Trap catches of the sweetpotato whitefly （Homoptera： Aleyrodidae） in the Imperial Valley, California, from 1996 to 2002

An outbreak of the sweetpotato whitefly, Bemisia tabaci （Gennadius）, biotype B occurred in the Imperial Valley, California in 1991. The insects destroyed melon crops and seriously damaged other vegetables, ornamentals and row crops. As a result of the need for sampling technology, we developed a whitefly trap （named the CC trap） that could be left in the field for extended time periods. We used the traps to monitor populations ofB. tabaci adults during year-round samplings from 1996 to 2002 to study variations in the weekly trap catches of the insect. The greatest number ofB. tabaci adults was recorded in 1996, followed by a continuing annual decrease in trap catches each year through 2002. The overall decline of B. tabaci is attributed in part to the adoption of an integrated pest management （IPM） program initiated in 1992 and reduced melon hectares from 1996 to 2002. Other factors may also have contributed to the population reductions. Seasonally, B. tabaci trap catches decreased during the late summer and fall concurrent with decreasing minimum tempera- tares that are suggested to be a significant factor affecting seasonal activity and reproduction.     

卡拉麦里山有蹄类野生动物保护区野驴的夏季栖息地及种群数量

1982年7月航空调查了卡拉麦里山有蹄类野生动物保护区内野驴Equus hemionus hemionus Pallas的夏季栖息地及种群数量。见野驴358头,平均密度为每平方公里0.02头,多集中栖居在保护区的东北部。初步分析影响野驴夏季栖息地的因素是水、地形及人为干扰。     

庆祝《昆虫学报》创刊三十五周年

值此中华人民共和国成立三十六周年之际,迎来了《昆虫学报》创刊三十五周年。这是一件值得祝贺的事。自从党的十一届三中全会以来,我国形势有了巨大进展。十二届三中全会又作出了关于经济体制改革的决定,鼓舞了全国人民的雄心壮志。展现在我们面前的政通人和,一派兴旺发达的景象,无论在工农业生产和各条战线都取得了伟大成就。科学工作在此大好形势下,蒸蒸日     

中国钩蛾亚科(鳞翅目:钩蛾科)——距钩蛾属Agnidra Moore, 1868

本文记述钩蛾亚科距钩蛾属13种,内有3亚种,包括4新种及1新亚种,此记录已超过前人记载。为节省学报篇幅,旧种记述略去,新种亦只扼要记述。详细记述将来另行发表。模式标本存于动物研究所。 中国的钩蛾科只有两亚科,其中山钩蛾亚科已整理发表,钩蛾亚科将陆续发表。本科与圆钩蛾科(已发表)的地理分布最为奇特,绝大多数种类为中国产。研究其发源地及扩展方向,颇饶兴趣。     

The nitrogen balance of Raphanus sativus x raphanistrum plants. II. Growth, nitrogen redistribution and photosynthesis under NO3− deprivation

Abstract. Wild radish plants deprived of, and continuously supplied with solution NO^?₃ for 7 d following 3 weeks growth at high NO^?₃ supply were compared in terms of changes in dry weight, leaf area, photosynthesis and the partitioning of carbon and nitrogen (NH₂-N and NO^?₃-N) among individual organs. Initial levels of NO^?₃-N accounted for 25% of total plant N. Following termination of NO^?₃ supply, whole plant dry weight growth was not significantly reduced for 3 d, during which time plant NH₂-N concentration declined by about 25% relative to NO^?₃-supplied plants, and endogenous NO^?₃-N content was reduced to nearly zero. Older leaves lost NO^?₃ and NH₂-N, and roots and young leaves gained NH₂-N in response to N stress. Relative growth rate declined due both to decreased net assimilation rate and a decrease in leaf area ratio. A rapid increase in specific leaf weight was indicative of a greater sensitivity to N stress of leaf expansion compared to carbon gain. In response to N stress, photosynthesis per unit leaf area was more severely inhibited in older leaves, whereas weight-based rates were equally inhibited among all leaf ages. Net photosynthesis was strongly correlated with leaf NH₂-N concentration, and the relationship was not significantly different for leaves of NO₃^?-supplied compared to NO^?₃-deprived plants. Simulations of the time course of NO^?₃ depletion for plants of various NH₂-N and NO^?₃ compositions and relative growth rates indicated that environmental conditions may influence the importance of NO^?₃ accumulation as a buffer against fluctuations in the N supply to demand ratio.     

硝基精氨酸抑制巨噬细胞内一氧化氮合成的研究

运用体外分离培养方法,研究硝基精氨酸(N^ω-nitro-L-arginine,L-NNA)抑制巨噬细胞内诱生性一氧化氮合成.发现L-NNA能抑制一氧化氮的合成,而且在一定的范围内,其抑制作用随L-NNA作用剂量的增大而增强;在培养体系中加入L-精氨酸能够逆转这种抑制作用.说明L-NNA可能通过竞争性地与诱生型一氧化氮合成酶(iNOS)活性位点结合,抑制巨噬细胞内的一氧化氮合成.     

Detection of lettuce necrotic yellows virus by an enzyme-linked immunosorbent assay in plant hosts and the insect vector

An enzyme-linked immunosorbent assay (ELISA) system for the rapid detection of the plant rhabdovirus, lettuce necrotic yellows virus (LNYV) in plant hosts and individual aphid vector is described. The method has been shown to be reliable and sensitive, and to have a number of advantages over the conventional methods of detecting LNYV in plants and insects by infectivity tests.     

The effect of pollen grains on infections caused by Botrytis cinerea Fr

The addition of pollen to spores of Botrytis cinerea Fr. in droplets of distilled water stimulates spore germination, growth of germ tubes and lesion development. Aqueous diffusate from pollen is as effective as pollen grains, and frozen pollen is more stimulatory than freshly collected pollen. The presence of pollen grains reduces considerably the number of spores needed to allow infection to occur. The lost germination ability and infectivity of old spores is restored by pollen. The stimulatory effect of the presence of pollen has been demonstrated both in vitro and on the surfaces of strawberry petals, strawberry fruits and broad bean leaves. Complete removal of the source of pollen, the anthers from strawberry fruits, markedly affected the speed and severity of infections of strawberry fruits. On broad bean leaves the addition of pollen grains to spores induced the development of spreading aggressive lesions. Preliminary work indicates that the effective principle in pollen is water-soluble, dialysable and heat-stable. Although glucose and fructose are important components of diffusate, neither glucose solution nor fructose solution nor a mixture of the two showed as marked effects as did pollen. Orange juice produces similar effects.     

稻株上杀螟腈残留量的初步研究

本工作的试验结果表明杀螟腈是一种残效期短、基本上不污染稻株的低毒农药。它在田间自然环境条件下受外界气候环境影响,分解消失较快,特别是雨水冲刷更使它在水稻上的残留量剧降。但在室内控制条件下分解稍为缓慢。 田间药效试验指出,杀螟腈防治纵卷叶螟虽效果显著,但由于残效短,施药必需与害虫的发生关键时期紧密配合。     

棉蚜在棉田中的发生和扩散

棉田中的棉蚜是由棉蚜的越冬寄主植物上迁移而来,这已由试验证明。但当棉蚜到达棉田以后,如何由少成多地扩散开来,造成棉田的灾害,是我们防治棉蚜工作中极需了解的问题。大家知道当早期治了极少数的棉蚜便可以防止了它的大批发生,更重要的是免得棉株受害影响产量。由於棉蚜的繁殖力强大,在短期内便可由少成多由点及面,往往使人不易察觉它的发展过程和规律。同时便可以搅乱了我们的防治措施,而造成我们工作中的很大损失。