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1.
Diflubenzuron (DFB), applied by dipping on newly emerged pupae of Tenebrio molitor L., disturbs the pupal-adult development. Four main types of treated insects were obtained according to external morphology: blocked pupae, adults unable to ecdyse, adults partially ecdysed, and adults completely ecdysed. The proportion of these four types varied with the time of treatment during the pupal life. When DFB was administered by dipping at a 10 g/liter concentration to newly emerged pupae, HPLC measurements showed that the different responses were due to a difference in the levels actually incorporated. Histological and ultrastructural observations of sternal cuticles revealed that DFB disturbs the cuticle deposition: reduction of its thickness and modifications of its architecture. Tritiated thymidine incorporation and cell density measurements in sternal epidermis show that DFB affects both mitoses and DNA synthesis in blocked pupae. These findings suggest that DFB interferes with other biochemical processes besides the chitin biosynthesis; whether these effects are primary or secondary remain to be determined.  相似文献   

2.
Diflubenzuron was found to be effective on the pupae of Tenebrio molitor L. (Coleoptera, Tenebrionidae) when applied topically, by dipping, or by injection. Death occurred before or at adult ecdysis, or during the first few days after emergence. Its effectiveness decreases with increasing age of the pupa. Diflubenzuron delays adult ecdysis and decreases the longevity of normally ecdysed adults. After diflubenzuron had been applied topically or by dipping, the compound was determined, on the pupal cuticle, in the body and on the rearing tray, by highperformance liquid chromatography. The results showed that diflubenzuron penetrated rapidly into the body and was not degraded during the pupal life. The level of incorporation of the insecticide, in dipping experiments on pupae at the same stage, varied from one individual to another. Moreover, the mean amount of insecticide incorporated was lower after dipping of older pupae than of younger pupae. It is suggested that the lower efficacy of diflubenzuron on older pupae may be caused by the decrease both in the permeability of the cuticle and in the sensitivity of the target cells.  相似文献   

3.
The insect growth regulator, methoprene, is active against the imported fire ant, Solenopsis invicta Buren. This report presents data on the degradation of [14C]methoprene in the imported fire ant. The relative rates of absorption, metabolism, and excretion of methoprene in imported fire ant stages were found in the following order: adults>larvae>pupae>pharate pupae. Metabolism of methoprene by adults and pupae was primarily by O-demethylation to yield the alcohol-ester. Larvae and pharate pupae metabolized methoprene principally by esterase cleavage of the isopropyl ester which yielded the ether-acid. In larvae and pharate pupae there was a rapid increase in methoprene metabolism prior to the pharate pupal transformation and pupal molt. During the molt from pharate pupae to pupae, metabolism of methoprene appeared to occur in the cuticle, resulting in the accumulation of metabolites within and on the cuticle. The retention of these more polar compounds in the cuticle may contribute to the effectiveness of the insect growth regulator. The adults have a direct role in distributing the insect growth regulator and its metabolites, whereas the immatures may serve as a reservoir for maintenance of effective levels of insect growth regulator and active metabolites in the colony.  相似文献   

4.
Holometabolous insects develop without feeding and excreting during the pupal period and thus require repository organs for metabolic waste, or meconium. The rectal sac is an organ for storing meconium during pupal-adult development of holometabolous insects. Although the rectal sac has an essential function, hormonal and developmental regulation of waste-accumulation and the consequences of rectal sac distention are still unknown. In the silkworm, Bombyx mori, the rectal sac distends with meconium in the middle pupal period under the regulation of ecdysteroid. Here, we show that juvenile hormone analog (JHA) delayed rectal sac distention and disturbed adult emergence. Distention was not restored completely by an injection of 20-hydroxyecdysone (20E) into pupae applied with JHA, suggesting that JHA suppresses 20E action and delays the timing of ecdysteroid elevation. Thus the “status quo” action of JHA may function in two different ways during pupal-adult development.  相似文献   

5.
Pyriproxyfen, an analog of the juvenile hormone (JH) in insects, has been evaluated in vivo and in vitro on an important stored product pest, the mealworm Tenebrio molitor. On newly ecdysed pupae, this insect growth regulator (IGR) was applied topically (at 0.10 and 0.20 μg/insect). Enzyme immunoassay measurements showed a decrease of the ecdysteroid titer in the hemolymph of treated specimens. In addition, the treatment induced an increase of the protein concentration in the hemolymph, however, there was no significant effect on the protein band pattern. Using in vitro pupal integument explant cultures, pyriproxyfen (at 1 and 10 μM in the medium) caused a significant inhibition of ecdysteroid amounts and of the thickness of new cuticle secreted. These new results are discussed in relation to the physiology of this IGR with a JH action.  相似文献   

6.
对孪斑唇瓢虫成虫、幼虫和蛹的空间分布型及抽样技术研究表明,各项聚集度指标均符合聚集分布的检定标准。聚集的原因是由其自身的行为习性和环境条件共同作用引起的。应用Taylor幂法则、Iwao回归分析法测定出孪斑唇瓢虫成虫、幼虫和蛹的空间分布型是基本成分为个体群的聚集分布,聚集强度随种群密度的升高而增加。同时采用Iwao方法求出了最适抽样数。  相似文献   

7.
Tribolium castaneum adults and pupae were exposed to carbon monoxide (CO) at concentrations of 20%, 30% and 40% in air, for 24, 48, 72, 96 and 120 h. The toxic effect on the treated adults was insignificant except for the longest exposure at the highest CO concentration, at which mortality values reached 11.3%. Adult emergence from the treated pupae was affected considerably, resulting in zero emergence (100% pupal mortality) at the highest dosages. Deformed adults emerged from pupae treated with 30% and 40% CO. The inhibitory effect of CO on the cytochrome P-450-dependent mono-oxygenase system or another oxidase system functioning at the pupal stage is proposed as a possible explanation for the failure of adult emergence.  相似文献   

8.
辐射对亚洲玉米螟体内几种水解酶活力的影响   总被引:2,自引:0,他引:2  
研究了亚洲玉米螟Ostriniafurnacalis(Guen.)不同虫成3-4龄幼虫、1-2d龄蛹,当天羽化成虫)体内羧酸酯酶(CarE)、酸性磷酸酯酶(AP)和碱性磷酸酯酶(AlP)的活力在不同^60Coγ辐照条件下的变化,结果表明,亚洲玉米螟不同虫态的CarE活力顺序为:幼虫  相似文献   

9.
利用人工卵赤眼蜂蛹规模化饲养七星瓢虫的可行性研究   总被引:7,自引:0,他引:7  
利用人工卵赤眼蜂蛹规模化饲养七星瓢虫的结果表明:(1)人工卵赤眼蜂蛹基本上能满足七星瓢虫幼虫的生长发育,并能正常羽化,但发育历期延长2.7d,蛹重降低;(2)成虫取食人工卵赤眼蜂蛹后,产卵前期、产卵期、总产卵量分别为12.3d、45.6d和1589.7粒,与蚜虫对照组差异显著。(3)用人工卵赤眼蜂蛹连续饲养七星瓢虫至6代时,生殖力有明显退化。(4)幼虫期饲喂人工卵赤眼蜂蛹、成虫期饲喂蚜虫与幼虫期及成虫期均用蚜虫饲喂的七星瓢虫具有相似的生殖力。(5)用人工卵赤眼蜂蛹饲养成虫,添加取食刺激剂(5%的蔗糖 0.1%橄榄油)后,其生殖力接近用蚜虫饲养的水平。综上所述,人工卵赤眼蜂蛹可满足幼虫的生长育,但对成虫的生殖力有一定影响;连代饲养后出现退化现象,这些影响主要是成虫产卵前期的营养得不到满足,可通过在成虫期添加取食刺激剂或成虫产卵前期改喂蚜虫解决。  相似文献   

10.
短时高温暴露对草地贪夜蛾存活及生殖的影响   总被引:1,自引:0,他引:1  
本文研究短时高温暴露对草地贪夜蛾存活和生殖的影响,为其夏季的预测预报及综合防治提供技术支持.分别以卵、不同龄期幼虫、蛹、成虫作为研究对象进行不同时间高温暴露处理,研究高温暴露处理后幼虫和成虫的成活率,幼虫的化蛹率、羽化率、蛹重以及成虫的生殖能力.结果 表明.37℃对卵的孵化率无显著影响,40℃暴露4h卵的孵化率显著降低...  相似文献   

11.
Metabolites produced from 14C-labelled C-18 juvenile hormone (JH-I) topically applied to the flour beetle Tribolium castaneum were measured in larvae aged 21 and 28 days, pupae at four stages of development, and newly emerged and mature adults. The hormone was metabolized rapidly, in all stages examined, to form the corresponding diol-ester, acid-epoxide, and acid-diol derivatives, the diol-ester derivative being the major metabolite produced. The metabolism of JH-I was most rapid at the times of the larval/pupal and pupal/adult transformations. The differences in the rate of metabolism appeared to be correlated with changes in the production of the diol-ester derivative. Similar metabolic changes may regulate the levels of endogenous juvenile hormones during development in this species.  相似文献   

12.
多杀菌素对菜蛾绒茧蜂的致死和亚致死效应   总被引:5,自引:0,他引:5  
以对多杀菌素高抗的小菜蛾纯合子品系作寄主饲养菜蛾绒茧蜂,用多杀菌素田间推荐使用浓度(25 mg/L)分别处理处于卵期、幼虫期和蛹期的绒茧蜂,其中卵期和幼虫期通过处理寄主幼虫间接处理,并测定该药剂对成虫的毒力,系统观察该杀虫剂对绒茧蜂各虫期的致死和亚致死作用。与对照相比,绒茧蜂卵期或幼虫期其寄主受药后,可导致蜂幼虫死于寄主体内或啮出寄主的过程中,使结茧化蛹率下降43% ~56%,成虫羽化率下降19% ~33%,成蜂雌性比下降11% ~25%,而成虫大小、寿命和寄生力未受显著影响;在蛹期受药使成虫羽化率下降10%,成蜂寿命缩短,但对成虫寄生力无显著影响;对成虫24 h的LC99为4.31 mg/L。结果表明,多杀菌素可进入寄主作用于其体内的蜂卵和幼虫,或直接作用于蜂蛹和成虫,从而对绒茧蜂各个虫态产生显著的致死和亚致死效应,尤以对成虫高毒。  相似文献   

13.
S,S-Di-isobutyl N ethylethylenebis(thiocarbamate) (R-31026) had a strong morphogenetic effect, acting by contact on the newly formed pupae of Tribolium confusum and Tribolium castaneum and thereby disrupting adult development. At a dietary concentration of 20 mg kg?1, 95% of pupae of T. confusum produced pupa-adult intermediates; T. castaneum pupae were affected to a smaller extent. Topical application with 0.002 μg per 0–24-h-old pupa of T. confusum resulted in the formation of 88% malformed intermediates. The larvae brought into contact with R-31026 were not affected and pupated normally, hence the compound differs in its activity from that of a typical juvenile hormone compound. On the other hand, the pupal morphogenetic activity of R-31026 resembles that of the typical juvenoid compound 3-[5-(4-ethylphenoxy)-3-methylpent-3-enyl]-2,2-dimethyloxirane (R-20458). The progeny of the emerging adults from pupae treated with either R-20458 or R-31026 were strongly affected. The effective dosages were far below those required for pupal morphogenetic activity. Biochemical studies showed an increase in the soluble protein fraction during the pupal stage after treatment with either R-31026 or R-20458 indicating disturbances in protein build-up. The bis(thiocarbamate) R-31026 has more favourable practical properties than R-20458 for controlling agricultural insects, because it does not prolong the larval feeding stage.  相似文献   

14.
Penultimate and last instar larvae of the common citrus swallowtail butterfly, Papilio demoleus L. (Papilionidae: Lepidoptera), were treated with different doses of a novel juvenoid, diofenolan. Several deformities were observed as a result of topical administration of diofenolan which include delay in larval–larval and larval–pupal ecdysis, ecdysial failure, mortality, severe reduction in pupation, deformed pupae and complete inhibition of adult emergence. The juvenoid diofenolan severely hampers the normal growth, development and metamorphosis of P. demoleus and can be incorporated into integrated pest management programs for successful control of this important pest of citrus all over the world.  相似文献   

15.
Flufenoxuron (“Cascade”) is a novel acylurea with acaricidal and insecticidal properties. It acts in a similar manner to diflubenzuron (DFB) by impairing chitin incorporation into insect cuticle. Chitin can be localised cytochemically using the lectin, wheat germ agglutinin (WGA), which binds specifically to N-acetylglucosamine-containing polymers. WGA adsorbed to monodisperse colloidal gold (WGA-gold) was used as an electron-dense marker for localising chitin in the cuticle of sixth-instar Spodoptera littoralis. In the cuticle of control insects, the deposition zone and endocuticle were heavily labelled. In flufenoxuron- and DFB-treated insects, only the endocuticle (formed before treatment) was labelled, the deposition zone being devoid of label. These results show that flufenoxuron and DFB act in similar manner in reducing chitin incorporation in the cuticle of S. littoralis.  相似文献   

16.
为了探究七星瓢虫不同虫态的低温贮藏条件,本研究在不同恒定低温-时间与变温预处理后恒定低温-时间组合下分别测定了七星瓢虫卵、蛹及成虫的孵化率、羽化率及成虫存活率。结果表明,无论恒定低温或变温预处理,卵在常温下3 d均可孵化,恒温和变温的孵化率分别为72.56%和73.93%,且当保存时间不超过5 d时,卵在8℃、10℃及12℃时孵化率均在50%以上,保存时间为10 d时,卵在10℃及12℃时孵化率均在50%以上。七星瓢虫蛹在恒温和变温预处理条件下,在10℃保存3 d时均可完全羽化,且羽化率与对照组无显著差异,但当保存时间达到50 d,恒定温度在2℃、4℃、6℃和8℃下畸形率达到了100%,而其余保存天数下均未出现畸形率,当变温预处理后,仅在2℃下保存20、30和50 d分别出现100%、50%和100%的畸形率。在25℃保存时,恒温和低温预处理下的成虫保存40 d时,全部死亡,但恒温8℃下保存60 d和变温预处理10℃下保存60 d的成虫存活率分别达到60.46%和63.29%。综合分析表明,一定时间下的恒定低温和变温预处理保存均能延长七星瓢虫卵、蛹及成虫寿命,从而为七星瓢虫不同虫态商品化及其货架期的延长提供有效支持。  相似文献   

17.
为了探讨寄生不同寄主对花绒寄甲Dastarcus helophoroides(Fairmaire)生长发育和耐寒性的影响,于室内分别用鞘翅目的Zophobas morio蛹、麻竖毛天牛Thyestilla gebleri和松褐天牛Monochamus alternatus Hope的幼虫作为寄主,统计和分析花绒寄甲的发育历期、成虫产出数、成虫个体大小和过冷却点。结果发现:寄生不同寄主对花绒寄甲的成虫产出数无显著影响,但对其幼虫历期、蛹历期、成虫体长、成虫体重和过冷却点有显著影响。寄生Zophobas morio蛹的花绒寄甲幼虫历期(10.58 d)和蛹历期(30.17 d)均最长,成虫体长最长(8.68 mm),体重最重(360.22 mg),过冷却点最低(-18.81℃);而寄生麻竖毛天牛幼虫的花绒寄甲幼虫历期(8.94 d)和蛹历期(22.84 d)均最短,成虫体长最短(6.33 mm),体重最轻(184.38 mg),过冷却点最高(-16.50℃)。相比麻竖毛天牛和松褐天牛的幼虫,Zophobas morio蛹所繁育的花绒寄甲成虫体型更大且耐寒性更强,Zophobas morio蛹是繁育更为健壮和耐寒的花绒寄甲种群的理想替代寄主。  相似文献   

18.
为探明枸杞奈实蝇Neoceratitis asiatica幼期各虫态的形态发育特性,采用田间取样和室内饲养相结合的方法对其卵、幼虫、蛹的生长发育过程、形态变化及识别特征进行系统观察,通过测量口钩和头咽骨的长度来划分幼虫龄期,解剖并观察不同发育时期蛹及蛹壳颜色,利用图像分析系统提取并分析蛹壳颜色的RGB值。结果表明:枸杞奈实蝇卵的发育可分为初期卵、口钩显现期卵和破壳期卵3个阶段。幼虫分为3个龄期,均具有1对能够自由收缩的骨化口钩及头咽骨,其形态和大小在各龄幼虫之间存在明显差异。预蛹期是从幼虫到蛹蜕变的过渡时期,蛹的形态发育呈规律性变化,可分为隐头蛹期和显头蛹期2个阶段,显头蛹期又可细分为显头蛹初期、黄色眼期、红色眼期、鬃毛蛹期及预成虫期5个阶段。蛹壳颜色随蛹的发育呈不均衡加深趋势,在预蛹期、鬃毛蛹期和预成虫期变化尤为明显。根据蛹壳颜色的RGB值,可制作对应不同发育阶段的蛹壳颜色标准比色板,用于枸杞奈实蝇的发育生物学及防治技术研究。  相似文献   

19.
氟铃脲对韭菜迟眼蕈蚊不同虫态的致毒特点及毒力   总被引:1,自引:1,他引:0  
为明确氟铃脲对韭菜迟眼蕈蚊不同虫态的致毒特点及毒力,采用胃毒触杀联合毒力法、药液定量滴加法及药膜法分别对韭菜迟眼蕈蚊卵、幼虫、蛹、成虫进行了生物测定。结果表明,经氟铃脲处理的0.5~1、1.5~2和2.5~3日龄韭菜迟眼蕈蚊卵至孵化24 h后,LC_(50)依次为2.27、1.60和0.64 mg/L,对1.5~3日龄卵的毒力高于对0.5~1日龄卵;经氟铃脲处理的2日龄卵、2龄幼虫、4龄幼虫、1日龄和3日龄蛹至羽化时LC_(50)分别为0.06、0.30、0.34、24.05和27.42 mg/L,毒力程度随韭菜迟眼蕈蚊发育而逐步下降;对蛹和成虫毒力较低,100 mg/L氟铃脲染毒1、3日龄蛹的羽化率分别高于10%和20%;药膜法100、1 000 mg/L氟铃脲处理成虫24 h,校正死亡率低于20%。研究表明,氟铃脲对韭菜迟眼蕈蚊各虫态的生长发育均有不利影响,抑制卵的孵化并导致初孵幼虫存活率降低;对幼虫毒杀作用较慢,对蛹及成虫阶段毒力较低。  相似文献   

20.
Effects of the chitin synthesis inhibitor diflubenzuron (DFB) on the integument of 5th instarGalleria mellonella L. larvae were investigated. When larvae were fed with semi-artificial diets containing 250, 500 and 1000 ppm of the compound, DFB affected the integument. The affected larvae failed to ecdysis, their cuticle was ruptured, lost haemolymph and blackened. In treated larvae, cuticle deposition was disrupted and the cuticle thickness was decreased by ∼50% compared with the untreated control, particularly at day 3 1/2. However, statistically there was no significant difference among the three concentrations (P>0.05). This may indicate that all three concentrations are equally effective in decreasing level. DFB at 500 and 1000 ppm also affected the epidermal cells and caused the occurrence of vacuoles. http://www.phytoparasitica.org posting Dec. 16, 2003.  相似文献   

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