磷化氢熏蒸南洋臀纹粉蚧的效果及对火龙果品质的影响

本文在25℃条件下,利用磷化氢熏蒸南洋臀纹粉蚧以及越南进口红心、白心火龙果4 h,研究了磷化氢熏蒸处理对南洋臀纹粉蚧的杀灭效果以及对火龙果采后储藏品质的影响。耐受性比较试验结果表明,不同发育阶段的南洋臀纹粉蚧对磷化氢的耐受性为雌成虫>3龄若虫=2龄若虫>1龄若虫。毒力分析试验表明,使用1.70 mg/L磷化氢熏蒸雌成虫4 h可在95%置信区间下达到99.996 8%的死亡率。品质试验结果表明,使用0.55～2.21 mg/L磷化氢熏蒸处理对两种火龙果冷藏和货架期间的色泽、硬度、可溶性糖、酸度均无显著影响,但在熏蒸后短期内会提高呼吸强度,随着储存时间延长,呼吸强度恢复正常。这些结果显示,磷化氢熏蒸用于进口火龙果携带南洋臀纹粉蚧的检疫处理可达到理想效果,在25℃使用1.66～2.21 mg/L磷化氢熏蒸4 h可作为口岸检疫熏蒸的技术指标。     

溴甲烷熏蒸对山楂叶螨和桃蛀果蛾的毒力研究

苹果是我国的重要出口水果,山楂叶螨(Tetranychus viennensis Zacher)和桃蛀果蛾(Carposinasasakii Matsumura)在苹果主产区广泛分布,严重威胁我国苹果出口。为确定溴甲烷检疫处理山楂叶螨和桃蛀果蛾的技术指标,本文系统测定了一系列温度条件下溴甲烷对山楂叶螨成螨和富士苹果中桃蛀果蛾老熟幼虫的毒力,确定在5℃、10℃、15℃、20℃和25℃下,溴甲烷熏蒸山楂叶螨死亡率达到机率值9所需浓度时间乘积(CT值)分别为126.66、84.35、59.15、45.23和40.33mg.h/L,溴甲烷熏蒸桃蛀果蛾死亡率达到机率值9所需CT值分别为128.05、81.80、52.91、41.56和36.43mg.h/L。根据上述结果,建议采用10.0～14.9℃40g/m3 2h、15.0～19.9℃32g/m3 2h、20.0～24.9℃24g/m3 2h和大于25.0℃20g/m3 2h作为出口苹果的溴甲烷熏蒸处理技术指标。     

苹果蠹蛾磷化氢熏蒸技术研究

为了明确磷化氢熏蒸技术在苹果蠹蛾检疫处理中的应用可能,本文在常温和低温条件下分别使用不同剂量磷化氢对苹果中的苹果蠹蛾幼虫进行了熏蒸,并测定了不同条件磷化氢熏蒸对苹果品质的影响。结果表明,25℃下0.76mg/L磷化氢熏蒸96h虽然能完全杀灭苹果中的苹果蠹蛾幼虫,但是会产生药害;5℃下3.04mg/L磷化氢熏蒸264h可完全杀灭苹果中的苹果蠹蛾幼虫,且无药害;进一步的品质测定结果表明,5℃不同剂量磷化氢熏蒸264h的苹果在室温贮藏14d后,其失重率、糖度、酸度等品质指标均无明显变化。本文的结果表明,磷化氢低温熏蒸能在保持苹果品质的同时有效杀灭其中的苹果蠹蛾幼虫,因而在苹果的检疫处理中极具应用前景。     

低温条件下溴甲烷和硫酰氟对紫穗槐豆象的毒力

熏蒸环境温度为5℃、10℃的条件下,设计6～10个不同剂量分别开展溴甲烷和硫酰氟熏蒸杀灭紫穗槐种子携带紫穗槐豆象(Acanthoscelides pallidipennis)老熟幼虫的毒力试验,应用PoloPlus软件进行机率值分析的结果表明:在5℃条件下,预计紫穗槐豆象老熟幼虫达到99.9968%死亡率所要求的CT值(Lct_(99.9968))为溴甲烷2855.7g.h/m~3、硫酰氟3973.5g.h/m~3,熏蒸24h所需剂量为119.3g/m~3、158.7g/m~3;在10℃条件下,Lct_(99.9968)为溴甲烷2145.2g.h/m~3、硫酰氟1436.3g.h/m~3,熏蒸24h所需剂量为88.1g/m~3、59.0g/m~3。因此,随着熏蒸温度的提高,硫酰氟对紫穗槐豆象老熟幼虫的毒力作用增长明显,可作为进出口紫穗槐种子检疫处理的有效熏蒸剂,但熏蒸的环境温度须高于10℃。     

磷化氢和辐照复合处理对桔小实蝇的控制技术研究

桔小实蝇严重危害水果健康，是世界范围内的检疫性有害生物，通常在贸易前需进行检疫处理，由于单一处理技术均有局限性，复合处理技术成为检疫处理的趋势。本文开展了常温磷化氢熏蒸和辐照复合处理对桔小实蝇影响的研究，结果表明，25℃条件下，3龄幼虫为复合处理最耐受虫态，磷化氢熏蒸对辐照有增效作用，以ED_99.9968测算，0.278、0.862和1.443 g/m³磷化氢复合处理协同比率分别为2.21、1.98和1.95。0.862 g/m³磷化氢和60 Gy辐照复合处理南丰蜜桔后5℃储存21 d，维生素C含量增加，转至25℃储藏7 d后对南丰蜜桔硬度、可溶性糖、酸度、维生素C含量无显著影响。     

溴甲烷熏蒸对桃蛀果蛾的毒力作用

对溴甲烷熏蒸处理桃蛀果蛾结果进行机率值法分析,推算出在25℃温度条件下溴甲烷熏蒸处理1.5h和2h,达到桃蛀果蛾Carposina sasakii Matsumura幼虫死亡率99%的浓度时间乘积(CT值)分别为43.79g·h/m3和46.77 g·h/m3;15℃和10℃温度条件下熏蒸处理3h,达到桃蛀果蛾幼虫死亡率99%的溴甲烷浓度分别为50.84 g·h/m3和118.55 g·h/m3.研究表明,溴甲烷熏蒸对桃蛀果蛾幼虫的毒性作用随着溴甲烷熏蒸浓度的增加而增加,相同熏蒸剂浓度条件下,随着温度升高,溴甲烷熏蒸效果明显增加.     

玉米象各发育期对磷化氢的敏感性

结果表明,磷化氢对玉米象(Sitophilus zeamais Motschlscky)成虫有较强的毒力。玉米象各发育期对磷化氢的敏感性为:成虫>幼虫>卵>蛹,幼虫的耐药力与成虫接近,卵与蛹的耐药力几乎相同,卵、蛹的耐药力比成虫、幼虫约大2倍。因此,磷化氢熏蒸效果检查,不仅应对所有虫态检查,而且应保持储粮中较长时间没有活虫发生;在保持磷化氢有效浓度条件下,增加暴露时间能增效;CT值能全面检查磷化氢实仓熏蒸效果。未来用CT值代替剂量值,对进一步改善磷化氢熏蒸技术和提高药效,具有重要的现实意义。     

桔小实蝇热响应数学模型比较

利用恒温水浴槽对桔小实蝇的卵(16+2h)、1龄幼虫(48+2h)和非取食3龄老熟幼虫进行不同温度和时间组合的热水浸泡处理,分别利用热动力学模型、机率值模型、Logit模型和Log-Log模型对死亡率与处理时间的关系进行了分析比较,以明确最佳分析数学模型和热处理最耐受虫态。试验结果表明:热动力学模型为预测热处理致死时间的最佳数学模型;在44℃、45℃和46℃等温度条件下,桔小实蝇卵的耐热能力最强,其次为1龄幼虫,3龄幼虫耐热能力最差。该结果为利用热水浸泡处理等热处理技术对桔小实蝇进行检疫处理奠定了基础。     

氟铃脲对韭菜迟眼蕈蚊不同虫态的致毒特点及毒力

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。     

梨小食心虫过冷却点及结冰点测定

梨小食心虫Grapholita molesta(Busck)是世界性的果树害虫,以老熟幼虫越冬。由于果树新品种的选育以及气候变暖等原因,梨小食心虫寄主植物的适生区扩大。为了明确梨小食心虫的耐寒能力,即是否可以随着寄主植物种植范围的扩大而向寒冷地区发生迁移,本试验对不同虫态、不同龄期幼虫、不同性别的蛹与成虫以及来源于不同环境下的幼虫的过冷却点和结冰点进行测定,进而为判断梨小食心虫是否可以顺利越冬提供理论依据。结果表明:(1)梨小食心虫不同发育阶段的过冷却点及结冰点差异显著,结冰点和过冷却点表现为幼虫蛹成虫;(2)不同龄期幼虫的过冷却点及结冰点差异显著。5龄幼虫的过冷却点(-12.47±0.27)℃与结冰点(-8.21±0.41)℃最低,4龄幼虫的过冷却点(-9.23±0.38)℃与结冰点(-5.06±0.37)℃最高;(3)雌雄成虫与蛹的过冷却点及结冰点差异不显著;(4)不同环境下幼虫的过冷却点及结冰点差异显著,外采幼虫的过冷却点(-24.42±0.69)℃和结冰点(-10.21±0.71)℃最低,室内幼虫经冷驯化后过冷却点降低。因此,在越冬过程中梨小食心虫老熟幼虫的抗寒能力较强,提前经历低温环境可提高其抗寒能力。     

Influence of concentration, temperature and humidity on the toxicity of phosphine to the strongly phosphine-resistant psocid Liposcelis bostrychophila Badonnel (Psocoptera: Liposcelididae)

BACKGROUND: The psocid Liposcelis bostrychophila Badonnel, is a widespread, significant pest of stored commodities, has developed strong resistance to phosphine, the major grain disinfestant. The aim was to develop effective fumigation protocols to control this resistant pest. RESULTS: Time to population extinction of all life stages (TPE) in days was evaluated at a series of phosphine concentrations and temperatures at two relative humidities. Regression analysis showed that temperature, concentration and relative humidity all contributed significantly to describing TPE (P<0.001, R(2)=0.95), with temperature being the dominant variable, accounting for 74.4% of the variation. Irrespective of phosphine concentration, TPE was longer at lower temperatures and high humidity (70% RH) and shorter at higher temperatures and low humidity (55% RH). At any concentration of phosphine, a combination of higher temperature and lower humidity provides the shortest fumigation period to control resistant L. bostrychophila. For example, 19 and 11 days of fumigation are required at 15 degrees C and 70% RH at 0.1 and 1.0 mg L(-1) of phosphine respectively, whereas only 4 and 2 days are required at 35 degrees C and 55% RH for the same respective concentrations. CONCLUSIONS: The developed fumigation protocols will provide industry with flexibility in application of phosphine.     

Fumigant doses for the control of Trogoderma granarium1

The diapausing larvae of Trogoderma granarium are among the most tolerant of all storage pests to fumigation and effective dosage schedules are required. For this purpose, the toxicity of methyl bromide (MeBr), phosphine, methyl chloroform (MC), ethylene dichloride (EDC) and chlorobromomethane, and of mixtures of MeBr and MC, EDC and MC, and phosphine and MeBr, to diapausing larvae of the pest was examined at 15, 20 or 25°C. At 15 and 20°C the tolerance of larvae was high and very high dosages of MeBr or liquid fumigants, or long exposures to phosphine, were required for total kill. At 25°C larvae were more susceptible to phosphine but retained a high tolerance of other fumigants. A mixture of 2% MeBr in MC showed evidence of potentiation at 25°C and achieved control of larvae at moderate dosages.     

中国番木瓜出口蒸热杀虫处理研究

中国番木瓜出口蒸热杀虫处理研究,包括海南产日升番木瓜鲜果内橘小实蝇(Bactrocera dorsalis(Hendel))和瓜实蝇(B.cucurbitae(Coquillett))的卵和不同龄期幼虫忍耐力比较试验,番木瓜小规模、大规模蒸热杀虫试验,以及蒸热处理对番木瓜品质的影响等。结果显示,番木瓜鲜果内2种实蝇的耐热力由强至弱的发育期依次为3龄幼虫→2龄幼虫→1龄幼虫→卵;其中,橘小实蝇的耐热力大于瓜实蝇,以橘小实蝇3龄幼虫的耐热力最强;完全杀灭番木瓜鲜果内2种实蝇的卵和幼虫(死亡率100%)的蒸热处理条件是番木瓜在蒸热室相对湿度60%～70%、约经3～3.5 h果心温度缓慢升温至41℃时,使用饱和热蒸汽(相对湿度90%～95%)25 min内快速升温至47℃后水淋冷却至常温。国产番木瓜小规模、大规模蒸热杀虫处理进一步确认和验证,在上述蒸热处理条件下,鲜果内总计数量分别为10 000头和32 000头最具耐热力的供试橘小实蝇3龄幼虫全部被杀灭,超过美国采用的机率9(Probit 9)检疫安全水平(99.9968%死亡率),完全可确保检疫安全。同时,蒸热处理后第7天的番木瓜鲜果与对照鲜果品质(包括色泽、口感,以及还原糖、蔗糖、总糖、总酸、维生素C和可溶性固形物的含量)的比较测定数据表明,除维生素C的含量有微量损失外,基本可保持鲜果的品质不变。     

Fumigation of citrus fruit with ethylene dibromide: Desorption of residues and ethylene evolution

The desorption of ethylene dibromide (EDB) residues from fumigated Shamouti citrus fruits is fitted by a single exponential equation at 17 and 22°C, and by an equation with a double exponential term at 5°C. Establishing the rate constant enables calculation of the initial concentration of EDB residues in the peel, thereby obtaining information on conditions during fumigation and on the possibility of peel injury development in the fumigated fruit. Healthy, harvested Shamouti citrus fruit evolve ethylene at a low rate, which is increased by EDB fumigation. Fumigated fruit in which EDB caused peel injury evolved ethylene at a higher rate than fumigated fruit in which peel injuries did not develop. This information could be used for predicting peel injuries and in studies aimed at a better understanding of the processes leading to the development of peel injuries in fumigated citrus fruit.     

溴虫氟苯双酰胺对小菜蛾的毒力及相关酶活性的影响

溴虫氟苯双酰胺是一种全新的双酰胺类杀虫剂,主要用于防治鳞翅目、鞘翅目、白蚁以及蚊蝇等害虫。为了明确溴虫氟苯双酰胺对小菜蛾的生物活性及解毒酶活性的影响,本研究选择氯虫苯甲酰胺为对照药剂,采用叶片药膜法测定了溴虫氟苯双酰胺对小菜蛾的生物活性,并测定了亚致死剂量(LC20、LC40)的溴虫氟苯双酰胺和氯虫苯甲酰胺对小菜蛾多功能氧化酶、谷胱甘肽S-转移酶和羧酸酯酶活性的影响。结果表明,溴虫氟苯双酰胺与氯虫苯甲酰胺对小菜蛾的生物活性相当,两者对小菜蛾的LC50分别为0.042和0.056μg/mL。与氯虫苯甲酰胺相似,亚致死剂量的溴虫氟苯双酰胺能够诱导小菜蛾体内羧酸酯酶活性升高,但溴虫氟苯双酰胺对多功能氧化酶和谷胱甘肽S-转移酶活性没有显著影响。     

应用天然植物产品川楝素防治菜青虫试验

川楝素是从川楝树分离得到的一种四环三萜类化合物。它对菜青虫有较强的拒食及毒杀作用,因此施药后能很快地得到保护叶片的效果,且在田间也有较长的残效期。经试验,川楝素对天敌凤蝶金小蜂及蚜茧蜂安全。     

The relation between phosphine sorption and terminal gas concentrations in successful fumigation of food commodities

Owing to increased tolerance and the development of resistance in stored product insects to the fumigant phosphine, in recent years there has been a shift in the target terminal concentration from 100 ppm (100 mL m(-3)) to a higher level of 1000 ppm to achieve 100% insect mortality in 7 day commodity treatments. Therefore, there is a need to investigate whether the revised target concentration could be achieved for food commodities fumigated with phosphine at the standard dose of 2 g m(-3) for 7 days under airtight conditions at > or = 25 degrees C. When different types of food commodity (total 74) were fumigated (300 g per replicate) with phosphine at 2 g m(-3) for 7 days, the terminal gas concentrations in the free space of the commodities varied from 0 to > 2000 ppm. In chambers containing no substrate, a 1417 ppm concentration was recorded. Paddy rice, most of the oilseeds, shelled tree nuts, butter beans, cardamom, green gram splits, coriander powder, rice bran and cocoa powder were more sorptive (> or =60%), such that the target concentration of 1000 ppm was not achieved at the end of 7 days. For these commodities, increased doses of 3-6 g m(-3) were required to attain 1000 ppm. In-shell almonds, green cardamom, in-shell peanuts, leaf tea, tamarind pulp and sunflower seeds were exceptionally sorptive (>90%), so that 0, 41, 112, 168, 203 and 217 ppm respectively were noted at the end of 7 days; the dose must exceed 6 g m(-3) for effective fumigation of these commodities.     

桃小食心虫经济阈值的研究

［目的］ 研究苹果不同品种桃小食心虫危害的经济阈值,为合理制定苹果桃小食心虫的防治策略提供依据。［方法］ 选取卵果率作为防治指标,对卵果率和苹果产量及产量损失的统计关系进行分析。［结果］ 产量损失率(y)与卵果率(x)呈正相关,其线性回归式分别为：‘津青’,y=0.650 8x+2.091 6(R=0.994 06*);‘黄元帅’,y=2.099 5x+0.984 5(R=0.986 0*);‘乔纳金’,y=0.589 1x+2.373 3(R=0.910 9*)。［结论］ 应综合有关因素确定不同品种苹果不同产量水平的经济允许产量损失率,制定出相应的经济阈值。