滞育和非滞育棉铃虫血淋巴类固醇蜕皮素含量变化的比较

采用放射免疫分析法对不同时期的注定滞育和非滞育棉铃虫的血淋巴中的类固醇蜕皮素的含量进行了测定,发现在预蛹期间,注定滞育的棉铃虫的类固醇蜕皮素含量高于非滞育的棉铃虫,化蛹后,注定滞育的棉铃虫的类固醇蜕皮素含量则迅速降到极低的水平,明显低于非滞育棉铃虫。用20-羟基蜕皮素处理不同时期的滞育蛹,均能打破滞育。由此可见,类固醇蜕皮素含量的降低或缺乏乃是导致棉铃虫滞育的关键因子之一。     

滞育和非滞育棉铃虫血淋巴中蛋白质含量及图谱的比较

昆虫在滞育期间和非滞育期间,由于某些器官的生理功能产生差异,致使血淋巴中的化学成份发生了量或质的变化,特别是蛋白质的变化,如在浦育的马铃薯叶甲Leptinotarsadecemlineata[1,2]及西南玉米杆草螟Diatraeagrandiosella[3,4]的血淋巴中,均发现了特殊蛋白质,即滞育蛋白。为了弄清滞育棉铃虫Helicoverpaarmigera的血淋巴中是否也出现滞育蛋白或与滞有相关联的蛋白,及注定滞育和非滞育棉铃虫在不同发育阶段中蛋白质含量的变化和谱带特征,以进一步探索棉铃虫滞育的生理生化机制,我们通过电泳等手段对不同时期的滞育和非滞育棉铃虫…     

不同氰戊菊酯抗性水平的棉铃虫滞育比较研究

本文利用人工诱导滞育的方法,对不同氰戊菊酯抗性水平的棉铃虫蛹滞育进行了比较研究。结果表明,氰戊菊酯抗性高的棉铃虫滞育率低,滞育蛹历期长,耐寒性差。不同氰戊菊酯抗性水平的棉铃虫蛹重无显著差异。     

温度对棉铃虫滞育的影响

在前人研究的基础上［１,２］,我们已经了解到光照和温度乃是影响和决定棉铃虫是否进入滞育状态的关键外界环境因子。但光照和温度,哪一个在决定棉铃虫的滞育中起着更关键的主导地位,则无文献述及,为此,我们设计了如下几个实验,试图来解答这个问题以及进一步了解温度对棉铃虫滞育的影响。１材料与方法１．１实验昆虫虫源由中国科学院动物研究所何忠教授提供,系采自河南郑州,在２５℃、每天光照１６小时的条件下用人工饲料［１］饲养繁殖。滞育的棉铃虫在２０℃、每天光照１０小时的条件下饲养,其滞育率可达１００％;非滞育的棉铃…     

滞育和非滞育棉铃虫前胸腺的形态解剖学比较研究

该文用解剖镜和电子显微镜对滞育和非滞育棉铃虫Helicoverpa armigera前胸腺的形态解剖结构进行了比较研究。结果发现滞育棉铃虫的前胸腺细胞及其细胞间隙相对较小,不易着色,细胞核规则,较小,细胞质中几乎见不到光滑内质网和粗面内质网,线粒体极少,这些观察到的现象充分说明滞育棉铃虫的前胸腺活性较低。     

早熟素对棉铃虫滞育的终止作用(英文)

用外源激素和某些化合物处理棉铃虫的滞育蛹 ,结果发现早熟素与蜕皮素一样可终止棉铃虫蛹的滞育 ,使其进入到发育阶段。而保幼激素类似物ZR 5 1 5 ,环腺氨酸 (cAMP)和色氨类化合物 (5 HT)则完全不具有终止棉铃虫滞育的作用。结合早熟素还可终止蚜虫寄生蜂AphidiusmatricariaeHaliday和PraonvolucreHaliday的预蛹滞育的报道 ,建议早熟素应具有终止多种类昆虫滞育的功能     

棉铃虫取食转Bt棉后蛹的抗寒力测定

在棉铃虫HelicoverpaarmigeraH櫣bner人工饲料中分别添加转Bt基因棉叶粉和常规棉叶粉饲喂幼虫,经滞育诱导后,发现2个处理间棉铃虫蛹的滞育率相似,2个处理间滞育蛹的自由水和结合水含量没有差异;但取食含Bt棉叶粉人工饲料的棉铃虫滞育蛹的过冷却点和结冰点显著高于对照组,蛹重及与抗寒性有关的脂肪和糖原含量均显著低于对照组。     

光周期对棉铃虫幼虫发育历期和蛹重的影响

在亚热带和温带地区,棉铃虫HelicoverpaarmigeraHubner以蛹滞育越冬,秋季低温和短光照是诱导滞育的主导因素[1]。对棉铃虫及其近缘种美洲棉铃虫H.zea（Boddie）、澳洲棉铃虫H.punctigera（Harbwick）、烟芽夜娥Heliothisvirescens（Fabricus）的研究表明,滞育蛹和发育蛹在外部形态、呼吸代谢、抗逆性、内部器官发育、生化成分、激素水平等方面均明显不同。由于它们滞育的诱导过程主要发生于幼虫期,故其滞育和非滞育个体的某些生理生态特性差异在幼虫期即有所体现。例如,棉铃虫两类个体的呼吸代谢速率在5龄幼虫期即有所差异,到6龄…     

光周期与温度的联合作用对棉铃虫种群滞育的影响

<正> 棉铃虫Heliothis armigera Hbner是一种多化性并且具有兼性滞育的昆虫,在北京郊区每年发生四代。目前国内对棉铃虫种群滞育问题研究不多,为了明确北京郊区棉铃虫种群的光周期反应的一般特点,以及光周期与温度的联合作用对该虫种群滞育的影响,为分析该虫种群数量变化的原因提供一些科学依据,我们以北京郊区昌平县中越人民公社史各庄村大队的棉铃虫种群为材料,进行了初步研究。 材料和方法 1977年10月,自北京郊区昌平县中越人民公社史各庄村大队棉田采回的第四代棉铃虫老龄幼虫,于室内饲养至化蛹。滞育的蛹在5℃     

光温条件明显影响棉铃虫的滞育强度

为了探明不同地理种群棉铃虫Helicoverpa armigera滞育强度的地理变异, 本研究系统地比较了光温条件（光照时数 11～16 h, 恒温20, 22, 25, 28和31℃及变温）对来自中国的4个地理种群（广东广州、 江西永修、 山东泰安和辽宁喀佐）棉铃虫滞育强度的影响。结果表明： 滞育诱导的光周期对继后棉铃虫的滞育强度有明显影响。在光照时数11～14 h范围内, 各地理种群的滞育持续期均随着光照时数的增加而延长。滞育强度也受到滞育诱导的温周期影响, 当光期温度相同时, 低纬度的GZ种群温周期比恒温有更强的诱导效应; 中纬度的YX种群温周期与恒温具有相同的滞育诱导强度; 高纬度的KZ和TA种群温周期所诱导的滞育强度一般低于恒温。滞育解除过程中的温度也显著影响到滞育的解除, 在20~31℃下, 温度愈高滞育解除愈快; 滞育持续期同时受到滞育诱导温度的影响, 对于北方的泰安种群和喀佐种群, 较高的滞育诱导温度能诱导更强的滞育。     

Cold hardiness in summer and winter diapause and post-diapause pupae of the cabbage armyworm, Mamestra brassicae L. under temperature acclimation

Cold hardiness and biochemical changes were investigated in winter and summer pupae of the cabbage armyworm Mamestra brassicae at the diapause and post-diapause stages under temperature acclimation. Diapause pupae were successively acclimated to 25, 20 and then 10 degrees C (warm-acclimated group). Pupae at the diapause and post-diapause stages were successively acclimated to 5, 0, -5 and then -10 degrees C (cold-acclimated groups). Supercooling point values in winter and summer pupae remained constant regardless of the diapause stages and acclimated temperatures. Warm-acclimated pupae at the diapause stage did not survive the subzero temperature exposure, whereas, cold-acclimated pupae achieved cold hardiness to various degrees. Winter pupae were more cold hardy than summer pupae, and pupae at the post-diapause stage were more cold hardy than those at the diapause stage. Trehalose contents in winter pupae rose under cold acclimation. Summer pupae accumulated far lower trehalose contents than winter pupae, with the maximal level occurring in winter pupae at the post-diapause stage. Glycogen content remained at a high level in diapause pupae after warm acclimation, whereas it decreased after cold acclimation. Alanine, the main free amino acid in haemolymph after cold acclimation, increased at lower temperatures in both diapause and post-diapause pupae, but the increase was greater in the diapause pupae. These results suggest that cold hardiness is more fully developed in winter pupae than in summer pupae, and cold acclimation provides higher cold hardiness in winter pupae at the post-diapause stage than at the diapause stage.     

Physiology of diapause and cold hardiness in overwintering pupae of the apple leaf miner Phyllonorycter ringoniella in Japan

Abstract The apple leaf miner Phyllonorycter ringoniella (Matsumura) (Lepidoptera: Gracillariidae) overwinters as a diapausing pupa. The diapause rate reaches 100% in early October. Diapause intensity decreases gradually from early October and diapause terminates in early February. The fresh body weight of diapausing pupae is 1.6 times that of non-diapausing pupae. The main cryoprotectant in P. ringoniella pupae is trehalose. Three stages are distinguishable as indicated by the correlations between diapause intensity, levels of cold hardiness and the trehalose content: diapause induction occurred in October, diapause development from November to December, and post-diapause quiescence from January to April. During diapause induction, the pupae accumulate low levels of trehalose and do not survive exposure to −15 °C. During diapause development, the pupae gradually accumulate more trehalose and show some ability to survive exposure to −15 °C, but not to −20 °C. During post-diapause quiescence, the pupae accumulate relatively more trehalose and cold hardiness fully develops, but decreases quickly in April. The trehalose content in pupae sampled in December is unaffected by acclimation temperatures in the range 0–30 °C, but decreases in pupae sampled in March after acclimation at temperatures from 5 to 15 °C. These results suggest that overwintering pupae of P. ringoniella have the ability to accumulate trehalose and develop a high level of cold hardiness during diapause development.     

Relationships between cold hardiness and diapause, and between glycerol and free amino acid contents in overwintering larvae of the oriental corn borer, Ostrinia furnacalis

To elucidate the relationship between diapause and cold hardiness in the oriental corn borer, Ostrinia furnacalis, the levels of various substances, cold hardiness and respiration were measured in diapausing and post-diapausing overwintering larvae. Under field conditions, diapause terminated between November and January, although O(2) consumption, measured at 20 degrees C in the laboratory, remained at a high level from October to January. Glycerol content was low during October and November but greatly increased during December and January. Serine was the most abundant of the free amino acids, and its concentrations were especially high during October and November, while the concentration of alanine increased in December and January. Under laboratory conditions, glycerol levels were low in diapausing larvae, and in post-diapausing larvae that were acclimated at either high temperatures or under anaerobic conditions, while they were high in post-diapausing larvae kept under aerobic, low temperature conditions. The survival rate (cold hardiness) was strongly correlated with glycerol content but not with serine or alanine levels. These results suggest that O. furnacalis has a highly developed cold hardiness mechanism in which termination of diapause enables the larvae to increase glycerol levels when the temperature decreases.     

Overwintering strategies and cold hardiness of two aphid parasitoid species (Hymenoptera: Braconidae: Aphidiinae)

The role of winter diapause in two aphid parasitoid species, Aphidius ervi Haliday and Aphidius rhopalosiphi DeStefani-Peres (Hymenoptera: Braconidae: Aphidiinae), in host synchronization and the induction of cold hardiness was investigated. Parasitoids were reared during three successive generations on Sitobion avenae Fabricius, at 15 degrees C under a photoperiod of 9 h light 15 h dark. Although these conditions are known to be strongly diapause inducing, neither parasitoids showed an incidence of diapause above 65% over the three generations; the rest of the population underwent quiescence. In both parasitoid species, diapausing mummies exhibited greater cold hardiness than non-diapausing mummies, resulting in significantly lower supercooling points (SCP) and in a higher survival rate during long-term exposures at 0 and -10 degrees C. The induction of increased cold hardiness in parasitoids was thus associated with the diapause state. SCPs of third instar larvae of S. avenae were similar to those of non-diapausing mummies of both parasitoid species, but significantly higher than those of diapausing mummies. The effect of winter climate on the stability of the host-parasitoid interaction is discussed.     

Physiology of diapause and cold hardiness in the overwintering pupae of the fall webworm Hyphantria cunea (Lepidoptera: Arctiidae) in Japan

The fall webworm Hyphantria cunea Drury, which was accidentally introduced to Japan in 1945, overwinters on the ground in pupal diapause. Diapause termination, as indicated by the respiration rate and the period required for adult emergence, began in March and ended in April. Cold hardiness (the ability to survive exposure to -15 degrees C) decreased linearly with diapause development from November to the following April under field conditions. Cold hardiness of diapause pupae (DP) decreased as the acclimation temperature decreased from 15 to -10 degrees C, whereas cold hardiness of non-diapause pupae (NDP) remained high as the acclimation temperature decreased from 5 to -5 degrees C. However, H. cunea in Japan can survive exposure to -5 degrees C for two weeks, whether it is in a diapause or non-diapause state. Trehalose was the main sugar detected in the body, but its level was less than 0.8%. Trehalose levels increased in field-collected pupae from January to March. DP accumulated less trehalose than NDP, as the acclimation temperature was decreased from 5 to -5 degrees C. The alanine content in field-collected pupae increased from November to February. Both diapause and low temperature caused an accumulation of alanine. These results suggest that under field conditions, overwintering pupae of H. cunea in Japan do not accumulate high levels of sugars and polyols and do not develop a high level of cold hardiness. Furthermore, DP do not accumulate high levels of sugars and polyols and their ability to survive exposure to -15 degrees C is not greater than that of NDP. The physiological and biochemical bases of diapause in H. cunea from Japan are discussed.     

Expression of mRNA for the t-complex polypeptide-1, a subunit of chaperonin CCT, is upregulated in association with increased cold hardiness in Delia antiqua

Summer-diapause and winter-diapause pupae of the onion maggot, Delia antiqua (Diptera: Anthomyiidae), were significantly more cold hardy than nondiapause, prediapause, and postdiapause pupae. Moreover, cold acclimation of nondiapause pupae conferred strong cold hardiness comparable with that of diapause pupae. Differential display analysis revealed that the expression of a gene encoding TCP-1 (the t-complex polypeptide-1), a subunit of chaperonin CCT, in D antiqua (DaTCP-1) is upregulated in the pupae that express enhanced cold hardiness. Quantitative real-time polymerase chain reaction analyses showed that the levels of DaTCP-1 messenger RNA in pupal tissues, brain, and midgut in particular, are highly correlated with the cold hardiness of the pupae. These findings suggest that the upregulation of DaTCP-1 expression is related to enhanced cold hardiness in D antiqua. The upregulation of CCT in response to low temperature in an organism other than the yeast is newly reported.     

Seasonal changes in glycerol content and cold hardiness in two ecotypes of the rice stem borer, Chilo suppressalis, exposed to the environment in the Shonai district, Japan

The rice stem borer, Chilo suppressalis, is divided into at least two ecotypes in Japan, the Shonai ecotype (SN) which is distributed in the northern part of Japan, and the Saigoku ecotype (SG) which is distributed in the southwestern region. Cold hardiness is positively correlated with the level of glycerol in both ecotypes. To investigate whether ecological distribution affects glycerol accumulation and cold hardiness development in these two ecotypes, overwintering larvae of the SN and SG ecotypes were concurrently exposed to the Shonai district. Obvious differences in the progress of glycerol accumulation and cold hardiness development in SN and SG larvae were found in early winter in the Shonai district. The levels of glycerol content and cold hardiness were low in October and high in January in both ecotypes, but those levels were different within this period (November and December) between ecotypes; the levels in SN larvae quickly reached their maximum, whereas, in SG larvae levels increased slowly. Under controlled conditions, the effect of the period of acclimation at 10 degrees C and subsequent low-temperature (5 degrees C) exposure on glycerol accumulation was investigated. These results indicated that glycerol accumulation in SN was stimulated by the progression of diapause termination, whereas a higher cumulative effect on glycerol production in SG was found when diapause was in a deep state.