不同温度下苜蓿叶象甲实验种群生命表研究

为了研究温度对苜蓿叶象甲(Hypera postica Gyllenhal)种群动态的影响,组建了其在18℃,22℃,26℃,30℃下的实验种群生命表。结果表明:18~30℃范围内,苜蓿叶象甲发育速率随温度的升高而加快,并符合Logistic模型。苜蓿叶象甲的卵、幼虫、前蛹、蛹及产卵前期成虫的发育起点温度分别为8.82,10.47,8.60,11.91和9.53℃,有效积温分别为99.38,143.80,48.63,55.71和140.15℃·d,完成整个世代需要的有效积温为480.96℃·d。实验温度条件下其生存曲线呈A型,26℃时世代存活率及单雌产卵量最高,分别为47.6%,847.7粒。苜蓿叶象甲世代存活率(S)、种群趋势指数(I)与温度(t)间均呈抛物线关系,其生长发育繁殖的最适温区为25~27℃。     

意大利蝗对温度耐受力的初探

对意大利蝗(Calliptamus italicus)各虫态过冷却点、成虫耐高温能力和体温调节行为进行测定,并初步探究意大利蝗对温度的耐受力。结果表明,意大利蝗各虫态的过冷却点均服从正态分布;各虫态的过冷却点及冰点有所差异,其中越冬卵的过冷却点及冰点最低(P0.05),3龄蝗蝻过冷却点最高(P0.05),其他各龄蝗蝻及成虫雌雄之间过冷却点均无显著差异(P0.05)。环境温度为41℃时,雌成虫和雄成虫的LT50、LT90均最长,分别为623.83、1 604.98h,459.52、1 181.97h;成虫的体温与环境温度均呈极显著的线性关系(P0.01);当环境温度以0.5℃·min-1速率上升时,成虫的体温升高速率在0.30~0.36℃·min-1,其中雄成虫体温升高速率(0.36℃·min-1)显著高于雌成虫体(0.30℃·min-1)。     

桑螟幼虫的越冬死亡率及过冷却点的研究

本文运用NTC-TD热敏电阻法测定了桑螟越冬幼虫的过冷却点、冰点。统计了桑螟幼虫的越冬死亡率。结果表明：前年9月到翌年4月间，过冷却点和冰点随温度降低而降低，随温度的升高而升高，并且均呈现一定的滞后性，但两者变化幅度不同，过冷却点的变化幅度显著大于冰点的变化幅度。4个处理中，越冬幼虫死亡率以枯枝落叶中为最高，室内最低。外界温度和过冷却点的变化，可能是引起桑螟死亡的重要原因。     

柑桔云翅粉虱的发生初报

1997年开始 ,在广西恭城县莲花镇红岩屯个别果园发现柑桔云翅粉虱为害柑桔及恭城月柿。 2 0 0 0年波及全县 (个别山区乡除外 ) ,主要为害恭城月柿 ,其寄主还有柑桔类、四季青、黄荆柴等。该虫繁殖快 ,扩散迅速 ,危害严重 ,已成为恭城月柿生产上的一种最主要的害虫。云翅粉虱属同翅目 ,粉虱科 ,以末龄若虫越冬 ,翌年 3月开始羽化成虫 ,虫体为浅褐色 ,翅白色 ,成虫寿命约为 5～ 7天 ,主要产卵于叶背。幼虫初孵化期为浅黄色 ,随虫龄增长而变深。幼虫吸食叶液 ,为害树体 ,幼虫期约为 15～ 2 0天。识别该虫主要依据是蛹壳的特征 ,蛹壳为白色、近…     

桦南县柞褐叶螟生物学特性初报

2012年至2013年，在黑龙江省桦南县大八浪林场场部南山42林班27小班的柞树林区，柞褐叶螟大发生，该虫为暴发性食叶害虫，一年两代，第一代成虫见于6、7月份，第二代成虫见于8、9月份，成虫有褐色型和棕色型两种，卵产在叶面，呈一字形双行排列，幼虫共5龄，在被害寄主残叶中做薄茧化蛹，以幼虫越冬。     

桦南县柞褐叶螟生物学特性初报

2012年至2013年,在黑龙江省桦南县大八浪林场场部南山42林班27小班的柞树林区,柞褐叶螟大发生,该虫为暴发性食叶害虫,一年两代,第一代成虫见于6、7月份,第二代成虫见于8、9月份,成虫有褐色型和棕色型两种,卵产在叶面,呈一字形双行排列,幼虫共5龄,在被害寄主残叶中做薄茧化蛹,以幼虫越冬。     

黔西北山区核桃果象甲发生规律调查及防治试验

摘要：核桃果象甲(Alcidodes jucundus)成为黔西北山区核桃的主要害虫，调查发现一年发生１代，成虫翌年４月下旬出蛰取食，５月上旬始产卵，中下旬为产卵盛期，幼虫蛀果为害，６月中下旬受害果大量脱落，7月老熟幼虫化蛹，成虫羽化，8月上中旬成虫上树危害芽苞、嫩梢。随着海拔的上升，为害有下降趋势， 海拔1450m地带山区乔化树株产量损失4.9-5.3kg。5月上旬产卵孵化初期施药防治幼虫为害效果显著，同时应配合捡拾落果杀灭幼虫、蛹和捕捉成虫方法进行防治 .     

桑褶翅尺蛾在苹果树上的发生与防治技术

桑褶翅尺蛾又名桑刺尺蛾、桑褶尺蠖,属鳞翅目,尺蠖蛾科。以幼虫食害花芽、叶片和幼果。３～４龄幼虫食量最大,严重时可将叶片全部吃完,幼果吃成缺刻状,造成大量脱落,削弱村势及降低产量。已在部分地区苹果上大面积发生造成严重损失。 桑褶翅尺蛾在河北邢台一年发生１代。以蛹在果园中石块下、杂草间及树干基部土下紧贴树皮的茧内越冬。３月中旬开始羽化,４月中旬苹果萌芽时始见初孵幼虫,５月中下旬老熟幼虫开始结茧化蛹。成虫羽化与降水量关系很大,雨后第２天羽化成虫数量猛增。成虫有假死性,寿命只有５～９天。雄成虫有很强的趋…     

8种杀虫剂对苜蓿叶象及条纹根瘤象的毒力测定

采用喷雾法对8种药剂对苜蓿叶象及条纹根瘤象进行室内毒力测定,结果表明：2%噻虫啉微囊粉剂对苜蓿叶象四龄幼虫的活性较高,其 LC50为107.408 mg/L,4.5%高效氯氰菊酯微乳剂的活性最低,其 LC50为549.342 mg/L;8种杀虫剂对三龄幼虫的 LC50为140.176-453.784 mg/L。40%毒死蜱乳油对条纹根瘤象成虫活性较高,其 LC50为71.017 mg/L,其次为2%噻虫啉微囊粉剂,其 LC50为80.157mg/L。     

紫斑螽斯越冬卵过冷却现象研究

采用温差热电偶法测定了紫斑螽斯越冬卵的过冷却点和结冰点,观察了越冬卵的过冷却现象。结果表明,紫斑螽斯的过冷却点为-29.6℃,结冰点为-14.1℃,在室内温度为-9℃,低温环境温度为-33.2℃条件下,紫斑螽斯过冷却点和结冰点分别出现在第4min49s和5min21s。同时,就温度因素,依据过冷却点和结冰点,讨论分析了紫斑螽斯分布的适合性。     

美国白蛾Hyphantria cunea(Drury)越冬蛹的抗寒性研究

基于为控制美国白蛾Hyphantria cunea(Drury)对桑树和柞树的的危害提供理论依据,测定了美国白蛾越冬蛹不同时期的过冷却点和含水量。结果显示,越冬蛹的过冷却点以2月份最低,为(-27.07±0.38)℃,11、12月份最高,分别为(-20.38±2.26)℃和(-22.99±4.03)℃;含水量以11、3月最高,分别为67.03%和65.07%,1月份开始下降,2月份降至最低30.76%,3月份又增加到45.95%。含水量的变化与过冷却点的变化趋势相似,含水量的下降降低了越冬蛹的过冷却点,可增强其抗寒能力。     

In vitro acaricidal effect of plant extract of neem seed oil (Azadirachta indica) on egg, immature, and adult stages of Hyalomma anatolicum excavatum (Ixodoidea: Ixodidae)

Effects of the plant extract of neem seed (Azadirachta indica) on eggs, immature, and adult stages of Hyalomma anatolicum excavatum was studied at concentrations of 1.6, 3.2, 6.4, and 12.8%. The extract was found to have a significant effect on the hatching rate of eggs. It significantly increased the hatching rate during the first 7 days post-treatment (DPT) giving incompletely developed and dead larvae; however, it cause hatching failure at DPT 15. Neem Azal F induced a significant increased in mortality rates of newly hatched larvae, unfed larvae, and unfed adults reaching 100% on 15th, 3rd, and 15th DPT, respectively. The mortality rates increased with the extract concentrations. Although, it had no significant effect on the moulting rates of fed nymphs, it caused malformation or deformities in 4% of adults moulted. It was concluded that the concentration of Neem Azal F which may be used for commercial control of this tick species were 1.6 and 3.2%.     

Laboratory investigation of the chemical disinfection against different developmental stages of the housefly (Musca domestica Linnaeus, 1758)

Possibilities for disinfection of the developmental stages from the housefly (Musca domestica) were investigated under laboratory conditions. The developmental stages (eggs, larvae I, II, III, pupae and adults) were sprayed with solutions of disinfectants on the basis of p-chlorine-m-cresol and o-phenylphenol at different concentrations (0.025%-3%). The effectiveness of both disinfectants was established by determining the emergence rate of eggs and pupae and of the live evidence of larvae and adults. Transmission electron microscopic investigations of the cover of the eggs revealed the bactericidal effect of both disinfectants. These results show the necessity of extending its use also to noxious arthropods.     

The effect of ivermectin treatment against inhibited early third stage, late third stage and fourth stage larvae and adult stages of the cyathostomes in Shetland ponies and spontaneous expulsion of these helminths.

A controlled and critical test on the efficacy of ivermectin against larval and adult stages of the cyathostomes was carried out in six yearling castrated male Shetland ponies. The ponies grazed together as one group from 3 May to 4 October 1990, after which they were housed. Three ponies were treated with ivermectin on 29 October while the others served as controls. The shedding of helminths in the faeces was followed in all ponies until necropsy on 14 November. Comparison of worm counts of both groups before and after necropsy showed no evidence for an effect of ivermectin against inhibited early third stage larvae (EL3) and mucosal late third stage (LL3) and fourth stage larvae (L4). However, a high, but not 100%, efficacy was observed against adults and lumenal L4. A remarkable observation was the high incidence of spontaneous expulsion of L4 and adult populations of some species in two of the untreated ponies.     

桑粉虱研究初报

室内饲养桑粉虱，感温20℃，卵期平均7．6d；在18.38～19．59℃，幼虫期1龄平均6.2d，2龄3.1d，3龄4．0d，4龄及蛹期8.5d。室内饲养结合田间实验，桑粉虱成虫的单雌产卵量平均为21粒。成虫寿命室内为2～6d，室外有长于8d的。以蛹在落叶、土表和杂草中越冬。     

0.4% Dimeticone spray,a novel physically acting household treatment for control of cat fleas

The cat flea, Ctenocephalides felis, is the most important ectoparasite of cats and dogs worldwide as a cause of irritation and health problems. Most products to control these pests in the household environment rely upon a combination of neurotoxic insecticides and insect growth regulators to inhibit development of flea eggs and larvae into adults. However, some of these are affected by problems of insecticide resistance as well as public concerns about their potential for toxicity in domestic use. Heavy synthetic oils, like the siloxane dimeticone, are currently widely used to treat human ectoparasite infestations, acting by a physical mode of action, and have been used in a variety of presentations for killing all life stages of fleas. We have investigated the activity of low concentrations of high molecular weight dimeticone in a volatile silicone base for ability to immobilise flea life stages without asphyxiating them. We found that cat flea adults and larvae were immobilised by a surface film of dimeticone that inhibited movement of cuticular joints, apparently forming an effective sticky trap. When cocoons were treated the fleas continued to develop within the pupae but failed to emerge. An aerosol spray incorporating 0.4% concentration of dimeticone, for use as a residual household treatment, showed no significant difference in knock down capability compared with that of a widely used pyriproxifen/permethrin spray in a repeat challenge test, with effects persisting to inhibit adult flea emergence in the test arena area for more than 3 weeks after application.     

Studies on the critical water mass, rehydration capability and potential, acute chill tolerance and supercooling point of Argas (Persicargas) walkerae (Acari: Argasidae)

The critical water mass, defined as the water mass remaining in a dehydrated tick in the non-ambulatory state, differed only slightly between light and heavy mass groups of Argas walkerae and averaged 23.6% and 23.2%, respectively, in males and 28.4% and 28.0%, respectively, in females. All ticks survived dehydration to 50%, 75% or 100% of their critical water mass, and 95% of them rehydrated during their subsequent incubation at 95% relative humidity (RH) and 28 degrees C for 14 days and regained their ambulatory status. Unfed adults were able to balance water loss frequently over a period of several months. When ticks were repeatedly dehydrated at 0% RH for 14 days, females and males suffered 50% mortality after 16 and 19 cycles of de- and rehydration, respectively, over a period of 278 days and 337 days, respectively. Water itself was not attractive to either dehydrated or non-dehydrated ticks and drinking was not observed. After submergence in water for 3 days, most of the dehydrated adult ticks gained mass. Judged by 50% mortality, larvae tolerated short-term extreme chilling to -24 degrees C, nymphs 1 to -22 degrees C, nymphs II to -20 degrees C, females and males to -19 degrees C. None survived tissue freezing. At a chilling rate of 0.3 degrees C/min, mean supercooling points (SCP) ranged from -25.9 degrees C in eggs to -16.5 degrees C in unfed females. The SCP of all other stages was significantly higher than that of eggs. Mean SCPs of unfed adult ticks dehydrated to 50% or 75% of their critical water mass were significantly lower than that of fully hydrated ticks. The SCPs of ticks acclimated by several weeks exposure to 0 degrees C or to 38 degrees C were significantly lower than those of adult ticks kept constantly at 28 degrees C.     

Photodynamic action of erythrosin B as a toxic mechanism for infective larvae of bovine gastrointestinal nematodes

The effect of erythrosin B on adults and 3rd stage larvae of gastrointestinal nematodes of cattle was studied by treating calves per os with 20 mg kg-1, 40 mg kg-1, and 60 mg kg-1 of the dye daily for 21 days and monitoring its effect. Erythrosin B had no detectable effect on adult nematode fecundity or viability. Data collected did indicate, however, that erythrosin B produced a consistent toxic effect on 3rd stage larvae after exposure to fluorescent light. This toxic effect was dependent upon dosage of erythrosin B administered, time of light exposure and, to a much lesser extent, the length of time the larvae were left in culture in the presence of the dye.     

催青温度对家蚕二化性品种丙酮酸脱氢酶激酶基因(BmPDK)表达的影响

丙酮酸脱氢酶激酶(PDK)在生物体的新陈代谢中具有重要的生理功能。为了探讨家蚕(Bombyx mori)PDK基因的表达特性,用蛾区半分法将二化性家蚕品种的活化越年卵(丙2期)分别以常温(25℃)光照和低温(15℃)黑暗催青,通过实时荧光定量PCR技术检测分析2种温度催青处理后家蚕不同发育阶段和不同组织的BmPDK表达水平。常温光照催青区BmP-DK的表达水平表现出发育时期和组织差异:胚胎发育阶段BmPDK在己4期的表达水平最高,其次是戊2、己3和己5期;幼虫发育阶段BmPDK的表达水平在蚁蚕期极显著高于其它龄期,5龄期在卵巢和精巢的表达水平高于其它组织;蛹期BmPDK的表达水平比其它发育时期低;成虫期的表达水平与胚胎发育末期相当,其中雌蛾的脂肪体和卵巢中BmPDK的表达水平较高。推测BmPDK在家蚕胚胎发育末期及产卵过程中有重要作用。催青温度影响BmPDK在家蚕各发育时期及卵巢组织中的表达水平:胚胎发育阶段戊2期BmPDK的表达水平为常温催青区显著高于低温催青区,己3～己5期常温催青区BmPDK的表达呈低-高-低的趋势,而低温催青区则呈上升趋势;蚁蚕期BmPDK表达水平为低温催青区极显著低于常温催青区;蛹期和成虫期卵巢中,常温催青区BmPDK的表达水平极显著高于低温催青区。催青温度对二化性家蚕BmPDK的表达的影响主要出现在胚胎戊2期、胚胎己3期～蚁蚕期、蛹期、成虫期。     

粤北桑芽瘿蚊的世代及生活史和习性调查

调查表明 :粤北桑芽瘿蚊 1年发生 10代 ,世代重叠现象明显 ,从 5月初一直为害至 11月 ,11月底以结成囊包休眠体的老熟幼虫在桑田土表层中进行越冬 ,但从 6月下旬开始各代均有部分老熟幼虫结成囊包休眠体在桑田土表层中进行越夏、越冬 ;全年以第 1～ 3代发生量最大。各虫态历期 :卵 1～ 2d ,幼虫 5～ 12d ,蛹 5～ 12d ,成虫 1～3d ,完成 1个世代需 15～ 2 6d ,大多要 2 0d左右。雌雄成虫比例 (性比 )约为 2 5 1∶1。