Listening to the environment: hearing differences from an epigenetic effect in solitarious and gregarious locusts

Locusts display a striking form of phenotypic plasticity, developing into either a lone-living solitarious phase or a swarming gregarious phase depending on population density. The two phases differ extensively in appearance, behaviour and physiology. We found that solitarious and gregarious locusts have clear differences in their hearing, both in their tympanal and neuronal responses. We identified significant differences in the shape of the tympana that may be responsible for the variations in hearing between locust phases. We measured the nanometre mechanical responses of the ear''s tympanal membrane to sound, finding that solitarious animals exhibit greater displacement. Finally, neural experiments signified that solitarious locusts have a relatively stronger response to high frequencies. The enhanced response to high-frequency sounds in the nocturnally flying solitarious locusts suggests greater investment in detecting the ultrasonic echolocation calls of bats, to which they are more vulnerable than diurnally active gregarious locusts. This study highlights the importance of epigenetic effects set forth during development and begins to identify how animals are equipped to match their immediate environmental needs.     

粗股蚱Tetrix grossifemura Zheng & Jiang雌性的首次发现（直翅目：蚱总科）

首次记述粗股蚱Tetrix grossifemura ZhengJiang,1997的雌性,研究标本保存于河池学院化学与生物工程学院标本室。     

Development of microsatellite markers in black locust (Robinia pseudoacacia) using a dual‐supression‐PCR technique

Black locust (Robinia pseudoacacia) is an economically and ecologically important tree species in the world. We isolated seven polymorphic microsatellite loci from R. pseudoacacia using a dual‐suppression‐PCR technique. These loci provided microsatellite markers with high polymorphism ranging from three to 12 alleles per locus and expected heterozygosity between 0.538 and 0.944. The markers are now available for more detailed investigation of population genetic structure and pollen and seed dispersal.     

河北省南大港农场2002年夏蝗发生特点及原因浅析

进入 90年代以来 ,南大港蝗区东亚飞蝗Locustamigratoriamanilensis(Meyen)大发生 6次 ,2 0 0 1年夏秋蝗发生面积达 2 6万hm2 ,5龄蝗蝻最高密度为 1 0 0 0 0头 m2 。 2 0 0 2年形势更为严峻 ,仅夏蝗发生面积超过 2万hm2 ;分别造成 1 3 0 0hm2 和 2 70 0hm2 的芦苇被吃成光杆和被啃食的严重破叶。出土时间早、孵化时间长、龄期悬殊大是今年夏蝗发生的主要特点。主要原因是去年越冬卵块基数大 ,其次是受气候条件和农业环境的影响     

我国蝗虫暴发成灾的现状及其持续控制对策

概述并分析了我国蝗虫暴发成灾的现状及原因 ,认为全球气候变暖和区域性气候异常、人类活动的影响、监测预警技术手段落后、成灾蝗种增多和发生为害类型复杂、蝗虫研究队伍锐减及基础理论与高新技术研究滞后导致了近年来蝗虫的暴发成灾。对此 ,作者从蝗虫灾害的规律性、监测预警高新技术和综合治理技术等方面提出了实现蝗灾可持续控制的对策     

Role of Olfactory and Visual Cues in the Attraction/Repulsion Responses to Conspecifics by Gregarious and Solitarious Desert Locusts

Desert locusts [Schistocerca gregaria Forskål (Orthoptera, Acrididae)] change phase in response to population density: solitarious insects avoid one another, but when crowded they change to the gregarious phase and aggregate. The attraction/repulsion responses of gregarious and solitarious locusts maintain phase differences in locust populations. Despite considerable research, the cues for aggregation are poorly understood; moreover, the repulsion response of solitarious locusts has not previously been investigated. This study analyzes the role of visual and olfactory stimuli in triggering these different responses to conspecifics. Isolation-reared insects were repelled by both olfactory and visual stimuli from other locusts. Crowd-reared insects were attracted by the combination of olfactory and visual cues. In addition, olfactory stimuli affected other behaviors in both phases, and behavioral differences between isolation- and crowd-reared locusts were clear even in the absence of conspecifics. The sensory and neurological mechanisms underlying these responses are not well understood and will form the basis for neurobiological investigations of locust phase.     

杨树刺槐混交林及纯林枯落叶分解

研究了杨树（Ｐｏｐｕｌｕｓｓｐｐ．）、刺槐（Ｒｏｂｉｎｉａｐｓｅｕｄｏａｃａｃｉａ）纯林及混交林枯落叶一年中的分解及养分动态变化规律．结果表明,杨树枯落叶分解速度较慢,刺槐较快,而混交林则较杨树有较大提高．在分解过程中,杨树枯落叶Ｎ、Ｐ释放困难,需经过长达１０个月的养分富积过程;刺槐枯落叶Ｎ、Ｐ元素释放较为容易;混交林枯落叶养分富积时间缩短、幅度下降,分解速度加快,说明杨树和刺槐混交有利于枯落叶分解和Ｎ、Ｐ循环．     

刺槐上分离的花生矮化病毒的研究

刺槐花叶病是我国北方刺槐（Ｒｏｂｉｎｉａｐｓｅｕｄｏａｃａｃｉａ）常见病害。１９８７～１９９５年对河南、河北、山东和北京部分地区刺槐进行调查,刺槐花叶病发病率为４％～８７．５％。该病害主要特征是：叶片出现浅绿与绿色相间带有疱疹的花叶症状,叶缘波状扭...     

Non-target grasshoppers as indicators of the side-effects of chemical locust control in the Karoo, South Africa

In most locust or grasshopper control programmes, the proximate aim is to suppress grasshopper numbers. However, in the semi-arid Karoo, South Africa, only the brown locust (Locustana pardalina) has significant pest status. Non-target grasshoppers form a conspicuous and important part of the Karoo ecosystem, many being endemic. Grasshopper diversity was monitored in treated and untreated plots (0.25 ha) to establish the impact of spraying. Grasshopper abundance was significantly reduced one day after treatment. Vagile species recovered by immigration from the surrounding areas following the breakdown of chemical residues. Endemic apterous bushhoppers with low vagility recovered the following season after rainfall triggered hatching. Grasshopper numbers hatching in treated plots were significantly lower than in untreated plots the following summer season because of a reduction in the number of individuals in the preceding generation. However, species composition was similar to untreated plots and this reduction is unlikely to have significant, long-term biological effects in such small treated areas (0.25 ha being usual for hopper band control). The rate of recovery of grasshoppers, particularly bushhoppers, was linked to rainfall indicating that the timing of control relative to rainfall is important. Grasshopper assemblages are potentially useful indicators of the effect of chemical locust control in the Karoo.     

我国新发现一种外来蚜虫——刺槐附毛斑蚜Appendiseta robiniae

记述了采自北京刺槐上的1种中国的记录外来蚜虫——刺槐附毛斑蚜,它原产于北美,寄主为刺槐,在当地一些地区较为常见,并已扩散到欧洲等地。描述了有翅孤雌蚜、无翅雌性蚜和有翅雄性蚜的鉴别特征,并提供了生态图片。最后讨论了它的潜在危害性及蚜虫寄主植物、蚜群生活状及生态照片在蚜虫识别上的重要性。