Reversal of embryonic diapause in the Australian plague locust, Chortoicetes terminifera (Walker), by temperatures above the development threshold

Diapause was induced in embryos of Chortoicetes terminifera (Walker) by transferring adults from an L:D 15:9 regime to an L:D 12.5:11.5 regime. When incubated at 20°C all eggs in all pods entered and remained in diapause but when incubated at 26, 32 and 38°C a proportion of eggs in some pods did not. Pods incubated at 32°C for up to 6 days, when diapause intervenes and then transferred to 20°C gave the same result as pods incubated at 20°C throughout development. All eggs entered and remained in diapause. If the period at 32°C was extended to 8 days, the proportion remaining in diapause was not significantly different from that found when pods were incubated at 32°C throughout development. In eggs which broke diapause at 32°C there was a pause or slowing down of development for about 2 or 3 days around the stage at which diapause intervenes.     

盐胁迫下刺槐无性系生长和矿质营养平衡研究

以一年生盆栽刺槐无性系BH327和B56为材料,对盐胁迫下刺槐无性系生长和矿质营养平衡进行了研究。结果表明：盐胁迫下BH56生长受抑不明显,组织水平上K^＋、Ca^2＋、Mg^2＋保持较高水平,尤其是在高盐下上部叶片足Ca^2＋、Mg^2＋的选择性吸收增强;而BH327,的生长受盐胁迫明显的抑制,组织水平上K^＋、Ca^2＋、Mg^2-水平相对较低,在高盐下上部叶片对Ca^2-、Mg^2＋的选择性吸收能力低于BH56。同时,从体内离子分配及选择性运输角度讨论了各无性系盐伤害或耐盐的原因。     

Multiple origins of Locusta migratoria (Orthoptera: Acrididae) in the Japanese Archipelago and the presence of two major clades in the world: evidence from a molecular approach

Phylogenetic relationships among migratory locust (Locusta migratoria) populations in different climatic regions were analysed by sequencing four mitochondrial DNA regions, with special reference to the origin of Japanese populations. The populations are clearly separated into two clades: one consists of individuals from temperate and cold‐temperate areas of Japan and the Chinese continent, and the other comprises those from subtropical islands of Japan, Hainan Island in China, Timol Leste, Australia, Ethiopia, France, and some individuals from Tsushima Island and Honshu of Japan. The divergence time between the two clades is estimated to be 0.86–1.89 Mya. The phylogenetic analysis revealed that Japanese L. migratoria populations were composed of individuals of six different origins: (1) Hokkaido populations possibly from the Russian continent; (2) Honshu–Kyushu populations from the Chinese continent; (3) Southwest Island populations from Hainan Island or adjacent areas; (4) Ogasawara populations that might have originated from Micronesia; (5) part of the Tsushima population that originated from somewhere in the Asian tropics; and (6) a possible relict population of ancient southern haplotypes that exists in western areas of northern Honshu. The Tsugaru Straits and Tokara Straits have acted as effective geographical barriers, as in other organisms, isolating locust populations for a few thousand years. © 2010 The Linnean Society of London, Biological Journal of the Linnean Society, 2010, 99 , 570–581.     

An effective method for axillary bud culture and RAPD analysis of cloned plants in tetraploid black locust

An efficient micropropagation technique by axillary bud multiplication was established for cloning tetraploid black locust tree (Robinia pseudoacacia L.). The result showed that the optimal medium for shoot multiplication and elongation was Murashige and Skoog (MS) medium supplemented with 0.5 mg/l 6-benzylaminopurine in combination with 0.5 mg/l kinetin and 0.1 mg/l 1-naphthaleneacetic acid. The best medium for rooting was half-strength MS medium with 0.25 mg/l indole-3-butyric acid. In the present report, we examined the genetic fidelity of the micropropagated plants by the randomly amplified polymorphic DNA (RAPD) method with 25 primers. The cloned plants of tetraploid black locust showed complete stability.Abbreviations BAP 6-Benzylaminopurine - GA₃ Gibberellic acid - IBA Indole-3-butyric acid - KIN Kinetin - MS Murashige and Skoog medium - NAA 1-Naphthaleneacetic acid - PCR Polymerase chain reaction - RAPD Randomly amplified polymorphic DNACommunicated by M. Beckert     

山东嘉祥县土蝗种类组成、分布和区域防治

连续 2年普查结果表明 ,嘉祥县共有土蝗 1 7种 ,分属 2总科 6科 1 5属 ,同时还摸清了土蝗的优势种类、分布区域范围及发生规律。不同生态环境条件下其优势种分布有明显不同 ,地形地貌及植被覆盖度对土蝗发生有明显的影响     

昆虫神经生物学研究技术:细胞内记录

细胞内记录是昆虫神经生物学研究中的常用技术。它用来获得神经元兴奋和抑制过程及神经脉冲产生机制的信息。该技术的特点是把一根微电极的顶尖插入到神经细胞内进行电生理记录 ,这根电极还能用于向膜内输入电流。作者以对蝗虫Schistocercagregaria后胸神经节内的 2个运动神经元的活性记录为例介绍了这一技术     

Feeding behaviour, sensory physiology and nutrient feedback: a unifying model

The design features of gustatory systems are considered in relation to the need for insect herbivores (or indeed any animal) to regulate their nutrient intake. The gustatory system (defined to include both peripheral and central components) should ideally be designed to reflect: (a) the average nutritional requirements of the insect during its various developmental stages; (b) the predictably unpredictable variation in nutrient supply-demand which occurs about that average; and (c) the distribution and composition of foods available in the environment. A mathematical model is presented which makes detailed predictions regarding behavioural and electrophysiological responses to foods or simple solutions varying in nutrient content.     

Chloromethyl ketones are insulin-like stimulators of lipid synthesis in locust fat body

Nα-p-tosyl-L-lysine chloromethyl ketone (TLCK) stimulates lipid synthesis in locust fat body in vitro, and is able to reverse the inhibitory effects of AKH-I on lipid synthesis. Effective stimulatory concentrations of TLCK were in the range of 0.2–1.0 mM. Similar stimulatory effects were also achieved with phenylalanine chloromethyl ketone (PheCK) and leucine chloromethyl ketone (LeuCK), but not with tosyl-phenylalanine chloromethyl ketone (TPCK), dansyl-glu-gly-arg-CK, chloroacetone, chloroacetic acid, chloroacetamide, chloroacetaldehyde, chloroacetyl-L-leucine or acetylated or fluorescamine-labelled TLCK, PheCK, and LeuCK. The level of stimulation caused by TLCK was dependent on incubation time, so that after a 5-h preincubation of fat body tissue with TLCK the stimulated rate was severalfold higher than the control. TLCK also increased the rate of uptake of trehalose and uridine, but not glucose, deoxyglucose or glycine. Increasing concentrations of bovine serum albumin (BSA) in the incubation medium caused a reduction in the rate of TLCK-stimulated acetate uptake, such that levels of uptake were no higher with 1% BSA than in the controls. A range of more specific protease and kinase inhibitors was tested, but none caused stimulation; thus the mode of action of TLCK on the stimulation of acetate uptake has yet to be identified. Elucidation of the mode of action of TLCK may facilitate the development of novel compounds for insect pest control. Arch. Insect Biochem. Physiol. 39:9–17, 1998. © 1998 Wiley-Liss, Inc.     

Curvature-electric effects in artificial and natural membranes studied using patch-clamp techniques

Methods for applying sound pressure to membrane patches formed at the tips of patch-clamp pipettes have been developed. Artificial membrane patches were formed from diphytanoyl phosphatidylcholine using a pipette dipping technique. Natural membrane patches were excised (inside-out mode) from collagenase-treated locust muscle membrane. Curvature-electric signals were registered under both voltage clamp and current clamp conditions. The phenomenon of flexoelectricity in membranes has previously been attributed to curvature-induced polarization originating from the liquid crystalline properties of membranes. The estimated magnitude (2·10^-18 C) of the flexoelectric coefficient of the artificial lipid bilayers is consistent with previous findings while that of the muscle membrane was in certain cases several times larger. The present study is the first to report on flexoelectricity in a natural membrane and raises the question of the biological significance of this phenomenon.     

A new form of insect cuticle

A hitherto unnoticed, harder form of cuticle, which occurs on the mandibles of the Australian plague locust, Chortoicetes terminifera , is described