飞蝗抱对行为的进化意义及两型间相异的交配策略

飞蝗Locusta migratoriaL.不仅交配时间长,而且进行频繁的、长时间的交配前抱对。一般认为,交配前抱对行为是雄虫为了等待时机获取适时的交配。最近的研究表明,飞蝗的交配时间与P2值(最后交配雄虫子代的比例)、交配前抱对时间与交配时间存在显著的正相关关系,即飞蝗长时间的交配前抱对行为能延长其后续的交配时间,从而提高P2值。飞蝗具变型现象,散居型和群居型在形态特征、生理机能、行为及体色等方面存在明显差异。最近的研究结果显示,散居型较群居型具更高的P2值,较短的交配前抱对和较长的交配时间。冲绳和筑波种群散居型成虫的交配前抱对时间与交配时间存在显著的正相关关系,而群居型无此相关性。这些结果证实飞蝗散居型和群居型之间存在着繁殖策略的差异。     

蝗虫多型现象的神经内分泌调控

蝗虫有两种型,即散居型和群居型。蝗灾通常由群居型蝗虫所引发。多年来人们试图找到控制蝗虫由散居型向群居型转变的关键因子,以期控制蝗虫危害。该文主要从神经内分泌的角度概述了蝗虫多型性的生理机制,重点介绍了保幼激素、蜕皮激素和脑神经肽［His7］-corazonin在蝗虫多型性中的主要作用和机制。     

白边痂蝗在青藏高原上的地理变异

蝗虫的种类很多,是为害农作物和牧草的重要害虫。有些种类的形态在不同地点或不同时间有很大的差异,这些差异给分类工作者带来了很大的麻烦,并且往往由于标本数量少或工作粗糙而鉴定错误,甚至错订成新种或新亚种。就飞蝗(Locusta migratoria L.)而言,Uvarov(1921)发表了变型学说,揭示了飞蝗的群居型、散居型、中间型之间后代可以互变的秘密。而在此学说发表之前,人们都把群居型和散居型飞蝗当作二个种。这种种内变异现象引起了分类工作者和生态工作者的重视。近来国内外学者对种下分类工作研究颇多,(1972)对雏蝗[Chorthippus macrocerus (F.-W.)]的种内变异进行了研究,利用t值来区分亚种。     

型变过程中亚洲小车蝗体内保幼激素滴度及其代谢相关基因表达量的变化

【目的】本研究旨在明确亚洲小车蝗Oedaleus asiaticus在不同发育阶段和型变过程中的保幼激素(juvenile hormone, JH) JHⅢ滴度及其代谢相关基因表达量的变化情况，为阐明保幼激素调控亚洲小车蝗型变中的生理功能奠定基础。【方法】采用高效液相色谱法测定散居型和群居型亚洲小车蝗不同发育阶段(4和5龄若虫及1, 4, 7, 10, 13和20日龄成虫)和3龄若虫群居化处理1, 3, 5和7 d时亚洲小车蝗血淋巴中的保幼激素JHⅢ的滴度变化；用qRT-PCR检测在群居化处理亚洲小车蝗3龄若虫1, 3, 5和7 d时保幼激素代谢相关的3种基因保幼激素酯酶(juvenile hormone esterase, JHE)基因、保幼激素甲基转移酶(juvenile hormone methyltransferase, JHAMT)基因和保幼激素环氧水解酶(juvenile hormone epoxide hydrolase, JHEH)基因的表达量；利用JHⅢ浸液处理散居型亚洲小车蝗3龄若虫后进行群居化处理，测定亚洲小车蝗型变率。【结果】JHⅢ在亚洲小车蝗血淋巴中的滴度甚微...     

群居型和散居型东亚飞蝗雌成虫飞行肌的超微结构

应用电子显微镜对群居型和散居型东亚飞蝗Locusta migratoria manilensis（Meyen）雌成虫背纵肌进行了比较观察。结果表明：群居型和散居型成虫背纵肌具有类似的亚细胞结构,飞行肌的肌原纤维具有1∶3粗细丝比例,每根粗丝由6根细丝环绕排列成六角形结构。飞行肌的发育和线粒体的形成均是渐进的过程,在不同日龄成虫间存在差异。肌节长度为2.1～3.4 μm;7和10日龄时群居型成虫肌节长度小于散居型;7日龄群居型肌原纤维直径显著大于散居型。背纵肌内线粒体含量约占肌纤维的20%～43%,两型飞蝗之间存在着显著的差异,7日龄时群居型线粒体占肌原纤维的比例高达42.96%,而散居型的只有22.45%;10日龄群居型线粒体含量为41.32%,散居型线粒体29.98%。上述差异可能是东亚飞蝗群居型成虫飞行能力显著强于散居型成虫的重要原因之一。     

西藏飞蝗触角感器的扫描电镜观察

应用扫描电镜对西藏飞蝗Locusta migratoria tibetensis Chen触角的外部形态结构及其感器进行了观察和研究.结果表明,西藏飞蝗触角上存在5种感器即毛形感器、刺形感器、腔锥形感器、锥形感器和腔形感器.通过对各种感器的形态特点进行描述,发现西藏飞蝗群居型与散居型、蝗蝻与成虫、雌性与雄性的感器在类型...     

黑化粘虫的形态特征及其遗传模式

本文首次研究报道了黑化粘虫Mythimna separata的形态特征及其遗传模式。所获的结果表明,黑化型与正常型粘虫的外部形态特征差异主要表现在成虫期。与正常型粘虫相比,黑化粘虫的成虫体色几乎全部变黑,正常型成虫所具有的黑色特征在黑化粘虫中已完全看不见,其他的颜色特征也由于黑化而产生了变异。卵、幼虫和蛹的颜色与正常型的没有明显的区别,只是黑化型的蛹在将羽化时的体色比正常型的深。黑化粘虫的遗传遵循孟德尔的隐性遗传规律,由位于常染色体上的单基因控制。这些结果表明,黑化型与正常型粘虫虽然仍属于同一个种,但黑化粘虫已经演变成了不同的基因型。最后,对黑化粘虫产生的原因及其在进化上的适应意义进行了讨论。     

东亚飞蝗行为和形态型变的判定指标

通过田间、室外罩笼、室内行为测试等一系列实验,研究了东亚飞蝗群居型和散居型之间的行为和形态差异。确立了东亚飞蝗不同生态型个体的形态和行为指标．结果表明,雌雄散居型蝗蝻每分钟的跳跃次数均在1．4以下,转向次数分别在1．3和1．4以下;雌雄群居型蝗蝻每分钟的跳跃次数均在1．6以上,转向次数分别在1．6和1．5以上．群居型蝗虫的跳跃次数、转向次数显著高于散居型蝗虫。所以跳跃次数、转向次数可作为东亚飞蝗行为型变判定指标．在同型不同性别的蝗虫之间行为型变指标没有显著差异．F／C值可作为4龄以上东亚飞蝗的形态型变判定指标。而E／F值可作为东亚飞蝗成虫的形态型变判定指标．两型的F／C值都随龄期的增长而增加,且同龄期雄虫F／C均大于雌虫F／C．F／C、E／F值在不同型态和同型不同性别间均存在极显著差异．因此,确定两型形态型变标准时应将雌、雄虫分开,即雌性和雄性散居型第4、5龄及成虫的F／C值分别大于2．5、2．8、3．3和2．6、2．9、3．5;雌性和雄性群居型第4、5龄及成虫的F／C值分别小于2．5、2．7、3．1和2．5、2．8、3．3．成虫的E／F值也可以作为成蝗形态型变的判断指标．     

东亚飞蝗二型的形态测量比较

东亚飞蝗的群居型、散居型,不仅在生物学特性上有显著差异,而且在形态学上也有显著不同。由于二型的发生特点不同,在研究飞蝗的发生规律时,必须弄清二型在种群中所占的比例,首先从形态学来区别二型。国外对沙漠蝗及亚洲飞蝗二型的形态研究已做了很多工作,对不同蝗虫种类所采用的指标是不同的,除了普通所采用两个比较明显的区别特征——体色及前胸背板以外,还采用其他部分的测量指标。关于东亚飞蝗二型的形态测量比较,前人研究较少。作者自1958年开始,从蝗区采集了部分标本进行测量,并以在不同密度饲养下的成虫进行形态比较。现将初步研究结果简单报导,以供参考。 一、工作方法 野外材料采自河北漳河蝗区,饲养的材料分别来自室内及田间。窒内饲养时温度控制30℃,饲养笼容积39×39×39厘米,分别置放蝗蝻6头、54头。田间     

亲本体色及环境因子对长绿飞虱成虫体色、寿命与繁殖的影响

【目的】明确亲本体色和环境因素对长绿飞虱Saccharosydne procerus F1代成虫体色的影响及不同体色成虫个体在不同环境中产卵量、交配率、成虫寿命的变化。【方法】长绿飞虱不同体色(黑化与非黑化)亲本所产若虫在室内经不同温度(30℃和22℃)和光周期(20L∶4D和16L∶8D)组合处理,观察成虫黑化率;将不同体色的成虫同样经历这些温度和光周期组合处理,记录成虫寿命、产卵量和交配率变化,分析不同因素对其的贡献率。【结果】长绿飞虱不同体色亲本所产若虫在实验室内经过上述温度和光周期组合处理后,成虫黑化率变化范围为18.6%~60.8%。若虫期高温、长光照以及黑化亲本均显著增加子代中黑化个体的比例。低温短光照条件下非黑化个体寿命显著长于黑化个体,高温长光照则相反;黑化个体交配率与产卵量随着温度和光照时间的下降而下降,非黑化个体的交配率与产卵量则主要受到光周期影响。统计分析表明,在几种因子中,温度对长绿飞虱的交配率变化贡献率最高,为39.1%;光周期对长绿飞虱体色及产卵量变化贡献率最高,分别达到42.5%和47.4%。体色与温度交互作用对长绿飞虱雌、雄成虫寿命的贡献率最高,分别可达50.3%和60.6%。【结论】本研究表明,若虫期光周期对长绿飞虱成虫体色变化影响最显著,且该虫体色变化在一定程度上改变了其成虫生物学特性,提高了该虫对环境的适应性。     

Hormonal control of body-color polymorphism in Locusta migratoria: interaction between

The effects of injection of [His(7)]-corazonin and juvenile hormone (JH) III on the body color in L. migratoria were investigated using albino and normal (pigmented) nymphs. Most albino nymphs turned green in the fourth instar if injected with JH III during the last 2 days of the previous instar. When albino third instar nymphs injected with 10 pmol of [His(7)]-corazonin on different days were treated with 100 μg of JH III on day 3.5, they developed various body colors in the following nymphal instar: those injected with [His(7)]-corazonin during the first 2 days developed very dark green or black color, whereas some of those injected after this period turned green and their legs and ventral side of the body were variously pigmented, the coloration being similar to green solitary individuals often found in the field. Field-collected brown solitary nymphs injected with 1 nmol of [His(7)]-corazonin and kept individually, turned reddish without any black spots in the following nymphal instar when the ecdysis occurred within 1 day after injection. Injection of [His(7)]-corazonin 2 days before the following ecdysis induced black patterns on an orange background color, the coloration characteristic of gregarious forms. Similar injections into field-collected green solitary nymphs also induced black patterns but the rest of their body remained green. These results may indicate that the temporal changes in the hemolymph titers of [His(7)]-corazonin and JH play an important role in the control of body-color polymorphism in this locust.     

Endocrine mechanisms controlling body-color polymorphism in locusts.

The present article reviews recent published and unpublished findings on the hormonal mechanisms for the control of body-color polymorphism in locusts. Emphasis is placed on the dark color-inducing factors and their role in the induction of various types of body coloration observed under different environmental conditions. Implantation of corpora cardiaca (CC) taken from normal nymphs of Locusta migratoria induced dark color in nymphs of an albino strain. Using the albino strain for the bioassay, a neuropeptide, [His7]-corazonin, was identified as a dark color-inducing factor for L. migratoria and Schistocerca gregaria. In the former, depending upon the dose and timing of the injection, this peptide and juvenile hormone developed various body colors looking like those found in nature. The body coloration characteristic of gregarious forms was also induced in isolated albino nymphs and field-collected solitary nymphs. In S. gregaria, on the other hand, the peptide induced black patterns, but the orange or yellow background color observed in gregarious forms was not induced when the peptide was injected into solitary individuals. [His7]-corazonin also induced darkening in other grasshoppers and locusts, but not in katydids. Albino L. migratoria developed dark color when implanted with brains or CC taken from other insects belonging to 10 major insect orders, but not with those from Coleoptera. [His7]-corazonin or a similar compound is widespread among insects and plays a pivotal role in controlling body color in some species and presumably other physiological roles in other species. Arch.     

The role of

The effect of [His(7)]-corazonin on the body color in Locusta migratoria was examined by varying the injected dose and the time of injection in both an albino and a normal (pigmented) strain. Albino nymphs injected with a high dose (100pmol) of [His(7)]-corazonin at the beginning of the third instar turned completely black in the following instar, whereas those injected with the same dose in the middle of the instar developed black patterns with an orange background color, the body coloration characteristic of normal gregarious (crowded) individuals. Injection at the end of the third instar induced a reddish color with few black spots. Irrespective of the time of injection of the peptide, most of these individuals became completely black after ecdysis to the fifth instar. A similar result was obtained with a lower dose (1pmol), although the color expressed was lighter. In the normal strain, injection of 1nmol or 100pmol into crowded third instar nymphs also caused most of them to become completely black in the fourth and fifth instars, but a lower dose apparently had no influence. These results suggest that the temporal changes in hemolymph titer of [His(7)]-corazonin are important in the expression of body color in L. migratoria.     

Effect of [His7]-corazonin on the number of antennal sensilla in Locusta migratoria

Abstract.  Certain types of antennal sensilla are known to be more abundant in solitarious individuals than in gregarious ones in the migratory locust, Locusta migratoria . We tested the hypothesis that injection of a neurohormone, [His⁷]-corazonin, into isolated-reared nymphs of this species mimics the effect of crowding on the frequencies of various types of antennal sensilla. One nmol of the hormone was injected into nymphs on two occasions, on the third days of the second and third stadia, respectively. Upon adult emergence, the numbers of different types of sensilla on the eighth antennal segment were compared with those of oil-injected controls. [His⁷]-corazonin did not influence the numbers of basiconic sensilla type A, basiconic sensilla type B and trichoid sensilla significantly compared to oil-injected controls. However, the number of coeloconic sensilla was reduced significantly by the hormone injections. Because the length of the antennal segment was not affected by the hormone injection, it appears that the hormone influenced the development of coeloconic sensilla. The results support the hypothesis tested and are consistent with the idea that [His⁷]-corazonin plays an important role in the control of phase polymorphism in L. migratoria .     

Phase-related morphological changes induced by [His7]-corazonin in two species of locusts, Schistocerca gregaria and Locusta migratoria (Orthoptera: Acrididae)

The effects of a neurohormone, [His(7)]-corazonin, on phase-related morphological traits (F/C and E/F ratios; F = length of the hind femur, C = maximum width of the head; E = length of fore wing) were re-examined in the desert locust, Schistocerca gregaria Forsk?l. The F/C ratio was significantly different between adults with five and six nymphal instars, respectively, indicating that they need to be analysed separately. Injections of the synthesized peptide (1 nmol) into individually-reared (solitary) nymphs at the second and third instars caused a shift in classical morphometric ratio towards the value typical for crowded (gregarious) individuals in both sexes. The E/F ratio, which is smaller in solitary locusts than in gregarious ones, was also influenced significantly by injections of [His(7)]-corazonin into individually-reared locusts. The effect of [His(7)]-corazonin on E/F ratios was shown more clearly when the nymphs were injected at a higher dose (2 nmol) at the beginning of the third instar. Single injections of the peptide into individually-reared nymphs at different instars revealed that the earlier the injection the larger the 'gregarizing' effects of the peptide on F/C and E/F ratios. The same tendency was also detected in Locusta migratoria Linnaeus. These results supported the hypothesis that [His(7)]-corazonin plays an important role in the control of phase polymorphism in locusts.     

Effects of temperature and [His7]-corazonin on the body darkening in Locusta migratoria

Abstract.  [His⁷]-corazonin is a neuropeptide that induces dark coloration in locusts. This study examined the effect of temperature on body colour in the migratory locust, Locusta migratoria . L. Injection of a low dose (1 pmol) of [His⁷]-corazonin caused albino nymphs to develop dark coloration at 25–34 °C, but little darkening occurred at 38 and 42 °C. However, injection of a high dose (10 pmol) induced darkening even at these high temperatures. Transfer of nymphs injected with 1 pmol of [His⁷]-corazonin from 30 to 42 °C, and vice versa, indicated that temperature influenced darkening at any time after injection. Measurements of the luminance of the pronotum were made using commercially available computer software to follow continuous changes in darkening of the body. The body colour of nymphs injected with [His⁷]-corazonin was reddish-brown at 25 °C, blackish at 30 and 34 °C, and greyish or whitish at 38 and 42 °C. High temperature also suppressed darkening in a normal (pigmented) strain. Most nymphs transferred from 30 to 42 °C during the first three stadia developed a light colour in the fifth stadium without the striking black patterns that are typically manifested in gregarious nymphs at lower temperatures. Such individuals developed black patterns in the fifth stadium when injected with [His⁷]-corazonin at a mid stage of the previous stadium. These results indicate that high temperature may induce light body coloration by suppressing the release of [His⁷]-corazonin in normal locusts.     

Behavioural differences in Locusta migratoria associated with albinism and their relation to [His7]-corazonin

Abstract. The neuropeptide [His⁷]-corazonin induces black colouration in locusts, a feature typically occurring in gregarious animals. To date, the function of this neuropeptide in relation to phase transition has not been fully clarified. Unanswered questions on its involvement in behavioural and morphometrical phaseshifting and possible temperature-induced regulation still remain. In the African locust, Locusta migratoria migratorioides (Reiche and Fairmaire) (Orthoptera: Acrididae), the gregarious form possesses mainly a brown colouration with typical intense black pigmentation. To find a possible behavioural function, an albino L. migratoria mutant, deficient in [His⁷]-corazonin and thus lacking the typical gregarious colour, was used. Between these two phenotypes, nonphase specific behavioural differences in a phase-dependent behavioural set-up were found. Additionally, a wild-type of the Okinawa strain was screened behaviourally and located in comparison to the other groups. Treatment of albinos with corazonin induced normal phenotype behaviour. The degree of interference of corazonin in relation to these findings and a possible effect at the level of visual perception is discussed.     

The dark-color inducing neuropeptide, [His(7)]-corazonin,causes a shift in morphometic characteristics towards the gregarious phase in isolated-reared (solitarious) Locusta migratoria

The neurohormone, [His⁷]-corazonin is known to induce dark color in the cuticle and epidermis of Locusta migratoria. In the present study, we examined the effects of this hormone on development and morphometrics in two strains, albino and normal, of this locust under isolated conditions. Injection of [His⁷]-corazonin induced dark color in both strains. In either strain, [His⁷]-corazonin injected at the second and third instars did not affect duration of nymphal development or the number of nymphal instars. The shape of the pronotum was more convex in isolated-reared animals than in crowd-reared ones, and injection of [His⁷]-corazonin caused isolated-reared animals to develop a less convex pronotum in the normal strain injected at a high dose (1 nmol×2) but not in the albino strain injected at a low dose (50 pmol×2). [His⁷]-corazonin injected into isolated-reared nymphs caused a shift in classical morphometric ratios (F/C and E/F; F=length of the hind femur, C=maximum width of the head, E=length of the fore wings) towards values typical for crowd-reared (gregarious) individuals of the two strains. This study demonstrated for the first time that [His⁷]-corazonin affected morphometric characteristics in L. migratoria.     

Hormonal control of phase-related changes in the number of antennal sensilla in the desert locust, Schistocerca gregaria: possible involvement of [His7]-corazonin

The effect of [His(7)]-corazonin on the abundance of antennal sensilla in the desert locust, Schistocerca gregaria, was investigated to test the hypothesis that injection of this neuropeptide would mimic a crowding effect. Solitarious locusts (reared in isolation) were injected with [His(7)]-corazonin at the 3rd nymphal instar and the numbers of sensilla on the 2nd, 8th and 14th antennal segments in the adult stage were compared with those for oil-injected solitarious controls or un-injected gregarious locusts (reared in group). The numbers of sensilla on these antennal segments were all reduced significantly after [His(7)]-corazonin injection compared with those for oil-injected controls, but similar to the values for gregarious individuals. Among the four major types of olfactory sensilla, coeloconic, trichoid, basiconic type A and basiconic type B, [His(7)]-corazonin injection influenced the abundance of all but the last type. The effect of [His(7)]-corazonin injection varied with the time of injection; the earlier the injection the larger the effects on the abundance of total antennal sensilla on the 8th segment, although the way in which the injection affected the abundance varied with the sensillum type. A hypothesis explaining how crowding affects the abundance of antennal sensilla and other phase-related characteristics through changes in [His(7)]-corazonin concentrations was proposed.