植物对蝗虫行为及种群的调控作用

蝗虫食性广,取食量大,对植物的破坏作用极大。植物不仅是蝗虫食物的直接来源,还为其提供栖息场所,对蝗虫个体行为和种群动态均有重要影响。植物挥发物和次生代谢物质对蝗虫的取食、求偶、繁殖、产卵行为和个体生长发育等具有明显的调控作用。植被覆盖度能够直接影响蝗群的聚集度和迁移距离,同时蝗虫对产卵地的植被覆盖度也有严格要求,特别对蝗虫群集产卵行为影响明显。本文综述了植物对蝗虫行为及种群动态的影响,讨论了植被与蝗灾发生的关系,以期为蝗虫综合治理提供更广泛的思路。     

虫口密度和龄期对东亚飞蝗群居型向散居型转变的影响

采用笼养方法研究了东亚飞蝗虫口密度和龄期对其由群居型向散居型转变的影响。结果表明,不同密度条件下饲养的蝗虫其由群居型转变成散居型的速度不一样。密度越高,转变的速度越慢;当密度过高时,即使由三龄期开始隔离也无法转变其生态型。将处于三龄期群居型蝗蝻在低密度下隔离,到四龄时为过渡型,到五龄和成虫时为群居型;而四龄期的群居型蝗蝻经隔离后,在五龄和成虫时仅偏向于群居型;五龄期的群居型蝗蝻经隔离后,在成虫时仍为群居型。所以,三龄期可能是东亚飞蝗由群居型向散居型转变的临界期。超过三龄,即使在低密度下也不易发生生态型转变。     

两型亚洲小车蝗卵巢发育的分级及差异研究

亚洲小车蝗Oedaleus decorus asiaticus是我国北方草原区的重要害虫,其聚集、迁移暴发给草原、农田及城市带来了恶劣影响。本文根据亚洲小车蝗卵巢发育形态特征的变化,将其分为5个级别:I级为透明期,Ⅱ级为卵黄沉淀期,Ⅲ级为卵粒形成期,Ⅳ级为成熟待产期,Ⅴ级为产卵期。群居型亚洲小车蝗的卵巢发育起始时间为羽化后5.20d,产卵时间为羽化后50.21d,发育历期为43.75d;散居型亚洲小车蝗的卵巢发育起始时间为羽化后5.75d,产卵时间为羽化后52.25d,发育历期为46.50d,群居型亚洲小车蝗的卵巢发育比散居型种群快,且两者差异均达到极显著水平(P0.01)。研究结果从亚洲小车蝗发育繁殖角度验证了该蝗虫具有两型分化现象,且差异明显,同时对卵巢发育时间的研究可应用于亚洲小车蝗产卵期的预测预报,为田间蝗虫防治工作提供依据。     

高山草地蝗虫群落生物多样性和空间聚集强度对植物群落的响应

为明确高山草地蝗虫群落生物多样性和空间聚集强度变化及其对植物群落的响应,在位于甘肃省祁连山中段北坡的研究区调查温性草原、山地草甸和高寒草甸3类草地中的蝗虫种类和数量,对不同蝗虫群落进行生物多样性分析,并观察不同蝗虫种群的聚集程度。结果显示,共捕获蝗虫15种,8月温性草原内蝗虫虫口密度最大,为8.17头/m²,且此时Shannon-Wiener指数和Margalef丰富度指数均最大,分别为1.58和2.27;7月蝗虫群落的空间聚集程度高于其他两类草地。山地草甸和高寒草甸中蝗虫空间聚集高峰出现在8月,晚于温性草原。东亚飞蝗Locusta migratoria manilensis种群的空间聚集程度最高,其次为白边痂蝗Bryodema luctuosum、狭翅雏蝗Chorthippus dubius和小翅雏蝗Chorthippus fallax种群,鼓翅皱膝蝗Angaracris barabensis种群的聚集程度最弱。冗余分析结果显示,蝗虫群落种类组成和数量以及空间聚集强度与植物群落生物多样性、覆盖度和高度存在显著相关性。     

群居型、散居型亚洲小车蝗形态特征的数量分析

亚洲小车蝗(Oedaleus decorus asiaticus Bei-Bienko)是草原蝗虫的主要优势种之一,为了明确亚洲小车蝗两型现象与形态特征的关系,本文利用11个形态指标和5个形态指标比值采用数值分类学的方法对两型亚洲小车蝗成虫进行了测量和分析。结果表明,11个形态指标在亚洲小车蝗种群中均表现出一定的差异性,与能量储存、运动和飞行相关的体长(L)、前翅长度(E)、后足股节长度(F)在群居和散居型种群中具有极显著性差异(P0.01)。形态指标比值中,前翅长度和后足股节长度的比值(E/F)对两型蝗虫区分效果明显,群居型亚洲小车蝗成虫的E/F比值在1.68~1.74之间,散居型成虫的E/F比值在1.44~1.59之间,群居型E/F比值显著大于散居型(P0.05)。主成分分析构建了3个反映形态特征及其比值信息的综合指标,前两个主成分累积贡献率为99.84%,同时确定了E/F比值在两型区分上具有重要的指示作用,可以作为亚洲小车蝗成虫两型现象的判定指标。     

深色和浅色两种表型东亚飞蝗对蝗虫微孢子的敏感性比较

为验证群居型飞蝗深浅2种表型对蝗虫微孢子Paranosema locustae的敏感性差异,本研究以东亚飞蝗Locusta migratoria manilensis为研究对象,测定并比较了深色型和浅色型2种表型的东亚飞蝗经蝗虫微孢子侵染后其发育历期、死亡率、免疫血淋巴细胞数量以及免疫基因表达量等变化情况。结果显示,浅色型东亚飞蝗的发育历期因蝗虫微孢子侵染而延长近1.0 d左右,比深色型东亚飞蝗多延长0.5 d;浅色型东亚飞蝗发死亡率明显高于深色型的;浅色型东亚飞蝗的免疫血淋巴细胞数量低于深色型的;蝗虫微孢子侵染后,深色型东亚飞蝗免疫基因toll基因和attacin基因的表达量上升,而浅色型东亚飞蝗的toll基因表达量无明显变化,attacin基因的表达量甚至出现下调。而且,蝗虫微孢子在浅色型飞蝗体内增殖更多。表明深色型东亚飞蝗在应对蝗虫微孢子侵染时较浅色型更有优势,浅色型东亚飞蝗较深色型对蝗虫微孢子更敏感。     

河北省蝗虫气象预测信息服务系统

根据河北省蝗虫发生的特点和防治需求,建立了河北省蝗虫气象预测信息服务业务系统。它具有气象和蝗虫查询统计服务、预测服务和咨询服务三大功能。该系统的建立与应用,提高了蝗虫气象系列化综合服务水平,可为河北省蝗虫防治决策提供可靠的信息与服务。     

蝗虫对高温的耐受性及其机制的研究进展

全球气候变化日益加剧,给昆虫等变温动物的发育和繁殖带来巨大影响,进而影响其种群动态分布甚至物种生存。蝗虫作为世界上最重要的农业害虫种类之一,对于温度等气候变化非常敏感,其种群动态及成灾程度与温度变化密切相关。近年来,除了低温耐受性,蝗虫对高温的耐受能力也很强。成虫的致死温度高达40℃左右。在短时高温下,蝗虫可以通过体内抗逆物质及酶含量的变化机制、不连续气体交换循环呼吸代谢模式以及体温调节行为来避免机体受到损伤,甚至短时高温往往有利于蝗虫交配。蝗虫自身的体温调节行为,在其适应环境和抵御病菌方面起着关键性作用,大大增加了蝗虫的生存能力。该文综述近年来蝗虫对高温耐受性的研究进展,加深全球气候变暖背景下对蝗虫种群发生规律的认识。     

中国蝗虫学研究60年

蝗虫灾害是人类历史上三大自然灾害之一,对农牧业、环境和经济构成严重威胁。我国是世界上遭受蝗灾最严重的国家之一,有关蝗虫学的研究有较长的历史。60年前,通过改治结合,我国控制了大规模的飞蝗Locusta migratoria蝗灾发生,取得了举世瞩目的成就。60年过去了,中国蝗虫学研究发生了翻天覆地的变化。该文主要综述了最近60年中国蝗虫学研究的发现与创新,展示蝗虫分类学、生态学、生殖与发育生物学、分子生物学、基因组学研究以及蝗虫控制技术研究等多个方面的成就。这些研究成果是世界昆虫学研究的重要组成部分。特别是近30年,我国科学家深入揭示蝗虫两型转变的遗传和表观遗传机制,在国际上产生了重要影响。飞蝗的综合生物学研究积累使飞蝗成为继果蝇之后又一个昆虫模式系统。更重要的是,我国科学家开发的真菌生物农药和群聚信息素可以作为重要的防治手段用于蝗灾的治理。     

内蒙古典型草原蝗虫群落结构和生态位研究

采用定点调查和生物量定量分析方法对内蒙古典型草原不同草地蝗虫群落结构和生态位进行研究,结果表明,典型草原蝗虫群落结构丰富,主要蝗虫有11种,草原蝗虫的时间分布揭示了蝗虫时间生态位的分化,宽须蚁蝗[Myrmeleotettix palpalis(Zubowsky)],亚洲小车蝗(Oedaleus decorus asiaticus B.-Bienko)、短星翅蝗(Calliptamus abbreviatus Ikonnikov)分别构成镶黄旗草原蝗虫早期、中期、晚期优势种;根据蝗虫种群地位,将11种蝗虫划分为优势种、附属种、稀少种,把11种蝗虫按空间地位划分为禾草地类、荒草类、特殊类和全域类4类,优势种蝗虫的种群与空间地位,反映了蝗虫与植被、蝗虫与蝗虫之间关系。优势种蝗虫中短星翅蝗的时空生态位宽度最大,其次是亚洲小车蝗和宽须蚁蝗,说明短星翅蝗对时空"资源"的利用程度最高,共存的蝗虫种类在"资源"利用上存在着明显的分化,亚洲小车蝗与宽须蚁蝗的生态位重叠最大,说明两者利用资源的相似性程度最高。我们用生态位来体现蝗虫种群地位及对资源的利用,同时也用资源的系统聚类来预测蝗虫的潜在发生与危害。本文系统地研究了蝗虫群落结构和蝗虫生态位,将为评价草原蝗虫潜在发生与危害、蝗虫宜生区划分和制定草原有害生物防治策略提供理论基础。     

Hymenopteran Parasitoids on Fruit-infesting Tephritidae (Diptera) in Latin America and the Southern United States: Diversity, Distribution, Taxonomic Status and their use in Fruit Fly Biological Control

We first discuss the diversity of fruit fly (Diptera: Tephritidae) parasitoids (Hymenoptera) of the Neotropics. Even though the emphasis is on Anastrepha parasitoids, we also review all the information available on parasitoids attacking flies in the genera Ceratitis, Rhagoletis, Rhagoletotrypeta, Toxotrypana and Zonosemata. We center our analysis in parasitoid guilds, parasitoid assemblage size and fly host profiles. We also discuss distribution patterns and the taxonomic status of all known Anastrepha parasitoids. We follow by providing a historical overview of biological control of pestiferous tephritids in Latin American and Florida (U.S.A.) and by analyzing the success or failure of classical and augmentative biological control programs implemented to date in these regions. We also discuss the lack of success of introductions of exotic fruit fly parasitoids in various Latin American countries. We finish by discussing the most pressing needs related to fruit fly biological control (classical, augmentative, and conservation modalities) in areas of the Neotropics where fruit fly populations severely restrict the development of commercial fruit growing. We also address the need for much more intensive research on the bioecology of native fruit fly parasitoids.     

Brief Guide for Authors

正Journal of Arid Land(JAL)is an international journal(ISSN 1674-6767;CN 65-1278/K)for the natural sciences,sponsored by the Xinjiang Institute of Ecology and Geography,Chinese Academy of Sciences and Science Press.It is published by Science Press and Springer-Verlag Berlin Heidelberg bimonthly.JAL publishes original,innovative,and integrative research from arid and semiarid regions,ad     

The parasitoid complex ofLiriomyza cicerina on chickpea (Cicer arietinum)

Liriomyza cicerina (Diptera: Agromyzidae) is an important pest on chickpea in Turkey. The objective of this study was to determine the parasitoids and rates of parasitism ofL. cicerina on chickpea (Cicer arietinum L.) during the 2005 and 2006 seasons in ?anl?urfa province, Turkey. Leaves with mines were sampled weekly and kept in the laboratory to observe and count emerging leafminer and parasitoid adults. Eight parasitoid species were collected: the braconidsOpius monilicornis Fischer andOpius tersus Foerster and the eulophidsDiaulinopsis arenaria (Erdös) andNeochrysocharis formosa (Westwood), which occurred in both the winter and summer seasons;Diglyphus crassinervis Erdös,Neochrysocharis ambitiosa Hansson,Neochrysocharis sericea (Erdös) andPediobius metallicus (Nees), which occurred only in the summer growing areas.Diaulinopsis arenaria was the predominant parasitoid with 4–7.7% parasitism rate whileN. ambitiosa andO. monilicornis were the second and third most predominant species. The results of these trials show that sinceDia. arenaria occurred throughout every season, it could potentially be used for control of the leafminerL. cicerina.     

Plant–herbivore asynchrony necessitates augmentative releases of the exotic beetle,Zygogramma bicolorata,to enhance the biological control of P arthenium hysterophorus

Systematic information on the quantitative impact of Z ygogramma bicolorata on the biology of P arthenium hysterophorus is crucial as the seeds of this weed continue to germinate from the accumulated soil seed bank throughout the year in the form of different germinating flushes, while the activity of the beetle ceases during winter as it enters diapause. Therefore, plant–herbivore interactions need to be explored to develop predictions of the overall impact of the introduced beetle on the weed. The findings revealed that defoliation by Z . bicolorata had a significant impact on the plant height, density and flower production in flushes F ₃, F ₄ and F ₅, but not in F ₁ and F ₂ that exhibited longer periodicity, profuse branching, a longer flowering period and maximum flower production and contributed mostly to the existing seed soil bank. Therefore, total depletion of the existing soil seed bank was not possible. Consequently, the effect of augmentative field releases of laboratory‐reared beetles was explored on F ₁ and F ₂ in February for three consecutive years (2011–2013). Before initiating the trial, random soil samples were taken from the plots that were assigned to the paired treatments (i.e. with the beetle and without the beetle [insecticide‐treated]) and it was found that the seed bank in those samples did not differ. The single release of Z . bicolorata adults at five per plant at the six‐leaf stage significantly reduced the soil seed bank, compared to without the biocontrol agent, irrespective of the flushes at the end of the season.     

Effects of the saprophytic leaf mycoflora on growth and productivity of winter wheat

The effects of the saprophytic mycoflora and its interference with cereal aphids on growth and yield of winter and spring wheat was studied in field experiments in 1980, 1981 and 1982.Yields varied between 5000 and 8000 kg dry matter of kernels per ha. The effect of the saprophytic mycoflora on yield was determined in different treatments: A) no control measures against cereal aphids and saprophytic and necrotrophic fungi, B) no control of cereal aphids, control of saprophytic and necrotrophic fungi, C) control of cereal aphids and control of saprophytic and necrotrophic fungi, D) control of cereal aphids and stimulation of saprophytic mycoflora and E) control of cereal aphids, no control of saprophytic and necrotrophic fungi nor stimulation of saprophytic mycoflora.Considerable differences in top densities of saprophytic mycoflora (10 times as large in A and D as in B and C) were determined. The consequences of these differences for the growth and productivity of wheat were minor. A negative effect of saprophytic mycoflora on the yield could not be detected in 1981 and 1982, whereas a small positive significant effect was found in 1980. This stimulation may have been due to competition between necrotrophic fungal pathogens and saprophytic mycoflora. As a result of favourable weather conditions necrotrophic fungal pathogens were very numerous in 1980 and could form an important yield reducing factor. Yield levels may effect the importance of the necrotrophic and saprophytic mycoflora as yield reducing factors. Additionally, in the presence of aphid honeydew captafol was found to be relatively ineffective against saprophytic fungi.     

Relationship Between Production of the Phytotoxin Prehelminthosporol and Virulence in Isolates of the Plant Pathogenic Fungus Bipolaris sorokiniana

A gas chromatographic method was developed to quantify the phytotoxin prehelminthosporol, which is a sesquiterpene metabolite of the plant pathogen Bipolaris sorokiniana. The toxin was extracted from mycelium or culture filtrates, pre-cleaned using solid phase extraction, and analyzed by gas chromatography as a trimethylsilyl-derivative. The detection limit of the method was 5ngl^–1 (signal to noise ratio 4:1) which corresponds to ca. 15ng prehelminthosporol per mg dry weight of mycelium or 15ng prehelminthosporol per ml culture filtrate. The total amount of prehelminthosporol (mycelium plus culture filtrate) increased with cultivation time when examined in six isolates of B. sorokiniana after 6, 9, 12 and 15 days of incubation. The screening experiment of 17 isolates for prehelminthosporol production after 8 days of incubation revealed significant differences in the toxin production between the isolates. The isolates with low toxin production had lower virulence towards barley roots compared to those with higher production of the toxin. However, the virulence did not increase with prehelminthosporol level among the high producing isolates. Prehelminthosporol was also analyzed in a number of related Bipolaris and Drechslera species. In addition to B. sorokiniana, three out of six Bipolaris species (B. setariae, B. zeicola, B. victoriae) produced prehelminthosporol, which indicates that ability to produce prehelminthosporol is conserved among closely-related Bipolaris species.     

Effect of botanical insecticides and bacterial toxins on the gut enzyme of the rice leaffolderCnaphalocrocis medinalis

The effect of botanical insecticides and bacterial toxins on gut enzyme activity of larvae of the rice leaffolderCnaphalocrocis medinalis (Guenée) (Insecta: Lepidoptera: Pyralidae) was investigated. Gut enzyme activities were affected by botanical insecticides and bacterial toxin individually and in combination. When fed a diet of rice leaves treated with botanical insecticides and bacterial toxins, in bioassays the activities of gut tissue enzymes — acid phosphatases (ACP), alkaline phosphatases (ALP) and adenosine triphosphatases (ATPase) — of rice leaffolder larvae were affected. When combined, the effect was more severe at a low concentration. Larvae that were chronically exposed to botanical insecticides and bacterial toxins showed a reduction in weight (59–89%) and exhibited a significant reduction in ACP, ALP and ATPase activities. The combination ofBacillus thuringiensis kurstaki and botanical insecticides caused a decrease of twofold in enzyme activity even at reduced concentration. A synergistic effect was found when botanical insecticides and bacterial toxins were combined at low doses. These effects were most pronounced in early instars. Clear dose-response relationships were established with respect to enzyme activity. In conclusion: (i) biopesticides are relatively safe and biodegradable; (ii) a synergistic effect of botanical insecticides and bacterial toxins was found; (iii) less expensive, readily available and naturally occurring biopesticides could be an alternative for organic and inorganic pesticides in controlling RLF. http://www.phytoparasitica.org posting Sept. 28, 2004.