New mite-borne virus isolates from rakkyo,shallot and wild leek species

Flexuous viruses were transmitted from rakkyo (Allium chinense) and wild leek species (especiallyA. commutatum) to plants of crow garlic (A. vineale), by transfer of dry bulb mites. By electron microscope decoration tests using three antisera and by inoculations onto test plants, it was concluded that from each of the two natural host species at least two viruses were isolated. The viruses from wild leeks are both pathogenic onAllium spp. and may be of economic importance. Decoration tests on a virus mixture from shallot obtained earlier, revealed another new mite-borne virus in this species. The mite-borne viruses ofAllium spp. appear to be very common; they are largely diverse and their identification remains difficult.     

枸杞瘿螨的生物学特性及其有效积温的研究

室内恒温条件下测定了枸杞瘿螨Aceria pallida Keifer的发育起点温度和有效积温。枸杞瘿螨产卵前期的发育起点温度和有效积温分别为7．23℃和50．99日度；卵和幼若螨期发育起点温度和有效积温分别为5．51℃和167．68日度；全世代的发育起点温度和有效积温分别为6．08℃和217．05日度。发育进度有效积温模型分别为4N4卵前=50．99／[T-7．23]；4N4卵幼=167．68／[T-5．51]和4N4世代=217．05／[T-6．08]。在15℃～35℃恒温条件下发育历期与温度呈负相关，其中在25℃～30℃之间时枸杞瘿螨发育快，数量多，该温度范围是枸杞瘿螨生长发育的最适温度。根据呼和浩特地区气象资料，枸杞瘿螨在呼和浩特地区1a发生的理论代数为10代～12代。     

毒死蜱、乙酰甲胺磷、阿维菌素防治枸杞瘿螨药效试验

枸杞生长期长，害虫种类多且危害严重。枸杞瘿螨是危害枸杞的主要螨类，危害广泛而严重。除4月中旬枸杞展叶，5月下旬，6月上旬新枝萌发瘿螨向嫩叶、新枝扩散而暴露于瘿外，其余时间都在瘿内危害，防治难度非常大。该试验在室内就40%毒死蜱、30%乙酰甲胺磷、0.9%阿维菌素3种药剂毒力及其对枸杞瘿螨防治效果进行试验检测，表明这3种药剂对枸杞瘿螨均有显著的防治效果，可以在生产中推广应用。     

A new tray-type arena to mass rear Neoseiulus baraki, a predatory mite of coconut mite, Aceria guerreronis in the laboratory

Neoseiulus baraki Athias-Henriot (Acari: Phytoseiidae) is an important predatory mite of the coconut mite, Aceria guerreronis Keifer (Acari: Eriophyidae) and attempts are now being made to evaluate the effectiveness of augmenting N. baraki to control coconut mite in the field. These studies require a steady supply of N. baraki in large numbers. One major constraint of the existing method to mass rear N. baraki on Tyrophagus putrescentiae Shrank (Acari: Acaridae) in a closed arena without a water barrier was frequent contamination of cultures by other mites. This paper describes the development of an efficient method to mass rear N. baraki in the laboratory with less monitoring and relatively minimal contaminants. Three box-type arenas and a tray-type arena were tested to mass rear T. putrescentiae. Mites were successfully developed on two box-type arenas and the tray-type arena, but the production (2197 mites per tray in 4 weeks) of T. putrescentiae was significantly higher on the tray-type arena. A 110-fold increase of T. putrescentiae was achieved in tray-type arenas in 4 weeks. None of the box-type arenas could be maintained more than 5 weeks without acarine and fungal contaminations. N. baraki could be successfully reared on the tray-type arena at least for 6 weeks. More than 4800 mites per tray, a 240-fold increase was achieved in 5 weeks when T. putrescentiae was added at 3-week intervals. Advantages and disadvantages of the new method are described.     

Mite-borne virus isolates from cultivated Allium species,and their classification into two new rymoviruses in the family Potyviridae

While testing several samples of onion and of vegetatively propagated garlic, sand leek and shallot from a number of countries, virus isolates with unusually flexuous particles were obtained by mite (Aceria tulipae) or sap transmissions. No aphid-borne poty-or carlavirus was transmitted by mites, and mite-borne virus isolates could not be transmitted by aphids. The mite-borne isolates did not react with antisera to aphid-borne potyviruses ofAllium spp. or with the Agdia potyvirus group monoclonal. In contrast to the mite-borne onion and garlic mosaic viruses reported in the literature, our mite-borne isolates induced no visible or only very mild symptoms inAllium spp., except isolates from shallot ‘Santé’ which caused diffuse striping. Heavily mite-infested test plants or plant samples showed streaking and malformation due to mite feeding (tangle-top). The mite-borne virus isolates could be classified with test plants and a discriminating antiserum into three groups, representing two viruses and a strain of one of them. They are tentatively named onion mite-borne latent virus (OMbLV), garlic strain of this virus (OMbLV-G), and shallot mite-borne latent virus (SMbLV). Mite transmission, length of virus particles (ca. 700 to 800 nm), and the presence of granular inclusion bodies in infected tissue indicate that the viruses belong to the mite-borne genusRymovirus of the familyPotyviridae. OMbLV from shallot and onion, and OMbLV-G from garlic and sand leek, can be assayed onChenopodium murale but differ in their natural hosts. They are very common. SMbLV, to whichC. murale does not react, was isolated from shallot originating from Asia and Russia.     

新疆奇台县无芒雀麦穗肿病的防治

采用良种繁育体系，结合早春火烧与重复放牧茬地，早春和晚秋灌水，轮作倒茬，深翻，浸种和药剂防治等措施对新疆奇台县无芒雀麦穗肿病进行了防治。结果表明，这些方法均有不同程度的防治效果，结合使用可有效地防治瘤瘿螨的发生及危害。     

奇台无芒雀麦品种比较试验

1988～1990年在乌鲁木齐市老满城进行了奇台无芒雀麦、昭苏无芒雀麦、八农无芒雀麦、林肯无芒雀麦和老芒麦(CK)的品种比较试验。结果表明奇台无芒雀麦产草量很高,极显著地高于对照老芒麦,与林肯无芒雀麦和八农无芒雀麦均属于丰产型品种,其生长速度和再生速度快,饲草品质好,种子产量表现最高,并且抗病虫害能力较好,是新疆优良的禾本科牧草品种,在生产中可以取代老芒麦。奇台无芒雀麦是地方品种,个体间在许多性状上一致性较差,提高该品种的一致性和生长,再生的整齐度是今后育种的重要目标。     

生物农药混配对枸杞瘿螨联合毒力的测定

采用浸渍法,在室内条件下测定了1.8%阿维菌素EC与2.5%鱼藤酮EC、1%苦参碱AS、0.5%藜芦碱EC、10%吡虫啉SG混配制剂对枸杞瘿螨的联合毒力.试验结果表明,1.8%阿维菌素EC与2.5%鱼藤酮EC、1%苦参碱AS、0.5%藜芦碱EC对枸杞瘿螨均有显著的增效作用,其中1.8%阿维菌素EC与1%苦参碱AS有效成分比为1:1.4混配物增效作用最强,共毒系数(CTC)最高,为479.9,而1.8%阿维菌素EC与10%吡虫啉SG有效成分比为1:11.2,共毒系数(CTC)为52-3,表现为拮抗作用.     

拉哥钝绥螨对荔枝瘤瘿螨的功能和数值反应

研究了拉哥钝绥螨捕食荔枝瘤瘿螨的功能反应和数值反应,进行了拉哥钝绥螨雌成螨捕食量与猎物荔枝瘤瘿螨密度、捕食量与拉哥钝绥螨自身密度之间、拉哥钝绥螨雌成螨产卵量与荔枝瘤瘿螨密度之间、拉哥钝绥螨发育历期与捕食量等成对便量之间的关系的试验。结果表明：在一定的猎物密度范围内,随着猎物密度的增长,拉哥钝绥螨成螨捕食量逐渐增加,两者之间有密切的相关性。在室温为25℃、相对湿度为80％～85％的实验条件下,其对荔枝瘤瘿螨成螨的日捕食量上限为37头;当猎物密度不变时,拉哥钝绥螨随着自身密度的增加,个体的捕食量减少;当猎物密度在一定范围内逐渐增大时,其平均产卵量也相应增加,而其发育历期则随捕食猎物量在一定范围内逐渐增大而相应缩短。     

荔枝瘿螨生物学及其防控研究进展

荔枝瘿螨是为害荔枝的一类重要害虫,体型小、种类多、分布广。随着荔枝种植面积的扩大、荔枝果实和荔枝苗木的远距离运输,给荔枝瘿螨的传播创造了条件。本文主要总结了国内荔枝瘿螨的研究结果,阐明了荔枝瘿螨的种类及其分布特点;以荔枝瘤瘿螨Aceria litchii和荔枝分位瘿螨Disella litchii为例,阐述了荔枝瘿螨的生物学特性及种群动态、天敌、寄主(荔枝品种)的抗虫(瘿螨)性、种群监测技术、防治措施等方面的研究进展。结合产业发展,指出生产中亟待解决的问题和研究方向,并提出建立“以农业防治为基础、生物防治相结合、化学防控为辅助”的荔枝瘿螨综合防控技术体系的具体措施。