芫菁体内斑蝥素的含量及存在形式

【目的】测定芫菁体内斑蝥素的含量及其存在形式。【方法】利用气相色谱法测定了8种芫菁和作为对照的黑翅红蝉体内总斑蝥素和游离斑蝥素的含量,总斑蝥素含量是通过酸水解法测得的,游离斑蝥素含量是通过直接浸提法测得的,以总斑蝥素与游离斑蝥素含量之差作为结合斑蝥素含量; 并比较了结合斑蝥素与钙、镁含量之间的相关性。【结果】芫菁体内总斑蝥素的含量为游离斑蝥素含量的1～9倍,总斑蝥素的含量一般多于虫体干重的2.0%,而游离斑蝥素的含量均低于虫体干重的1.7%。黑翅红蝉体内不含任何形式的斑蝥素。斑芫菁属和豆芫菁属昆虫中的结合斑蝥素含量与钙元素呈正相关,斑芫菁属中结合斑蝥素含量与镁元素呈正相关,而豆芫菁属中结合斑蝥素含量与镁元素呈负相关。斑芫菁属昆虫体内钙元素的摩尔量要低于结合斑蝥素的摩尔量。【结论】芫菁体内总斑蝥素含量远高于游离斑蝥素的含量;结合斑蝥素可能是以斑蝥素酸钙和斑蝥素酸镁形式存在。     

芫菁体内斑蟊素的合成、 转移和生物学功能

斑蟊素是芫菁科昆虫合成的一种防御物质, 已经被证实对多种癌症和其他疾病有着特殊的疗效。芫菁体内存在不同结合态的斑蟊素或斑蟊素衍生物, 包括斑蟊素酸镁、斑蟊素酸钙、羟基斑蟊素、甲基斑蟊胺和脱甲斑蟊素等。不同芫菁种类、不同发育阶段其斑蝥素合成量有显著的差异, 并且有着典型的性二型现象, 性成熟的雄成虫斑蝥素含量最高可达10%。关于斑蝥素的生物合成途径以及斑蝥素在虫体内的分布, 尽管有一些研究, 但仍然没有定论。本文从斑蟊素在芫菁体内的含量、分布、生物合成、代谢及生物学功能等方面对国内外的研究进行概括, 以期为充分发掘芫菁科昆虫资源、指导芫菁的人工养殖、合理的利用资源以及人工合成斑蟊素提供参考。     

芫菁科昆虫体内斑蝥素的气相色谱法测定

分别采用酸水解法和直接浸提法处理不同种芫菁样品、短翅豆芫菁Epicauta aptera Kaszab的卵和大斑芫菁Mylabris phalerata Pallas的不同虫体部位,后用气相色谱仪测定斑蝥素含量。结果表明:用酸水解法处理后的芫菁体内斑蝥素含量较之用直接浸提法处理后有显著提高,增高幅度在1~9倍之间,其中以豆芫菁属Epicauta昆虫的增高幅度最大,一般在7倍以上,而斑芫菁属Mylabris的斑蝥素含量增幅不高,芫菁卵中斑蝥素含量变化不显著;斑蝥素主要富集于大斑芫菁的腹部。     

斑蝥素在细纹豆芫菁成虫体内的变化和配偶间的运转

将采自野外的同一批细纹豆芫菁成虫用半人工饲料饲养,取刚结束交配（A组）、交配结束后单养4天（B组）和未交配（C组）的两性成虫的血淋巴和各器官,分别测其斑蝥素含量。结果显示,斑蝥素含量在两性个体内和配偶间的器官间呈规律性地起伏。探讨了规律发生的过程和起因。     

人工饲养条件下眼斑芫菁不同发育阶段斑蝥素含量的变化

【目的】分析人工饲养条件下眼斑芫菁Mylabris cichorii Linnaeus不同发育阶段体内斑蝥素含量的变化。【方法】收集不同发育阶段的眼斑芫菁,通过热碱浸提法提取斑蝥素,而后以气相色谱法检测含量。【结果】在幼虫期,1龄幼虫斑蝥素相对含量最高,2龄幼虫斑蝥素相对含量降到最低点;以后随着虫体的发育,幼虫体重和斑蝥素含量都逐渐增加。羽化后的成虫经隔离饲养,雄虫在羽化后5～30天大量合成斑蝥素,而雌虫体内斑蝥素含量则极低,具有典型的性二型现象;雌雄混合饲养组中,20～30天雌虫体内可以检测到大量斑蝥素,而同期雄虫斑蝥素含量远低于隔离饲养组。【结论】幼虫期斑蝥素含量随虫体发育而增加;成虫期主要由雄虫合成斑蝥素。混合饲养组成虫平均单头斑蝥素含量高于隔离饲养组雌雄虫平均斑蝥素含量。成虫身体各部位的斑蝥素含量以腹部最高,胸部次之。     

宽纹豆芫菁Epicauta watwerhousei

宽纹豆芫菁Epicauta watwerhousei属鞘翅目,芫菁科,豆芫菁属,是豆类作物及蔬菜的食叶害虫。豆芫菁属昆虫的成虫分泌的斑蝥素,早在李时珍的《本草纲目》中已记载有起泡、利尿、壮阳等作用,近年来在中国医学上亦用于治疗某些癌症。 摄影买国庆 （中国科学院动物研究所）     

斑蝥麦在细纹豆芫菁成虫体内的变化和配偶间的运转

将采自野外的同一批细纹豆芫菁在虫用半人工饲料饲养,取刚结束交配（A组）,交配结束后单养4天（B组）和未交配（C组）的两性成虫的血淋巴和各器官,分别测其斑蝥素含量,结果显示,斑蝥素含量在两性个体内和配偶间的器官间呈规律性地起伏,探讨了规律发生的过程和起因。     

疆芫菁科的区系组成及药用价值(鞘翅目：芫菁科)

调查表明,新疆芫菁科(Meloidlc)昆虫有41种,分隶于5属,以斑芫菁属Mylabris F.种类最多,达32种,占78.0%;在41种中,有10种为我国首次纪录。区系组成含中亚细亚,蒙古,欧洲,准噶尔和泛古北种五种成分,其中以中亚细亚种最多,达23种,约占56.0%。芫菁是药用昆虫,对常见的10种芫菁药用有效成分-斑蝥素含量进行了测定,发现其中,种含量较高,药用价值明显。     

芫菁斑蝥素对几种动物蛋白磷酸酶2A的抑制作用

研究斑蝥素对马、兔、猪、鸡、眼斑芫菁Mylabris cichorii(L.)等几种动物体内PP2A的抑制作用。将斑蝥素作用于马、兔、猪、鸡、眼斑芫菁等几种动物体内的PP2A,采用蛋白磷酸酶抑制法-比色法测定斑蝥素对PP2A的抑制率。斑蝥素对马、兔、猪等哺乳动物体内的PP2A有明显的抑制作用,IC50分别为0.07、0.12、0.23 g/L;斑蝥素对鸡体内的PP2A有一定的抑制作用,而对于眼斑芫菁体内PP2A抑制作用不明显。马、兔、猪体内的PP2A对斑蝥素很敏感,而鸡和眼斑芫菁体内的PP2A对斑蝥素较不敏感。     

细纹豆芫菁和大斑芫菁的性行为

本文对细纹豆芫菁EpicautamannerheimiM kl和大斑芫菁MylabrisphalerataPallas的求偶和交配过程进行了描述。列举了芫菁亚科 5族 1 3属 3 4种芫菁的性行为 ,并讨论了雄成虫在形态构造上对求偶和交配行为的适应性行为。     

芫菁寄生菌降解斑蝥素

选用2种芫菁的寄生菌——球孢白僵菌Beauveria bassiana和曲霉Aspergillus sp.,进行斑蝥素的抑菌试验和对斑蝥素的降解试验。结果表明:斑蝥素对这2种真菌没有抑制作用,球孢白僵菌可以有效地降解斑蝥素,降解率为90.45%,而曲霉不能降解斑蝥素。     

Cantharidin world on islands: Species diversity of canthariphilous arthropods in the Izu–Ogasawara Arc

Cantharidin is a defense chemical produced by only two beetle families, Meloidae and Oedemeridae. This compound also functions as an attractant for certain groups of arthropods (canthariphilous arthropods). Cantharidin‐producing beetles and canthariphilous arthropods build a cantharidin‐mediated community, called cantharidin world. In this study, to clarify the canthariphilous arthropod community formed on small islands, the arthropods were collected by cantharidin‐baited traps and compared among the mainland, peninsula and 11 small islands of the Izu–Ogasawara Arc, Japan. Control traps without cantharidin were also used to collect non‐canthariphilous arthropods. Cantharidin‐producing beetles were distributed across the study area, but the number of species was reduced on islands. We identified 10 species of five families as canthariphilous arthropods in this study area: two species of Anthicidae and Pyrochroidae (Coleoptera), four species of Ceratopogonidae (Diptera), three species of Formicidae (Hymenoptera) and one species of Podoctidae (Opiliones). The number of canthariphilous species was not correlated with island size (area) but was negatively correlated with the distance of island from the mainland. These tendencies were also seen in non‐canthariphilous fauna. The canthariphilous arthropods increased with the number of cantharidin‐producing beetle species, but the non‐canthariphilous fauna did not. Thus, the cantharidin world on islands seems to be affected not only by the geographic characteristics of islands, particularly the degree of isolation from the mainland, but also by the diversity of cantharidin‐producing members within it.     

Cantharidin content in two Mediterranean species of blister beetles,Lydus trimaculatus and Mylabris variabilis (Coleoptera: Meloidae)

Cantharidin (CA), a toxic terpene produced by blister beetles (Coleoptera: Meloidae), attracts the interest of many researchers for its renowned medical properties. The CA content in blister beetles has been mainly quantified in some Oriental species, due to their use in traditional Chinese medicine, or in few other species of toxicological importance. As CA quantification has been largely ignored in many other members of this family, we aimed at estimating CA content in natural populations of two of the most abundant species in central Italy, Mylabris variabilis and Lydus trimaculatus. Nearly 100 individuals for each species were collected in the field, identified and reared in fauna‐boxes until CA collection. Available protocols were optimized for CA extraction from both dried‐body tissues and exuded hemolymph collected from leg joints using capillary tubes. The CA content was quantified in a gas chromatography system coupled to a mass spectrometer using a calibration curve with diethyl‐ester of norcantharidin as the internal standard. We observed: (i) high variability in CA content among specimens, which was positively related to individual dry‐weight; and (ii) slightly larger (though non‐significant) amount of CA in males than in females for both species. Our data are consistent with the available published reports about CA content, transfer and distribution in blister beetles and suggest a conserved biological role of this terpene in Meloidae.     

Males of a Strongly Polygynous Species Consume More Poisonous Food than Females

We present evidence of a possible case of self-medication in a lekking bird, the great bustard Otis tarda. Great bustards consumed blister beetles (Meloidae), in spite of the fact that they contain cantharidin, a highly toxic compound that is lethal in moderate doses. In addition to anthelminthic properties, cantharidin was effective against gastrointestinal bacteria that cause sexually-transmitted diseases. Although both sexes consumed blister beetles during the mating season, only males selected them among all available insects, and ingested more and larger beetles than females. The male-biased consumption suggests that males could use cantharidin to reduce their parasite load and increase their sexual attractiveness. This plausibly explains the intense cloaca display males perform to approaching females, and the meticulous inspection females conduct of the male''s cloaca, a behaviour only observed in this and another similar species of the bustard family. A white, clean cloaca with no infection symptoms (e.g., diarrhoea) is an honest signal of both, resistance to cantharidin and absence of parasites, and represents a reliable indicator of the male quality to the extremely choosy females. Our results do not definitely prove, but certainly strongly suggest that cantharidin, obtained by consumption of blister beetles, acts in great bustards as an oral anti-microbial and pathogen-limiting compound, and that males ingest these poisonous insects to increase their mating success, pointing out that self-medication might have been overlooked as a sexually-selected mechanism enhancing male fitness.     

Sclerotised spines in the female bursa associated with male’s spermatophore production in cantharidin-producing false blister beetles

Cantharidin is a defence chemical synthesised in only two beetle families Meloidae and Oedemeridae. In Meloidae, cantharidin is used as a defence chemical in eggs. However, in Oedemeridae the function of cantharidin remains unclear. Based on morphological comparison of female internal reproductive organs in 39 species of Oedemeridae, we found that some species have sclerotised spines in the bursa copulatrix (bursal spines), while others have no such spines. Molecular phylogenetic trees inferred from mitochondrial 16S and nuclear 28S rRNA gene sequences suggested multiple evolutionary origins of bursal spines from an ancestor without spines. In the species which lacked spines, males transferred small amounts of ejaculates to females; however, in species with spines, males transferred large spermatophores. Deposited spermatophores gradually disappeared in the bursa, probably owing to absorption. To compare the amounts of cantharidin in eggs laid by species with and without bursal spines, we constructed a new bioassay system using the small beetle Mecynotarsus tenuipes from the family Anthicidae. M. tenuipes individuals were attracted to droplets of cantharidin/acetone solution, and the level of attraction increased with cantharidin concentration. This bioassay demonstrated that the eggs of Nacerdes caudata and N. katoi, both of which species have conspicuous bursal spines, contain more cantharidin than the eggs of N. waterhousei, which lacks spines. In the former species, males transfer large spermatophores to the female, and spermatophores are eventually broken down and digested within the female’s spiny bursa. Thus, females with bursal spines may be able to provide more cantharidin to their eggs.     

Male mating strategies and reproductive constraints in a group of wild tufted capuchin monkeys (Cebus apella nigritus)

Tufted capuchin monkeys (Cebus apella) provide an extreme example of active female sexual solicitation of males. In spite of being targeted by females for sex, males may delay copulation for hours or days. Data were collected on the sexual interactions in one wild capuchin group at the Estação Biológica de Caratinga in Brazil from September 1996 to August 1997. All successful conceptions during this year occurred in the dry season, yet sexual behavior was observed during 9 months of the year. This study tested whether male sexual response to female proceptivity was seasonally‐mediated. Male consortship participation, solicitation of females, latency to copulation, and copulation frequency were compared between fertile and nonconceptive females. Seasonal patterns in copulation interference, mating style, and alternative mating strategies were also examined. Thirty‐two copulations were observed. The alpha male was solicited for significantly more consortship days per female, but his mating success, in terms of copulation frequency, did not differ from that of two other adult males in the group. In the dry season, when the females were fertile, the males showed increased contest competition for mates, a higher frequency of alternative mating strategies against copulation interference, and increased monitoring of the females' condition. However, contrary to expectations, the alpha male's latency to copulation was significantly longer in the fertile season than in the nonconceptive months, and no males were observed to mate more than one time per day, even at the conceptive peak. Male mating strategies were affected by both season and rank, and there was evidence for reproductive constraints on males throughout the year. Limited male ejaculatory capacity and male choice in the timing of copulations within female proceptive phases may both be important factors in driving the sexual dynamics of this species. Am. J. Primatol. 67:313–328, 2005. © 2005 Wiley‐Liss, Inc.