A novel target for antidiuretic hormone in insects

Diuresis in insects is controlled by two antagonistic hormone groups: diuretic hormones, which promote water loss, and antidiuretic hormones, which inhibit it. All known antidiuretic factors act solely to promote fluid reabsorption by the hindgut and do not affect secretion by the Malpighian tubules. In the house cricket, Acheta domesticus, an antidiuretic hormone was found that inhibits fluid secretion by the Malpighian tubules but has no effect on the hindgut. Correlations were found between the density of neurosecretory granules and the presence of antidiuretic hormone in the corpora cardiaca, suggesting that the hormone is released from specific axons. Its release is triggered by dehydration; the hormone is detectable in the hemolymph of water-deprived crickets. These results imply that an unusual mechanism regulates water balance in these insects.     

烤烟塑料托盘假植育苗的研究

为了提高烟苗的素质,在聚乙烯塑料托盘上,用猪粪渣、可沙、大田本土作为不同基础材料配方进行烤烟假植育苗的研究。结果表明,以50%猪粪渣加50%河沙处理的烟苗素质最佳,其次是50%猪粪渣加505大田本土的处理,这两种处理的烟苗素质均优于稻草圈假植苗,达到了壮苗标准。托盘假植苗的适栽苗龄为15～20d,移栽大田后,此稻草圈假植苗株有效叶数增加0.8片,产量增加5.0%,产值提高5.1%,育苗成本降低60%,纯收入增加8.2%。     

Thermoregulation in endothermic insects

On the basis of body weight, most flying insects have higher rates of metabolism, and hence heat production, than other animals. However, rapid rates of cooling because of small body size in most cases precludes appreciable endothermy. The body temperature of small flies in flight is probably close to ambient temperature, and that of flying butterflies and locusts is 5 degrees to 10 degrees C above ambient temperature. Many moths and bumblebees are insulated with scales and hair, and their metabolism during flight can cause the temperature of the flight muscles to increase 20 degrees to 30 degrees C above ambient temperature. Curiously, those insects which (because of size, insulation) retain the most heat in the thorax during flight, also require the highest muscle temperature in order to maintain sufficient power output to continue flight. The minimum muscle temperature for flight varies widely between different species, while the maximum temperature varies over the relatively narrow range of 40 degrees to 45 degrees C. As a consequence, those insects that necessarily generate high muscle temperatures during flight must maintain their thoracic temperature within a relatively narrow range during flight. Active heat loss from the thorax to the abdomen prevents overheating of the flight motor and allows some large moths to be active over a wide range of ambient temperatures. Bumblebees similarly transfer heat from the flight musculature into the abdomen while incubating their brood by abdominal contact. Many of the larger insects would remain grounded if they did not actively increase the temperature of their flight muscles prior to flight. Male tettigoniid grasshoppers elevate their thoracic temperature prior to singing. In addition, some of the social Hymenoptera activate the "flight" muscles specifically to produce heat not only prior to flight but also during nest temperature regulation. During this "shivering" the "flight" muscles are often activated in patterns different from those during flight. The muscles contract primarily against each other rather than on the wings. However, the rate of heat production during shivering and flight is primarily a function of the action potential frequency rather than of the patterns of activation. Thermoregulation is a key factor in the energetics of foraging of some of the flower-visiting insects. The higher their muscle temperature the more flowers they can visit per unit time. When food supplies are ample, bees may invest relatively large amounts of energy for thermoregulation. While shivering to maintain high body temperatures during the short intervals they are perched on flowers (as well as while in the nest), bumblebees often expend energy at rates similar to the rates of energy expenditure in flight. Unlike vertebrates, which usually regulate their body temperature at specific set points, the body temperature of insects is labile. It often appears to be maintained near the lower temperature at which the muscles are able to perform the function at hand. The insects' thermal adaptations may not differ as much from those of vertebrates as previously supposed when size, anatomy, and energy requirements are taken into account.     

我国食用昆虫研究、开发现状与发展前景

介绍了中国食用昆虫的历史及食虫习俗、食用昆虫种质资源,分析了食用昆虫产品开发的现状及影响其开发的因素,指出了开发食用昆虫资源的应对措施及食用昆虫在中国的发展前景。     

多效农用棚膜应用

对大棚内每日最高地温、气温,最低地温、气温及光照强度的观测结果表明,多效聚乙烯棚膜的增温、保温效果良好且棚面灰尘污染轻微,无滴效果可保持６个月,使用寿命可达１年以上。     

Supramolecular Archimedean cages assembled with 72 hydrogen bonds

Self-assembly of multiple components into well-defined and predictable structures remains one of the foremost challenges in chemistry. Here, we report on the rational design of a supramolecular cage assembled from 20 ions of three distinct species through 72 hydrogen bonds. The cage is constructed from two kinds of hexagonal molecular tiles, a tris(guanidinium)nitrate cluster and a hexa(4-sulfonatophenyl)benzene, joined at their edges through complementary and metrically matched N-H···O-S hydrogen bonds to form a truncated octahedron, one of the Archimedean polyhedra. The truncated octahedron, with an interior volume of 2200 cubic angstroms, serves as the composite building unit of a body-centered cubic zeolite-like framework, which exhibits an ability to encapsulate a wide range of differently charged species, including organic molecules, transition metal complexes, and "ship-in-a-bottle" nanoclusters not observed otherwise.     

深水网箱的分类及性能

探讨了深水网箱的分类方法，选择网箱的工作方式、结构特点、框架柔性、框架材料等对深水网箱进行分类。对17种典型的大型深水网箱的结构特性、力学特性、抗风浪能力等进行了分析。结果表明，按工作方式的分类中，浮式网箱的品种最多，占52．9％；按网箱力学结构分类中，重力式和自张式网箱较多，分别占52．9％和41．2％；按框架材料柔性分类中，柔性框架和刚性框架各占一半；按框架材质分类中，金属网箱居多数，达52．9％。其中，浮式重力式网箱结构简单，成本较低，操作管理方便，应用较广。但它在强水流作用下，网衣水平漂移严重，网箱容积损失率高，而加载保持网型的同时，会使网衣承受的张力增加，容易造成网衣撕破，因此，在流速较大海域中，该网箱的使用受到限制。自张式刚性网箱具有稳固的操作平台，易于实现自动化，同时，框架承受了相当的载荷，网衣受力和网型相对稳定，在新材料、新工艺的支持下，该类结构的抗风浪网箱具有较大发展潜力。     

生物导弹防治农林害虫新技术

生物导弹防治农林害虫新技术为中科院武汉病毒所开发,主要利用卵寄生蜂为媒介在目标害虫中传播病毒造成流行病,达到长期有效防治害虫的目的,是一种新型生物治虫技术.文章从技术原理特点、应用前景等方面对该技术进行了介绍.     

林木昆虫演变为重大害虫的主要环境因子

综述了有关林木害虫产生的环境机制，主要包括大气污染、干旱、全球气候变化、外来有害生物的入侵、害虫自身生物学特性与森林经营模式的影响等，以便为害虫的综合防治提供基础理论资料。同时提出今后研究方向：树种、害虫、天敌和生存环境4者关系开展研究，特别调控森林生态系统的主体一植被的时空结构；同时协调运用与环境和其他有益物种的生存和发展和谐的各类措施，将害虫控制在不成灾水平，并在时空上达到可持续控制的效果。表2参33