赤眼蜂寄生后亚洲玉米螟卵内保幼激素酯酶活力与蜕皮激素滴度的变化

采用放射化学法（RC）与放射免疫法（RIA）分别测定了被玉米螟赤眼蜂（Trichogramma ostriniae)寄生的亚洲玉米螟（Ostrinia furnacalis)卵内保幼激素酯酶活力与蜕皮激素滴度的变化。结果发现，被寄生的卵内，保幼激素酯酶活力和蜕皮激素滴度的变化在很大程度上反映了玉米螟赤眼蜂从卵到蛹的个体发育过程中体内激素的动态变化。与玉米螟卵内激素变化显不同，说明早期被寄生的玉米螟卵内进行的是玉米螟赤眼蜂的个体发育，而玉米玉米螟的胚胎发育受到了抑制。     

Effects of Ufra Disease on Yield Loss of Deepwater Rice in Bangladesh

Abstract

Ufra, caused by the stem nematode, Ditylenchus angustus (Butler, 1913) Filipjev, 1936, is a serious disease of deepwater rice in southern Bangladesh. It was studied between 1977 and 1979 as part of a joint project with the Overseas Development Administration at the Bangladesh Rice Research Institute. Three symptom types are distinguished according to the extent of panicle emergence: Ufra1 (none), Ufra2 (partial) and Ufra3 (complete). All three represent total loss from that panicle. The number of Ufra2 as a percentage of the total number of panicles present in a specified area is selected as a disease index (UfraII). A function relating yield to the level of UfraII is proposed on the basis of selective samples from a field with a well-defined ufra patch. This function is compared with another derived from random samples in different fields along a linear transect through an area where ufra is endemic. Loss of panicle density, i.e. panicles/m², is identified as a major component of yield loss, approximately equal to the loss associated with all three symptom types added together. Although severe and widely distributed throughout the southern part of the deepwater rice region in 1977 and 1978, it was very difficult to find in 1979 when there was a spring drought. Ufra is worse in wet years, in areas which flood early, and where the crop is harvested late. The length of the over-winter decay phase appears to be a critical factor regulating the survival of the pathogen from one season to the next. This suggests an approach for ufra control.     

Is the parasitization rate of<Emphasis Type="Italic">Diaeretiella rapae</Emphasis> influenced when<Emphasis Type="Italic">Brevicoryne brassicae</Emphasis> feeds on<Emphasis Type="Italic">brassica</Emphasis> plants?

The development time and parasitization rate ofDiaeretiella rapae (M’Intosh) onBrevicoryne brassicae (L.) feeding on differentBrassica cultivars was studied in the laboratory at 20°C. The shortest development time from egg to adult parasitoid was 11.6 days on cabbage cv. ‘Yalova 1’ and the longest was 12.1 days on turnip cv. ‘Antep’ and rapeseed cv. local variety. Females lived significantly longer than males on the host plants used in the study. Females and males had the shortest longevity on rapeseed at 11.1 and 5.1 days, respectively. The highest percent parasitism ofB. brassicae byD. rapae was found on cabbage (40.20%), and the lowest was recorded on turnip (32.64%). Our results demonstrate that parasitism rate could be influenced by the plant quality, probably due to the nutritional status of the aphids or to toxic compounds ingested through the plant. Cabbage, cauliflower and broccoli were found to be suitable plants for the parasitoid, considering the development time of pre-adults, and the parasitization rate ofD. rapae onB. brassicae. http://www.phytoparasitica.org posting Jan. 23, 2007.     

河南麦田蚜茧蜂研究初报

1982—1986年,对河南各小麦产区的蚜茧蜂发生情况进行了调查,共发现7种蚜茧蜂,其中以烟蚜茧蜂和燕麦蚜茧蜂发生量最大,持续时间最长。在麦田,蚜茧蜂主要寄生麦长管蚜和麦二叉蚜的2—3龄若虫,麦长管蚜的被寄生率最高,占总寄生量的79%。室内饲养和田间观察表明,蜂羽化后半小时即可交尾,盛期在早上6—8点半和下午5—7点,产卵盛期在早上8—10点和下午4—6点。一头雌蜂可连续寄生3—5头蚜虫,多者达18头。每头蚜虫只被蜂产卵一次,发育成僵蚜后只出一头蜂,凡是出多头蜂者均为重寄生蜂,蚜茧蜂有产雄孤雌生殖现象。     

Parasitoids of the grapeleaf skeletonizer, Harrisina brillians Barnes and McDunnough (Lepidoptera: Zygaenidae) in northwestern Mexico

Nine species of parasitoids were collected from pupae of the grapeleaf skeletonizer, Harrisina brillians Barnes and McDunnough (Lepidoptera: Zygaenidae) in Caborca, Sonora in northwestern Mexico. The parasitoids detected and the percentage parasitization observed were: Ametadoria misella (Wulp), (Diptera: Tachinidae) 29.3%; Hockeria rubra (Ash.), and a species from the genus Euchalcidia (Hymenoptera: Chalcididae), plus five suspected species, all from the family Eulophidae, and a species from the genus Arachnophaga (Hymenoptera: Eupelmidae), 21.6%. Mortality due to unknown causes was 13.7%. In all, 64.6% parasitization and mortality was observed. The most abundant parasitoids were the five unidentified suspected species of Eulophidae, which corresponded to 46% of the total collected; the species from the genus Euchalcidia made up 31% of the total; the tachinid fly, Ametadoria misella comprised 15%; Hockeria rubra comprised 8%, and the species from the genus Arachnophaga comprised < 1%.     

菟丝子寄生后紫茎泽兰的叶绿素及酶类活性变化研究

为寻找防治紫茎泽兰的新方法,利用菟丝子对紫茎泽兰的寄生作用,对寄生后紫茎泽兰的叶绿素、POD、SOD和PAL酶的OD值及其MDA含量的变化进行了测定,结果表明:紫茎泽兰被菟丝子寄生后其叶绿素含量下降,POD和SOD酶活性下降,PAL酶活性则上升,菟丝子防控紫茎泽兰具有一定的可行性.     

不同波长LED光源对稻螟赤眼蜂发育与繁殖的影响

为探究不同波长LED光源对稻螟赤眼蜂生长发育及繁殖的影响,本研究在实验室条件下,采用6种不同波长LED光源,400 nm（紫光）、450 nm（蓝光）、530 nm（绿光）、580 nm（黄光）、630 nm（红光）和6000 k（白光）,在稻螟赤眼蜂生长发育及繁殖过程中进行光照处理,观察统计其母代的单雌寄生数、子代的单雌寄生数、寿命、发育历期及雌蜂占比。试验结果表明,不同波长LED光照处理下稻螟赤眼蜂的寄生数、寿命、发育历期及雌蜂占比等指标均有显著性差异。在黄光处理下,母代及子代的寄生数量均受到了明显的抑制,但是黄光在延长稻螟赤眼蜂寿命上起到了较为显著的效果。红光处理下稻螟赤眼蜂子代的发育历期为235 h,红光明显延长了稻螟赤眼蜂子代的发育历期,对稻螟赤眼蜂的高效繁育起到了抑制作用。蓝光则可以增加种群中的雄蜂数量,使种群雌雄性比向雄性一方偏移,不利于稻螟赤眼蜂种群的繁育及应用。综上所述,不同波长的LED光源对稻螟赤眼蜂的生长发育及繁殖起到一定的调控作用,在繁育的过程中,应该避免使用黄光、蓝光等有抑制效果的光源,对稻螟赤眼蜂的实际应用提供一定的技术指导,并为进一步深入研究稻螟赤眼蜂对环境的适应性及提升其在生物防治中大规模饲养的扩繁效率提供了重要的理论依据。     

Biodiversity of Entomophagous Fauna of Spilarctia obfiqua （Walker） and Their Potential for Biological Control

Investigations on the biodiversity of entomophagous fauna of Spilarctia obiqua revealed the occurrence of twelve different natural enemies, out of which five Hymenoptera, four Dipterous parasitoids and three predators viz., two Hemiptera and one Neuroptera were found attacking different stages of the host. Biological notes on four parasitoids viz. Cotesia obliqua, Goniophthalmus halli, Meteorus sp. and Cotesia （glomeratus group） were also made. Estimation of field parasitization of the three species of entomophagous insect viz. C. obliqua, G. halli, and Meteorus sp. revealed that the C. obliqua was the most dominant parasitoid and maximum 21.6 per cent parasitization was observed during the month of October followed by 16% of by Meteorus and 14% by G. halli during February. Conservation of the biodiversity of these entomophagous fauna is advocated for BIPM programme.     

菜蛾盘绒茧蜂寄生对寄主小菜蛾脂肪体细胞变态的影响

结果表明,小菜蛾(Plutella xylostella L．)幼虫被菜蛾盘绒茧蜂(Cotesia plutellae(Kurdjumov))寄生后,不能正常化蛹,寄主的脂肪体细胞变态受到明显的抑制．在多分DNA病毒(Polydnavirus,PDV)、畸形细胞等寄生因子存在状态下,经蛋白质双向电泳分析表明,不同寄生状态的小菜蛾脂肪体蛋白组分存在明显差异,与正常发育的寄主脂肪体完全不同．说明菜蛾盘绒茧蜂PDV、畸形细胞以不同的调控方式影响寄主脂肪体的蛋白合成和积累,以满足寄主体内幼蜂发育时营养的需求．