烟盲蝽对不同虫态烟粉虱的捕食作用及捕食偏好性

杂食性昆虫烟盲蝽Nesidiocoris tenuis是烟粉虱Bemisia tabaci的重要天敌之一。为探索烟盲蝽对不同虫态烟粉虱的捕食作用及捕食偏好性,在室内进行了非选择性和选择性试验。结果表明,在非选择性试验中,烟盲蝽雌成虫、雄成虫以及5龄若虫可以捕食烟粉虱成虫和各龄若虫,但极少捕食卵。其中,烟盲蝽雌成虫、雄成虫及5龄若虫对烟粉虱1龄若虫的捕食量最大,分别为134.2头、101.3头和88.1头,其次是2~3龄若虫,捕食量分别为94.1头、64.2头和53.4头。而在选择性试验中烟盲蝽雄虫更偏好捕食烟粉虱的2~3龄若虫,其次是1龄若虫、4龄若虫和成虫。该结果对了解烟盲蝽控制烟粉虱的作用以及如何对烟盲蝽和其他天敌组合应用提供了参考信息。     

“秕谷草-伪褐飞虱-中华淡翅盲蝽”载体植物系统的可行性

为明确用于防治稻飞虱的“秕谷草-伪褐飞虱-中华淡翅盲蝽”载体植物系统的可行性,本文开展了靶标作物水稻、载体植物秕谷草和靶标害虫褐飞虱、替代猎物伪褐飞虱组合对中华淡翅盲蝽成虫形态、种群增长参数、产卵选择性和取食选择性的影响研究.结果表明: 中华淡翅盲蝽水稻种群(取食褐飞虱卵)的雌雄成虫个体均显著大于秕谷草种群(取食伪褐飞虱卵).取食褐飞虱卵的中华淡翅盲蝽种群增长参数单雌产卵量、净增长率、内禀增长率、周限增长率明显高于取食伪褐飞虱卵的种群,但取食伪褐飞虱卵也有较高的种群增长能力,足以扩繁种群.对于靶标作物水稻和载体植物秕谷草,无论是水稻种群还是秕谷草种群均偏好在水稻上产卵.同时,2个种群的雌虫、雄虫和若虫对褐飞虱卵和伪褐飞虱卵捕食量没有显著性差异.在上述研究基础上,讨论了在田间建立“秕谷草-伪褐飞虱-中华淡翅盲蝽”载体植物系统的可行性.     

黑肩绿盲蝽捕食褐飞虱卵的功能与数值反应

褐飞虱作为水稻的重要迁飞性害虫,至今未见有效的生物防治技术报道。黑肩绿盲蝽对褐飞虱卵及低龄若虫有较强的捕食能力,为评价黑肩绿盲蝽对褐飞虱的控害能力,研究了黑肩绿盲蝽若虫各虫期和雌雄成虫对褐飞虱卵的捕食功能反应与数值反应。功能反应研究结果表明,黑肩绿盲蝽对褐飞虱卵的捕食功能反应符合HollingⅡ型方程,捕食量在一定范围内随着猎物密度的增加而增加,若虫的捕食能力大于成虫;四龄若虫理论捕食量最大,为104.2粒卵/d。数值反应研究结果表明,不同褐飞虱卵密度对黑肩绿盲蝽的生长、发育、繁殖有着显著影响。随着猎物密度增大,黑肩绿盲蝽若虫发育速率、雌虫产卵量、孵化率及雌性比增大,成虫寿命减小,最后趋于稳定。猎物密度1、3、5卵/d分别是黑肩绿盲蝽若虫存活、成虫羽化及维持种群最低繁殖力的临界值。在天敌控害潜能的研究过程中,数值反应的研究目的在于探讨捕食者对猎物密度的依赖程度,探明能引起捕食者种群衰退的猎物密度临界值,为大田释放捕食者时增补替代寄主,增强捕食者持续控害能力提供理论依据。     

稻田氮肥施用量对黑肩绿盲蝽捕食功能的影响

在实验室条件下研究了黑肩绿盲蝽Cyrtorhinuslividipennis Reuter在不同含氮量稻株上对褐飞虱Nilaparvata lugens Stal卵和低龄若虫的捕食能力、对褐飞虱卵的捕食功能反应以及褐飞虱蜜露和水稻伤流液对其捕食 能力的影响。结果表明,黑肩绿盲蝽对褐飞虱卵和若虫的捕食量均与寄主植物的含氮量呈显著 负相关。黑肩绿盲蝽在相同氮肥施用量的稻株上连续饲养2代后对褐飞虱卵的捕食能力没有改变 。黑肩绿盲蝽对褐飞虱卵的功能反应呈Holling Ⅱ型方程,其参数瞬时发现率(a)和处置时间(T_h)只与寄主含氮量有关,而与黑肩绿盲蝽种群和褐飞虱卵的来源无关。 在高氮量稻株上黑肩绿盲蝽种群对褐飞虱卵的瞬时发现率(a)下降导致了功能反应的减弱, 而在相同含氮量稻株上黑肩绿盲蝽种群之间的捕食功能没有明显差异。黑肩绿盲蝽成虫取食水 稻伤流液和褐飞虱蜜露时寿命明显延长,取食高氮稻株的褐飞虱分泌的蜜露对延长黑肩绿盲蝽 雌成虫寿命的作用最大。但是,在高氮稻株上褐飞虱蜜露显著降低黑肩绿盲蝽的捕食能力。这 些结果表明黑肩绿盲蝽对褐飞虱自然控制作用的下降是稻田过量施用氮肥后褐飞虱种群增加的 主要原因之一。     

替代猎物红蜘蛛Tetranychus nr. fijiensis对小黑瓢虫实验种群的影响

本文在实验室条件下,以自然猎物烟粉虱Bemisia tabaci为对照,研究了替代猎物红蜘蛛Tetrany-chus nr．fijiensis对小黑瓢虫的发育、存活、繁殖及实验种群增长的综合影响,结果表明：小黑瓢虫以红蜘蛛为猎物时,成虫可产卵并可完成整个世代。与自然猎物烟粉虱相比,小黑瓢虫取食替代猎物红蜘蛛时,各虫态及世代历期延长,世代死亡率提高,产卵前期延长,总产卵量及平均每雌日产卵量减少,而两者之间的性比、产卵率、产卵期及雌虫寿命无显著差异。2种猎物条件下的种群增长指数和内禀增长率分别为8．85、0．0658(红蜘蛛)和55．38、0．1905(烟粉虱)。     

引进天敌越南斧瓢虫的形态特征和生物学特性

引进天敌越南斧瓢虫Axinoscymnus apioides Kuznetsov & Ren原产于东南亚,是烟粉虱Bemisiatabaci(Gennadius)的重要捕食性天敌之一。文章详细描述越南斧瓢虫的形态特征,并研究其基本的生物学特性。越南斧瓢虫可取食烟粉虱的卵、若虫、伪蛹等各虫态,可有效地控制烟粉虱种群,具有很好的利用价值。在(26±1)℃条件下,越南斧瓢虫捕食烟粉虱的世代平均发育历期为20.33d,世代存活率为73.04%,雌成虫寿命为143.17d,平均单雌产卵量为284.33粒。越南斧瓢虫取食烟粉虱的内禀增长率(rm)为0.0457,净增殖率(R0)为103.4050,平均世代历期(T)为99.3626,周限增长率(λ)为1.0478。     

人工饲料饲养的叉角厉蝽对昆虫的捕食能力评价

叉角厉蝽Eocanthecona furcellate(Wolff)是广泛分布于热带亚热带地区的一种重要捕食性天敌昆虫。为评估人工饲料饲养的叉角厉蝽的捕食能力,在实验室采用捕食功能反应的方法,以黄粉虫作为中介猎物饲养的叉角厉蝽为对照,评价了人工饲料饲养的叉角厉蝽3龄若虫、5龄若虫以及雌成虫对黄粉虫Tenebriomolitor(L.)幼虫及斜纹夜蛾Spodoptera litura(Fabricius)3龄幼虫、5龄幼虫的捕食效能。结果表明,两种饲料饲养的不同虫态叉角厉蝽的捕食量均随着猎物密度的增加而上升,当猎物密度增加到一定水平,捕食量趋于稳定,其捕食功能反应均符合HollingII模型。人工饲料组饲养的各虫态叉角厉蝽与对照组的对黄粉虫幼虫的捕食量没有明显差异;在饱和猎物密度条件下,人工饲料饲养的叉角厉蝽3龄若虫、5龄若虫以及雌成虫对斜纹夜蛾3龄幼虫的日最大捕食量分别为7.20、9.20、14.60头,对斜纹夜蛾5龄幼虫的日最大捕食量分别4.20、5.80、6.20头,均略低于对照组,但从取食猎物数量上来看,仍保持较强的捕食能力。     

Research on the application of Typhlodromips swirskii for the control of Bemisia tabaci

评价斯氏小盲绥螨Typhlodromips swirskii(Athias-Henriort)在我国日光大棚中对黄瓜上的烟粉虱Bemisia tabaci(Gennadius)控制作用.在不同温度条件下研究斯氏小盲绥螨以烟粉虱为猎物的试验种群生命表,以及在日光大棚中释放斯氏小盲绥螨控制黄瓜上的烟粉虱所取的防治效果.斯氏小盲绥螨取食烟粉虱的卵、成虫、若虫、伪蛹能完成世代并能正常产卵.在19～35℃范围内总产卵量25～41粒／雌,产雌率60％～62.68％.在(20±1)℃.(25±1)℃,(30±1)℃,(34±1)℃温度条件下斯氏小盲绥螨净增殖率(R0)分别为12.6160、22.1021、17.4500、16.7463;内禀增长率(rm)分别为0.0865、0.1528、0.1535、0.1690.在大棚黄瓜上应用结果表明:释放斯氏小盲绥螨与目前大棚中的常规化学防治比较,生防区能有效地控制烟粉虱成虫、卵、若虫的种群数量增长.根据斯氏小盲绥螨和烟粉虱的生物学特性,结合大棚黄瓜栽培过程中的环境条件,笔者提出了在日光大棚中应用斯氏小盲绥螨控制黄瓜上烟粉虱的策略:在黄瓜生长的整个期间释放2～3次斯氏小盲绥螨,每20～25d释放1次,苗期每株释放20～25只,后期每株释放25～50只,才能达到预期效果.生防园每季减少农药使用次数5次.     

南方小花蝽在不同试验空间对西花蓟马的捕食及搜寻效应

【背景】南方小花蝽是一类很有利用前景的捕食性天敌,而有关其在不同捕食空间下对我国局部地区暴发成灾的重要入侵害虫西花蓟马捕食控制效能的研究较少。【方法】在实验室条件下比较研究了南方小花蝽成虫在不同试验空间对西花蓟马成虫、若虫的捕食选择性、捕食功能反应与搜寻效应。【结果】南方小花蝽成虫对西花蓟马若虫的捕食选择性强于成虫;在相同的试验空间,南方小花蝽成虫的日均捕食量随猎物数量的增加而增大,其对西花蓟马成虫和若虫的捕食量在猎物数量为每指形管中60头时最大,分别为15.90和19.30头;而搜寻效应随猎物数量的增加而降低。在各供试条件下,捕食功能反应均符合Holling Ⅱ型方程;南方小花蝽成虫在小饲养容器中对西花蓟马若虫的瞬时攻击率最大,为1.2794;而在大饲养容器中对西花蓟马成虫的瞬时攻击率最小,仅为0.3506,其处理1头西花蓟马成虫的时间约需0.0402d,而处理1头若虫的时间仅需0.0242d。在相同的猎物数量下,南方小花蝽成虫在大饲养容器中对西花蓟马的日均捕食量均低于其在小饲养容器中对西花蓟马的日均捕食量。【结论与意义】南方小花蝽对西花蓟马有很强的捕食效能,对西花蓟马的种群消长具有一定控制作用。本研究旨在为应用南方小花蝽防治西花蓟马积累资料,同时为西花蓟马的综合治理奠定理论基础。     

四种猎物对南方小花蝽生长发育和繁殖的影响

南方小花蝽是多种猎物的天敌,为评价西花蓟马、二斑叶螨、蚕豆蚜和腐食酪螨饲养南方小花蝽的效果,研究了南方小花蝽取食四种猎物时的生长发育和繁殖情况。结果表明南方小花蝽取食腐食酪螨时若虫只能发育到5龄,4龄若虫累计存活率仅为6.8%。其它3种猎物均可使南方小花蝽正常生长发育和繁殖,其中南方小花蝽取食西花蓟马时生长发育时间最短,繁殖率最高;取食二斑叶螨时生长发育时间最长,繁殖率最低。取食西花蓟马的南方小花蝽净生殖率、内禀增长率和周限增长率明显高于其它两种猎物。用3种猎物连续饲养南方小花蝽两代,以蚕豆蚜和二斑叶螨为猎物时南方小花蝽的未成熟期、成虫的寿命、繁殖情况和生命参数在第一代和第二代之间都有所不同,但以西花蓟马为食料时南方小花蝽第一代和第二代之间生长发育和繁殖情况没有明显的差异。以上结果表明在供试猎物中西花蓟马对南方小花蝽实验种群的增长最有利。     

Feeding on gastropods by lake-dwelling Polycelis in the absence and presence of Dugesia polychroa (Turbellaria, Tricladida)

SUMMARY. Using a serological technique, the extent of feeding upon snails by Polycelis tenuis was compared in habitats lacking and containing Dugesia polychroa which is the major triclad predator of snails. It was found that P. tenuis ate significantly more snails when D. polychroa was absent. It was concluded that in the field interspecific competition for snails between these two triclad species was a more powerful process than any social feeding by P. tenuis on snails captured by D. polychroa .
Feeding on snails as a group by P. tenuis and P. nigra in the habitat where the two triclads co-existed was of a similar magnitude and this was also true of their feeding on the common snail species and genera. Approximately 10% of the triclads gave a positive reaction to snail antisera.
Feeding on snails by P. nigra in the three habitats lacking D. polychroa was similar in extent and did not differ from that of P. tenuis . It was concluded that P. nigra would be similarly affected by the presence and absence of D. polychroa as shown for P. tenuis .
No definitive seasonal pattern was detected in the incidence of feeding upon snails by either Polycelis species but this may have been obscured by seasonal changes in the detection period of snail antigens due to temperature effects. There was some evidence that such feeding increased during the period when small snails were present in the population.     

Field study of the fate of labelled fertilizer ammonium-N applied to sesame and sunflower in a sandy soil

The recovery in crop and soil of labelled fertilizer ammonium-N applied to sesame and sunflower growing on sandy soil was measured. The sesame and sunflower received respectively 238 and 143 kg Nha⁻¹ as (NH₄)₂SO₄ enriched with 4.63 At. %¹⁵N excess. In the plants, the Ndff was 31.19% and 31.96% in sesame and sunflower, respectively. The fertilizer recovery by sunflower was 22.3%, by sesame only 12.3%. The amount of fertilizer N remaining in the soil at harvest was 13.04% for the sesame and 5.95% for the sunflower plot. The loss of fertilizer N under sesame was 74.66% and 71.75% under sunflower. The average of seed yield of the plants inside the¹⁵N plot was compared with the seed yield of the same amount of plants from outside the¹⁵N plot. They did not differ significantly, indicating that the results obtained from the¹⁵N plot can be extrapolated to the rest of the field.     

Population dynamics of the coprophilous moss Tayloria tenuis in a Pyrenean forest

Three populations of Tayloria tenuis (Splachnaceae) growing on three isolated cattle droppings in coniferous forests of the Eastern Pyrenees were sampled by permanent grids through three years. Each population was initially in a different stage of the dung colonization process. At first, T. tenuis developed a conspicuous protonema on the dropping surface. After one or two years, the moss completed development and fruited abundantly. Eventually, the populations were covered by larger pleurocarpous mosses, which were common on the forest soil.
There were important differences between the two stages of development of the T. tenuis gametophyte: the protonema stage exhibited high mortality but rapidly covered nearly all the free surface of the dropping. Afterwards, the gametophore stage established more permanently.
Pleurocarpous mosses growing over Tayloria tenuis gametophores produced changes in the vegetative and reproductive pattern of this species. Tayloria tenuis disappeared gradually from the places covered by pleurocarps, although these larger species exhibited high rates of mortality at a micro-scale level.     

黄曲条跳甲人工饲养技术改进

通过室内人工饲养建立实验种群,是开展黄曲条跳甲Phyllotreta striolata(Fabricius)各种研究的基础,解决其幼虫阶段的人工饲养技术是建立其实验种群的关键。介绍经改进后的黄曲条跳甲室内人工饲养技术,该方法简单易行,可以方便地获取试虫的不同虫态;采用"小菜苗法"和"萝卜薄片堆叠法"室内饲养黄曲条跳甲幼虫,最高存活率可达90%以上。     

Settlement-competency period of planulae and genetic differentiation of the scleractinian coral Acropora digitifera

Broadcast-spawning corals expel eggs and sperm, and the fertilized eggs develop into planulae in the water column. As these sessile corals generally disperse during the planktonic larval stage, their larval characteristics (e.g., survival and settlement rates) are thought to be important for their dispersal. Although some studies of coral larval dispersal have focused on the maximum time that larvae can remain viable and settle, the relevance of this maximum settlement competency period for long distance dispersal remains unclear. To examine the relationship between competency periods and genetic differentiation, we performed laboratory experiments to investigate settlement rates of planulae and determine the degree of genetic differentiation in Acropora digitifera in the Ryukyu Archipelago, southern Japan. In addition, we compared our findings to published data for A. tenuis, which was studied using our methods. Our results indicated that the maximum settlement competency period was lower in A. digitifera planulae (54 days) than in A. tenuis (69 days) planulae. The mean survival rates at 45 days and 59 days after spawning were less than 10%. Furthermore, percentages of planulae that remained viable and settle at 30 days after spawning (survival rate x settlement rates at 30 days) were approximately 18% and 25% in A. digitifera and A. tenuis, respectively. By contrast, gene flow (N(e)m: number of migrations per generation) was significantly higher in A. digitifera (7.8 to 41.4) than in A. tenuis (3.1 to 22.5). These results indicate that the settlement competency period and survival rates are unlikely to be robust predictors of gene flow. Overall, we detected significant genetic differentiation between Kerama and Okinawa in A. digitifera. As direct observation of planula dispersal between Kerama and Okinawa has been reported, we concluded that genetic mixing is not complete, but that some localized planulae may disperse from Kerama to Okinawa via a specific current depending on reef or locality.     

Parasites, diseases, and health status of sympatric populations of fallow deer and white-tailed deer in Kentucky

In August 1983, a study on parasites, diseases, and health status was conducted on sympatric populations of fallow deer (Dama dama) and white-tailed deer (Odocoileus virginianus) from Land Between The Lakes, Lyon and Trigg counties, Kentucky. Five adult deer of each species were studied. White-tailed deer had antibodies to epizootic hemorrhagic disease (EHD) virus and Leptospira interogans serovariety icterohemorrhagiae, and fallow deer had antibodies to bluetongue and EHD viruses. Serologic tests for bovine virus diarrhea virus, infectious bovine rhinotracheitis virus, parainfluenza3 virus, and Brucella spp. were negative. One white-tailed deer had an infectious cutaneous fibroma, and one fallow deer had pulmonary mucormycosis. White-tailed deer harbored 16 species of parasites, all of which are considered typical of the parasite fauna of this host in the southeastern United States. Fallow deer harbored nine species of parasites, including eight species known to occur in white-tailed deer on the area and one species (Spiculopteragia assymmetrica) that is not. All fallow deer had inflammatory lesions in the spinal cord and/or brain that were attributed to prior infection with meningeal worm (Parelaphostrongylus tenuis), indicating that P. tenuis infections are not always fatal for this species. The apparent high rate of exposure of Land Between The Lakes fallow deer to P. tenuis without a resultant high rate of clinical cerebrospinal parelaphostrongylosis is hypothesized to be due to a low prevalence and intensity of P. tenuis, partial innate resistance of fallow deer, and acquired immunity.     

Population biology of Trichostrongylus tenuis, a parasite of economic importance for red grouse management

The caecal nematode, Trichostrongylus tenuis, is associated with dramatic decreases in the density of red grouse (Lagopus lagopus scoticus) resulting in a significant loss of sporting income to many upland estates in the UK. In this article Peter Hudson and Andrew Dobson describe the dynamics of the grouse-T. tenuis system, show that the parasites can cause population crashes and present preliminary findings from the development of new control methods.     

幼虫密度对甜菜夜蛾生长发育与繁殖的影响

为了研究甜菜夜蛾Spodoptera exigua(Hübner)幼虫的密度对其发育及繁殖的影响,本实验观察了5种幼虫密度下（1,5,10,20,30头/瓶）,幼虫发育和成虫繁殖情况。结果表明：幼虫和蛹历期、存活率和蛹重均差异显著。幼虫和蛹历期均以20头/瓶的最短,1头/瓶的最长,其余随幼虫密度增加而延长;幼虫至蛹存活率以10头/瓶的最高,其余随幼虫密度增加而降低;1头/瓶的蛹最重,显著高于其他密度的,其余随幼虫密度增加而下降。尽管密度间成虫羽化率和产卵前期均无显著差异,但成虫产卵量、寿命和畸形率差异显著。1头/瓶的产卵量最多,其次为10头/瓶的,其余随幼虫密度增加而减少,30头/瓶的产卵量显著少于其他密度的; 密度在1～20头/瓶范围内,雌蛾寿命均较短,显著短于30头/瓶的,而雄蛾寿命以5头/瓶的最短,显著短于其他密度的（10头/瓶除外）,10头/瓶的次之,其余密度间差异不显著;不同幼虫密度下羽化的成虫畸形率差异显著,10头/瓶的最低,其余随幼虫密度增加而升高; 生命表结果表明甜菜夜蛾在10头/瓶下世代存活率和种群增长指数均最高,幼虫密度过低或过高均不利于种群增长;世代存活率（S）和种群增长指数（I）与幼虫密度之间的关系均呈抛物线关系：S =－0.2087x²+2.5694x+211.52 (R²=0.88),I=－0.0552x²+0.9166x+54.168 (R²=0.95)。结果提示幼虫密度影响甜菜夜蛾种群动态的重要生态因子之一。     

饲养黄曲条菜跳甲实验种群的一种新方法

介绍一种简便可行的饲养黄曲条菜跳甲Phyllotretastriolata(F.)的新方法———整苗大瓶罩养法。用5种植物根部饲养越冬代,黄曲条菜跳甲均可成功地完成其生活周期,未成熟期最高存活率为63.3%,成虫平均寿命最长为219.2d,平均产卵量最大为192.4粒雌。