土蝽——善于土栖生活的半翅目昆虫

土蝽是半翅目异翅亚目蝽总科中多数适应于地栖生活的蝽类。文章简要描述该类昆虫的形态特征、分类历史以及生物学,同时对该类昆虫目前的生物学和系统学研究进展也给予简要介绍。文中还提供形态特征图6幅,臭腺特征扫描电镜照片6幅。     

水生异翅亚目昆虫化石简介

半翅目异翅亚目昆虫俗称"蝽",该类昆虫出现于三叠纪晚期,最古老的蝽类昆虫大多为水生蝽类。概述了水生蝽类的地质历史,并介绍了划蝽、仰泳蝽、水蝽、负子蝽、三叠蝽及中蝽等代表类群。     

污网蝽属记述及一新种描述(半翅目,网蝽科)

补充头刺、后胸臭腺和生殖节等特征后重新定义了东洋区特有属-污网蝽属,并确认该属单质.记述中国污网蝽属昆虫3种,其中狄氏污网蝽Ildefonsus distanti为新种,窄污网蝽Ildefonsus nexus Drake et Ruhoff为中国新纪录种.文中给出了污网蝽属名录及种类检索表.新种的模式标本保存于南开大学昆虫标本室.     

封面照片

正照片示在荔枝Litchi chinensis花穗静息的荔枝蝽Tessaratoma papillosa(半翅目:蝽科)成虫。该虫是传播龙眼鬼帚病病原体的传病介体昆虫,以若虫及成虫为害荔枝龙眼果树,在中国南方及东南亚地区危害严重。本期报道了荔枝蝽生物学,触角和臭腺,预测预报及防治研究进展综述(pp. 645-654)。照片由全林发于2021年3月摄于广东省广州市白云区钟落谭荔枝龙眼实验基地。     

荔枝蝽成虫对其臭腺分泌物组分的触角电生理和行为反应

培养皿生物测定结果表明,荔枝蝽Tessaratoma papillosa(Drury)臭腺分泌物的乙醚提取物对成虫有显著的驱避作用.气质联用仪(GC-MS)分析结果表明,荔枝蝽雌雄成虫臭腺乙醚提取物中具有5种挥发性物质,即(E)-2-辛烯醛、十一烷、十二烷、十三烷及一个未知组分.荔枝蝽对(E)-2-辛烯醛、十一烷、十二烷与十三烷这4种组分的触角电生理(EAG)反应结果表明,这些化合物均能引起荔枝蝽成虫的EAG反应,其中(E)-2-辛烯醛引起雌雄成虫触角的反应最强,分别为0.50 mV与0.4 mV;"Y"型嗅觉仪生测结果表明,(E)-2-辛烯醛对荔枝蝽成虫能产生极显著的驱避作用(P <0.01).可见,荔枝蝽成虫臭腺分泌物对荔枝蝽具有显著的生物活性,可望通过进一步研究应用于荔枝蝽的防控体系.     

荔枝蝽生物学及防治技术的研究进展(英文)

荔枝蝽Tessaratoma papillosa是荔枝和龙眼生产中的重要害虫,在中国南方及东南亚地区危害严重。该虫以若虫及成虫吸食寄主植物的嫩芽、嫩梢、花穗和幼果,成虫和3龄以上若虫是传播龙眼鬼帚病病原体的传病介体昆虫。本文综述了近60年来国内荔枝蝽的研究情况,旨在为广大科研工作者提供更详尽的荔枝蝽研究现状,以期为该虫的深入研究及绿色防控技术的研发提供参考。荔枝蝽为不完全变态昆虫,一年发生1代,若虫期80 d左右,成虫寿命为203~371 d,单雌产卵总量190粒左右,在习性上表现出明显的聚集性、趋光性、趋色性和趋嫩梢性。近年来,通过荔枝蝽触角感受器分类及分布观察,触角转录组数据测定和分析,臭腺解剖观察以及臭腺分泌物组分分析,对该虫触角和臭腺两大器官组织已有较深入研究及了解。目前,荔枝蝽的发生期主要通过卵巢发育分级法进行预测预报,对该虫的防治仍然是以化学防治为主,农业防治、物理防治和生物防治为辅的策略。其中,荔枝蝽生物防控技术研究报道最多,主要集中在天敌的保护利用和生物源农药的应用。由于荔枝蝽虫源的季节性制约和发生为害地域限制,对该虫的研究进展缓慢,深层次的研究较少,且所涉及到的研究领域也比较窄。从组学、分子生物学、细胞生物学等多角度探明荔枝蝽对寄主植物的选择机制,与寄主植物、天敌及共生菌间的互作关系,以及抗药性机理等,将为荔枝蝽绿色防治技术带来新思路。     

云南紫胶虫栖境蝽类昆虫多样性

在云南绿春县,采用网扫法调查了培育云南紫胶虫5年的天然次生林（样地Ⅰ）和培育3年（样地Ⅱ）、1年（样地Ⅲ）及未培育紫胶虫（样地Ⅳ）的人工林中的蝽类昆虫群落。共采集蝽类昆虫423头,隶属于7科,47种。4个样地蝽类昆虫群落的物种组成和多样性各不相同。天然次生林蝽类物种组成丰富,条棘缘蝽占有较突出优势而导致多样性不高;人工林中,样地IV蝽类物种最丰富,优势度最低,均匀度和多样性最高;样地III次之;样地II物种最贫乏,优势度最高,均匀度和多样性最低。可见,紫胶虫与其栖境内蝽类的竞争将导致蝽类昆虫群落物种丰富度及多样性下降。     

前翅鞘翅型的蝽类昆虫

鞘翅型蝽类昆虫前翅发达,与甲虫的前翅相似。类群涉及鞭蝽型、蝎蝽型、细蝽型、臭虫型、蝽型中的栉蝽科、裂蝽科、小潜蝽科、固蝽科、蚤蝽科、涯蝽科、网蝽科、盲蝽科、长蝽科、缘蝽科共10个科。它们的生境多样,包括水底小石块下面、水生植物上、海岸潮间区石隙中、蚂蚁巢穴中、沙漠灌木植物上、土中、沙砾中、枯枝落叶层和苔藓上,这些生境的共同点是其对前翅的保护功能的选择压力明显大于对前翅飞行功能的选择压力。此类昆虫的前翅特化的类型分为两类,一类膜区完全退化或极度退化,由革区和爪区(愈合或不愈合)构成鞘质前翅的主体;另一类膜区发达,占鞘质前翅的主体;大部分前翅鞘质化的蝽类属于第一种类型;仅个别长蝽科的昆虫属于第二类,如巨膜长蝽Jakowleffiasetulosa(Jakowleff)。     

中国二十个省、自治区蝽科昆虫种数比较

从广泛和长期的采集工作中可以体会到:南方昆虫种类多,北方昆虫种类少;植被丰茂的地方昆虫种类多,植被贫乏的地方昆虫种类少。但我国各省、区的昆虫种数,多的究竟多到什么程度,少的究竟少到什么程度,却始终没有见到一个具体的数据,足资比较说明。下面选取对蝽科昆虫采集工作做得比较细致的20个省、区,代表国内不同方位及生态类型,列出每一省、区所采蝽科及各亚科的种数,供分析比较。 观表1,知参加比较的蝽科昆中计共389种,其中属于盾蝽亚科44种,荔蝽亚科24种,兜蝽亚科15种,短喙蝽亚科16种,益蝽亚科46种,蝽亚科244种。这个数字,与1935年胡经甫教授编写的《中国昆虫名录》所列蝽科301种及1977年肖采瑜教授等编著的《中国蝽类昆虫鉴定手册》第一册所列蝽科     

昆虫外胚层腺体

本文介绍了昆虫外胚层的一些腺体,重点介绍的是丝腺、胶腺、蜡腺、毒腺、臭腺、蜕皮腺,以及它们的分泌物的化学成分、经济价值等.     

Comparative morphology of the odoriferous system in three predatory stink bugs (Heteroptera: Asopinae)

The metathoracic scent system in Heteroptera produces and releases defensive volatile compounds. The odor produced by predatory stink bugs differs from phytophagous bugs, suggesting a variation between the structure and function of the metathoracic scent system. The anatomy and ultrastructure of the external thoracic efferent system, scent gland, and reservoir in the stink bug predators Brontocoris tabidus, Podisus nigrispinus, and Supputius cincticeps (Heteroptera: Pentatomidae: Asopinae) were studied. External thoracic efferent systems of B. tabidus, P. nigrispinus, and S. cincticeps have anatomical differences in ostiole, peritreme, and evaporatorium. Scent glands have a secretory portion and a reservoir. The reservoir has irregular projections, and in B. tabidus, it is enlarged and heart shaped, whereas in P. nigrispinus and S. cincticeps it is flattened and semicircular. The secretory tissue of the scent gland has well-developed globular secretory cells that produce odorous compounds, and the reservoir has a single layer of cubical cells lined by a cuticular intima. Secretory cells are type III with an intracellular end apparatus, well-developed nucleus with decondensed chromatin, and cytoplasm rich in mitochondria, lysosomes, granules, and smooth endoplasmic reticulum. These findings suggest that there are differences in physiological function of the odoriferous system and the volatile compounds produced by the secretory cells, which may indicate variation in defensive behavior of these species.     

The adult scent glands and scent of nine bugs of the superfamily Coreoidea

In most of the six coreoid genera examined there are differences in the scent gland complex. This comprises a median, ventral, metathoracic reservoir with either one, two, or three pairs of accessory glands.

The nine adult bugs examined all produced a colourless, single-phase scent, the components of which were similar although the relative proportions varied. Either n-hexanal or n-hexyl acetate, or both, were usually the major constituents (about 90 per cent of the total) and n-hexanol and acetic acid were also present in amounts varying from traces to about 10 per cent. In one species n-butanal was detected and in two species n-butyl butyrate and (probably) butyric acid were present.

The characteristic, ester odour of these coreoid bugs is quite unlike that of pentatomid bugs examined so far and the two groups do not possess a single component in common; nevertheless there are interesting analogies between the scent components of both groups.     

The comparative morphology of epidermal glands in Pentatomoidea (Heteroptera)

The Heteroptera show a diversity of glands associated with the epidermis. They have multiple roles including the production of noxious scents. Here, we examine the cellular arrangement and cytoskeletal components of the scent glands of pentatomoid Heteroptera in three families, Pentatomidae (stink bugs), Tessaratomidae, and Scutelleridae (shield-backed bugs or jewel bugs). The glands are; (1) the dorsal abdominal glands, (2) the tubular glands of the composite metathoracic gland, and (3) the accessory gland component of the composite metathoracic gland. The dorsal abdominal glands are at their largest in nymphs and decrease in size in adults. The metathoracic gland is an adult-specific gland unit with a reservoir and multiple types of gland cells. The accessory gland is composed of many unicellular glands concentrated in a sinuous line across the reservoir wall. The lateral tubular gland is composed of two-cell units. The dorsal abdominal glands of nymphs are composed of three-cell units with a prominent cuticular component derived from the saccule cell sitting between the duct and receiving canal. The cuticular components that channel secretion from the microvilli of the secretory cell to the exterior differ in the three gland types. The significance of the numbers of cells comprising gland units is related to the role of cells in regenerating the cuticular components of the glands at moulting in nymphs.     

Scent gland apparatus in the Western conifer seed bug Leptoglossus occidentalis Heidemann (Heteroptera: Coreidae)

The coreid Leptoglossus occidentalis is a Nearctic bug responsible for severe seed losses to pine orchards. When disturbed, adults and nymphs emit a defensive secretion deemed an allomone. Here we describe the gross morphology of the scent gland apparatus and the related evaporatory structures in nymphs and adults of L. occidentalis, through light microscopy and scanning electron microscopy. Adults of both sexes possess a metathoracic scent gland complex (MTG) including a central orange‐yellow reservoir and a pair of white lateral glands, connected by ducts to the reservoir. The MTG belongs to the diastomian type, with two ostioles located on the metathorax associated with a microsculptured cuticular accumulation area, i.e. evaporatory area, which can prevent the spread of the secretion on to non‐evaporative cuticle and increase scent fluid evaporation. A high number of male‐specific sternal gland pores were observed. These pores and associated glands are likely the source of an attractant pheromone, which could be extremely useful in monitoring and combating this invasive pest. In nymphs, MTG is replaced by two dorsal abdominal scent glands (DAGs) located between the 4th and the 6th urotergites. DAGs are reddish cuticle‐lined sacs with gland cells forming the gland wall; the scent substances are released through two orifices lying on the mid‐dorsal abdominal line between urotergites IV–V and V–VI. Also in nymphs, peculiar cuticular evaporatory areas surround both orifices.     

Volatile compounds released by disturbed and undisturbed adults of Anchomenus dorsalis (Coleoptera, Carabidae, Platynini) and structure of the pygidial gland

Volatile compounds produced by adults of Anchomenus dorsalis under undisturbed and disturbed conditions were investigated with an all-glass aeration apparatus. GC-MS analysis of the crude extracts from undisturbed and disturbed adults highlighted four major volatile compounds, undecane, heneicosane, Z-9 tricosene and tricosane, of which significantly more undecane was released by disturbed adults compared to undisturbed beetles. The pygidial glands of adults of Anchomenus dorsalis were investigated using light and Transmission Electron Microscopy (TEM). Each gland showed dense aggregates of secretory cells organized into visually distinct lobes; a long collecting canal that drains the secretion towards the reservoir, a bean-shaped double lobed muscular reservoir in which secretion is stored and a short duct (efferent duct) through which the secretion is discharged. The function of the pygidial glands and the possible role played by undecane as a defensive allomone and/or chemical signalling molecule are discussed.     

Semiochemistry of aposematic seed bugs

(E)-2,7-Octadienyl acetate and (E)-2-octenyl acetate (1:10 by volume) were identified as a pheromone attractive to both sexes of the lygaeid bug, Tropidothorax cruciger. In a parallel investigation of Neacoryphus bicrucis (Lygaeidae), (E,E)-2,4-hexadienyl acetate and phenethyl acetate (≈9:1) were identified from males, and found attractive to both sexes of adults in the field plus a tachinid fly parasitoid of the bugs. In N. bicrucis, the pheromone was clearly shown to come from the tubular accessory glands of the metathoracic scent gland; this evidence, plus earlier literature reports for other species, indicate that male lygaeids are the pheromone emitters. In another lygaeid, Oncopeltus fasciatus, 2-isobutyl-3-methoxypyrazine was identified in the cardiac glycoside-laden fluid sequestered from milkweed hosts and expelled by these bugs when they are attacked. Alkyl methoxypyrazines are warning odorants associated with poisonous insect secretions, and their presence in O. fasciatus indicates that the plant-derived chemical defense of lygaeines is more elaborate than previously appreciated.     

Petunia flowers solve the defence/apparency dilemma of pollinator attraction by deploying complex floral blends

Flowers recruit floral visitors for pollination services by emitting fragrances. These scent signals can be intercepted by antagonists such as florivores to locate host plants. Hence, as a consequence of interactions with both mutualists and antagonists, floral bouquets likely consist of both attractive and defensive components. While the attractive functions of floral bouquets have been studied, their defensive function has not, and field‐based evidence for the deterrence of floral‐scent constituents is lacking. In field and glasshouse experiments with five lines of transgenic Petunia x hybrida plants specifically silenced in their ability to release particular components of their floral volatile bouquet, we demonstrate that the emission of single floral‐scent compounds can dramatically decrease damage from generalist florivores. While some compounds are used in host location, others prevent florivory. We conclude that the complex blends that comprise floral scents are likely sculpted by the selective pressures of both pollinators and herbivores.     

Functional anatomy of scent glands in Paranemastoma quadripunctatum (Opiliones,Dyspnoi, Nemastomatidae)

The morphological organization and functional anatomy of prosomal defensive (scent) glands in Paranemastoma quadripunctatum, a representative of the dyspnoid harvestmen, was investigated by means of histological semithin sections, software‐based 3D‐reconstruction and scanning electron microscopy. Scent glands comprise large, hollow sacs on either side of the prosoma, each of these opening to the outside via one orifice (ozopore) immediately above coxa I. In contrast to the situation known from laniatorean, cyphophthalmid and some eupnoid Opiliones, ozopores are not exposed but hidden in a depression (atrium), formed by a dorsal integumental fold of the carapace and the dorsal parts of coxae I. Glandular sacs are connected to ozopores via a short duct which is equipped with a specific closing mechanism in its distal part: A layer of modified epidermal cells forms a kind of pad‐like tissue, surrounding the duct like a valve. Several muscles attached to the anterior parts of the glandular reservoir and to the epithelial pad may be associated with ozopore‐opening. The actual mechanism of secretion discharge seems to be highly unusual and may be hypothesized on the basis of corroborating data from behavioral observations, scent gland anatomy and secretion chemistry as follows: Enteric fluid is considered to be directed towards the ozopores via cuticular grooves in the surface of the coxapophyses of legs I. Then, the fluid is sucked into the anterior part of the scent gland reservoirs by the action of dorsal dilator muscles that widen the reservoir and produce a short‐term negative pressure. After dilution/solution of the naphthoquinone‐rich scent gland contents, a secretion‐loaded fluid is thought to be discharged with the help of transversal compressor muscles. This is the first detailed study on the functional anatomy of scent glands and the mechanisms of secretion discharge in the Dyspnoi. J. Morphol. 2011. © 2011 Wiley‐Liss, Inc.     

Social Insect Pheromones: Their Chemistry and Function

Exocrine secretions of social insects are often characterizedby extraordinarily complex mixtures of natural products. Thus,chemical communication in social insects must be interpretedin terms of signals generated by multicomponent systems, theindividual constituents of which can affect the informationalcontent of the message. Alarm pheromones have been identified chiefly in three subfamiliesof ants and their distribution appears to be chemosystematicallysignificant. Myrmicine genera emphasize 3-alkanones as alarmreleasers, whereas methyl ketones, primarily of terpenoidalorigin, are widely utilized as alarm pheromones in the subfamilyDolichoderinae. Formicine species may employ formic acidas analarm pheromone in addition to the compounds produced in themandibular and Dufour's glands. The mandibular gland pheromonesare chiefly acyclic monoterpene aldehydes (e.g., citronellal)which are relatively low boiling compounds. Higher boiling n-alkanesare produced in the Dufour's glands and may serve as more persistentreleasers of alarm behavior. Alarm pheromones as well as thecaste-specific pheromones of male bees and ants, probably alsoserve as defensive products. In many cases it is likely thatpheromones were originally utilized as defensive compounds andtheir communicative function is a secondary development.     

Cardenolide‐defended milkweed bugs do not evoke learning in Nephila senegalensis spiders

Antipredator defense of herbivorous insects often relies on the potential toxicity of defensive chemicals sequestered from their host plants. The colorful Lygaeinae (Heteroptera: Lygaeidae) store a concentrated mixture of toxic cardenolides (cardiac glycosides) in specialized storage compartments of the bugs' integument, from which they are released upon attack. Larvae and adults of the large milkweed bug Oncopeltus fasciatus (Heteroptera: Lygaeinae) are specialized to feed on cardenolide‐containing milkweeds in the plant genus Asclepias and display a conspicuous red and black colorations. To investigate whether O. fasciatus gained improved protection by feeding on a toxic host plant (Asclepias syriaca), compared to a nontoxic alternative (sunflower seeds), we fed nymphs and adults of O. fasciatus to the golden orb‐weaver Nephila senegalensis. While visually oriented vertebrates, such as avian predators, have been intensively investigated for their reaction to defensive compounds and aposematic coloration, less attention has been paid to invertebrate predators. Their different perceptual abilities can provide important opportunities for testing hypotheses on warning coloration and chemical defenses. The predation trials showed that the bugs fed on Asclepias were significantly less likely to be killed than the bugs reared on a cardenolide‐free diet. This suggests that sequestered cardenolides in O. fasciatus nymphs and adults represent a significant fitness advantage on an individual level against this invertebrate predator. Yet, when testing for avoidance learning in the spiders, negative experience did not change the way how similar prey was attacked at the next encounter. In this case, visual or chemical aposematism thus does not seem to matter for predator learning.