微波处理对赤拟谷盗各虫态的致死效果

分别采用微波功率160、320、480、640和800W处理裸露的和混合于小麦粉中的各虫态赤拟谷盗Tribolium castaneum(Herbst)的卵、幼虫、蛹和成虫。结果表明:对于裸露的赤拟谷盗用上述功率各处理5、10、15、20、25和30s时,800W、25s可完全致死卵,320W、30s可使幼虫和成虫完全致死;800W、20s可完全致死幼虫、蛹和成虫。对混合于小麦粉中的各虫态赤拟谷盗,当用上述功率各处理20s时,均不能完全致死各虫态;单独使用800W分别处理5、10、15、20和25s时,仅800W、25s可完全致死各虫态。微波处理对赤拟谷盗杀虫效果显著。     

微波处理对米象致死效果及小麦发芽率的影响

以米象为试虫,采用G80F20CN2L-B8(SO)型平板微波炉分别以160、320、480、640和800W微波功率处理不同虫态米象5、10、15、20、25和30s,研究米象致死情况;另外以上述微波功率处理20s,及800W分别处理5、10、15、20和25s,测定混合于小麦中米象成虫的致死情况.同时考察微波对小麦...     

电子束对磷化氢抗性品系和敏感品系赤拟谷盗成虫的辐照效应

辐照处理在防治储粮害虫方面有重要意义,为了缓解储粮害虫的磷化氢抗性问题,采用电子加速器对磷化氢抗性品系和敏感品系赤拟谷盗成虫进行辐照处理,研究了0~1 000Gy电子束辐照对两品系赤拟谷盗的生物效应,并分析了二者对辐照的敏感性。结果表明,电子束处理对赤拟谷盗的致死效应与辐照剂量有关,两品系赤拟谷盗的致死规律大致相同。两品系赤拟谷盗成虫对电子束的敏感性存在差异,但差异不显著。两品系赤拟谷盗成虫经200Gy剂量辐照后不能产生下一代,因此,200Gy可以作为辐照防治赤拟谷盗的参考剂量。本试验为电子束防治储粮害虫提供了技术支持,对促进辐照技术在绿色储粮中的应用提供理论基础。     

电子束辐照对印度谷螟发育的影响

利用0～2kGy电子束对不同虫态的印度谷螟进行辐照处理,研究电子束辐照对卵、幼虫、蛹发育及成虫繁殖力的影响。结果表明,印度谷螟对电子束辐照的敏感性高低依次为：卵〉幼虫〉蛹〉成虫。辐照后试虫的孵化率、化蛹率、羽化率及成虫的繁殖力均随着辐照剂量的升高而显著降低。分别经100、250和600Gy的剂量辐照的卵、幼虫、蛹不能羽...     

电子束处理对玉米象繁殖力的影响

本研究用电子加速器辐照处理玉米象成虫以及隐藏于小麦籽粒中的玉米象卵、幼虫和蛹 ,研究不同发育阶段玉米象辐照后的繁殖力。结果表明 ,高于 1 80Gy的辐照处理的成虫不能产生后代 ,辐照处理具有明显的当代延迟发育效果 ;高于 1 80Gy剂量辐照处理玉米象的蛹 ,羽化出的成虫不能产生下一代成虫 ;高于 90Gy以上的辐照处理玉米象的幼虫和卵 ,其羽化出的成虫不能产生下一代的成虫。 1 80Gy辐照可以作为阻止不同虫态玉米象的继续繁殖下一代的有效剂量。     

稻米仓储害虫的微波致死作用研究

以米象和锯谷盗为对象,研究微波作用对稻米害虫的致死作用,探索适宜的微波杀虫条件.结果表明微波条件对米象和锯谷盗成虫和虫卵致死率有极显著影响,对虫卵致死率的影响较成虫显著.在微波参数中,对米象致死率的影响以能量密度最大,其次是时间和能耗.在相同微波处理条件下,虫卵致死率大于成虫致死率.在较高能量密度下,米象致死的能耗较高,100%致死的能耗为6.0×10-5kW·h/g以上.在较低能量密度下,米象100%致死的能耗为3.0×10-5kW·h/g以上.较低能量密度和稍长时间的微波处理有利于害虫的杀灭,且能耗较低.     

绿线螟的生活史和生活习性研究初报

(1) 绿线螟在广西分布较广,有甘蔗绵蚜和竹笋蚜的地区均有发生。 (2) 在自然情况下绿线螟主要捕食甘蔗绵蚜、竹笋蚜和竹叶蚜,其他蚜群中尚未发现此虫。 (3) 经在室内饲养,此虫每年能发生11个世代,主要以蛹和老熟幼虫越冬。而在自然情况下,由于发生代次比较重迭,各虫态的发育起点温度较低,所以在田间冬春季除可见到蛹和老熟幼虫外,亦能见到成虫、卵和低龄幼虫。 (4) 绿线螟的卵散产于蚜群间,幼虫有吐丝结缀隧道潜居道内的习性,觅食时头胸部伸出隧道或爬出隧道把蚜虫拖至隧道内,然后啮食。当隧道附近无捕食对象时,则藉爬行或吐丝下垂迁移他处。其蛹多化于幼虫结缀的丝质隧道内或附近,化蛹前先吐丝结茧。常若干个聚集成堆。 (5) 绿线螟各虫态的发育情况经初步试验考查,卵的孵化和幼虫的活动取食、脱皮均在日平均温度13.5℃以上,羽化成虫9℃以上,成虫交配产卵16.5℃以上。     

电子束辐照对不同虫态的嗜卷书虱的辐照作用

采用HJIY-6M2高频单枪电子辐照加速器产生的电子束辐照处理嗜卷书虱,研究了0、25、50、100、200、300、400、500、1000Gy的剂量对混于饲料中的嗜卷书虱成虫、若虫和卵等不同虫态的影响。结果表明：嗜卷书虱各虫态对电子束辐照的敏感性由高至低依次为卵、若虫、成虫;经50Gy辐照后嗜卷书虱的卵不能孵化;成虫和若虫辐照后4周的半致死剂量LD50分别为186.1Gy和122.0Gy,经300 Gy辐照后的成虫和若虫分别在8周和6周内完全死亡。考虑到辐照不应对粮食营养品质和加工特性造成明显影响,300Gy剂量电子束可作为有效防治嗜卷书虱的参考剂量。     

微波处理对醉马草内生真菌的杀灭效果及发芽活力的影响

为探索构建禾草内生真菌不感染试验种群的方法,选用醉马草为材料,以150W和300W微波功率分别处理醉马草种子30、40、50和60s,研究不同微波处理强度下内生真菌的致死情况,同时考察微波对醉马草发芽活力的影响。结果表明,150W和300W处理40s以上,醉马草带菌率分别显著降到19.38%、5.22%以下,300W处理60s,醉马草内生真菌可完全致死;150W处理30、40s和300W处理30s后,醉马草的发芽率、发芽势、发芽指数和活力指数与对照(未经微波处理,CK)相比均无显著差异,其他处理下上述指标随处理强度的增加出现不同幅度的下降;150W或300W处理30s和40s的醉马草芽长、根长和生物量与CK无显著差异,其他处理下各指标均受到不同程度的抑制。因此,150W处理40s为剔除醉马草种传内生真菌的最佳方法。本研究为探索无毒醉马草作为饲料及优良牧草的选育提供了技术支持。     

玉米铁甲虫自然种群生命表的初步研究

玉米铁甲虫自然种群指数较高 ,I值为 30 .97。其全世代的平均种群累计死亡率为 64.0 7%。各虫态的自然死亡率差异极显著。越夏越冬成虫和 1～ 2龄幼虫的死亡率较高 ,分别为 38.1 %和 2 1 .7%。低龄幼虫的死亡原因主要为高温引起的自然死亡和天敌的捕食 ,而成虫则主要为白僵菌感染致死。玉米铁甲虫不同时期产下的卵 ,其幼虫自然存活率有较大差异 ,在产卵盛期和高峰期产下的卵 ,1～ 2龄幼虫存活率较高 ,而产卵盛末期产下的卵 ,则存活率较低     

Feeding deterrents from Aconitum episcopale roots against the red flour beetle, Tribolium castaneum

The screening for insecticidal principles from several Chinese medicinal herbs showed that the ethanol extract of Aconitum episcopale roots possessed significant feeding deterrence against the red flour beetle, Tribolium castaneum . From the ethanol extract, six feeding deterrents were isolated by bioassay-guided fractionation. The compounds were identified as chasmanine, crassicauline A, karacoline, sachaconitine, talatisamine, and yunaconitine from their spectroscopic data. Chasmanine, talatisamine, karacoline, and sachaconitine exhibited feeding deterrent activity against T. castaneum adults, with EC(50) values of 297.0, 342.8, 395.3, and 427.8 ppm, respectively. Yunaconitine and crassicauline A also possessed feeding deterrent activity against T. castaneum adults, with EC(50) values of 653.4 and 1134.5 ppm, respectively.     

Development of polyclonal antibodies for the detection of Tribolium castaneum contamination in wheat grain

Two polyclonal antibodies (Pab) were developed for the detection of Tribolium castaneum, which is a stored product pest of medical and economical importance. Selected Pab anti- T. castaneumK51 showed low cross-reactivity to other stored product arthropods but revealed high reactivity to T. destructor, T. confusum, and partly to Tenebrio molitor. PTA-ELISA was used to detect adults, larva, and feces of T. castaneum in artificially contaminated grain samples. Calibration methods were applied to determine detection limits for each type of contaminants. Anti- T.castaneumK51 enabled detection of T. castaneum in grain samples; detection limits reached 60 and 640 individuals/kg of grain for larvae and adults, respectively, and 4 mg of feces/kg of grain. After recalculation, the detection limit for feces enables detection of 30 larvae after 5 days of feeding in optimal conditions. The main advantage of the developed assay is traceability of T. castaneum contamination, especially when the adults and larvae are removed from contaminated material, based on the detection of feces that persist in the grain.     

Native fluorescence from juvenile stages of common food storage insects

Insect infestation of stored foods has significant economic and health consequences; the development of novel methods of detection thus presents considerable opportunities. The fluorescence from nine species of storage insects (beetles and moths) was studied; the juvenile stages of all nine species exhibited fluorescence under long-wave (365 nm) UV light; none of the adult insects emit fluorescence, so the fluorophore(s) might be a compound(s) associated with the unsclerotized cuticle. The spectra of larval stages of Ephestia kuehniella, Oryzaephilus surinamensis, Corcyra cepahlonica, Tribolium castaneum, and Tribolium confusum exhibited excitation maxima in the range from 345 to 350 nm and emission maxima in the range from 421 to 427 nm, suggesting that fluorescence arises from a common chromophore; similarities in fluorescence properties implicate one of the many pteridine ring-containing compounds (pterins) commonly found in insects. Larvae and even eggs were readily imaged on foods using fluorescence under 365-nm excitation. Fluorescence thus appears to be ubiquitous in immature food storage insects, and fluorescence detection may be useful as a general method to detect insects in foods and agricultural commodities during storage or processing.     

Repellent constituents of essential oil of Cymbopogon distans aerial parts against two stored-product insects

The screening for bioactive principles from several Chinese medicinal herbs showed that the essential oil of Cymbopogon distans aerial parts possessed strong repellency against the booklouse, Liposcelis bostrychophila , and the red flour beetle, Tribolium castaneum . A total of 36 components of the essential oil were identified by GC and GC-MS. trans-Geraniol (16.54%), (R)-citronellal (15.44%), (+)-citronellol (11.51%), and α-elemol (9.06%) were the main components of the essential oil followed by β-eudesmol (5.71%) and (+)-limonene (5.05%). From the essential oil, four monoterpenes were isolated by bioassay-guided fractionation. The compounds were identified as limonene, citronellol, citronellal, and trans-geraniol. Geraniol and citronellol were strongly repellent against the booklouse, L. bostrychophila, whereas citronellal and limonene exhibited weak repellency against the booklouse. Geraniol and citronellol exhibited comparable repellency against the booklouse relative to the positive control, DEET. Moreover, geraniol and citronellol exhibited stronger repellency against the red flour beetle than DEET, whereas the two other compounds showed the same level of repellency against the red flour beetle compared with DEET.     

X‐ray Image Analysis to Detect Infestations Caused by Insects in Grain

Insect infestations in stored wheat affect the chemical characteristics and baking qualities of wheat flour, and insect‐infested flours are unacceptable in the baking industry. The efficiency of the soft X‐ray method to detect infestations caused by Cryptolestes ferrugineus (Stephens), Tribolium castaneum (Herbst), Plodia interpunctella (Hübner), Sitophilus oryzae (L.), and Rhyzopertha dominica (F.) in wheat kernels was determined in this study. Wheat kernels infested by different insects were prepared by artificial implantation of insect eggs or by introducing adult insects in wheat samples. Kernels infested by different stages of the insects were X‐rayed until the adults emerged from the kernels. A total of 57 features using histogram groups, histogram and shape moments, and textural features were extracted from the X‐ray images and a linear‐function parametric classifier was used to identify the insect‐infested kernels. The parametric classifier identified more than 84% of infestations due to C. ferrugineus and T. castaneum larvae. The infestations by C. ferrugineus pupae‐adults and P. interpunctella larvae were identified with >96% accuracy. Kernels infested by different stages of S. oryzae and R. dominica larvae were identified with >98% accuracy. Using the Berlese funnel method, 67, 51, and 81% of first, second, and third instars of C. ferrugineus, respectively, were extracted in 6 hr. The same infested kernels were all categorized as infested by the parametric classifier. When kernels infested by different insects were pooled together, the parametric classifier correctly identified 74% of uninfested and 94% of infested kernels by the internal and external grain feeders. The 26% false positives identified from the independent test was caused by one sample infested by T. castaneum. When that sample was removed from the training set, the false positives were reduced to 16%, and 92.7% of infested kernels by different insects were correctly identified.     

电子束辐照对朱砂叶螨成螨存活和繁殖力的影响

以朱砂叶螨成螨为试材,研究了电子加速器辐照处理对成螨存活和繁殖的影响,以为叶螨的辐照检疫处理提供依据。叶螨成螨用0.4、0.8、1.2、1.6、2.0kGy辐照处理后于室温（28℃～30℃）自然光照下饲养,每天检测死亡率、产卵及其孵化情况。结果表明,成螨死亡率随剂量增加而增加,相关和回归分析显示,剂量与机率值（死亡率的...     

Response of Tribolium castaneum (Coleoptera, Tenebrionidae) to Salpichroa origanifolia Withanolides.

Biological effects on Tribolium castaneum larvae were evaluated for three withanolides isolated from Salpichroa origanifolia (Solanaceae), (20S,22R,24S,25S,26R)-5alpha,6alpha:22,26:24,25-triepoxy-26-hydroxy-17(13-->18)-abeo-ergosta-2,13,15,17-tetraen-1-one (salpichrolide A, 1), (20S,22R,24S,25S,26R)-22,26:24,25-diepoxy-5alpha,6beta,26-trihydroxy-17(13-->18)-abeo-ergosta-2,13,15,17-tetraen-1-one (salpichrolide C, 2), and (20S,22R,24S,25S,26R)-5alpha,6alpha:22,26:24,25-triepoxy-15,26-dihydroxy-17(13-->18)-abeo-ergosta-2,13,15,17-tetraen-1-one (salpichrolide G, 3), and for several chemically modified analogues. The compounds were incorporated into the larval diet at concentrations of 500 and 2000 ppm. Salpichrolide C (2) produced a significant delay in the development of neonate larvae to adults at the highest concentration (2000 ppm); development delays and lethal effects were produced by salpichrolides A (1) and G (3) at both concentrations assayed. The size of surviving adults was used as a criterion for assessing feedant deterrent effects; the results suggest that these compounds act as feeding inhibitors. Influence of chemical modifications in development delay was analyzed.     

Determining tolerance limits for restoration and phytoremediation with Spartina patens in crude oil-contaminated sediment in greenhouse

Oil spills may detrimentally damage sensitive coastal habitats, such as coastal wetlands. Successful restoration of oiled habitats primarily depends on the tolerance of vegetation transplants to oil. In this study, tolerance limits of the dominant coastal brackish marsh plant Spartina patens to South Louisiana crude (SLC) oil and its phytoremediation effectiveness on petroleum hydrocarbons in wetland sediments were investigated in the greenhouse environment. Spartina patens was transplanted into brackish marsh sediments contaminated with SLC oil at concentrations of 0, 40, 80, 160, 320, 640 and 800 mg SLC oil g^?1 dry sediment. High oil concentrations adversely affected plant stem density, aboveground biomass and belowground biomass even one year after transplantation. At the 320 mg g^?1 oil dosage, plant belowground biomass was significantly lower than the control although aboveground variables were not significantly different from the control. All plant parameters mentioned above at the 640 mg g^?1 oil dosage were less than 50% of the control. Spartina patens did not survive the 800 mg g^?1 oil dosage. The tolerance limit of S. patens to SLC was estimated about 320 mg oil g^?1 dry sediment. In addition, S. patens transplants enhanced oil degradation in the sediment; concentrations of residual total petroleum hydrocarbons (TPH) in the sediments vegetated by S. patens were significantly lower than those of un-vegetated sediments for both the surface and subsurface sediment at the 40 and 160 mg g^?1 SLC oil dosages. Decreases in the concentrations of polycyclic aromatic hydrocarbons (PAHs) further demonstrated the capacity of S. patens to phytoremediate residual oil; residual total targeted PAHs in the phytoremediation treatment were less than 20% of the un-vegetated treatment at the 40 mg g^?1 oil dosage. These results demonstrated the potential of phytoremediation with S. patens to simultaneously restore and remediate petroleum-contaminated coastal marsh habitats.     

抚顺煤矿西露天采场裸露岩石的污染潜势研究

利用净产酸量、净产酸势实验和连续化学浸取实验,研究了抚顺西露天采场裸露岩石的酸化潜势和重金属的表生活动性。结果表明,露天采场的裸露岩石在自然风化过程中会发生酸化,油母页岩属于中高度产酸范围,绿色泥岩、褐色泥岩处于低度产酸范围。原岩中Zn的潜在表生活动性最强,原岩中Zn含量的95%左右可被带出,进入表生环境;Cd,Cu,N i的潜在表生活动性有所差异,但原岩中Cd,Cu,N i含量的50%以上可被浸出进入表生环境;Pb的潜在表生活动性相对较小,只有20%的可被浸出进入表生环境。研究结果为预测煤矿开采环境污染的程度和防治提供了理论依据。