黑翅土白蚁下唇腺解剖构造研究

本文利用显微解剖和测量,研究黑翅土白蚁Odontotermes formosanus下唇腺解剖构造及其在不同类型个体间职能的分化。黑翅土白蚁的下唇腺由左右对称的两部分组成,每侧构造由9～11个腺泡群、1个下唇腺囊及相关的导管组成。每侧的腺泡群导管与下唇腺囊导管首先汇合成分导管,两侧的分导管在舌基部后方汇合,形成一条主导管,主导管开口于舌基部下方。黑翅土白蚁下唇腺发达程度与个体的职能有关。有翅成虫下唇腺最发达,3龄无翅芽若虫下唇腺最小。巢内工蚁是口交哺物质的主要提供者,在下唇腺长度、腺泡直径及腺泡数量方面均极显著高于采食工蚁。兵蚁下唇腺及下唇腺囊转化为与防卫职能相关的器官。前兵蚁与兵蚁下唇腺囊均发达,老龄兵蚁下唇腺囊内充满黄色粘稠液体。冰冻保存后下唇腺明显缩小。冰冻保存后下唇腺腺泡直径的校正系数为1.19,腺泡群长度校正系数为1.14。     

黑胸散白蚁幼期不同品级的发育和分化

在黑胸散白蚁Reticulitermes chinensis发育和分化过程中,发现有假工蚁、假若蚁两种虫态。假工蚁由6龄和7龄工蚁转化发育而来,假若蚁由4龄和5龄若蚁转化发育而来。显微测量结果表明,黑胸散白蚁的胚后发育主要包括2个龄期的幼蚁期、6个以上龄期的工蚁期、4个龄期的若蚁期和有翅成虫。在此基础上分析了其他虫态的分化来源,发现兵蚁由3～7龄工蚁分化发育而来,翅鳞型和长翅芽型补充生殖蚁由6龄若蚁转化发育而来,短翅芽型补充生殖蚁由4龄和5龄若蚁转化发育而来,微翅芽型补充生殖蚁既可由4～6龄工蚁转化发育而来,又可由假工蚁和假若蚁转化发育而来,无翅型补充生殖蚁由3～7龄工蚁转化发育而来。提出了黑胸散白蚁群体中不同品级个体的可能分化途径。     

黑胸散白蚁幼期不同品级的发育和分化

在黑胸散白蚁Reticulitermes chinensis发育和分化过程中,发现有假工蚁、假若蚁两种虫态。假工蚁由6龄和7龄工蚁转化发育而来,假若蚁由4龄和5龄若蚁转化发育而来。显微测量结果表明,黑胸散白蚁的胚后发育主要包括2个龄期的幼蚁期、6个以上龄期的工蚁期、4个龄期的若蚁期和有翅成虫。在此基础上分析了其他虫态的分化来源,发现兵蚁由3～7龄工蚁分化发育而来,翅鳞型和长翅芽型补充生殖蚁由6龄若蚁转化发育而来,短翅芽型补充生殖蚁由4龄和5龄若蚁转化发育而来,微翅芽型补充生殖蚁既可由4～6龄工蚁转化发育而来,又可由假工蚁和假若蚁转化发育而来,无翅型补充生殖蚁由3～7龄工蚁转化发育而来。提出了黑胸散白蚁群体中不同品级个体的可能分化途径。     

黑胸散白蚁工蚁与工蚁型补充生殖蚁体内抗氧化酶和解毒酶的活性及基因表达变化

【目的】社会性白蚁的工蚁可以转化成补充生殖蚁参与生殖,提高自身适合度。本研究旨在探究工蚁转变成补充生殖蚁后,与氧化应激抗衰老相关的抗氧化酶和解毒酶活性的变化,为揭示生殖蚁的繁殖和抗衰老机制提供参考。【方法】利用生化方法分别测定黑胸散白蚁Reticulitermes chinensis工蚁、工蚁型补充生殖蚁和原始生殖蚁体内的2种抗氧化酶过氧化氢酶(catalase, CAT)和超氧化物歧化酶(superoxide dismutase, SOD)与4种解毒酶酸性磷酸酶(acid phosphatase, ACP)、碱性磷酸酶(alkaline phosphatase, AKP)、羧酸酯酶(carboxylesterase, CarE)和细胞色素P450(cytochrome P450, CYP450)的酶活性;同时利用qRT-PCR检测这些酶对应的基因RsCAT, RsSOD, RsACP, RsCYP450和RsCarE的表达量。【结果】与雌性工蚁相比,黑胸散白蚁工蚁型补充生殖蚁体内的CAT, SOD, ACP, AKP和CarE活性显著上升,分别达到雌性工蚁的5.82, 1.41, 1.39, 2.27和2.70倍,CYP450活性在两品级间没有显著差异;RsCAT, RsSOD, RsACP, RsCarE和RsCYP450的表达量也显著增加。补充生殖蚁体内CAT和ACP活性显著高于原始生殖蚁的,而SOD和AKP活性在两品级间没有显著差异;雌雄补充生殖蚁RsCAT的相对表达量分别是原始生殖蚁的5.68和3.60倍,RsACP的相对表达量分别是原始生殖蚁的81.12和46.72倍。【结论】黑胸散白蚁工蚁由非生殖品级转化为生殖品级以后,体内抗氧化酶和解毒酶的酶活力和基因表达水平显著升高,从一定程度上揭示了生殖品级的抗衰老机制。     

白蚁唾腺及水分管理

白蚁唾腺及其水分管理是白蚁社会行为及生态功能的基础。白蚁唾腺包括上唇腺、上颚腺和下唇腺。上唇腺仅在少数白蚁中有报道,是否普遍存在尚存疑问。上颚腺为1对小型腺体,分别位于两侧上颚基部的头腔内,在不同种类白蚁中广泛存在。其分泌物可能与防卫、品级分化及保护上颚免于磨损有关。下唇腺在不同种类白蚁的各品级个体中广泛存在,是白蚁中功能最复杂的外分泌腺体;由腺泡群、下唇腺囊及相关的导管组成;其分泌物复杂多样,行使营养、防卫及水分管理等功能。本文介绍白蚁唾腺的解剖形态、超微结构、分泌物种类与功能、水分管理等方面的研究进展,提出了白蚁水分管理机制的可能途径。     

黑翅土白蚁巢群觅食群体大小与工蚁体长呈正相关

【目的】明确黑翅土白蚁Odontotermes formosanus巢群的觅食群体大小与工蚁体长之间的关系,为进一步研究其生态学特点以及更好地开展防治提供依据。【方法】在杭州植物园内选择5处有黑翅土白蚁活动区域作试验点,诱捕并以中性红(neutral red)标记捕获的白蚁工蚁,通过“捕获-标记-释放-重捕”试验测定黑翅土白蚁的觅食群体大小。【结果】5个试验点中有4个成功实施了“捕获-标记-释放-重捕”试验,4个试验点黑翅土白蚁巢群的觅食群体个体数量分别为443 133±45 469, 495 360±67 429, 674 345±101 703和1 224 662±93 112头。黑翅土白蚁觅食群体大小(Y)与觅食工蚁的体长(X)呈正相关,拟合的指数函数方程式为：Y=1.8389e^0.7185X(R²=0.7834)。【结论】本研究明确了黑翅土白蚁的觅食群体大小以及工蚁体长之间的函数关系,为开展区域防治提供了依据。     

圆唇散白蚁补充生殖蚁的类型与建群能力

摘要: 【目的】为了探讨圆唇散白蚁Reticulitermes labralis补充生殖蚁对巢群稳定和发展的作用。【方法】对野外巢群进行调查研究, 及对婚飞成虫通过雌雄配对与补充生殖蚁隔离巢群进行人工饲养的对比研究。【结果】在野外巢群只发现1对原始蚁王蚁后, 而补充生殖蚁的数量最多可达到689头/巢。圆唇散白蚁有3种类型的补充生殖蚁, 即由工蚁转化来的无翅型补充生殖蚁、若蚁转化来的翅芽型补充生殖蚁和末龄若蚁羽化来的拟成虫型补充生殖蚁。实验室条件下婚飞配对群体和隔离群体建群1个月后的存活率分别为64%和96%。建巢初期婚飞配对群体的子代数目增长缓慢, 2个月时的群体数量为6.3±1.54, 10个月时的群体数量也仅为8.4±1.47; 而隔离建群补充生殖蚁2个月时的群体数量为52.4±6.44, 10个月时的群体数量为164.3±20.85, 都高于婚飞配对群体。 此外, 野外巢群的补充蚁后跟原始蚁后一样都具有发达的卵巢。【结论】在圆唇散白蚁中补充生殖蚁是白蚁巢群主要的繁殖力量, 也是建立新巢群的重要繁殖品级。     

黑胸散白蚁的分飞成熟年龄及生殖蚁对子代个体分化的抑制作用

实验室配对饲养黑胸散白蚁Reticulitermes chinensis表明,黑胸散白蚁新群体在原始生殖蚁控制下,83.30%的群体在第9年分出了有翅成虫,16.70%的群体在第7年发生有翅成虫分飞,平均分飞成熟年龄为8.67年;由补充生殖蚁控制的群体在第6年即有53.85%的群体发生分飞,第7年有46.15%的群体分飞,平均分飞成熟年龄为6.38年,较原始生殖蚁控制的群体发生分飞平均提前2.29年。初次发生分飞时群体内个体数量前者明显多于后者。研究还发现,群体内补充生殖蚁的数量与分飞发生的早迟关系不大。作者认为在黑胸散白蚁中,原始生殖蚁对补充生殖蚁和若蚁的产生具有较强的抑制作用,而补充生殖蚁对上述品级的分化虽有一定抑制,但不如原始生殖蚁强。认为黑胸散白蚁群体发展速度在品级分化的调节上起到不可忽视的作用,但一定要在生殖蚁分泌外激素的能力开始减弱后才能发挥效应。     

黑翅土白蚁触角感器的扫描电镜观察

【目的】通过黑翅土白蚁Odontotermes fomosanus(Shiraki)幼蚁、工蚁、兵蚁触角感器种类、数量及分布的研究,分析不同龄幼蚁、工蚁和兵蚁的触角感器特征,为进一步研究触角感器发育特点及不同个体的行为分化机制提供参考。【方法】通过扫描电镜观察触角形态,分析触角节数、感器种类、数量及分布特征。【结果】工蚁、兵蚁、幼蚁个体触角长度差异显著,触角长度顺序:工蚁>兵蚁>3龄幼蚁>2龄幼蚁>1龄幼蚁;触角感器共有9种类型,分别为短毛形感器、长毛形感器、短刺形感器、长刺形感器、锥状B?hm氏鬃毛、球状钟形感器、刺突状钟形感器、球状钟形感器与刺突状钟形感器中间型、长刺具泡状感器。工蚁、兵蚁缺少长刺具泡状感器。幼蚁触角感器种类和数量随龄数而增加,1龄幼蚁具7种感器,缺少球状钟形感器和球状钟形感器与刺突状钟形感器中间型2种类型;2龄幼蚁具有8种感器,缺球状钟形感器;3龄幼蚁具有全部9种类型感器。【结论】黑翅土白蚁幼蚁、工蚁、兵蚁触角节数和感器显著差异,可作为幼蚁龄数以及非生殖品级判别的形态指标,应用于白蚁非生殖品级行为多型等相关研究。     

小头钩白蚁巢结构研究

【目的】了解小头钩白蚁Ancistrotermes dimorphus Tsai et Chen的蚁巢结构、各品级在腔室中的分布和巢群个体数量,为有效防控该种白蚁提供科学依据。【方法】采用蚁巢定位和巢体结构解剖法研究蚁巢结构;采用统计法确定各品级在腔室中的分布和巢群个体数量。【结果】小头钩白蚁巢由腔室、菌圃、蚁路、王室、候飞室和分飞孔六部分组成;巢群个体数量为12 255~24 230头(含卵粒);卵、幼蚁、若蚁、工蚁、兵蚁和有翅成虫分散分布在蚁巢腔室中,并不集中于某一特定区域。【结论】小头钩白蚁巢属于极端分散类型,巢群个体数量较少。     

Development of the labial gland of the ponerine ant Pachycondyla obscuricornis (Hymenoptera, Formicidae) during the pupal stage

The labial gland of adult workers of the ant Pachycondyla obscuricornis is made up of many acini, each consisting of one central cell surrounded by approximately 10 parietal cells. Both cell types are associated with a system of ramified canaliculi that remove the secretion towards a ductule outside the acinus. These ductules, each associated with one acinus, fuse together and form a ramified system of ducts, ending in two paired ducts. These paired ducts widen to form a reservoir and anteriorly join into a common unpaired duct, which ends at the base of the labium. During development in the pupal stage, epithelial acini are formed first, consisting of a monolayered epithelium lining a central lumen. In these acini, one cell grows out to become the central cell, while the others will re-arrange around it to form the parietal cells. At the end of the pupal stage, the canaliculi are formed inside the acini by the central and parietal cells that secrete a lipidic substance and a cuticle. This gland type, which also occurs in some other Hymenoptera, is structurally different from the epithelial glands and the glands consisting of bicellular units, that have been traditionally distinguished until now.     

Ultrastructural ontogeny of the labial gland apparatus in termite Prorhinotermes simplex (Isoptera, Rhinotermitidae)

The labial glands in Prorhinotermes simplex consist of secretory cells organized into acini, water sacs and the ducts connecting the gland parts to the basis of the labium. Acini are composed of central and parietal cells. Central cells type I contain predominantly lucent vacuoles and are involved probably in hydroquinone production. They are lacking in soldiers. Type II central cells produce vacuoles of proteinaceous content which are of the same electron density (type IIa) or present in more shades (type IIb). Type IIa cells are present in all older individuals, whereas type IIb are lacking in soldiers and neotenics. Type III cells represent a specific stage of type I cells development, but they are definite functional secretory cells in soldiers. Acini of first instar larvae contain undifferentiated cells which differentiate into type I cells during the second instar. Specific larval central cells start to change into type II cells during first instar. The central cells of presoldiers show a transition from the pseudergate into the soldier situation. The parietal cells keep a uniform structure throughout the whole ontogeny. Only one type of cells form the water sacs in all castes. The cells are very flat with scarce organelles. The water sac cells produce lipid-like secretion, small lucent vacuoles and bunches of angulated vacuoles. The water sac probably functions as water storage organ only. Ontogenetical changes in water sac development are small. The acinar ducts originate inside the acinus where they are formed by flat cells with rare organelles. At the acinus border, cells equipped with mitochondria, microvilli and basal invaginations appear. The water sac ducts are formed by flat cells with rare organelles. Acinar ducts outside the acinus and water sac ducts are equipped with taenidiuam.     

Caste differences in feeding and trophallaxis in the western drywood termite, Incisitermes minor (Hagen) (Isoptera, Kalotermitidae)

Summary: Differences in feeding and trophallaxis among castes of the western drywood termite, Incisitermes minor (Hagen), were determined using rubidium (Rb) as a tracer. Both 5th- and 6th-instar nymphs and 3rd- and 4th-instar larvae fed directly on Rb-treated paper and acted as both donors and recipients in trophallactic exchanges with other larvae and nymphs, and as donors for soldiers and alates. Soldiers and alates did not feed on Rb-treated paper suggesting that they do not feed directly on wood and are completely dependent on nymphs for their nutritional needs. Larvae paired with Rb-fed nymphs received the greatest amount of Rb suggesting that there may be a hierarchy of trophallaxis in drywood termites. Transfer efficiency, the percentage of the total Rb intake of donors that is passed to the recipients, ranged from 1.1 % (nymphal donors to alate recipients) to 16.6 % (larval donors to nymphal recipients).     

Comparative Study of the Labial Gland Secretion in Termites (Isoptera)

Labial glands are present in all castes and developmental stages of all termite species. In workers, their secretion contains a food-marking pheromone and digestive enzymes, while soldier secretion plays a defensive role. However, these functions were studied only in a limited set of species, and do not allow drawing general conclusions. Hence, we have investigated the chemical composition of the labial gland extracts from soldiers and workers in 15 termite species belonging to 6 families using an integrative approach based on proteomic and small-molecule profiling. We confirmed the presence of hydroquinone and cellulase in the labial glands of workers, and we identified new toxic compounds in soldiers and workers of several species. Our results highlight the dual role of labial gland secretion, i.e. the defensive role in soldiers and workers of several termite species, and the digestive function in workers.     

Age-dependent changes in ultrastructure of the defensive glands of Neocapritermes taracua workers (Isoptera,Termitidae)

Protection against predators and competitors is one of the main concerns of termite colonies, which developed a specialised defensive caste, the soldiers. However, soldiers are rare or even missing in several lineages of termites, while workers often develop new defence strategies especially in soil-feeding species. Here, we describe the morphology and ultrastructure of the autothysis-associated glands of Neocapritermes taracua workers and report their age-related changes in structure. The defensive glands of N. taracua workers consist of a pair of labial and a pair of crystal glands, whose secretions mix together through autothysis. Autothysis always occurs at the line of weakness connecting the anterior parts of the crystal-bearing pouches. The crystal glands consist of groups of bicellular secretory units (secretory and corresponding canal cells) which secrete the blue crystal material into external pouches. Their secretory activity is maximal in the middle of worker life, and is considerably lower in very young and old workers. The labial glands are composed of two types of secretory cells: the central and the parietal cells. While the central cells are developed similarly to other termites and secrete proteinaceous secretion into labial gland ducts, the parietal cells develop proteinaceous granules which may eventually bud off the cells. The secretory function of parietal cells is so far unique to N. taracua and differs from other termite species in which they are only responsible of water uptake by acini. The defensive device of N. taracua is truly exceptional as it involves a new gland and a previously undescribed function for parietal cells, being a remarkable example of evolution of morphological innovation.     

角倍蚜瘿内干雌蜜露的排泄和糖分组成

【目的】角倍是角倍蚜Schlechtendalia chinensis在第一寄主植物盐肤木Rhus chinensis叶片上取食而形成的一种封闭型虫瘿,瘿内蚜虫排泄物(蜜露)的清洁对于维持角倍蚜种群的生存至关重要。本研究旨在探究角倍蚜瘿内世代的蜜露排泄及糖分组成情况。【方法】采用倒置荧光显微镜连续观察角倍蚜瘿内干雌的蜜露排泄情况;用含有不同浓度蔗糖或淀粉的培养基饲喂瘿内干雌,统计泌露率,分析蔗糖和淀粉对角倍蚜瘿内干雌蜜露排泄的影响;利用液相色谱检测和分析蜜露的糖分组成和含量。【结果】角倍蚜瘿内,很少能观察到无翅干雌排泄蜜露,35.40%±2.41%的有翅干雌可被观察到排泄蜜露。但在琼脂糖培养基上,无翅干雌和有翅干雌均可排泄蜜露,泌露率分别为23.89%±5.58%和173.96%±28.61%;在含有不同蔗糖浓度的琼脂糖培养基上,无翅干雌和有翅干雌泌露率均随蔗糖浓度的升高而降低。在含有不同淀粉浓度的琼脂糖培养基上,无翅干雌泌露率随淀粉浓度的升高而降低;当淀粉浓度由0增加至2%时,有翅干雌泌露率由173.96%±28.61%增加至236.81%±55.67%,随后泌露率随淀粉浓度的升高而降低,当淀粉浓度达到10%时,有翅干雌泌露率降为55.92%±7.22%。角倍蚜瘿内干雌排泄的蜜露共检测出7种糖分,其中：果糖和葡萄糖的含量较高,分别为51.07%和31.68%;蔗糖的含量较低,仅为1.59%;另有4种未知组分占15.66%。【结论】角倍蚜瘿内干雌蜜露的主要成分为果糖和葡萄糖;食物中蔗糖和淀粉的含量对其蜜露的排泄有明显影响。     

Juvenile hormone titers and caste differentiation in the damp-wood termite Hodotermopsis sjostedti (Isoptera, Termopsidae)

Termites are social insects, presenting morphologically distinct castes, performing specific tasks in the colony. The developmental processes underlying caste differentiation are mainly controlled by juvenile hormone (JH). Although many fragmentary data support this fact, there was no comparative work on JH titers during the caste differentiation processes. In this study, JH titer variation was investigated using a liquid chromatography-mass spectrometry (LC-MS) quantification method in all castes of the Japanese damp-wood termite Hodotermopsis sjostedti, especially focusing on the soldier caste differentiation pathway, which was induced by treatment with a JH analog. Hemolymph JH titers fluctuated between 20 and 720pg/microl. A peak of JH was observed during molting events for the pseudergate stationary molt and presoldier differentiation, but this peak was absent prior to the imaginal molt. Soldier caste differentiation was generally associated with high JH titers and nymph to alate differentiation with low JH titers. However, JH titer rose in females during alate maturation, probably in relation to vitellogenesis. In comparison, JH titer was surprisingly low in neotenics. On the basis of these results in both natural and artificial conditions, the current model for JH action on termite caste differentiation is discussed and re-appraised.