左上和右上方时,两种药剂对第2代幼虫的致死率较低,只有20%～40%左右,对第1代幼虫的致死率更低,只有10%左右。     

萧氏松茎象幼虫虫道形状与注药致死率的关系

萧氏松茎象幼虫的死亡率与虫道形状关系较大。研究结果表明,当虫道形状为线形时,两种农药的致死率最高,对第一代幼虫可达80%,对第二代幼虫超过90%。虫道为S形时,致死率最低,对第一代只有不到40%,第二代略高,也只有60%。当虫道为T形、Y形和环形时,对第一代幼虫的致死率介于40%～60%,对第二代幼虫的致死率略高介于50%～70%。     

虫道注药防治萧氏松茎象幼虫的最佳注射点

对于第1代幼虫,当注射点距幼虫的距离为0～2㎝时,高效氯氰菊酯和吡虫啉两种药剂的致死率均高达100%,当距离为2～6㎝时,两种药剂的致死率达70%左右。对于第2代幼虫,当注射点距幼虫的距离为0～4㎝时,两种药剂的致死率均较高,接近100%,当距离为4～6㎝时,两种药剂的致死率达70%左右。因此,最佳注射点在距幼虫6㎝以内的虫孔处。     

用昆虫病原线虫防治韭菜蛆

在15±0.5℃和25±0.5℃下,测定了8个线虫品系对韭菜蛆的致死率和LT50,并用筛选出的高毒力线虫品系进行了田间小区试验.结果表明,在15℃下,各线虫品系的LT50范围为5.31～22.08天,其中PS4线虫对韭菜蛆的毒力最大,LT50为5.31天;在25℃下,供试的线虫对韭菜蛆的毒力明显比在15℃下高,其中PS4品系的LT50为2.71天.综合在15℃和25℃下对韭菜蛆的毒力,认为PS4是防治韭菜蛆最适宜的线虫品系.在15℃下,120条/ml的线虫剂量侵染韭菜蛆12天的致死率达85.7%,在25℃下,60条/ml侵染8天能达到82.3%的致死率.田间施用线虫后30天,韭菜蛆的防治效果达55.32%,受害株率减少71.37%,防治效果略低于化学农药辛硫磷.     

斯氏线虫CB—2Y品系对李实蜂的侵染试验

李实蜂是李子果实的重要害虫。本文探讨了斯氏线虫 CB-2Y 品系对李实蜂幼虫、茧的室内及田间侵染力。结果表明:1.李实蜂幼虫对该线虫很敏感,96小时死亡率93.3%～100%,茧不敏感,死亡率0～6.2%。2.该线虫对李实蜂幼虫侵染力很强,幼虫死亡率随作用时间及剂量浓度增加而增高。3.该线虫侵染李实蜂的田间效果7天后死亡率为70%左右,18天后死亡率达75%以上。     

利用昆虫病原线虫防治蔗扁蛾的研究

通过应用昆虫病原线虫斯氏线虫属小卷蛾线虫的Agriotos、Beijing和CB163个品系,格氏线虫的NC34品系,以及异小杆线虫属嗜菌异小杆线虫的E67品系对蔗扁蛾进行室内及田间防治试验。结果表明:小卷蛾线虫Agriotos和Beijing2个品系对蔗扁蛾幼虫具有明显的防治效果。应用注射法将含侵染期线虫1000～2000条/ml线虫悬浮液约200ml注入巴西木受害部位表皮下,5d后防治效果达7363%。     

白僵菌孢子不同浓度对萧氏松茎象成虫的毒力差异

应用白僵菌在1×10^5个孢子／ml、1×10^6个孢子／ml、1×10^7个孢子／ml、1×10^8个孢子／ml和1×10^9个孢子／ml 5个不同浓度对萧氏松茎象成虫进行毒力测定。其中以10^9个孢子／ml毒力最强,接种20d后,平均校正死亡率达100％,白僵率达95％,对萧氏松茎象成虫的致死和白僵速度最快,其LT50分别为8．39d和9．52d,10^8个孢子／ml次之,分别为9．30d和11．20d。各浓度对萧氏松茎象成虫的致死率和白僵率均随时间的增加而增加。在同一时间,致死率和白僵率均随孢子浓度的增加而增加。虽然10^9个孢子／ml和10^8个孢子／ml毒力强,但所需孢子量大,不适合应用于生产实践;10^7个孢子／ml毒力也很强,所需孢子量适中,因此较适合在生产实践推广应用。     

Entomopathogenic fungi and nematodes against larvae of the chestnut weevil,Curculio elephas (Coleoptera: Curculionidae): a laboratory evaluation

Pest control in chestnut orchards is mainly achieved by chemicals, but there is growing focus on the potential use of biological control agents. The larval susceptibility of the chestnut weevil Curculio elephas L. (Coleoptera: Curculionidae) to different strains/species of entomopathogenic fungi and nematodes was evaluated in laboratory by soil cup bioassays. In the experiments with fungi, a wild strain of Metarhizium anisopliae caused the highest larval mortality (about 90%) compared with a commercial and a wild strain of Beauveria bassiana (80% and 77% respectively). Regarding nematodes, the commercial strain of Heterorhabditis bacteriophora was more effective in the control of chestnut larvae (77% insect mortality) than Steinernema carpocapsae (43%).     

Biological control potential of Turkish entomopathogenic nematodes against the Mediterranean fruit fly <Emphasis Type="Italic">Ceratitis capitata</Emphasis>

The entomopathogenic nematodes Steinernema weiseri, S. feltiae, S. carpocapsae and two strains of Heterorhabditis bacteriophora, isolated from Turkish soils, were evaluated against larvae of the Mediterranean fruit fly (medfly) Ceratitis capitata in plastic cups under laboratory conditions with sandy loam soil and 10% moisture level. At a rate of 100 infective juveniles (IJs)/cm², the last instar larvae of C. capitata were susceptible to the entomopathogenic nematodes: the S. feltiae 09-31 strain recovered from Aydin provided 78% mortality, whereas S. weiseri and S. carpocapsae killed 50% and 56% of the larvae, respectively. Both strains of H. bacteriophora species caused less than 50% mortality. Except for S. feltiae, the majority of infected medflies died as prepupae or pupae within the puparia. More than 90% larval mortality was recorded at 200 and 400 IJs/cm² for S. feltiae. None of the nematode isolates infected the medfly pupae within the puparia. In pot experiments containing soil, S. feltiae caused 96% and 97% mortality at 100 and 200 IJs/cm², respectively. In pot experiments with grass present, more than 94% mortality was obtained in the presence of grass roots.     

防治斜纹夜蛾蛹和2龄幼虫的棒束孢菌株筛选

为获取对斜纹夜蛾Spodoptera litura(Fabricius)具致病力的生防真菌资源,通过对8株寄主为鳞翅目蛹的棒束孢属Isaria spp.真菌进行形态学和分子系统学鉴定;以斜纹夜蛾的蛹和2龄幼虫为试虫,分别采用拌土法和浸渍法测试菌株的致病力。结果显示:菌株GZUIFR08XS1、GZUIFR04XS8、GZUIFR08XS13为环链棒束孢I.cateinannulata,菌株GZUIFR08LYS4、GZUIFR04XS5、GZUIFR04XS7、GZUIFR08XS12、GZUIFR04XS16为粉棒束孢I.farinose。8株菌对斜纹夜蛾的蛹和2龄幼虫均有致病力。土壤接种5 mL浓度为2×10~8个/mL的分生孢子,环链棒束孢GZUIFR08XS1、GZUIFR04XS8对蛹的致死率均为100%。接种浓度为1×10~8个/mL的分生孢子,环链棒束孢GZUIFR04XS8对2龄幼虫致死率为(78.21±2.22)%,较其他菌株有差异显著(P0.05)。将环链棒束孢GZUIFR04XS8分别接种在2～5龄幼虫时,对同一龄期幼虫的致死率随接种浓度的增大而上升,其中,接种孢子浓度为1×10~9个/mL可致2龄幼虫100%死亡;同一接种浓度下,对幼虫致死率随幼虫龄期的增大而下降,其中,2龄幼虫的致死中浓度LC_(50)为1.28×10~5个/mL。环链棒束孢GZUIFR04XS8有较好防治斜纹夜蛾蛹和低龄幼虫的生防潜力。     

Biological control of Otiorrhynchus sulcatus with Heterorhabditid nematodes in the glasshouse

AHeterorhabditis species, found in dead larvae ofOtiorrhynchus sulcatus, was tested for its efficacy as a biological control agent of this insect in glasshouse experiments. In a preliminary test all weevil larvae were killed in pots with primula, 88% in strawberry and 50% in cyclamen. In a second test with strawberry plants good results were obtained when the nematodes were applied about the hatching time of the weevil eggs. At a dosage of 100 nematodes per cm² of soil area, 90–97% of the larvae were killed and 90% of the plants remained undamaged. A dosage of 50 nematodes per cm² produced roughly the same level of larval mortality, but left 30% of the plants damaged. Both early and late application of nematodes protected the plants insufficiently, because too many larvae survived. In a third test with strawberry, cyclamen and primula, soil treatment with 50 and 100 nematodes per cm² gave comparable results at both application times, i.e. one and three weeks after hatching of the weevil eggs. In strawberry 100% of the larvae were killed and all plants remained in good condition. Also in cyclamen nearly all larvae were killed and the plants remained in good condition, although the root systems had, less fine roots in comparison with control plants without insects. In primula 4–12% of the weevil larvae survived, whereas up to 20% of the plants died, indicating that soil structure, soil moisture, and condition of the plants have an important impact on the control results. A dosage of 25 nematodes per cm² appeared to be too low in all cases. The results of these experiments open new perspectives for control of the black vine weevil in glasshouses.Samenvatting Een inheemse, nematode van het geslachtHeterorhabditis werd door middel van potproeven in kassen getoetst op zijn werkzaamheid als biologisch bestrijdingsmiddel tegen larven van de gegroefde lapsnuitkever,Otiorrhynchus sulcatus. In een oriënterende proef werden in potten met primula's alle keverlarven gedood, bij aardbeiplanten werden 88% gedood en bij cyclamen 50%. In een tweede proef met alleen aardbeiplanten werden goede resultaten verkregen als de aaltjes werden toegediend in de periode dat de kevereieren uitkwamen. Bij een dosering van 100 aaltjes per cm² grondoppervlak werd 90–97% van de keverlarven gedood en bleef 90% van de planten onbeschadigd. Bij een dosering van 50 aaltjes per cm² was de doding van de keverlarven weliswaar vrijwel hetzelfde, maar de schade aan de planten was te groot; 30% van de planten ging dood. Ook bij een eerder of later bestrijdingstijdstip was de schade aan de planten aanzienlijk en was de doding van de keverlarven onvoldoende. In een derde proef werd in zowel aardbei als in cyclamen vrijwel 100% van de keverlarven gedood bij een dosering van zowel 50 als 100 aaltjes per cm² en op beide bestrijdingstijdstippen, te weten toen de keverlarven circa 1 en 3 weken oud waren. Alle aardbeiplanten en cyclamen bleven in goede staat, hoewel bij cyclamen het aantal fijne wortels minder was dan bij de controle planten zonder keverlarven. De resultaten met primula's waren in deze proef iets minder goed. Het percentage overlevende keverlarven variëerde van 4 tot 12, terwijl tot 20% van de planten dood ging. Een dosering van 25 aaltjes per cm² was in alle gevallen te laag. De resultaten van deze proeven bieden gunstige perspectieven voor toepassing van dit aaltje bij de bestrijding van de gegroefde lapsnuitkever in kassen.     

芜菁夜蛾线虫与玉米螟接触时间对寄主死亡率及死亡速度的关系

在试验室条件下,研究了芜菁夜蛾线虫北京品系与亚洲玉米螟幼虫接触时间,对玉米螟死亡率和死亡速度的影响。结果表明,线虫与玉米螟接触时间在0.5、1、2小时内,玉米螟死亡率随时间的延长而增加,分别为35.3、50.7和61％。4小时以上各处理玉米螟死亡率均达92％以上,差异不明显。线虫与玉米螟接触0.5、8和12小时,其寄主体内进入的线虫数分别为1.2、7.9和23.8～28.3条/虫。玉米螟幼虫的死亡速度也随进人体内线虫数增多而加快,进入一条线虫的寄主在48～96小时内死亡,2～5条线虫的72小时内死亡,6～30条的48小时死亡,31条以上的24小时内死亡。     

Evaluation of the entomopathogenic fungiMetarhizium anisopliae andBeauveria bassiana against the red palm weevilRhynchophorus ferrugineus

The red palm weevil (RPW,Rhynchophorus ferrugineus (Olivier) (Coleoptera: Curculionidae) is one of the most severe pests of various palm species, including date palms. While examining the susceptibility of RPW to two entomopathogenic fungi,Metarhizium anisopliae andBeauveria bassiana, strains of the former were found to be more virulent than those of the latter, achieving 100% larval mortality within 6–7 days. The most virulent strains ofM. anisopliae were then tested on RPW eggs and adults. Incubation in a substrate treated withM. anisopliae spores increased egg mortality and reduced their hatchability. The total percentage mortality of eggs and hatched larvae was 80–82%, compared with 34% in the controls. RPW adults were challenged with two types of fungal formulation: dry powder and aqueous suspension. Cumulative adult mortality of 100% was achieved in 2–3 weeks for the dry rice-based formulation and in 4–5 weeks for the spore suspension. As a result of decreased longevity, treated females had a shorter oviposition period and three times lower fertility than the controls. Possible strategies for fungus application are discussed in the light of the high susceptibility of eggs and larvae to fungal infection. http://www.phytoparasitica.org posting July 19, 2006.     

泡沫塑料塞孔法施病原线虫防治多纹豹蠹蛾幼虫

1990年在福建室内试验,用芜菁夜蛾昆虫病原线虫北京品系感染多纹豹蠹蛾,按每头豹蠢蛾接线虫500条,5天后即可将幼虫全部杀死。12天后杀死蛹95％。在木麻黄林间试验,线虫剂量均为1000条/毫升,用不同施线虫方法结果,以在蛀孔注入线虫水悬液法和线虫泡沫塑料塞孔法为最好,豹蠹蛾死亡率分别为97和93％,“线虫糊”涂孔法效果为75％。线虫泡沫塑料塞孔法操作简单,省水,省工。在平潭县莲花山林场用线虫泡沫塑料塞孔法处理木麻黄树38000株,豹蠹蛾平均死亡率达90％。     

Speed of action and toxicity of acylurea insect growth regulators against Spodoptera exempta (Walk.) and Spodoptera littoralis (Boisd.) larvae: Effect of inter-moult age

Ultra-low volume (ULV) spray bioassays at droplet densities (20–80 drops cm^?2) corresponding to field deposits were used to determine the efficacy of two acylurea insect growth regulators, teflubenzuron (‘Nomolt®’) and flufenoxuron (‘Cascade®’) against three different age groups of third-instar Spodoptera exempta and Spodoptera littoralis larvae. While no response (mortality and/or abnormal moulting with impaired ability to feed) was observed with one-day-old larvae until 48 h after treatment, two-day-old larvae showed some response (27–93% abnormal moulting and 3–10% mortality when larvae were sprayed; 80–100% abnormal moulting and up to 83% mortality when larvae and plants were sprayed) after 24 h and up to 100% mortality at 120 h. Studies with non-feeding, pre-moult larvae showed that cuticular uptake of acylureas was sufficient to affect an appreciable proportion of larvae after 24 h, with up to 100% mortality at 120 h. More detailed studies with pre-moult S. littoralis larvae showed that, while a few larvae which moulted between 1 and 5 h after treatment showed abnormal moulting to the L4 stage, a much larger proportion of larvae which moulted 6–20 h after treatment were affected. Previous studies with S. exempta have shown that different larval instars show similar levels of sensitivity to acylureas. The present work suggests that, while the age distribution within instars has little influence on the end-point mortality of acylureas, it can profoundly modify the speed of response, the majority of larvae within an instar being effectively controlled at the moult following treatment. The significance of these observations in relation to the crop protection activity of acylureas against field populations of Spodoptera larvae is discussed.     

球孢白僵菌对马铃薯块茎蛾的毒力及其与常用农药的生物相容性测定

室内测定了从云南分离的7株球孢白僵菌对马铃薯块茎蛾幼虫的毒力,结果表明,在接菌孢子浓度为10⁵个/mL和10⁷个/mL下,接种后7d马铃薯块茎蛾幼虫累积死亡率分别为23.3%～70.0%和33.3%～86.7%,添加吐温80的清水对照死亡率仅为3.3%。筛选出毒力较高的Bb7001、Bb7004、Bb8001 3个菌株,其中菌株Bb8001对马铃薯块茎蛾幼虫的毒力最高,在孢子浓度1×10⁵、1×10⁷个/mL下,第7天的累计死亡率分别为70.0%和86.7%,其毒力回归方程Y=0.366X+3.409(R=0.956),剂量效应LC₅₀=2.24×10⁴个/mL,孢子浓度10⁷个/mL下的LT₅₀为4.3d。测定了毒力较高的菌株与12种农药的生物相容性,结果表明在供试农药推荐用量及其101、00倍稀释液下,球孢白僵菌Bb7001、Bb7004、Bb8001的3个菌株孢子在含所选农药的营养液中生物相容性良好的农药有:苏云金芽孢杆菌可湿性粉剂(Bt)、10%吡虫啉可湿性粉剂、2.5%菜喜悬浮剂及松毛虫病毒可湿粉剂,可配伍使用;而阿维菌素、农安、卡死克、抑太保对球孢白僵菌有很强的抑制作用,应避免配伍使用。     

一株莱氏绿僵菌的筛选及其对草地贪夜蛾的毒力

开展草地贪夜蛾病原真菌的筛选和毒力测定可为草地贪夜蛾的绿色防控提供新的生物制剂。本研究从广西南宁田间采集的草地贪夜蛾幼虫僵虫上分离获得一株病原真菌,采用形态学和ITS-rDNA序列分析相结合的方法对该菌株进行了鉴定,并采用浸虫法测定了该菌株对草地贪夜蛾的致病力。结果表明新分离的菌株为莱氏绿僵菌Metarhizium rileyi,编号为CDTLJ1;该菌株对草地贪夜蛾幼虫、预蛹、蛹均有致病力,1.20×10⁷孢子/mL浓度下,接菌处理后第6 d,2~5龄幼虫的累积校正死亡率均达100%,6龄幼虫的累积校正死亡率为98.33%,预蛹和蛹的累积校正死亡率分别为28.33%、20.00%,草地贪夜蛾2~6龄幼虫的LT50值从3.91 d升至4.24 d;菌株CDTLJ1对草地贪夜蛾3龄幼虫的致死率随孢子悬浮液浓度的升高而增加,当浓度达1×10⁸孢子/mL时,幼虫的致死LT50为4.10 d,接菌处理后第6 d,3龄幼虫的累积校正死亡率达100%,LC₅₀为1.12×10⁴孢子/mL。结果表明,莱氏绿僵菌CDTLJ1对草地贪夜蛾有良好的生防潜力,具有进一步深入研究和开发利用的前景。