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1.
After about 25 years of intensive research a substantial moment of information has accumulated on the basic biology of Prostephanus truncatus in stored products. This article reviews the literature on the geographical distribution, biotypes, symbiotic associations, mating and flight behaviour, oviposition, and development on both agricultural and non-agricultural hosts. The current knowledge about the nutritional biology (including the role of symbionts) and host finding behaviour (including the inter-linked roles of plant chemicals and the insect's own pheronones) are highlighted as research areas which deserve future attention. In addition, few studies have been conducted to determine the extent to which the biology of P. truncatus permits it to survive and reproduce in non-agricultural environments. These areas of study should be pursued as possible routes to providing more effective integrated pest managements strategies for the larger grain borer.  相似文献   
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黄瓜对B型和Q型烟粉虱取食的不同生理生化反应   总被引:3,自引:0,他引:3  
【目的】烟粉虱(Bemisia tabaci)B生物型(中东-小亚细亚1种)和Q生物型(地中海种)是农业生产上的重要害虫,杀虫剂的滥用造成害虫产生抗药性,并危害到生态安全与人类健康,因此,制定安全有效的防控措施十分必要。利用植物抗性是害虫综合治理的重要方面,论文旨在探讨黄瓜植株被B型、Q型烟粉虱取食后营养和防御相关酶系的反应差异,阐明黄瓜植株应对烟粉虱取食防御反应的生理生化机制,为利用植物抗性防控不同烟粉虱生物型提供依据。【方法】以实验室长期培养的B型、Q型烟粉虱和黄瓜博杰1号品种为供试材料,在黄瓜植株4片真叶期分别接B型、Q型烟粉虱成虫200头,同时分别以不接虫的黄瓜植株为对照,在烟粉虱持续取食1、3、5、7、9 d后,分别测定黄瓜叶片中营养物质(可溶性糖和可溶性蛋白质)含量、多酚含量、防御物质合成相关酶活性以及保护酶活性。【结果】在整个实验期内,B型烟粉虱取食3 d后,黄瓜叶片中可溶性糖和蛋白含量均显著高于对照植株,而Q型烟粉虱取食1 d后,黄瓜叶片内可溶性糖和蛋白质含量均比对照植株显著下降。黄瓜叶片中多酚含量及其合成关键酶苯丙氨酸解氨酶(PAL)活性在两种生物型烟粉虱取食后均升高,但对Q型烟粉虱取食更敏感,即活性更高。B型烟粉虱取食后引起黄瓜叶片中超氧化物歧化酶(SOD)和过氧化氢酶(CAT)酶活性均升高、过氧化物酶(POD)酶活性下降;而Q型烟粉虱取食后则引起SOD活性升高、POD和CAT酶活性下降。【结论】烟粉虱B型和Q型取食诱导黄瓜的营养物质含量、防御酶或保护酶活性发生不同变化。B型、Q型烟粉虱取食均能诱导黄瓜植株防御物质多酚的合成,导致叶片内多酚含量升高;但二者对黄瓜营养物质及保护酶的活性诱导存在差异,B型烟粉虱诱导黄瓜营养物质增加,Q型取食导致营养物质下降,而黄瓜防御物质在Q型烟粉虱取食后活性更强。两种烟粉虱生物型在寄主适应性上存在差异,在制定防治策略上,应该因不同烟粉虱生物型或不同寄主植物而有所不同。  相似文献   
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Abstract

Seeds of 22 rice strains carefully selected for resistance by continuously testing under high gall midge pressure at Cuttack (Orissa) through 1979–198’ and three such strains from Raipur (Madhya Pradesh) were assembled along with susceptible standard Jaya and were simultaneously tested at both locations (Cuttack and Raipur) against the Asian rice gall midge Orseolia oryzae Wood‐Mason in wet season 1985. Eighteen entries proved resistant at both locations. While Asha, Usha and Samrudhi were resistant at Raipur and susceptible at Cuttack, Shakti IR.36, IR.50, Daya and Pratap were resistant at Cuttack and susceptible at Raipur, based on which characterization of the Cuttack (Orissa) and Raipur (Madhya Pradesh) gall midge biotypes was proposed. In gall midge biotypes testing, meticulous selection of only such entries with consistently proven resistance to gall midge at least at one location, carrying forward seed from resistant plants only each season under high gall midge pressure (with 100% seedling/hill infestation in oft repeated susceptible check) and classification of test entries at the strain's level either as resistant or as susceptible without scope for the third ‘moderate’ category to intervene, generally ignored by earlier workers, were stressed.  相似文献   
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In India, brucellosis was first recognised in 1942 and is now endemic throughout the country. The disease is reported in cattle, buffalo, sheep, goats, pigs, dogs and humans. B. abortus biotype-1 in cattle and buffaloes and B. melitensis biotype-1 in sheep, goats and man are the predominant infective biotypes. The long-term serological studies have indicated that 5% of cattle and 3% of buffaloes are infected with brucellosis. Economic losses due to brucellosis in livestock are considerable in an agrarian country like India. There is no organised and effective brucellosis control programme in the country. With the indigenous development of serum and milk based ELISA kits, the population survey of the disease has been undertaken on a large scale in several states and plans for the control of the disease through calf-hood vaccination are being worked out. An innovative approach—Bovine Brucellosis Progressive Control Programme (BBPCP) is targeted to overcome the basic problems of ban on cow slaughter, distress sale of animals following the positive serological diagnosis of brucellosis and absence of a disease control strategy. The work plan for the implementation of BBPCP is presented.  相似文献   
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Given the morphological characters of purple crabs identical with that of the tea-green ones except the body color, it is expected that the purple crabs and the tea-green ones were from the same species. In order to identify the phylogenetic relationships between them at the molecular level, we amplified and compared two conserved mitochondrial gene fragments of purple and tea-green crabs through PCR-SSCP and DNA sequencing analyses. The results showed that there was no distinct variation of DNA bands of both the CO1 and 16srRNA genes detected in polyacrylamide gels through SSCP analysis between purple and tea-green crab samples, and the following sequence analysis of color-different crab individuals presented 99.81% and 99.91% nucleotide sequence identity of the CO1 and 16srRNA genes respectively. These indicated that there was no species or subspecies differentiation between purple and tea-green crabs, meaning that they belonged to the same species, Portunus trituberculatus.  相似文献   
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The fitness of cotton aphid, Aphis gossypii Glover, on different host plants was studied. The results showed that the cotton aphid population in Nanjing formed host preference bio-types on cucumber and cotton. The aphids from cotton and cucumber could not inter-transplant successfully between the two host plants. The apterous and alate offspring of stem mother from hibiscus could not survive, reproduce and form population normally when they were transplanted to cucumber and water melon, but they could form normally when transplanted to cotton and muskmelon. There was no significant difference between the stylet length of cotton aphids from cucumber and cotton, so the stylet length was not the cause of the host preference. When the aphids originated on hibiscus were transplanted to cotton, water melon and muskmelon, the stylet could reach host phloem to absorb host plant‘s nutrients, but it couldn‘t when transplanted to cucumber. Cotton aphid can feed on muskmelon without secretion of water-soluble saliva. It could be concluded that the two host biotypes of cotton aphid came from different winter host plants.  相似文献   
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BACKGROUND: The cotton whitefly, Bemisia tabaci (Gennadius), is a cryptic species complex, and members of the complex have become serious pests in Pakistan because of their feeding and their ability to transmit cotton leaf curl virus (CLCuV). Here, an analysis was made of the identity of B. tabaci collected from cotton and a range of non‐cotton hosts in the cotton‐growing zones in Punjab and Sindh, the main cotton‐producing provinces of Pakistan, using a portion of the mitochondrial cytochrome oxidase 1 gene. The geographic distribution of the different members of the complex was then compared with the incidence of CLCuD. RESULTS: Using the Dinsdale nomenclature, the results revealed three putative species, Asia 1, Asia II 1 and Middle East‐Asia Minor 1. Asia II 1 (also referred to in the literature as biotypes K, P, PCG‐1, PK1, SY and ZHJ2) was only recorded from Punjab cotton plants, whereas Asia 1 (also referred to in the literature as biotypes H, M, NA and PCG‐2) was found in both Sindh and Punjab. Middle East‐Asia Minor 1 (commonly known as biotype B and B2) was found only in Sindh. Moreover, Asia II 1 was associated with high incidences of CLCuD, whereas regions where Middle East‐Asia Minor 1 was present had a lower incidence. Phylogenetic analysis showed that the Middle East‐Asia Minor 1 population in Sindh formed a distinct genetic subgroup within the putative species, suggesting that the Sindh province of Pakistan may form part of its home range. So far, no individuals from the putative species Mediterranean (commonly known as biotypes Q, J and L) have been found in Pakistan. CONCLUSIONS: The capacity to manage pests and disease effectively relies on knowledge of the identity of the agents causing the damage. In the case of CLCuD in Pakistan, this knowledge has been obscured to some extent because of the inconsistent approach to identifying and distinguishing the different B. tabaci associated with CLCuD. The situation has now been clarified, and a strong association between disease incidence and vector identity and abundance has been shown. Given this advance, future research can now focus on factors that influence the capacity of different vector species to transmit the viruses that cause CLCuD, the reason for differences in vector abundance and the lack of geographic overlap between the cryptic vector species. This knowledge will contribute to the development of improved methods with which to manage the disease in Pakistan. Copyright © 2010 Society of Chemical Industry  相似文献   
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烟粉虱是一种由许多生物型组成的复合种,是一种世界性的重要害虫.不同生物型的烟粉虱在寄主范围、传毒能力、抗药性等许多生物学特性方面存在差异.利用mtDNA COI基因作标记对上海地区的烟粉虱生物型进行了分析鉴定.结果表明,所测上海10个代表性地区中,闵行区只检测到B型烟粉虱,嘉定、青浦和徐汇区只检测到Q型烟粉虱,其余各地区B型和Q型两种生物型烟粉虱共存.所测上海地区共45个种群中,有31个种群为Q型,占所测种群的68.9%,14个种群为R型,占31.1%.而且,大棚采集种群多为Q型(Q型占87.0%).结果说明Q型烟粉虱已在上海地区广泛存在、大量发生,并有取代R型烟粉虱成为上海地区烟粉虱主要危害类型的可能.  相似文献   
10.
Seventeen rice cultivate resistant to brown planthoppers were genetically analyzed using the Bangladesh insect population. Seven cultivars were found to have a single dominant gene for resistance. These genes segregated independently of the recessive resistance gene bph-5. Tae dominant resistance gene of ‘Swarnalata’ was designated Bph-6. In ten cultivars, resistance is conferred by single recessive genes. In eight cultivars, the resistance genes are allelic to bph-5. However, the recessive genes o: two cultivars are non-allelic to bph-5. The recessive gene of T12 is designated bph-7.  相似文献   
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