Breeding-site productivity of the swamp forest mosquitoes Mansonia bonneae and Ma.dives in Sarawak, East Malaysia

Studies on larval population densities and adult emergence rates of the Brugian filariasis vectors Mansonia bonneae Edwards and Ma. dives Schiner were conducted in freshwater swamp forest bordering the Sadong River, Serian District, Sarawak, East Malaysia, during 1984-85. Three species of aquatic host-plants in the Family Araceae were identified as supporting immature stages of the Ma. bonneae/dives complex. Proportions of positive plants were 4.7%, 6.5% and 3.4% with 6.4 +/- 2.6, 7.3 +/- 2.8 and 10.1 +/- 1.1 larvae per positive plant, respectively, for the plant species Homalomena cordata Schott, H. rostrata Griffiths and Hydrostemma motleyi (Hook. f.) Mabberley. These data indicate no significant preferences between the three types of host-plant. Detailed monitoring of the host-plant H. cordata revealed no significant monthly fluctuations in larval density per plant nor the proportion of positive plants. 11.6% of larvae were Ma. dives and 88.4% were Ma. bonneae. Mean daily yields of Ma. bonneae/dives adults per square metre of H. cordata vegetated water surface were 0.45 males plus 0.57 females during the wet season (December-February) compared with 0.2 males plus 0.31 females during the dry season (June-August). Thus output of adults per plant was approximately halved, and suitable breeding areas were further reduced, during the dry season. By extrapolation from these rates, a crude mean estimate for productivity of Ma. bonneae/dives females is 1.6 million per hectare per annum in swamp forest habitats vegetated with any of the host-plants studied.     

Synthesis of Substance P

SUBSTANCE P has been synthesized by the solid-phase procedure of Merrifield^1,2 according to the sequence H-Arg-Pro-LysPro-Gln-Gln-Phe-Phe-Gly-Leu-Met-NH₂ reported in the previous letter.     

昆虫神经毒素的研究:各种神经毒剂引起毒素的产生

用五类(七种)神经毒性的杀虫药剂,对美洲(虫非)蠊测定了它们能否引起血淋巴中毒素的产生。DDT、溴氰菊酯及六六六均能引起血淋巴中毒素的产生,而E605、西维因、巴丹及杀虫脒均无此效果。纸层析及薄层层析,用标准样品(酪氨酸、酪胺、苯乙胺、L-亮氨酸及异戊胺)作比较,测定了这一产生的血淋巴中的毒素乃是酪胺,或主要是酪胺。增效试验,证明了杀虫脒与DDT或溴氰菊酯合用时,能增加酪胺的产量。讨论了这一毒素产生的条件,以及这一毒素有可能不是单一成分,而是几种单胺及氨基酸的复合物,但酪胺为其主要成分。     

蛴螬病原菌(Bacillus sp.)的初步研究

蛴螬是农林生产上的重要地下害虫,由于长期栖居地下,防治较为困难。多年实践证明,采用综合防治措施可以有效地控制为害,利用病原微生物防治蛴螬是综合防治中的一个环节,是值得今后深入研究的课题。 1975年9月,我们在河北省任邱县白洋淀附近玉米地采到数头自然患病的阔胸犀金龟(Pento-don patruelis Frivaldszkz)三龄幼虫。1976年5     

桃小食心虫生物学的研究——果实对幼虫蛀果、成活、生长发育及滞育的影响

桃小食心虫(Carposina niponensis Wals)是我国苹果、梨上的重要害虫,初孵幼虫在果面爬行片刻,即蛀入果内。幼虫能否入果,除受捕食性天敌和风雨等外界条件影响之外,与果实表皮组织有关系,蛀入果内幼虫的成活数量和生长情况亦受果肉组织及果实内含物的直接影响。因此,研究食料条件与桃小食心虫发生数量的关系,对提高该虫现有     

LYSINE METABOLISM IN THE RAT BRAIN: BLOOD—BRAIN BARRIER TRANSPORT, FORMATION OF PIPECOLIC ACID AND HUMAN HYPERPIPECOLATEMIA

Through the use of intravenous pulse injection of L-[U-¹⁴C] lysine, the blood-brain barrier transport of L-lysine was studied. The uptake of L-lysine plus metabolites in the brain remained essentially unchanged at approx 0.002–0.005 nmol/g in the low dose (3μg per kg body weight) injection, and 20–40 nmol/g in the high dose (30 mg/kg) injection throughout the time intervals of up to 60 min. The uptake of L-lysine plus metabolites in the heart, however, decreased substantially from 0.03 to 0.003 nmol/g in the low dose injection and from 320 to 62 nmol/g in the high dose injection. The plasma to heart uptake ratio only decreased slightly through the 60 min period: from 6 to 2 in either the low or high dose L-lysine injection. The plasma to brain uptake ratio, however, decreased rapidly from a high of 62 to a low of about 4 in either the low or high dose injection throughout the 60-min time course. Study of labeled L-pipecolate formation in the plasma and individual organs indicates that this compound was formed only in the brain to a significant level within 0.5 min of ¹⁴C-L-lysine intravenous pulse injection. Labeled pipecolate was recovered from heart, liver, kidney and plasma in significant quantities only at 2 min or later after pulse-injection. It is concluded that the blood-brain barrier of L-lysine in the rat is not particularly strong and that the rat brain may be primarily responsible for L-pipecolate synthesis from L-lysine. The possible etiology of human hyperpipecolatemia is also discussed in light of the current findings.     

瘿绵蚜属五新种和三堡瘿绵蚜新属新种

《蚜虫概论》(1957)中瘿绵蚜属仅有2种。本文记载9种,包括5新种。另记述三堡瘿绵蚜新属新种。这些蚜虫都为害杨树,在枝或叶上形成虫瘿。 中国已知的9种瘿绵蚜和二堡瘿绵蚜(节省篇幅,旧种记述略): 1.早螺瘿绵蚜Pemphigus protospirae Lichtenstein (图1-6,66)寄主:青杨。分布:北京;欧洲。 2.柄脉叶瘿绵蚜 Pcmphigus anobursarius Chang 新种 3.杨柄叶瘿绵蚜Pemphigus populi Courchet(图13—17,65)寄主:小叶杨。分布:北京、黑龙江、     

中国森林生态系统林冠层降雨截留特征

森林生态系统作为陆地生态系统的主体,其发达的林冠层通过调节降水量、改变降水强度等深刻影响着流域全过程水文通量及水分输出。以中国广泛开展的典型森林降雨再分配过程的年尺度监测数据为基础,揭示中国不同类型森林生态系统的降雨再分配及林冠层降雨截留特征,阐明森林生态系统林冠层截留特征与降雨、植被要素的关系。结果表明:我国不同森林生态系统年穿透雨量处于141.4-2450.0 mm之间,年穿透雨率为36.3%-92.3%。5种典型森林生态系统多年平均穿透雨量((445.3±252.9)-(1230.6±479.6) mm)占同期多年平均降雨量的(72.6±9.2)%-(77.4±8.9)%。不同森林生态系统年树干茎流量介于0-508.2 mm之间,占同期年降雨量的0-25.8%。5种典型森林生态系统树干茎流量多年平均值((9.8±17.3)-(87.8±81.6) mm)占同期多年平均降雨量的(1.4±1.9)%-(5.4±4.6)%。不同森林生态系统林冠层年降雨截留范围在25.7-812.9 mm之间,占年降雨量的4.2%-55.6%。5种典型森林生态系统多年平均林冠截留量((154.2±81.6)-(392.2±203.5) mm)占同期年平均降雨量的(18.7±7.4)%-(25.9±8.3)%。进一步分析表明,我国森林生态系统穿透雨量、树干茎流量和林冠层截留量随观测区年降雨量的增加而呈显著增大(P<0.05),年穿透雨率、年树干茎流率随年降雨量的增加呈显著线性上升趋势(P<0.05),而年林冠截留率与年降雨量呈显著的负相关关系(P<0.01),降雨量、叶面积指数是深刻影响森林生态系统林冠层降雨截留率等特征的重要因素。整体上,不同类型森林生态系统林冠截留降雨能力存在明显差异,林冠层截留率突出表现为:落叶林大于常绿林、针叶林大于阔叶林。     

农业害虫高温调控的研究进展

利用高温控制害虫具有无残留、无污染的优点,高温对害虫的致死作用在害虫种群生态调控研究和保证食品安全,促进绿色农产品生产中有潜在的应用价值。本文综述了国内外影响高温对昆虫致死效应的因子和应用高温防治害虫的技术方法。影响高温致死效率的因子包括：温度的高低和处理时间的长短,不同温度的处理顺序和预适应温度等温度处理模式,缺氧等逆境胁迫,昆虫种类及其发育阶段等。利用高温防治害虫的技术包括：温室内,在生长期采用高温闷棚,在播前产后用热蒸汽处理苗床或培养土。在田间,利用对作物安全的瞬间明火烧伤害虫敏感部位;利用害虫的趋光性点明火诱杀;作物生产空闲期采取覆膜封闭,利用太阳能产生高温、缺氧条件,减少或根除土传病菌和害虫。在仓库,利用微波、无线射频或流动床产生的热空气在短时间内升温,杀死储粮害虫。在储运场所,用热水浸泡、热蒸汽熏蒸、高温结合低氧或低温以及盐水浴结合无线射频处理鲜活农产品,杀死害虫。本文最后讨论了该领域存在的问题,指出阐明高温对昆虫影响的机理,降低防治成本,减轻作物和环境损害,是高温控制害虫技术推广应用的关键。