湖口县梨剑纹夜蛾为害棉花

棉小造桥虫为偶发性害虫,猖獗年分可将大量棉叶吃尽,影响产量与品质。 一、湿度与降雨量:据室内恒温下测定,相对湿度97％与75％时,卵的孵化率分别是77.1％、78.4％;幼虫长成,化蛹率88％、86.4％;蛹的羽化率91.7％、86.1％;雌蛾产卵量249粒、312粒,均比54％、32％、二种湿度为高。说明该虫适宜于较湿的环境条件。6月下旬至9月上旬降雨量大,雨日多,湿度大时,该虫发生严重。尤以6月下     

水分对复苏后亚洲玉米螟越冬代幼虫化蛹的影响

作者对复苏后玉米螟的饮水作用研究表明,玉米螟幼虫摄取水分的过程是通过口器主动饮水,饮水后促进虫体重量增加、死亡率降低和提高化蛹率。在一定范围内,饮水量取决于饮水时间的长短。死亡率（Ｄ）和化蛹率（Ｐ）与饮水时间（ｔ）的关系为：Ｄ＝７０．５１８０ｔ＾－０．３５７６（ｒ＝０．９１８８＾＊＊）和Ｐ＝３．５８９９＋１．０５１０ｌｇｔ（ｒ＝０．９５３５＾＊＊）。饮水量（Ｘ）与化蛹率的关系：Ｐ＝０．８４０８Ｘ＾     

空气湿度对灰霉菌侵染番茄叶片组织结构分析及抗氧化系统的影响

空气湿度对番茄灰霉病的发生有显著性影响。为了探明空气湿度对灰霉菌侵染番茄叶片的过程与机理,本研究以‘金棚14-6’番茄为材料,观察分析了高空气相对湿度(80%～95%)和低空气相对湿度(65%～80%)对灰霉菌侵染番茄叶片表型变化、细胞学差异、形态结构变化、活性氧含量和抗氧化酶的影响。结果表明：高湿接种60 h大量芽管伸长出现在叶片下表皮细胞并分化菌丝,叶肉细胞间隙分布了大量的菌丝并伴随病斑出现,灰霉菌在60 h完成侵染;低湿接种108 h芽管伸长出现在叶片下表皮并分化菌丝,叶肉细胞间隙有少量菌丝分布,没有明显病斑出现。随着灰霉菌的侵染,低湿与高湿相比栅栏组织和海绵组织结构从整齐紧密变为排列疏松的时间滞后;高湿和低湿处理的叶片厚度、栅栏组织和海绵组织厚度均呈先上升后下降的变化趋势,侵染后期低湿处理的叶片组织结构厚度显著高于高湿。随着接菌时间延长,高湿和低湿的活性氧含量和抗氧化酶活性处于相对活跃的调整、适应的变化过程,大致呈先上升后下降趋势,而对照和接菌相比无显著差异,变化趋势维持在基本的振幅上。研究显示灰霉菌发生的环境条件：湿度80%～95%和侵染完成时间60 h,即控制高空气湿度的持...     

利用人工卵繁殖玉米螟赤眼蜂

以柞蚕蛹血淋巴４０％,１０％的麦乳精溶液３０％,鸡蛋黄２０％,Ｎ‘Ｓ溶液１０％为培养液,聚丙烯薄膜为卵制成人工卵。除以８％聚乙烯醇溶液作为引诱剂,繁殖玉米螟赤眼蜂。处理组人工寄生率、化蛹卵率、羽化卵率和寄生效率分别为６１．８５％、７８．１６％、８５．７９％和０．５４８８,则对照组仅分别为２８．１８％、１８．５６％、２３．６０％、０．０１２３,产卵引诱物质能明显提高玉米螟赤眼蜂在人工卵上的寄生作用。     

温湿度对桃小食心虫蛹与成虫的影响

为探索温湿度对桃小食心虫(Carposina sasakii Matsumura)蛹与成虫的影响,在室内温度为20、23、26和29(±1)℃,土壤含水量5%、8%、11%、14%、17%条件下和相对湿度50%、60%、70%、80%、90%(±5%)条件下分别测定了桃小食心虫蛹的历期和羽化率以及雌虫的受精率、产卵量和寿命。结果表明:桃小食心虫蛹的历期随温度的升高而缩短,而羽化率则不受温度和土壤含水量的影响;在温度20~29℃、土壤含水量5%~17%的范围内,桃小食心虫蛹均能正常羽化;中温高湿是成虫交配和产卵的适宜条件,高温低湿不适宜成虫交尾;高温条件下雌虫寿命显著缩短且低湿条件可加剧高温对成虫寿命的影响。     

温湿度对草地螟阿格姬蜂飞行能源物质利用的影响

利用微小昆虫飞行磨对5日龄草地螟阿格姬蜂进行不同温湿度条件下吊飞处理后,测试其体内糖原,甘油三酯含量的变化。结果表明,温、湿度对成虫飞行能源物质消耗有显著影响。在最适温度20~24℃、湿度55%条件下飞行时,草地螟阿格姬蜂主要飞行能源物质(甘油三酯和糖原)消耗最少,并且其飞行单位距离所需的甘油三酯也最少,即能源利用效率最高,不适温、湿度条件下甘油三酯的消耗增多,但温、湿度对成虫飞行能源物质消耗会因性别的不同而异。高温下飞行时,雌虫比雄虫消耗的能源物质多;在高湿或低湿条件下,同样也是雌虫比雄虫消耗的多。     

5%锐劲特拌种剂对旱育秧稻瘿蚊,三化螟防效的试验

在室内人工接虫及田间自然虫源条件下,以５％锐劲特拌种剂拦种旱播,每公斤种子拌以原药５、１０、１５、２０ｍｌ,对稻瘿蚊的防效达到８９％～１００％,对三化螟防效达到９４％～１００％,药剂的持效期可达２０～３０ｄ。     

大蒜绿圆跳虫的发生规律与防治

绿圆跳虫是陕西省一种严重危害大蒜的新害虫。３月下旬至５月初虫口数量最多，田间最高有虫株率平均４０％，虫株平均有虫８头以上。虫口增长的适温为１５～２０℃，适宜相对湿度为５０％～７５％，高温高湿时虫口数量剧降     

菜豆象的生物学及防治初步研究

菜豆象Ａｃａｎｔｈｏｓｃｅｌｉｄｅｓｏｂｔｅｃｔｕｓ（Ｓａｙ）在碗町室内自然条件下每年发生７代，以老熟幼虫在豆粒内越冬。幼虫４龄，初孵幼虫的蛀入率与温、湿度有密切关系。成虫产卵对寄主豆粒有明显的选择性。寄主范围较广。室内危害深度可达１ｍ以上，为害造成的损失严重。经高温５５℃处理６０分钟、６０℃处理２０分钟、低温－１５Ｃ处理１８０分钟各虫态１００％死亡。于河沙和草木灰压盖能有效阻止成虫钻入产卵和幼虫钻入危害。草木灰拌种能有效杀死初孵幼虫。花生油、菜油和香茅油滴浸卵死亡率分别是５０．７％４４．７％和１００％；３种植物油拌种防虫的效果显著，其中以花生油的防效最佳，拌种５００天后再接虫幼虫，仍未能蛀入，且对豆类的发芽率无影响。磷化氢熏蒸，温度２６℃～２７℃、４８小时，卵、幼虫和蛹１００％死亡的浓度分别是０．７７２１ｍｇ／Ｌ、０．７６１５ｍｇ／Ｌ和１．３３４０ｍｇ／Ｌ；温度１５℃～２０℃、７２小时，卵、幼虫和蛹１００％死亡的浓度分别是０．４９８４ｍｇ／Ｌ、０．３８６０ｍｇ／Ｌ和０．７６８０ｍｇ／Ｌ。     

豚草卷蛾对温湿度的适应性

对豚草卷蛾温湿度的适应性作了研究。结果表明,豚草卷蛾的过冷却点在-6 84～-15 84℃之间,随入冬气温的逐渐降低而降低,越冬滞育幼虫的含水量明显低于生长期幼虫。在35℃高温条件下,发育期虫态的化蛹率为27.3%,其存活率、孵化率、正常羽化率和成虫的交配率在50 0%～68 4%之间,产卵量仅为87 6粒/♀,表明35℃已是豚草卷蛾生长发育的限制温度。在高温处理下各虫态50%个体死亡所需时间依次为成虫>幼虫>卵>蛹,以蛹的死亡历期最短。各虫态在不同湿度环境下以成虫产卵所受的影响较小。附着在新鲜叶片上的卵几乎不受环境湿度的影响。化蛹和羽化要求环境湿度在80%以上。     

高幼虫密度胁迫对二化螟生长发育的影响

为明确二化螟幼虫群集密度对种群增长的影响,在室内用人工饲料饲养比较了不同幼虫密度对二化螟生长发育的影响。结果表明,高幼虫密度800头/盒胁迫下,二化螟雌、雄幼虫和蛹的发育更快,其幼虫+蛹历期分别比低密度100头/盒处理要快8.0 d和6.0 d;化蛹率和羽化率较100头/盒处理分别显著下降了25.7和25.0个百分点,且雌、雄蛹重分别减少了9.4 mg和4.8 mg;但对二化螟成虫性比、寿命、产卵量和卵孵化率无显著影响。低密度100头/盒处理下二化螟幼虫发育最好,其种群增长指数为56.9,化蛹率达61.4%,羽化率达57.7%,雌、雄蛹重分别为58.3 mg和43.0 mg,但其幼虫+蛹历期较长,雌虫为58.5 d,雄虫为53.9 d。高密度800头/盒胁迫下二化螟幼虫发育最差,其种群增长指数仅为24.1,化蛹率仅为35.7%,羽化率为32.7%,雌、雄蛹重分别为48.9 mg和38.2 mg,但其幼虫+蛹历期较短,雌虫为50.5 d,雄虫为47.9 d。表明在恒定的空间和有限的食物中,幼虫密度过大会导致种内竞争加剧,使得幼虫可能倾向以更快的速度化蛹,确保其存活率以更好地繁殖后代。     

桃小食心虫病原菌—球孢白僵菌TST05菌株生物学特性研究

[目的]研究从自然染病的桃小食心虫幼虫上分离的球孢白僵菌TST05菌株的生物学特性.[方法]测定不同培养基、外界不同温度和湿度对该菌株菌丝营养生长及孢子萌发的影响.[结果]该菌株在PDA、PPDA、SDAY、SMAY 4种培养基上均生长良好,菌落厚而致密,产孢量均大于3.95×107孢子/mL;菌株适应的温度和湿度范围宽,15～30℃之间,RH 30 ％～100％之间孢子均可萌发、生长和产孢.随着温度接近25℃、湿度增大,孢子的萌发率、菌落的生长速率和产孢量都显著增加.15℃、RH 100％时产孢量为1.32× 107孢子/mL;25℃、RH 30％时,产孢量也能达到1.37×107孢子/mL;25℃、RH 100％时产孢量达到6.19×107孢子/mL.15℃、RH 100％孢子萌发率为52.28％;25℃、RH＞80％时,孢子萌发率都能达到90％以上.[结论]TST05菌株能适应北方干旱低温条件,可开发成为防治桃小食心虫的生物制剂.     

Induction of prolonged larval feeding stage by juvenile hormone analogues inTribolium Castaneum

Dietary ZR-512 and ZR-619 at concentrations of 10 — 1000 ppm induced prolongation of the larval feeding period up to tenfold, increasing larval weight up to double that of untreated larvae. A comparison study of four juvenoids, using 200 ppm of ZR-512, ZR-515, ZR-619 or ZR-777, showed that ZR-515 elicits the highest larval weight (6.2 mg) and ZR-777 the lowest (3.6 mg). In all cases a pronounced enhancement of larval weight — of 50 — 250% relative to untreated larvae (2.4 mg) — was obtained.Tr. castaneum larvae reared up to their 3rd instars on a diet containing 100 ppm of ZR-512, ZR-515, ZR-619 or ZR-777 and then transferred to a juvenile hormone-free diet, were not affected. The period between 4th instar larva and pupation should therefore be considered as critical for juvenile hormone effect. The induced prolongation of the larval stage after juvenile hormone treatment was followed by a pronounced enhancement of cuticle phenoloxidase activity, indicating an alteration of the larval biochemical processes. Although juvenile hormone treatment inhibitsTr. castaneum pupation and emergence, it markedly prolongs larval feeding stage and weight and thus accelerates damage.     

Production and Germination of Conidia of Trichoderma stromaticum, a Mycoparasite of Crinipellis perniciosa on Cacao

ABSTRACT Growth characteristics of the fungus Trichoderma stromaticum, a mycoparasite on the mycelium and fruiting bodies of Crinipellis perniciosa, the causal agent of witches'-broom disease of cacao, were evaluated under controlled environmental conditions. The ability of T. stromaticum to produce conidia and germinate on dry brooms was evaluated at three constant temperatures (20, 25, and 30 degrees C) and two constant relative humidities (75 and 100%). T. stromaticum produced abundant conidia on brooms at 100% relative humidity and incubation temperatures of 20 and 25 degrees C, but none at 30 degrees C. Sporulation of T. stromaticum was not observed at 75% relative humidity at any temperature. At 100% relative humidity and either at 20 or 25 degrees C, treatment of brooms with T. stromaticum suppressed C. perniciosa within 7 days. In contrast, at 30 degrees C, treatment with T. stromaticum had no effect on the pathogen in brooms maintained at either 75 or 100% relative humidity. Mycelium of C. perniciosa grew from brooms at all temperatures at 100% relative humidity. Conidial germination on broom tissue approximated 80% at temperatures from 20 to 30 degrees C. Results suggest that applying T. stromaticum under high-moisture conditions when the air temperature is below 30 degrees C may enhance the establishment of this mycoparasite in cacao plantations.     

Speed of action and toxicity of acylurea insect growth regulators against Spodoptera exempta (Walk.) and Spodoptera littoralis (Boisd.) larvae: Effect of inter-moult age

Ultra-low volume (ULV) spray bioassays at droplet densities (20–80 drops cm^?2) corresponding to field deposits were used to determine the efficacy of two acylurea insect growth regulators, teflubenzuron (‘Nomolt®’) and flufenoxuron (‘Cascade®’) against three different age groups of third-instar Spodoptera exempta and Spodoptera littoralis larvae. While no response (mortality and/or abnormal moulting with impaired ability to feed) was observed with one-day-old larvae until 48 h after treatment, two-day-old larvae showed some response (27–93% abnormal moulting and 3–10% mortality when larvae were sprayed; 80–100% abnormal moulting and up to 83% mortality when larvae and plants were sprayed) after 24 h and up to 100% mortality at 120 h. Studies with non-feeding, pre-moult larvae showed that cuticular uptake of acylureas was sufficient to affect an appreciable proportion of larvae after 24 h, with up to 100% mortality at 120 h. More detailed studies with pre-moult S. littoralis larvae showed that, while a few larvae which moulted between 1 and 5 h after treatment showed abnormal moulting to the L4 stage, a much larger proportion of larvae which moulted 6–20 h after treatment were affected. Previous studies with S. exempta have shown that different larval instars show similar levels of sensitivity to acylureas. The present work suggests that, while the age distribution within instars has little influence on the end-point mortality of acylureas, it can profoundly modify the speed of response, the majority of larvae within an instar being effectively controlled at the moult following treatment. The significance of these observations in relation to the crop protection activity of acylureas against field populations of Spodoptera larvae is discussed.     

瘦怒茧蜂的发育与生殖及对草地螟的控制作用

瘦怒茧蜂Orgilus ischnus Marshall是草地螟Loxostege sticticalis L.初龄幼虫寄生蜂。为探究它的生物学特性及其对草地螟的控害作用,本文在23 ℃、16L：8D光周期条件下,以1龄草地螟幼虫为寄主,测定了瘦怒茧蜂的发育历期和茧重、成虫生殖行为特征、能力和寿命,研究了瘦怒茧蜂对草地螟幼虫的功能反应和寄生率,探究了寄主幼虫的取食量及虫体大小与正常幼虫的差异。结果表明,瘦怒茧蜂卵和幼虫期为12.8 d,预蛹和蛹期10.5 d,世代历期23.2 d,平均茧重为4.1 mg。成蜂羽化当天即可交配产卵寄生,属卵育型,平均交配时间为49 s,雌蜂平均产卵量为100.5粒,产卵高峰期分别为交配后第4 d和第8 d,雌、雄蜂寿命分别为11和14 d。在5～40头/瓶（650 mL）8个密度条件下,瘦怒茧蜂的寄生量随草地螟幼虫密度的增加而增加,当密度≥15头/瓶时,寄生率会随幼虫密度的增加而减小,功能反应属HollingⅡ型;寄主幼虫一生取食量为106.7 mg,仅为正常幼虫的21.3%,寄主幼虫第6和12 d的体重、大小均极显著低于正常幼虫。本文研究结果明确了瘦怒茧蜂基本的生物学特性,证明该蜂对草地螟控害作用显著,为改善、提高草地螟的可持续控制技术提供技术支撑。     

饥饿胁迫对异色瓢虫幼虫发育的影响

异色瓢虫Harmonia axyridis(Pallas)幼虫在野外常遭遇间歇性食物短缺问题,为揭示食物缺乏对异色瓢虫发育的影响,以耐饥能力最强的4龄幼虫为研究对象,以禾谷缢管蚜Rhopalosiphum padi(Linnaeus)为食物,观察和分析饥饿处理(持续饲喂时间不同)和幼虫初始体重对幼虫存活、历期、成虫体型大小和寿命等发育指标的影响。结果表明,在"不饲喂"和"饲喂1 d"的饥饿胁迫处理下,4龄幼虫均不能存活至化蛹;在"饲喂2 d"的处理下,幼虫化蛹率随其初始体重增大而增大,但在"饲喂3 d"和"饲喂4 d"的处理下,幼虫化蛹率不受初始体重的影响,均为100%。饥饿处理和幼虫初始体重均显著影响4龄幼虫历期,"饲喂3 d"和"饲喂4 d"的幼虫历期与"饲喂2 d"的处理相比分别缩短58%和30%;而且在"饲喂2 d"和"饲喂3 d"处理下幼虫历期表现出随其初始体重增大而缩短的趋势。饥饿处理显著影响成虫的体重,但幼虫初始体重没有显著影响;与"饲喂2 d"的处理相比,"饲喂3 d"的成虫体重增大63.7%,"饲喂4 d"的成虫体重增大72.5%。幼虫初始体重不显著影响成虫寿命;但与"饲喂2 d"的饥饿处理相比,"饲喂4 d"的成虫寿命增大27.5%。研究结果表明,4龄幼虫需要取食足量蚜虫2 d以上方可完成发育至化蛹和羽化。     

棉铃虫核型多角体病毒对宿主昆虫的弱化作用

棉铃虫核型多角体病毒（ＨａＮＰＶ）感染２龄幼虫,感染３ｄ,幼虫体长和体重明显小于对照幼虫。病毒感染４龄幼虫,残留活虫幼虫历期延长,但取食量减少３７．５２％。病毒感染５龄幼虫,感染幼虫蜕皮时间延迟１８ｈ,幼虫历期延长２ｄ。幼虫血淋巴蛋白电泳结果表明,幼虫蜕皮时间延迟主要原因是蜕皮过程延长。病毒感染５龄初幼虫,残留活虫蛹重减轻１４．１９％,成虫产卵量减少２０．５８％。结果表明,ＨａＮ－ＰＶ感染棉铃虫幼     

大灰食蚜蝇幼虫饲养及温室释放试验

在室内用桃蚜、蔷无网蚜、桃粉大尾蚜、菊花蚜虫4种蚜虫饲养大灰食蚜蝇幼虫取得比较满意的结果,幼虫成活率76～80％,蛹羽化率92～94％,子代卵孵化率84～91％。用豌豆修尾蚜饲养,幼虫成活率仅48％,蛹羽化率50％,子代卵孵化率无明显差异。在大灰食蚜蝇幼虫发育期中,前期用桃蚜饲养,后期改用修尾蚜饲养,对幼虫成活率及蛹羽化率仍有影响.食物(蚜虫)充足时,幼虫自残程度低,可以集体饲养。以1:10的益害比释放大灰食蚜蝇3日龄幼虫,防治非洲菊上的蚜虫,3天后蚜虫下降85.9％,效果显著。