农用不育剂防治烟青虫的研究

不育治虫也称遗传防治,是害虫综合防治的一项崭新内容。当前,国内外成功的实例不多。本研究选出了烟青虫雄性不育剂和雌性不育剂,将其与烟青虫性诱剂结合,制成小型不育引诱器,每亩烟田插置一个,即可诱使田间烟青虫成虫吮食不育剂,食后即成为不育蛾。不育蛾仍可与正常蛾交配,不但使交配对象成为不育,还可使已正常交配的成虫成为不育。从而降低田间的虫量,减少为害。田间试验结果表明,对烟青虫的防治效果达90％以上。使用不育剂可以减少田间农药用量和施药次数。本研究选出的不育剂对人畜无害,使用简便,价格较低,对环境无污染。     

高温胁迫对红彩瑞猎蝽存活率及捕食作用的影响

为探明高温条件下红彩瑞猎蝽耐受能力及对斜纹夜蛾幼虫的控害潜能，在室内测定了红彩瑞猎蝽经不同高温胁迫48 h后的卵孵化率，5龄若虫羽化率，3、4、5龄若虫和雌、雄成虫存活率，评估了红彩瑞猎蝽不同虫态在高温条件下24 h内对斜纹夜蛾3龄幼虫的捕食能力。结果表明，高温胁迫对红彩瑞猎蝽各虫态的存活率、卵孵化率和羽化率有显著影响，经42℃处理48 h后红彩瑞猎蝽雌成虫和5龄若虫的存活率最高，达66.67%；红彩瑞猎蝽存活率、卵孵化率和羽化率在27～33℃时随温度升高而增加，在33℃后均随着温度升高而降低，36℃后存活率、卵孵化率和羽化率均下降明显。红彩瑞猎蝽各虫态在30～33℃范围对斜纹夜蛾的捕食量和捕食效能随温度升高而增大，在33～39℃范围，捕食量和捕食效能随温度升高而降低，红彩瑞猎蝽各虫态对斜纹夜蛾的捕食功能反应类型符合HollingⅡ型，随着猎物密度的增加，对猎物的搜寻效应逐渐减弱，个体间存在竞争和相互干扰作用。可见红彩瑞猎蝽对高温逆境有一定的耐受能力，其适宜生存的高温范围为33～36℃。     

六个品种小麦对玉米象的抗虫性比较研究

试验选用产自河北、河南、山东等省的6个小麦品种,分别是良星66、泛麦8号、西农979、郑麦7698、济麦22和矮抗58。从田间获取的样品分别将其水分含量调节为12.5%左右,每16 g粮食感染6头母代玉米象成虫(雌雄比为4∶2),之后检查其子代成虫羽化数量,羽化时间,并计算发育历期和敏感系数。主要结果为:济麦22中的玉米象平均发育历期最短(40.8 d),子代成虫数量最多(46头),对玉米象的敏感系数为9.40;西农979中的玉米象平均发育历期为42.6 d,子代成虫数量为8头,对玉米象的敏感系数为4.98。抗虫性最小的济麦22中玉米象子代成虫羽化初现时间、羽化高峰和终止时间都相应地是最短,抗虫性最大的西农979中害虫初现时间和终止时间有所延长,但并非最大值。良星66中的玉米象羽化终止时间最长,但其抗虫性却小于西农979。由样品感染卵至成虫初现的过程中小麦品种间的重量变化量差异不显著。结果表明:试验小麦品种间对玉米象的抗虫性差异显著,子代成虫出现数量多的小麦品种其敏感系数也相应地小,但羽化时间长短与小麦的敏感系数大小变化趋势不完全一致,小麦感染害虫后重量下降量与其敏感性相关性不明显。     

人工合成性诱剂对烟青虫控制作用的研究

应用人工合成性诱剂大面积布局能很好地控制烟青虫的危害。性诱防治区88．4％的雄蛾被诱杀，雌蛾交配率下降79．9％～85．7％，平均幼虫密度为百株虫量10头（防治指标为百虫量30头），烟青虫为害破叶率和食叶率分别下降93．34％和83．72％。     

S-烯虫酯防治拟谷盗持效性及解毒酶功能影响研究

在当前害虫抗药性强和社会安全健康意识增强的背景下，迫切需要开发生态友好的防治手段。因此，采用小麦入仓全仓拌和S-烯虫酯进行防治。通过分别扦取处理90天和365天后的小麦样品，在实验室内模拟了赤拟谷盗和杂拟谷盗的防治效果，并测定了S-烯虫酯对拟谷盗幼虫三种解毒酶的影响。研究结果表明，施药时间和虫态是影响S-烯虫酯杀虫效果的关键因素。在施用S-烯虫酯90天后的小麦样品中，武汉、成都和齐河3个品系的赤拟谷盗卵孵化率为0%，广东和北京2个品系的杂拟谷盗卵孵化率分别为1.67%±2.04%和0%。此外，施用S-烯虫酯90天后对赤拟谷盗和杂拟谷盗的杀蛹活性较好，羽化成虫无繁殖能力；施用365天后的杀蛹活性大大降低，羽化成虫有繁殖能力，而F1代蛹无法羽化。两处理组对两种成虫直接致死作用也有一定效果，但施用365天后的致死率大大降低，赤拟谷盗F1代仅有幼虫，而杂拟谷盗F1代有部分幼虫可化蛹但不能进一步转化为成虫。说明赤拟谷盗比杂拟谷盗更为敏感。S-烯虫酯胁迫之后，两种拟谷盗科幼虫体内的3种解毒酶活性受到了影响，且随着时间延长而增强。     

氮气气调胁迫对锈赤扁谷盗种群适合度的影响

为了解不同氮气浓度处理对锈赤扁谷盗Cryptolestes ferrugineus (Stephens)种群适合度的影响,本研究采用构建生命表的方法,研究了95%和98%两种氮气浓度胁迫24 h后锈赤扁谷盗试验种群的生长发育情况,并以此分析了不同氮气浓度对锈赤扁谷盗各生命参数和种群适合度的影响。结果显示,与对照组相比：95%氮气浓度处理后,子代锈赤扁谷盗的孵化率、化蛹率、羽化率均呈现下降的趋势,分别下降了2.00%、11.34%、8.80%,卵、幼虫、蛹及总发育历期分别延长了0.2 d、2.0 d、0.4 d、2.6 d：98%氮气浓度处理后,子代锈赤扁谷盗的孵化率、化蛹率、羽化率均呈现下降的趋势,分别下降了6.00%、25.33%、13.51%,卵、幼虫、蛹及总发育历期分别延长了0.4 d、4.3 d、1.0 d、5.8 d。此外,氮气气调胁迫导致处理当代锈赤扁谷盗单雌产卵量显著减少,子代雌虫占比升高,但子代单雌产卵量未受到影响。本研究分析了氮气气调胁迫对锈赤扁谷盗种群适合度的影响,为氮气气调防治储藏物害虫提供了参考依据。     

温度对蓼蓝齿胫叶甲生物学特性的影响

在人工气候箱中研究了不同温度条件下蓼蓝齿胫叶甲的生物学特性,结果表明,在18~27℃范围内,随着温度的升高,各虫龄蓼蓝齿胫叶甲的取食量、存活率以及成虫的产卵量和羽化率逐渐增加,温度与蓼蓝齿胫叶甲的取食量、存活率,成虫的产卵量和羽化率均呈极显著正相关,蓼蓝齿胫叶甲繁殖的适宜温度范围为24~30℃,以27℃最佳。     

2%和5%低氧处理赤拟谷盗不同虫态的乳酸测定研究

用乳酸测试盒测定了正常大气下5%和2%氧浓度处理24 h的赤拟谷盗(Tribolium castaneum Herbst)卵、幼虫、蛹和成虫的体内乳酸含量.结果表明:正常大气下,4种虫态试虫体内的乳酸含量明显不同,成虫的乳酸含量最高,蛹次之,幼虫较小,卵最低;雌成虫和雄成虫体内的乳酸含量,差异不显著(P>0.05).在5%氧浓度下处理24 h,前述4种虫态的乳酸含量分别是对照组相同虫态乳酸含量的2.1倍、2.5倍、2.3倍和1.1倍.2%氧浓度下处理24 h,4虫态的乳酸含量明显比5%氧浓度处理组各相同虫态的高,分别是对照组相同虫态乳酸含量的4.7倍、3.4倍、4.5倍和1.5倍.低氧条件下,四种虫态的乳酸含量都明显增加,卵和蛹的乳酸含量增加的最快,幼虫次之,成虫最慢.因此,低氧导致害虫各个虫态体内乳酸量的增加与低氧致死机理有一定的关系.     

烟粉虱MED隐种对不同烟草品种的适合度比较

烟粉虱MED隐种是近年来烟草上的重要害虫,为明确不同烟草品种对烟粉虱的抗性水平,应用微虫笼研究了烟粉虱在6个烟草品种上的寿命、产卵量、卵-成虫存活率、发育历期等重要生物学参数,比较了烟粉虱对不同烟草品种的适合度差异。结果表明：除卵孵化率外,烟粉虱MED隐种在供试烟草品种上的寿命、产卵量、卵-成虫存活率、发育历期均存在显著差异。雌成虫寿命和产卵量均以在翠碧1号上最高（35.9 d,236.5粒）,在NC89上最低（9.6 d,27.8粒）;雄成虫寿命在K326上最长（7.2 d）,在云烟87上最短（1.8 d）;卵-成虫存活率在红花大金元上最高（91.6%）,在云烟87上最低（81.4%）;发育历期在红花大金元上最短（19.5 d）,在云烟99上最长（21.1 d）。烟粉虱MED隐种对不同烟草品种的适合度高低顺序为翠碧1号、K326 > 红花大金元 > 云烟99、云烟87 > NC89。     

基于室内人工接虫法的象虫金小蜂防治烟草甲幼虫的可行性分析

为揭示象虫金小蜂(Anisopteromalus calandrae)用于生物防治的可行性,以烟草甲(Lasioderma serricorne)幼虫为寄主,采用室内人工接虫法比较了不同蜂虫比对象虫金小蜂繁殖效率和防治效果的影响,以及象虫金小蜂对不同包装材料的穿透能力。结果表明:(1)象虫金小蜂与烟草甲5龄幼虫以2(对)∶50(头)接虫时,后代羽化雌性成蜂数和总成蜂数最多,且雌蜂比例最大。(2)象虫金小蜂不能穿透牛皮纸、纸箱、滤纸和塑料薄膜等包装材料,但可以穿透孔径大于0.18 mm的孔洞。(3)室内寄生防治效果显示,当蜂虫比大于4(对)∶100(头)时,象虫金小蜂对烟草甲5龄幼虫的防治效果大于93.44%。表明象虫金小蜂是防治烟草甲的适宜天敌。     

Effect of high-temperature pre-irradiation on reproduction and mating competitiveness of male Sitotroga cerealella (Olivier) and their F1 progeny

Pupae of the Angoumois grain moth, Sitotroga cerealella (Olivier) were irradiated with substerilizing doses of 150, 180 and 210 Gy of gamma radiation. Inherited deleterious effects due to irradiation of P males irradiated as pupae were recorded for F₁ progeny. The radiation damage increased when pupae were kept at high temperature (32.5 °C) for 24 h before irradiation, where a marked reduction in fecundity and egg hatch was obtained among P males and their F₁ progeny. This reduction was significantly increased by increasing the dosage. F₁ progeny were more sterile than the irradiated parent generation, though F₁ males were more sterile than F₁ females. Also, the combination of high temperature and irradiation applied to parental male pupae decreased larval survival and percentage of F₁ female progeny, whereas it did not affect the mating frequency among P males and F₁ progeny at the tested doses. Laboratory mating competitiveness indicated that parental males heat-treated with 32.5 °C and irradiated with 150, 180 and 210 Gy and their F₁ progeny were fully competitive with their untreated siblings.     

A wild strain of Plodia interpunctella (Hübner) (Lepidoptera: Pyralidae) from farm-stored maize in South Carolina: Effect of temperature on mating, survival, and fecundity

The purpose of this study was to develop age-specific survivorship and fecundity schedules for adult Plodia interpunctella (Hübner) relevant to maize storages, with special reference to the southeastern states (USA). Laboratory cultures were established with moths collected from farm-stored maize in South Carolina and maintained on cracked maize at 30 °C and 60% r.h. Age-specific schedules of survivorship and fecundity, the length of the oviposition period, mating success, and mating frequency were determined at 20, 25, 30, and 35 °C and about 75% r.h. The maximum oviposition period was longest (18 d) at 20 and 25 °C, and shortest (8 d) at 35 °C. The optimum temperatures for reproduction (mating frequency and fecundity) were 25–30 °C, but mean life-span was longest (13.2 d) at 20 °C and declined linearly with increasing temperature. Mean total (lifetime) fecundity ranged from 16.9 eggs at 35 °C to 227.7 eggs at 25 °C.     

The influence of delayed mating on the reproduction of Ephestia cautella (Walker) (Lepidoptera: Phycitidae)

The influence of delayed mating on reproduction was studied for its possible value in the control of Ephestia cautella. When mating of both sexes was delayed for progressively longer periods, fecundity and fertility were both reduced correspondingly until no adult progeny were produced when mating was delayed for 8 days. Fecundity was also reduced where mating was delayed for females only. Female longevity increased from 6.8 days with no delay to 11.4 days with an 8-day delay. The period during which females could lay fertile eggs nevertheless was reduced from 5.4 days with no delay to 3.0 days with a 6-day delay. The number of eggs laid within 1 or 3 days after mating was also reduced as the delay was increased.Physiological causes of reduced fecundity in the female are discussed. Delayed mating induced by causes such as high background levels of sex pheromone is considered in relation to the control of E. cautella.     

低温冷藏对烟草粉螟亲代和子代适合度的影响

为明确低温冷藏对烟草粉螟亲代和子代适合度的影响,根据年龄-龄期两性生命表理论,对5℃冷藏160d后的烟草粉螟5龄幼虫亲代生殖适合度及其子代发育历期、存活率、繁殖率和种群参数进行研究。结果表明,低温冷藏160d后烟草粉螟F₀代的蛹期显著长于对照,雌雄成虫寿命、平均繁殖力和产卵时间均显著低于对照;但在F₁代中,除了低温处理的平均繁殖力（148.29粒）显著高于对照（113.93粒）外,其他参数均无显著差异。研究表明,低温冷藏显著降低烟草粉螟亲代的适合度,对子代的适合度则无显著影响。     

Phosphine-induced sterility in Ephestia cautella (Lepidoptera: Pyralidae)

The present study was conducted to explore the sterilizing effect of phosphine on Ephestia cautella. Three to four-day old pupae were exposed to 0, 0.007, 0.014, 0.021, 0.028, 0.035, 0.042 and 0.049 mg/l of phosphine for 24 h at room temperature. The normally developed adults of each treatment were pair mated and several physiological and genetical parameters were investigated. The results showed gradual increases with dose in pupal mortality and adult malformation. The crossing results showed no changes in adult longevity and mating frequency. However, consistent reduction was noted in the fecundity and fertility of normally emerged adults. Preliminary data indicated similar levels of inherited sterility in the F₁ adults raised from the above mentioned crosses.     

ENHANCEMENT OF SECONDARY METABOLITE PRODUCTION IN HAIRY ROOT CULTURES OF BETA VULGARIS AND TAGETES PATULA UNDER THE INFLUENCE OF MICROALGAL ELICITORS

The effect of aqueous extracts of green alga-Haematococcus pluvialis and blue green alga-Spirulina platensis was studied for accumulation of betalaines (food colourant) and thiophenes (insecticide useful against food grain spoilage) in hairy root cultures of Beta vulgaris and Tagetes patula, respectively. It was found that upon treatment with extracts (100 μg dry cell extract/ml of the culture medium each) of H. pluvialis and S. platensis there was an increase in biomass of cultured Beta vulgaris hairy roots which was 165.3 g fresh wt/L (14.38 g dry wt/L) and 149.4 g fresh wt/L (13 g dry wt/L), respectively from the initial inoculum of 1.25 g fresh wt/L (0.115 g dry wt/L). The accumulation of betalaines showed an increase of 2.28 fold on 15th day in hairy root culture treated with H. pluvialis over the control (7.9 mg/g dry wt) on the same day from the initial level of 0.67 mg/g dry wt. Similarly S. platensis extract treated hairy roots showed elicitation of betalaines 1.16 fold on 25th day over the control (11.08 mg/g dry wt) from the initial level of 0.67 mg/g dry wt. It was also observed that the H. pluvialis extract also influenced the biomass production in T. patula hairy roots which was 1.4 fold higher than the control (40 g fresh wt/L or 3.21 g dry wt/L) on 20th day from the initial inoculum of 1.25 g fresh wt/L (0.105 g dry wt/L). Whereas the accumulation of thiophene increased by 1.2 fold in cultures treated with H. pluvialis extract on the 20th day over the untreated control (510 μg/g dry wt) from the initial level of 200 μg/g dry wt, while S. platensis extract did not influence the growth as well as thiophene accumulation. In conclusion S. platensis extract influenced elicitation of betalaines in B. vulgaris hairy roots where as H. pluvialis extract elicited betalaine and thiophene production in hairy root cultures of B. vulgaris and T. patula respectively.     

Effect of gamma irradiation on pupal stage of Ephestia calidella (Guenée)

Mature pupae of Ephestia calidella (Guenée) were irradiated at doses of 200–1000 Gy. Variations in the percentage of adult emergence and percentage of malformed adults were used as criteria to evaluate the radiation effects. A dose of 1000 Gy prevented the emergence of both sexes. Females and males were sterilized with a dose of 350 and 400 Gy, respectively. Adult longevity and mating ability varied with regard to the dose. Males irradiated with sub-sterile doses (100, 150, and 200 Gy) were more sexually competitive with normal males than those irradiated with the sterilizing dose (400 Gy).     

温度和烟草粉螟密度对麦蛾茧蜂觅食行为的影响

为明确温度和烟草粉螟密度对麦蛾茧蜂觅食行为的影响,设置15、20、25、30和35℃梯度温度,测定了麦蛾茧蜂在不同密度烟草粉螟5龄幼虫条件下的功能反应、寄生量和产卵量。结果表明,麦蛾茧蜂的麻痹量随温度的升高和烟草粉螟密度的增大而增大,其功能反应为Holling II模型;麦蛾茧蜂的瞬时攻击率（a）随温度的升高先增大后降低（25℃最大）,处理时间（T_h）随温度的升高而缩短;在30~35℃条件下麦蛾茧蜂对烟草粉螟的控害潜力（a/T_h和T/T_h）最大。麦蛾茧蜂的寄生量、产卵量和转化率均随温度的升高而增大,随烟草粉螟密度的增大而减小。当温度在30~35℃和烟草粉螟为5~10头/盒时,麦蛾茧蜂的寄生量、产卵量和转化率较高。本研究为大量饲养和利用麦蛾茧蜂防治烟草粉螟等仓储害虫提供了理论依据。     

In vitro antioxidant activities of the methanol extracts of four Helichrysum species from Turkey

This study was designed to examine the in vitro antioxidant activities of the methanol extracts of four Helichrysum species (Helichrysum noeanum Boiss., H. chionophilum Boiss. & Bal., H. plicatum DC. subsp. plicatum, H. arenarium (L.) Moench. subsp. aucheri (Boiss.) Davis & Kuphicha). The extracts were screened for their possible antioxidant activitiy by two complementary test systems, namely DPPH free radical-scavenging and β-carotene/linoleic acid systems. In the first case, non-polar subfractions of the methanol extracts of Helichrysum species studied did not show any antioxidant activity, while the most active one was H. chionophilum (IC₅₀ =40.5 μg/ml) among the polar subfractions. In the β-carotene/linoleic acid test system, inhibition rates of the oxidation of linoleic acid of H. noeanum and H. arenarium were very close to each other. The inhibition rate of the synthetic antioxidant BHT was determined to be 96%. Since the polar extracts of Helichrysum species dealt with here exhibited interesting antioxidant activities when compared to BHT, we believe that it would be useful to take the results into consideration as an alternative for food processing industries.