温、湿度对家白蚁初建群体的影响

本文主要研究温、湿度因子对家白蚁初建群体的影响,实验指出家白蚁初建群体对温度及栖息地基质含水量要求严格,温度过高或过低都不利于种群发展,在20℃定温环境下,虽然能产几粒卵,但不能孵化。在25℃定温虽能产卵,但推迟孵化,影响以后种群数量的变动。家白蚁初建群体还要求基质含水量适中,过低的基质含水量,产卵量少且不能孵化,基质含水量过高,雌、雄虫死亡率亦高。实验室内要求的条件与野外群体飞行时要求的温湿度条件基本上是吻合的。     

两种鼻白蚁之间的入侵关系

设计了5个实验以研究台湾乳白蚁(Coptotermes formosanus)和黄肢散白蚁(Reticulitermes flavipes)的种间斗争关系。所试白蚁来自阿拉巴马州。实验1将两组白蚁的兵蚁和工蚁以自然比例混合(台湾乳白蚁工蚁：兵蚁＝20：5,黄肢散白蚁工蚁：兵蚁＝24：1);实验2观察了双方同数量(各25头)工蚁的种间斗争能力;实验3观察两者同数量(各5头)兵蚁的种间斗争关系;实验4、5分别研究双方工蚁与兵蚁的斗争关系。因两种工蚁形态相似,所以在实验前用0．1％Nile blue A染过的滤纸饲喂一方白蚁24h使虫体着色以便观察。所有实验在22℃,65％RH荧光灯下进行。每个实验将两方白蚁同时放入一培养皿中,观察至一方100％受伤,然后把培养皿移到培养箱内,24小时后统计死亡率。结果表明,实验一开始,双方的工蚁和兵蚁都立即进入残酷的厮杀斗争,台湾乳白蚁兵蚁和工蚁的斗争能力都明显强于黄肢散白蚁;兵蚁的斗争行为不受工蚁的影响,工蚁的斗争能力也不受兵蚁的制约。实验中台湾乳白蚁的工蚁与黄肢散白蚁的兵蚁攻击能力相当,但黄肢散白蚁的工蚁却远弱于台湾乳白蚁的兵蚁。上述结果说明,自然界中不可能出现此两种白蚁群体的偶然性融合;外来的台湾乳白蚁很可能在其群体建立的地区占据优势[动物学报49(3)：295—302,2003]。     

土壤含水量对黑翅土白蚁初建群体的影响

白蚁重要为害种黑翅土白蚁巢居于土壤中,研究土壤含水量对其初建群体的影响,了解黑翅土白蚁生活中薄弱环节,有利于今后控制其为害。 土壤含水量的高低,关系到分飞配对繁殖蚁入土营巢、繁殖新蚁群等。含水量14％以下和28％以上会阻碍配对蚁入土建巢或影响建巢速度;含水量22～26％初建幼年巢幼蚁群生活力强、群体壮大快、死亡率低:含水量18％以下和28％以上,兵蚁分化推迟5～8天;含水量14％以下孵前期延长9天左右,并且群体在2个月左右衰亡。     

不同饲料饲养的近暗散白蚁工蚁肠道中差异蛋白分析

【目的】本研究旨在通过比较不同木质纤维素含量的饲料对近暗散白蚁Reticulitermesperilucifugus工蚁前中肠和后肠内容物蛋白的组成和表达差异,为揭示白蚁的营养消化吸收机理提供蛋白水平上的依据。【方法】用木质纤维素含量不同的3种饲料(松木、秸秆和滤纸)饲养近暗散白蚁工蚁,然后用双向电泳分析肠道不同部位的内容物蛋白,并对差异蛋白进行MALDI-TOF/MS测序及生物信息学分析。【结果】双向电泳结果发现,同一饲料饲养的近暗散白蚁工蚁前中肠可辨蛋白点数明显多于后肠;不同饲料饲喂的工蚁前中肠和后肠可辨蛋白点数依次是松木饲养的＞滤纸饲养的＞秸秆饲养的。通过对115个蛋白点的测序分析表明,不同饲料饲喂的工蚁前中肠和后肠中的主要差异蛋白为具有催化活性的蛋白质,包括与氨基酸代谢、丙酮酸代谢、碳代谢、氮代谢、TCA循环、糖酵解、糖异生和纤维素降解等相关的酶,以及参与细胞组成和信号传导的蛋白。【结论】木质纤维素含量不同的饲料饲养的近暗散白蚁工蚁肠道中的差异蛋白主要为具有催化活性的蛋白、细胞组成蛋白和信号传导蛋白,表明不同的饲料影响近暗散白蚁的肠道蛋白组成。这些结果为揭示白蚁对木质纤维素的降解机理提供了参考。     

白蚁取食行为多型及其机理

对白蚁取食行为的研究涉及5科18属38种白蚁。其取食行为多型可归纳为3类:(1)工蚁主导型:采食活动基本上由工蚁完成,兵蚁不参与或仅极少数个体参与,食物侦查或保护采食工蚁的职能不显著;(2)工蚁-兵蚁协同型:这是白蚁采食组织的常见类型,兵蚁成为采食队伍的固定成员,负责采食活动的安全侦查与防卫、食物源侦查等工作;(3)假工蚁主导型:由于尚未分化形成专职的工蚁,因而大龄幼蚁(广义的假工蚁)成为采食活动的主力,同时兼有巢内的保护职能。在食物加工和分配过程中,低等白蚁的幼蚁在未获得消化纤维素能力前主要通过肛交哺获得营养物质和共生物,且肛交哺是新蜕皮个体重新获得共生鞭毛虫的途径。高等白蚁幼龄工蚁负责食物加工、依赖型品级通过口交哺获得营养物质。白蚁采食活动中的行为多型受踪迹信息素控制,不同品级个体腹板腺有明显分化;不同品级和发育阶段个体食性分化与消化道结构、消化酶活性密切相关;保幼激素影响交哺行为以及消化酶基因表达。本文在评述研究进展的同时,对进一步研究提出了展望。     

黑翅土白蚁与其它二种白蚁种群间的相容性

将黑翅土白蚁Odontotermes formosanus(Shiraki)与另外2个种群的白蚁按一定比例放置于同一培养皿中观察其斗争情况,研究黑翅土白蚁与台湾乳白蚁Coptotermes formosanus(Shiraki)和黑胸散白蚁Reticulitermes chinensisSnyder的相容性。结果表明,实验一开始,双方的工蚁和兵蚁都立即进入激烈的嘶咬斗争,在不同配比下,开始5min内的斗争次数均在40次左右,5h后开始5min内的斗争次数陡然下降,几乎不发生争斗。各种群白蚁在其数量占优势的情况下均表现出显著的斗争优势;而在双方数量相当时,黑翅土白蚁工蚁的斗争能力明显强于另外2个种群的工蚁。结果表明,自然界中不可能出现黑翅土白蚁与家白蚁和黑胸散白蚁群体的偶然性融合,黑翅土白蚁很可能在其群体建立的地区中占据优势。     

尖唇散白蚁的梳理清洁行为和食物交哺行为

为了了解尖唇散白蚁梳理清洁行为和交哺行为,为防治该种白蚁提供依据,通过定性观察和定量测定的方法对尖唇散白蚁的梳理清洁行为和交哺行为进行了研究。结果表明:尖唇散白蚁的梳理清洁行为主要由4龄以上工蚁完成,4~6龄的若蚁也参与,但不及工蚁频繁;梳理清洁行为占到其昼夜活动时间的1.6%左右,当白蚁体表沾染污物时,如体表沾有染料或真菌孢子等,梳理清洁行为的频率增加,占用的时间也增多,人为用染料污染白蚁体表,梳理清洁行为可占到6.5%;尖唇散白蚁的交哺行为可发生于各个品级之间,其中工蚁是交哺行为中最活跃的品级,其他各品级均可接受来自工蚁的饲喂;6龄以上工蚁对工蚁的染料食物交哺测试显示,取食后24 h受喂工蚁获得的食物量仅占原取食工蚁取食量的5.86%,48 h饲喂者与受喂者消化道食物量大致持平,并随时间推移逐渐减少,受喂者消化道中的食物始终低于饲喂者。本研究结果支持散白蚁的交哺行为属于层叠式交哺模式的观点。     

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。     

保幼激素类似物对白蚁的作用研究进展

本文介绍了保幼激素类似物对白蚁的影响,包括诱导前兵蚁、兵蚁和一些中间品级(形态畸形)的产生、抑制白蚁的取食、减少或消除白蚁的共生原生动物群、对白蚁产生不同水平的急性和慢性毒性、抑制工蚁蜕皮以及繁殖蚁建立新群体等方面的影响,其中最主要影响是诱导前兵、兵蚁和一些中间品级的产生破坏了白蚁群体品级比例的平衡性或完整性.因此,保幼激素类似物可用于白蚁的防治,并在田问防治散白蚁和乳白蚁均取得了较好的防治效果,并探讨了应用保幼激素类似物防治白蚁的潜力与前景.     

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。     

Environmental conditions and their impact on immunocompetence and pathogen susceptibility of the Caribbean termite Nasutitermes acajutlae

1. Little is known about interactions between environmental conditions surrounding insects and their immune responses. 2. The environment in and around termite colonies, including temperature, relative humidity, soil pH, and light was analysed using principal components analysis (PCA). 3. The relationship between these abiotic parameters and two aspects of termite immunity (phenoloxidase activity and lipid content) was examined in field‐caught workers of Nasutitermes acajutlae Holmgren. Finally, termites from warm/dry and cool/moist habitats were exposed to Metarhizium anisopliae to determine their susceptibility to mycosis. 4. PCA indicated that environmental components external to the nest [ambient temperature, ambient relative humidity (RH), soil temperature and light] comprised the majority (PC1 = 37.5%) of variation. Internal variables (nest temperature and RH) and nest volume accounted for 19.6% (PC2) of the variation with pH comprising 12.9% (PC3). 5. AIC and regression models suggested that ambient temperature was most strongly and positively associated with immune variables and that relative humidity may also play a role. Termites from warm/dry colonies were less susceptible to M. anisopliae than termites from cool/moist colonies. 6. Thus, termites nesting in warmer habitats may exhibit increased immune‐related measures and reduced susceptibility to mycosis compared with termites from cooler habitats.     

Thermoregulation of termite mounds: what role does ambient temperature and metabolism of the colony play?

Summary: Termites are well known for their ability to regulate the environment of their nest such as temperature and humidity. The influence of fluctuating ambient temperature and mound characteristics on mean nest temperature and daily fluctuation of nest temperature was analysed quantitatively in the fungus-cultivating, mound-building termite Macrotermes bellicosus (Macrotermitinae) in the savanna of the Comoé National Park (Côte d'Ivoire). Additionally, the nest temperatures of inhabited and uninhabited mounds were compared to analyse the contribution of ambient temperature to nest temperature in relation to metabolic heat production of the termites and their fungi. Mound structure alone resulted in a relatively constant nest temperature. Abiotic heat production via solar radiation alone yielded nest temperatures that corresponded to mean ambient temperatures. However, only the production of metabolic heat by the termites and the fungi increased these temperatures to the actual nest temperature. Therefore, and due to the high heat capacities of the mounds, large colonies (mound height above 2.0 m) had higher nest temperatures than smaller ones. Only large colonies attain constant nest temperatures of 30 °C that are largely independent from ambient temperatures and optimal for the growth and development of the termites and their fungi.     

Life Inside an Acorn: How Microclimate and Microbes Influence Nest Organization in Temnothorax Ants

Nests provide a buffer against environmental variation, but conditions may also vary at different locations within a nest. Conditions can vary based on abiotic factors, such as moisture and temperature, as well as biotic factors, such as the presence of microbes and potential pathogens. Therefore, characterizing how animals adjust their position inside their nests to track microclimate preferences while at the same time preventing pathogen exposure is necessary to understand the benefits nests provide. Here we studied how colonies of the acorn‐nesting ant Temnothorax curvispinosus responded to experimental manipulation of moisture, temperature, and microbial growth inside their nests. Colonies showed no response to differences in moisture and moved to the bottom of the acorn regardless of moisture treatment. When nests were heated from the top to simulate warming by the sun, workers preferentially moved brood to the warm, upper half of the acorn, which would stimulate brood development. Finally, the strongest factor that influenced colony position was the presence of microbes inside the nest—colonies avoided the bottom of the nest when it was inoculated with microbes, and colonies in new acorns shifted to the top of the acorn over time as mold and other microbes had time to grow. The relatively strong response of T. curvispinosus to microbial growth inside their nests suggests that pathogen pressures—in addition to microclimate—have a significant impact on how colonies use nest spaces. Social insects are known to invest heavily in antimicrobial compounds that kill or slow the growth of microbes, but avoidance may represent an additional line of defense to prevent pathogen exposure.     

Between a rock and a hard place: impact of nest selection behavior on the altitudinal range of an alpine ant, Formica neorufibarbis

Formica neorufibarbis Emery is a dominant alpine ant in North America. Above timberline, colonies nest under rocks, placing brood against the rock surface to warm during the day. We tested the hypothesis that nest rock preference represents a mechanism of behavioral thermoregulation and used a demographic model to explore its impact on the species' altitudinal range. Under sunny conditions rocks provide warm microclimates. Across a 400-m altitudinal gradient from below timberline to high alpine tundra, nest rocks warmed on average 5°C above ambient at mid-day, but cooled to near ambient before dawn. Soil was warmer at mid-day under rocks occupied by ants than under randomly chosen unoccupied rocks in the same area. Occupied nest rocks were painted white or black to manipulate temperature and test its impact on colony occupancy. In addition, black-painted and white-painted rocks of similar size were placed in the field to test for a temperature effect on nest site colonization. Likelihood of nest persistence and colonization decreased under cooler, white-painted rocks and depended strongly on rock warming capacity. Experimental results showed that nest site colonization and occupancy are favored in microsites maintaining mid-day temperature ≥22°C. Across the altitudinal gradient, 66-90% of nest microsites occupied by F. neorufibarbis met this temperature threshold. Conversely, none of the exposed microsites and only 15% of those microsites under randomly selected rocks warmed to 22°C at the high altitude site (3,900 m). Results support the conclusion that nest site preference contributes to the broad altitudinal distribution of F. neorufibarbis.     

Ant colonization and coarse woody debris decomposition in temperate forests

Ants are ubiquitous, abundant and have widespread impacts on ecological communities and ecosystem processes. However, ant effects on coarse woody debris decomposition are unexplored. Several ant species colonize coarse woody debris for nesting, and this puts them in contact with fauna and microbes that utilize coarse woody debris as habitat and food, potentially influencing nutrient cycling and, ultimately, forest productivity. We report results from a field experiment employing 138 artificial ant nests (routed pine blocks) across five locations in southeastern US deciduous forests. We examine the correspondence between ant, termite and wood-eating fungi colonization and variation in coarse woody debris decomposition. After 1 year, nests colonized by ants had 5% more mass than those not colonized. Ant colonization corresponded with significantly less termite- and fungal-mediated decomposition of the nests. Without ants, termites removed 11.5% and fungi removed 4% more wood biomass. Ants, termites and wood-eating fungi all colonized pine nests where temperatures were highest, and ants also preferred higher soil moisture whereas termites and fungi responded negatively to high soil moisture when temperatures were higher. Ants reduce termite colonies through predation, and may inhibit fungi through the secretion of antimicrobial compounds. Our results indicate that interactions between forest understory ants, termites and fungi may influence the rate of coarse woody debris decomposition—biotic interactions that potentially influence forest structure and function.     

Colony structure and caste distribution in living trees of the Ryukyu drywood termite,Neotermes sugioi (Blattodea: Kalotermitidae) in Okinawa Island

Termites are major pests of houses and buildings, and also living plants such as agricultural crops, trees in forests, urban areas and gardens. However, in Japan, the basic ecology of termites nesting in living trees is not fully understood. In this study, we observed 255 colonies (nests) of the drywood termite Neotermes sugioi, collected in the field on Okinawa Island, and reported the frequency composition of the reproductive castes, the size of wood with termite gallery, the population size of colonies, and the relative position of the reproductive and non-reproductive castes within nests. Most colonies were headed by a primary queen and a primary king. However, colonies headed only by primary queens, primary kings, or neotenic kings, each accounted for approximately 5% of the colonies. A colony size of 1,000– 4,000 individuals (2058.2 ± 1695.0 [mean ± SD]) was common and the average length of colony branches was less than 100 cm. Queens and kings were found in the same or nearby nest areas, and more predominantly in the central or root side of nest wood areas. The termites may experience colony fragmentation and reproductive loss as a consequence of typhoons. Incipient colonies (i.e., colonies at an early stage of development) were found on 11.3% of branches of Leucaena leucocephala that did not show any obvious signs of infestation. In future research, it will be necessary to update the list of trees damaged by this termite species, compare the damage by tree species, and evaluate the economic impact.     

羊草叶片气体交换参数对温度和土壤水分的响应

 采用生长箱控制的方法研究了羊草(Leymus chinensis)幼苗叶片光合参数对5个温度和5个水分梯度的响应和适应。结果表明：轻度、中度土壤干旱并没有限制羊草叶片的生长,对气体交换参数亦无显著影响,反映了羊草幼苗对土壤水分胁迫的较高耐性。叶片生物量以26 ℃时最大,其它依次为23 ℃、20 ℃、29 ℃和32 ℃。温度升高使气孔导度和蒸腾速率增加, 却使光合速率和水分利用效率降低。水分和温度对叶片生物量、光合速率、气孔导度和蒸腾速率存在显著的交互作用,表明高温加强了干旱对叶片生长和气体交换的影响, 降低了羊草对土壤干旱的适应能力。高温和干旱的交互作用将显著减少我国半干旱地区草原的羊草生产力。     

Extreme genetic mixing within colonies of the wood-dwelling termite Kalotermes flavicollis (Isoptera,Kalotermitidae)

The existence of altruism in social insects is commonly attributed to altruistic individuals gaining indirect fitness through kin selection. However, recent studies suggest that such individuals might also gain direct fitness through reproduction. Experimental studies on primitive wood-dwelling termites revealed that colony fusion often causes the death of primary reproductives (queen and king), allowing opportunities for workers to inherit the nest by developing into replacement reproductives (neotenics). Therefore, colony fusion has been proposed as an important factor that may have favoured sociality in termites. However, whether colony fusion occurs frequently in natural populations of wood-dwelling termites remains an open question. We analysed eleven colonies of the wood-dwelling termite Kalotermes flavicollis (Kalotermitidae), using two mitochondrial and five nuclear microsatellite markers. Nine of eleven colonies (82%) were mixed families, with offspring of three or more primary reproductives. To our knowledge, this result represents the highest frequency of mixed-family colonies ever reported in termites. Moreover, genetic mixing of colonies appeared extreme in two ways. First, the number of haplotypes per colony was exceptionally high (up to nine), indicating that colonies were composed of multiple queens' offspring. Second, some mixed-family colonies included individuals belonging to two highly divergent genetic lineages. F-statistics and relatedness values suggest that mixed-family colonies most likely result from colony fusion, giving support to the accelerated nest inheritance theory. These findings raise important questions about the mode of foundation of mixed-family colonies and the evolutionary forces that maintain them within populations.     

截头堆砂白蚁性比的研究

为了解截头堆砂白蚁Cryptotermes domesticus（Haviland）群体中不同品级、不同虫态的雌雄性比,本文研究了该种白蚁自行配对室温条件下饲养4年巢龄的实验群体与采集的自然群体的各个品级和不同虫态的雌雄性比。结果表明：自行配对室温饲养4年巢龄群体与自然环境群体中原始繁殖蚁、幼蚁、若蚁、兵蚁都有雌雄之分,其中自行配对室温饲养群体的原始繁殖蚁雌雄比例为1：1,兵蚁雌雄比例为1：1．24,幼蚁和若蚁雌雄比例为1：1．46;自然环境群体原始繁殖蚁雌雄比例为1：1,兵蚁雌雄比例为1：1．15,幼蚁和若蚁雌雄比例为1：1．43。     

Soil Moisture and Excavation Behaviour in the Chaco Leaf-Cutting Ant (Atta vollenweideri): Digging Performance and Prevention of Water Inflow into the Nest

The Chaco leaf-cutting ant Atta vollenweideri is native to the clay-heavy soils of the Gran Chaco region in South America. Because of seasonal floods, colonies are regularly exposed to varying moisture across the soil profile, a factor that not only strongly influences workers'' digging performance during nest building, but also determines the suitability of the soil for the rearing of the colony''s symbiotic fungus. In this study, we investigated the effects of varying soil moisture on behaviours associated with underground nest building in A. vollenweideri. This was done in a series of laboratory experiments using standardised, plastic clay-water mixtures with gravimetric water contents ranging from relatively brittle material to mixtures close to the liquid limit. Our experiments showed that preference and group-level digging rate increased with increasing water content, but then dropped considerably for extremely moist materials. The production of vibrational recruitment signals during digging showed, on the contrary, a slightly negative linear correlation with soil moisture. Workers formed and carried clay pellets at higher rates in moist clay, even at the highest water content tested. Hence, their weak preference and low group-level excavation rate observed for that mixture cannot be explained by any inability to work with the material. More likely, extremely high moistures may indicate locations unsuitable for nest building. To test this hypothesis, we simulated a situation in which workers excavated an upward tunnel below accumulated surface water. The ants stopped digging about 12 mm below the interface soil/water, a behaviour representing a possible adaptation to the threat of water inflow field colonies are exposed to while digging under seasonally flooded soils. Possible roles of soil water in the temporal and spatial pattern of nest growth are discussed.