黑绒金龟子初步研究

黑绒金龟子为防护林区主要害虫之一, 在东北地区每年发生一代, 以成虫在土中越冬, 越冬成虫4月上旬出土, 4月下旬到5月下旬为发生盛期, 成虫的发生消长和一定温度有关外, 更大程度和降雨量、湿度关系更为密切, 在通常情况下其发生高峰和多雨季节相吻合。成虫食性复杂, 不同饲料对其取食量、产卵量、产卵期有很大影响, 对于榆树叶的取食量最大、产卵量最多、产卵期也最长, 其余树种则次之。幼虫有3龄, 平均第一龄期19.29天, 第二龄期14.96天, 第三龄期31.42天。22—25℃温度范围的土层适合于1—2龄幼虫的活动。老熟幼虫潜入深层化蛹, 蛹期一般为半个月, 羽化后成虫在土中有升降活动, 当年一般不出土, 少数个体虽有出土活动或取食但不交配产卵。黑绒金龟子由于不同发育阶段受到不同温度的影响, 在土层中有不同深度的分布。部分成虫可以经二次越冬, 但第二次越冬后的成虫是否能正常产卵繁殖还有待进一步研究。     

云南河口县桔小实蝇生物学特性及防治

桔小实蝇Bactroceradorsalis (Hendel)在河口 1年发生 5代 ,世代重叠 ,5～ 8月为害虫发生盛期 ,以第 2和第 3代幼虫发生期对当地果蔬作物的危害最重。室内 1 8～ 30℃条件下 ,成虫日羽化高峰发生在上午 9:0 0～ 1 0 :0 0 ,卵、幼虫和蛹的历期随着温度的升高而缩短。成虫取食喜选成熟芒果的汁液。提出了防治此害虫的主要措施。     

防治铜绿金龟子的初步探讨

鲷绿金龟子(Anomala corpulenta Motsch.)在河南的郑州、灵宝、博爱、开封、仪封、许昌、新郑等地均有发生,危害幼龄果树和林木极为严重。成虫特别喜食苹果、沙果、花红、海棠及杨、柳等幼树嫩叶,每当成虫盛发时期,常将叶片吃光,对果木生长及水果产量的影响很大。 为了探讨防治途径,近几年来,我们就成虫发生特点与防治进行了研究。 一、成虫发生时期与降雨量的关系 据郑州地区的观察,铜绿金龟子每年发生1代,幼虫过冬,来年4月底、5月初化蛹羽化。成虫出现期与盛发期,和当年4、5、6月份的降雨量有关,特别是5、6月份的降雨量最为密切。据郑州诱虫灯下成虫出现期和数量的统计结果表明:1961年5月份降雨量为39.2毫米,6月份为91.4毫米,成虫于5月上旬开始出现,盛发期在6月上、中旬,末期延到8月下旬。1962年5月份降雨量仅12毫米,6月份69.5毫米,成虫于6月上     

小叶女贞新害虫黄环绢须野螟生物学特性

黄环绢须野螟Palpitaannulata(Fabricius)是小叶女贞(LigustrumquihouiCarr.)上新出现的一种害虫,严重危害小叶女贞叶片,造成植株枯萎、死亡,同时也危害金叶女贞(L.vicaryi)。该虫在湖南省衡阳地区1年发生3代,以蛹在土中越冬。越冬代成虫和第1、2代成虫分别于4月下旬、5月下旬和6月下旬出现。成虫产卵于嫩梢顶端叶片上,卵期3d,幼虫期9～12d。5月上旬和6月上旬分别是第1代和第2代幼虫盛发期,危害最重。越冬代成虫羽化期喷药是防治该虫的关键,在成虫期和幼虫期分别用40%氧化乐果乳油、50%辛硫磷乳油1000～1200倍或25%溴氰菊酯乳油2500～3000倍稀释液喷洒寄主叶面,可控制该虫危害。     

哈尔滨地区大猿叶虫发育历期与生物学特性

在哈尔滨对白菜上的大猿叶虫Colaphellus bowringi Baly的生活史和生物学习性进行观察研究。结果表明,大猿叶虫在哈尔滨地区绝大多数个体1年发生1代,少部分个体1年发生2代。主要以成虫入土在2～27cm土层中滞育越冬。越冬成虫翌年4月下旬开始出土活动。第1代发生在5上旬至7月上旬,第2代发生于6月中旬至7月中旬。所有成虫在7月下旬以后均滞育越冬。在25℃条件下,雌虫产卵期为6～55d,平均为30.95d,单雌平均产卵量为454.9粒。在25℃各虫态的发育历期为:卵(4.46±0.33)d,幼虫(8.22±0.26)d,蛹(4.17±0.22)d。各虫态发育起点温度卵为10.80℃,幼虫为10.95℃,蛹为9.79℃;有效积温卵为64.82日.度,幼虫为117.37日.度,蛹为64.36日.度。     

西藏飞蝗的生物学特性

西藏飞蝗Locusta.migratoria tibetensis Chen在四川甘孜州1年发生1代,某些地方(乡城县)1年发生不完整的2代,即以卵越冬,翌年3月下旬开始孵化出土,4月中、下旬为孵化盛期,1~3龄始盛期为4月中旬~5月中旬,高峰期为5月下旬,7月上旬初始羽化,7月下旬~8月上旬为羽化盛期,8月上旬始见产卵,8月下旬~9月上旬为产卵盛期,第1代成虫较早产下的卵块在条件适宜的情况下可于当年9月上旬孵化出土,但孵化出的蝗蝻不能越冬。该虫卵、全蝻期及全世代的发育起点温度分别为14.2,16.1,14.6℃,有效积温为179.1日.度、360.0日.度、787.8日.度。在18,21,24,27和30℃等5种恒温条件下其平均世代历期214.4,133.3,79.2,66.3和50.7d。     

克里角梢小蠹生物学特性及防治

克里角梢小蠹TrypophloeusklimeschiEggers为国内新记录种 ,近年来成为新疆杨 (PopulusalbawyPyramidalis)的重要害虫 ,在短期内可导致新疆杨死亡。该虫在新疆阿拉尔 1年发生 2代 ,主要以成虫在树干蛀盲孔越冬。危害部位集中于距地面高 40～ 2 0 0cm的主干。成虫出树活动 1年中有 3个高峰 ,即 :5月上旬至 5月中旬 ,7月下旬至 8月中旬 ,9月下旬。第 1代幼虫历期约为 3 0d。成虫出孔活动盛期是防治该害虫的关键时期。     

梦尼夜蛾生物学特性及其防治

1995～ 1999年 ,在新疆库尔勒市对梦尼夜蛾生物学特性及其防治进行了调查研究。梦尼夜蛾 1年发生 1代 ,以蛹在土壤 2 0～ 10 0 mm深处越冬。3月上旬始见成虫 ,发蛾高峰在 3月底 4月初 ,产卵部位集中 ,孵化整齐。幼虫共 6龄 ,平均历期为 2 9.6天 ,以幼虫食叶危害 ,危害盛期为 4月中旬至 5月上旬。本文还提出了该虫的防治措施     

筛阿鳃金龟的生物学特性及其防治

筛阿鳃金龟是龙眼、荔枝的主要害虫,在广西南宁每年发生1代,以成虫越冬。翌年3月下旬或4月上旬成虫出土取食为害,直至5月中下旬成虫开始交配产卵,8月下旬或9月上旬为幼虫化蛹盛期,9月中下旬为成虫羽化盛期,随之出土取食为害,11月下旬入蛰。其主要以成虫为害植株的新梢嫩叶,而且每年出现两次为害高峰期,分别在当年9～10月和翌年4～5月。用40％氧乐果或50％甲胺磷乳油800～1000倍稀释液喷雾,防治效果显著。     

乌苏里鸣螽生物学特性研究初报

研究了乌苏里鸣螽的生物学特性。该虫在河北省秦皇岛市 1年发生 1代 ,以滞育卵在土内越冬 ,翌年 3月下旬～ 6月上旬孵化为若虫。若虫共 7龄 ,1龄期 1 3～ 2 9d ,2龄期 8～ 2 0d ,3龄期 7～ 1 3d ,4龄期 6～ 9d,5龄期 6～ 9d ,6龄期 5～ 1 5d ,7龄期 1 2～ 1 7d。 6月下旬～ 8月中旬羽化为成虫 ,雌成虫产卵自 7月上旬至 9月下旬结束。成虫平均寿命 81 2 5d。     

Protective efficacy of lambdacyhalothrin-impregnated bednets against Phlebotomus orientalis, the vector of visceral leishmaniasis in Sudan

Field investigations on the sandfly Phlebotomus orientalis (Diptera: Psychodidae), the vector of Leishmania donovani causing visceral leishmaniasis (VL) in Sudan, were undertaken in two villages (Bellow and Elgamel) and Dinder National Park, to determine the protective value of bednets (polyester, 100 denier) impregnated with lambda-cyhalothrin 10 mg a.i./m2 pyrethroid insecticide. After exposure to treated netting for 30 s, P. orientalis females all died within 1 h. When field-tested in Acacia woodland, treated bednets provided complete protection from bites of the vector. Numbers of P. orientalis females landing on human collectors without bednets or using untreated bednets averaged 32.0 +/- 8.3 or 6.9 +/- 2.7 per man-night, respectively, whereas collectors using treated bednets experienced no sandfly bites during the same period (18.00-06.00 hours, 12 nights in June 1995). Socio-behavioural observations on the bed-time of people living in both study villages indicated that the use of impregnated bednets against P. orientalis would give more potential protection for women and children than for male adults. Overall the proportions of people and their durations of exposure to the risk of sandfly bites (i.e. after sunset until they went to bed) were 40% unprotected for< 1h, 50% for 1-2h and >10% for > or = 2h. Because visceral leishmaniasis in Sudan occurs mainly in children, the use of impregnated bednets (outdoors as well as indoors), and going to bed early could provide a high degree of personal protection against this zoonotic infection.     

The modifying effect of selenium and vitamins A, C, and E on the genotoxicity induced by sunset yellow in male mice

The use of food additives in various products is growing up. It has attracted the attention towards the possible correlation between the mutagenic potential of food additives and various human diseases. This work evaluated the protective role of selenium and vitamins A, C and E (selenium ACE)(1) against the genotoxic effects induced by a synthetic food additive, sunset yellow, in mice. Six groups were studied including two control groups (negative and positive control), two groups are given single dose of sunset yellow (either 0.325, 0.65 or 1.3mg/kg body weight(2) alone or with selenium ACE) and two groups are given sunset yellow daily for 1, 2 or 3 weeks (0.325mg/kg b.wt./day alone or with selenium ACE), respectively. The study examined the induction of sister chromatid exchanges (SCE's)(3) in bone-marrow cells, chromosomal aberration in somatic (bone-marrow) and germ cells (spermatocytes) after single and repeated oral treatment, and the induction of morphological sperm abnormalities. The results showed that sunset yellow had genotoxic effects as indicated by increased frequency of SCE's, by chromosomal aberrations in both somatic and germ cells, and by increased morphological sperm abnormalities and DNA fragmentation. The results also indicated that the oral administration of selenium ACE significantly reduced the genotoxic effects of sunset yellow, a result that may support the use of antioxidants as chemopreventive agents in many applications.     

Photosynthesis and Water Use Efficiency of Platycladus Orientalis and Robinia Pseudoacacia Saplings under Steady Soil Water Stress during Different Stages of Their Annual Growth Period

A simulated drought experiment was conducted in a rain-free shed to test the physiological response of Platycladus orientalis and Robinia pseudoacacia saplings to steady soil water stress during different stages. The five soil water treatments were: 100%, 87.84%, 70%, 52.16% and 40% of field capacity. The results showed that the net photosynthetic rate of R. pseudoacacla decreased as soil water potential decreased in the range between -0.041 MPa and -0.292 MPa.The threshold value at which the net photosynthetic rate changed significantly was -0.12 MPa. The relationship between net photosynthetic rate of P. orientalis and soil water potential could be described as a quadratic parabola in the range between -0.041 MPa and -0.648 MPa. Analysis of variance showed significant differences In the net photosynthetic rate of P. orientalis between soil water potentials of -0.061 MPa ～ -0.648 MPa. Average water use efficiency (WUE) increased as soil water potential decreased, but the influence mechanism of soil water stress on leaf WUE and photosynthetic rate for the two species were different evidently.     

A novel ribotoxin with ribonuclease activity that specifically cleaves a single phosphodiester bond in rat 28S ribosomal RNA and inactivates ribosome

A unique ribonuclease named Biota orientalis ribonuclease (Biota orientalis RNase) is purified to homogeneity from mature seeds of oriental arborvitae (Biota orientalis). The molecular mass of Biota orientalis RNase is about 13 kDa. When the concentration of Mg(2+) is 25 mM in the incubation buffer, the ribonuclease specifically cleaves the phosphodiester bond between C4453 and A4454 in region K (a region in domain VII) of 28S RNA in rat ribosome, resulting in inactivation of ribosome. Thus, it is a ribotoxin similar to alpha-sarcin. The region around C4453-A4454 in rat 28S rRNA is named "Biota orientalis RNase region." Rat ribosome treated by Biota orientalis RNase produces a small RNA fragment (S-fragment) that contains 333 nucleotides from the 3'-terminus of rat 28S rRNA. The distance between the cleavage-sites of alpha-sarcin (G4325) and Biota orientalis RNase (C4453) is 128 nucleotides. Under restricted conditions (25 mM Mg(2+)), the substrate specificity of Biota orientalis RNase is extremely high: it acts only on the "Biota orientalis RNase region" of the largest RNA in ribosomes from certain eukaryotes. The ribosome specifically damaged by Biota orientalis RNase is unable to EF-1alpha-dependently bind aminoacyl-tRNA, whereas the formation of the EF-2/GDP/ribosome complex is not affected. It is proposed that Biota orientalis RNase inactivates ribosome at least partially by interfering with the EF-1alpha-dependent binding of aminoacyl-tRNA to ribosome. Biota orientalis RNase might be a useful tool in studying the structure/function of ribosome.     

陕北黄土高原侧柏疏林草原的初步研究

侧柏疏林草原是陕北黄土高原森林草原地带东部重要群落类型之一,现仅残存于东北部的神府地区,常见者有4个类型:①茭蒿-侧柏疏林草原;②白草-侧柏疏林草原;③茭蒿+长芒草-侧柏疏林草原;④细叶柴胡+长芒草-测柏疏林草原。根据群落中乔木的更新状况分析,今后在气候不发生明显波动的情况下,侧柏疏林草原仍为该森林草原地带稳定的群落。     

Solar cues in the migratory orientation of the Savannah sparrow, Passerculus sandwichensis

Results clearly implicate the setting sun as a critical source of directional information in the migratory orientation of the savannah sparrow, Passerculus sandwichensis. Savannah sparrows allowed a view of both sunset and stars displayed oriented behaviour in biologically meaningful directions during spring and fall seasons. When the same individuals were denied a view of sunset, and tested under the stars alone, disorientation characterized their behaviour. Furthermore, birds allowed a view of sunset, but tested under ‘overcast’ night skies (no stars visible), displayed well-oriented behaviour indicating the sufficiency of sunset. Experiments in which the migrant's internal chronometer was shifted suggested a fixed-angle (menotactic) response to the sunset cue rather than a time-compensating compass mechanism. I believe stars are valuable to this migrant as celestial reference points. Orientational information gained at the time of sunset is transferred to stars on a nightly basis. The relationship between solar and stellar cues is apparently hierarchical in the savannah sparrow. Information necessary to select the appropriate migratory direction is gained from the primary cue, the setting sun, while maintenance of that heading is dependent on a secondary cue, probably the stars.     

Consumption rate, functional response and preference of the predaceous mite Iphiseius degenerans to Tetranychus urticae and Eutetranychus orientalis

The functional response of females of the phytoseiid mite, Iphiseius degenerans (Berlese), to increasing densities of females of its prey, Tetranychus urticae Koch and Eutetranychus orientalis Klein, on bean leaves, were studied under laboratory conditions. Our results indicated that the predator consumed significantly more items of E. orientalis than of T. urticae at all densities treatments. Daily consumption of the predator increased with increasing prey density until a plateau was reached-maximum number of prey consumed was ca. 4 for T. urticae and ca. 12 for E. orientalis. A Type II functional response was determined by a logistic regression model. The highest estimated value a (instantaneous rate of attack) and the lowest value of T ( h ) (handling time) were found for the predator feeding on E. orientalis. Prey selection was evaluated by simultaneously presenting both prey species to the predator in various ratios and at increasing densities. I. degenerans showed a higher predation rate and higher preference for E. orientalis at all the ratios and prey densities tested. This may be due to the smaller size or the inactivity of E. orientalis and the inability of the predator to cope with the webbing of T. urticae. Our results suggest that I. degenerans can be considered a suitable biological control candidate based on its preference for E. orientalis in the Mediterranean region.     

Integration of environmental stimuli in the migratory orientation of the savannah sparrow (Passerculus sandwichensis)

Two ‘cue-conflict’ experiments were designed to evaluate the role of (1) solar cues at sunset and stars, and (2) solar cues at sunset and geomagnetic stimuli, in the migratory orientation of the savannah sparrow (Passerculus sandwichensis). A sunset and stars experiment exposed birds in the experimental group to a mirror-reflected sunset followed by an unmanipulated view of stars. Experimental birds shifted their migratory activity in accordance with the setting sun despite exposure to a normal night sky. The sunset and geomagnetism experiment exposed birds in the experimental group to a simultaneous shift in both the position of sunset and the earth's magnetic field. Again experimentals shifted their activity in accordance with the setting sun rather than the artificially shifted magnetic field. Savannah sparrows probaly use stars as celestial landmarks to maintain a preferred direction and do not reorient their activity when exposed to an alternative cue once a direction is established. Moreover, savannah sparrows with experience of migration do not require geomagnetic information in order to use the solar cues available at sunset to select a migratory direction.