鞭角华扁叶峰幼虫期的呼吸代谢

报道了鞭角华扁叶蜂Chinolyda flagellicornis幼虫不同发育时期的耗氧量,试验表明,鞭角华扁叶蜂的耗氧量随着幼虫的生长发育而增加,在同一龄期内,耗氧量与虫体鲜重呈2次曲线相关;在不同的龄期之间,耗氧量则与虫体鲜重的0.8299次方成正比,在同一龄期内,幼虫的代谢速率呈抛物线状;在整个幼虫期随着龄期的增加而呈下降趋势。     

鞭角华扁叶蜂幼虫的营养成分分析

采用现代分析技术手段对鞭角华扁叶蜂Chinolydaflagellicornis(F.Smith)幼虫的主要营养成分进行分析,结果表明其鲜虫浆的蛋白质、氨基酸、粗脂肪、糖类及灰分含量分别为17.1%,13.5%,6.7%,1.0%和1.5%,胆固醇含量为0.3mg/g;含有7种人体必需氨基酸,其必需氨基酸占总氨基酸含量的43.0%,必需氨基酸与非必需氨基酸含量的比值为75.3%,第一限制性氨基酸为含硫氨基酸,即蛋氨酸和胱氨酸;同时,其不饱和脂肪酸与必需脂肪酸分别占总脂肪的61.3%和24.3%,特别是油酸和亚麻酸含量较高,分别达37.0%和18.4%;此外,还含有K,Ca,Mg,Fe,Zn,Cu,Mn等多种矿物质和微量元素。最后在分析其营养价值的基础上,对鞭角华扁叶蜂幼虫的开发利用价值进行了评价。     

鞭角华扁叶蜂自然种群生命表

鞭角华扁叶蜂Chinolydaflagellicornis（F．Smith）是危害柏木的主要害虫,近年来在长江沿岸柏木防护林区发生严重,造成灾害。为了解该虫的种群动态规律及影响虫口数量变动的致死原因,并为该虫的预测预报提供资料,笔者于1995～1996年在忠县、云阳两县对鞭角华扁叶蜂自然种群进行了观察,现将结果整理于后。1生命表的研制过程1．1生命表观察虫期的划分[1]：根据鞭角华扁鞭角华扁叶蜂平均生命表叶蜂的发育进度和生活习性,将整个世代划分为卵期,1、2、3、4～6龄幼虫期,预蛹期,蛹期和成虫期共8个发育阶段。l．2观察方法。于1995—1996…     

鞭角华扁叶蜂对自然生境柏木挥发物释放的影响

植物挥发物（Volatile organic compounds;VOCs）在植物抵御害虫侵袭的过程中具有重要作用。本研究以重庆市云阳县长江林场人工林中健康和受害柏木为研究对象,通过VOCs测定分析发现鞭角华扁叶蜂虫害发生之前,两种柏木共计有37种VOCs成分,主要为萜类化合物,其次为醇、酯、醛、烷烃等类化合物;其中健康柏木特有驱赶作用的2-莰醇（龙脑）,受害柏木特有吸引作用的顺式-2-癸烯醛,其余35种为共有成分;各成分浓度在两种柏木中存在较大差异。虫害发生之后,两种柏木共计有32种VOCs成分,而2-莰醇、顺式-2-癸烯醛、薄荷醇、臭樟脑和α-石竹烯等5种成分消失;许多成分的浓度变化趋势与虫害发生前的相反。结果表明健康与受害柏木VOCs释放的差异可能是柏木能否抵御鞭角华扁叶蜂侵害的主要防御机制之一,这将为优良抗虫柏木选育提供理论依据和参考指标。     

鞭角华扁叶蜂蜕皮甾类激素滴度的变化

用放射免疫分析法测定了鞭角华扁叶蜂Chinolyda flagellicornis末龄幼虫及滞育预蛹血淋巴中蜕皮甾类激素滴度。结果表明,末龄幼虫血淋巴中蜕皮甾类激素滴度在第2和4天各有一高峰;滞育预蛹血淋巴中保持一定滴度的蜕皮甾类激素,并随发育时期的不同有所波动;预蛹化蛹前一周血淋巴中蜕皮甾类激素滴度存在两个与变态相对应的峰值。表明鞭角华扁叶蜂的滞育与蜕皮甾类激素相关。     

鞭角华扁叶蜂虫卵数模型研究

该研究在野外获得了鞭角华扁叶蜂虫卵数与生境因子海拔、胸径、树高、海拔、冠幅坡向的数据;内业利用Matlab7软件分别建立了鞭角华扁叶蜂虫卵数的全变量模型、逐步回归模型和主成分模型,三模型的复相关系数R~2分别为0.9204,0.91841和0.9289,均方误差RMSE分别为322.4069,331.7300和310.9550,从两个系数看,得出一致结论以主成分法拟合最佳.逐步回归模型只采用了两个因子即树高和冠幅,主成分法采用了前三个主成分量,其信息量达93.6359%,可代表原特征变量的大部分信息.     

云杉阿扁叶蜂幼虫龄期与取食量观测

云杉阿扁叶蜂AcantholydapiceacolaXiaoetZhou的幼虫隐藏于虫粪结成的虫巢内,在取食针叶时将头、胸伸出虫巢,停息或受惊扰时即缩回。由于虫巢质地紧密、不易拉开,因此确定该虫龄期及发育进度很困难。曾有报道云杉阿扁叶蜂幼虫龄期为5龄[1],而各龄期幼虫取食量及虫体大小未见详细报道。为了确定此虫的最佳防治时期和防治阈值,获得可靠预测预报资料,我们于1995年在甘肃省山丹县大黄山林场对云杉阿扁叶蜂幼虫头宽、体长、龄期及取食量作了详细观测,现将结果整理如下。更方法（1）林间选择大小均匀的二年生青海云杉枝条,将刚孵化的幼…     

阿扁叶蜂属的系统分类学研究进展（膜翅目：扁叶蜂科）

阿扁叶蜂属Acantholyda最早可追溯至中新世早期,既包含绝灭的化石类群,又具有丰富的现生类群。其幼虫吐丝结网取食针叶为害,是一类重要的林业害虫。本文在前人研究的基础上整理了该类群的信息,包括分类研究史、名录及地理分布和系统发育学进展,总结目前分类研究中亟待解决的问题,并对今后研究工作进行展望。     

树杆注药防治油松扁叶蜂

用40%氧化乐果乳油对油松扁叶蜂Acantholyda posticalis posticalisMatsumura进行树杆注射用药,防治技术简单易行、省工省时、环境污染小、成本低、防效达97%,适用大田防治。     

Juvenile hormone and wing development during the last larval stage in aphids

The development of wingbud epidermis during the last larval stage of cabbage aphids (Brevicoryne brassicae) is described at the ultrastructural level, and compared with its development in juvenile hormone (JH) treated specimens. Cells in JH-treated aphids fail to undergo normal changes in shape and contain conspicuous bundles of microtubules. Cell division is also suppressed by JH treatment, but this alone cannot account for the juvenilised appearance of the adult wings. The possible mode of action of JH is discussed in terms of its observed effects on the abundance of microtubules within the cells.     

Carbohydrate and lipid metabolism during the last larval moult of the tobacco hornworm, Manduca sexta

Abstract. At 25°C and with a light regime of 17 h light and 7h dark, the last larval moult of the tobacco hornworm, Manduca sexta , lasts approximately 32 h, during which profound changes of metabolism were observed. At the onset of the moult, which coincides with the cessation of feeding, the proportion of active fat body glycogen phosphorylase increased from 10 (-2h) to 25–30% (Oh). A biphasic pattern with peak activities of 45–50% after t – 12 h and again just prior to the shedding of the cuticle (32 h) was subsequently observed. Haemolymph trehalose concentration decreased significantly from c. 35 (Oh) to 20mM (8h), but then recovered to an intermediate level (30mM; 12h). After completion of the moult, the trehalose concentration was 35–40 mM. The haemolymph glucose level in feeding fourth instar larvae was 4–5 mM, but decreased sharply before the onset of the moult to c. 1 mM, followed by a slow 6-fold increase over the next 20h. Prior to the shedding of the cuticle, the glucose level dropped again dramatically. The haemolymph lipid level increased slowly from an initial level of 1.2–1.4mg/ml during the early part of the moult, reaching a maximum of 1.8mg/ml after /= 16 h. Afterwards, a decrease of c. 50% was observed until ecdysis occurred. Oxygen consumption per animal decreased steadily from 30–35 μl/min pre-moult by approximately 70% to c. 10 μl/min but started to increase about 5 h before the animals resumed feeding.     

Ecdysone metabolism in Pieris brassicae during the feeding last larval instar

Ecdysone metabolism in Pieris brassicae during the feeding last larval stage was investigated by using ³H-labeled ecdysteroid injections followed by high-performance liquid chromatographic (HPLC

1 Abbreviations: 3DE = 3-dehydroecdysone; 3D20E = 3-dehydro-20-hydroxyecdysone; 2026E = 20,26-dihydroxyecdysone; E = ecdysone; Eoic = ecdysonoic acid; 2026E′ = 3-epi-20,26-dihydroxyecdysone; E′ = 3-epiecdysone; E′oic = 3-epiecdysonoic acid; E′8P = 3-epiecdysone 3-phosphate; 20E′ = 3-epi-20-hydroxyecdysone; 20E′3P = 3-epi-20-hydroxyecdysone 3-phosphate; FT = Fourier transform; HPLC = high-performance liquid chromatography; 20E = 20-hydroxyecdysone; 20Eoic = 20-hydroxyecdysonoic acid; NMR = nuclear magnetic resonance; NP-HPLC = normal phase HPLC; RP-HPLC = reverse phase HPLC; TFA = trifluoroacetic acid; Tris = tris(hydroxymethyl)-aminomethane.

) analysis of metabolites. Metabolites were generally identified by comigration with available references in different HPLC systems. Analysis of compounds for which no reference was available required a large-scale preparation and purification for their identification by ¹H nuclear magnetic resonance spectrometry. The metabolic reactions affect the ecdysone molecule at C-3, C-20, and C-26, leading to molecules which are modified at one, two, or three of these positions. At C-20, hydroxylation leads to 20-hydroxyecdysteroids. At C-26, hydroxylation leads to 26-hydroxyecdysteroids which can be further converted into 26-oic derivatives (ecdysonoic acids) by oxidation. At C-3, there are several possibilities: there may be oxidation into 3-dehydroecdysteroids, or epimerization possibly followed by phosphate conjugation. Thus, injected 20-hydroxyecdysone was converted principally into 20-hydroxyecdysonoic acid, 3-dehydro-20-hydroxyecdysone, and 3-epi-20-hydroxyecdysone 3-phosphate. Labelled ecdysone mainly gave the same metabolites doubled by a homologous series lacking the 20-hydroxyl group.     

Respiratory metabolism and gene expression during seed germination

Oxygen uptake and carbon dioxide release rapidly increase in seeds during imbibition. The oxygen uptake is associated with oxidative phosphorylation through cytochrome oxidase. During the early stage of germination substrate level phosphorylation may also contribute to ATP production. All indications suggest that this route of ATP production is insignificant during aerobic germination. However, during oxygen stress, substrate level phosphorylation does significantly contribute to ATP production in some species. Carbohydrate oxidation plays a significant role in the germination process. Up to two thirds of the carbon from carbohydrate breakdown enters the tricarboxylic acid cycle through the phosphoenolpyruvate carboxylase reaction. This anapleurotic input into the Krebs cycle most probably reflects the high demand on intermediates from the cycle for biosynthesis. The extent to which other substrates are utilized for respiration is uncertain. Information regarding the levels of key metabolites and enzymes, as well as their cellular distribution is limited. The involvement of gene expression in the regulation of respiratory metabolism is poorly characterised. Several genes which have been cloned are only expressed during germination. With the exception of the early methionine labeled polypeptide, little is known about the function of these genes.     

Interrelationship between the silk gland and other tissues in protein metabolism in the latest larval stage of the silkworm, Bombyx mori

Gamma irradiation at scheduled embryonic stages of silkworm eggs caused some disturbances in biological activities, i.e. cell proliferation of the silk gland, growth of larva and larval tissues, and cocoon production. The source of precursors for silk formation at the latest age of the fifth instar was found to be mainly in the ‘integument’ in its disintegrating state. Radioactivity in the tissues of the control and irradiated larvae labelled with ¹⁴C-glycine or ¹⁴C-leucine was used for analysis. Disturbance of synthesis of silk protein and of fat body protein with gamma irradiation decreased the degrading ability of the ‘integument’ and gut proteins.     

The metabolism of 3H-moulting hormone in Calliphora erythrocephala during larval development

The activity in whole insects for converting ³H-α-ecdysone to ³H-β-ecdysone after injection is low (half-maximal) in young last instar larvae, maximal in mature larvae, and minimal (fourth-maximal) at the white puparial stage. Because moulting hormone titre is low throughout the last larval instar and increases at the formation of the puparium it appears that hydroxylation at C-20 is not a key step in regulating β-ecdysone biosynthesis during larval development.The activity for catabolizing ³H-β-ecdysone is maximal in second instar larvae, about thirdmaximal throughout most of the third instar, and minimal at pupariation (thirtieth-maximal). Thus inactivation may play a rôle in regulating moulting hormone titre during larval development.     

Respiratory metabolism during cold storage of apple fruit. I. Sucrose metabolism and glycolysis

This study provides the first report on the occurrence of the respiratory climacteric during cold storage of apple fruit ( Malus domestica Borkh. cv. Reinette du Canada). The respiratory pattern at 4°C was very similar to that observed during postharvest ripening at room temperature, except that shelf life was considerably extended and the onset of the climacteric delayed. Increasing the calcium content of the apple fruit significantly reduced loss of firmness during cold storage, but showed no effect on respiration or on the other parameters determined. A gradual accumulation of soluble sugars occurred during the first 60 days after harvest and was effectively completed before the climacteric peak was reached. This increase in sugars correlated with an increase in the activity of sucrose-phosphate synthase (EC 2.4.1.14), and a marked change in the kinetic properties of the enzyme was observed after sucrose accumulation ceased. Changes in the hexose-phosphate pool and in glycolytic and gluconeogenic activities indicated an initial increase in the gluconeogenic flow at early stages of the climacteric, followed by activation of glycolysis, with the carbon flow being most likely regulated at the reversible phosphorylation of fructose-6-phosphate to fructose-1,6-bisphosphate (mostly via pyrophosphate:fructose-6-phosphate phosphotransferase, EC 2.7.1.90) and at the pyruvate kinase (EC 2.7.1.40) steps. The results presented indicate that the respiratory climacteric does not occur to accommodate extra ATP requirements during sucrose synthesis nor can it be a consequence of an increased supply of respiratory substrate.