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。     

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。     

大家白蚁对几种饵剂的选择性

在木材检疫中利用对白蚁有引诱作用的几种物质,进行不同的配比,对白蚁的食物选择性进行研究。室内结果表明:在5种配比中TB04(甘蔗粉+棕檬醛)的效果最好,其取食率、泥被面积及泥被覆盖率分别达到47.74%±4.69%、(8.06±0.18)cm2和89.53%±1.96%。室外诱集试验表明:TB03(甘蔗粉+木耳粉)、TB04均有较好的效果。温湿度试验表明:大家白蚁Coptotermes curvignathus Holmgren取食的最佳温度为23~29℃,湿度高的条件下的诱集效果明显高于干燥条件下的诱集效果。诱集时间试验表明,随着时间的延长诱集效果逐渐明显,72h诱集数量趋于稳定。     

黑胸散白蚁和台湾乳白蚁对镇江地区几种常见木材品种的取食偏好性研究

【目的】本文研究了黑胸散白蚁Reticulitermes chinensis和台湾乳白蚁Coptotermes formosanus对镇江几种常见木材树种的取食偏好性,分析了白蚁种类和木材品种对白蚁取食偏好性和死亡率的影响,以期为本地区白蚁治理及预防提供科学依据。【方法】采取白蚁非选择性取食试验,研究两种白蚁分别取食香樟Cinnamonum campora、银杏Ginkgo biloba、水杉Metasequoia glyptostrodoides、垂柳Salix babylonica、广玉兰Magnolia grandiflora、枇杷树Eriobotrya japonica、马尾松Pinus massoniana 7种树种食料的取食偏好和死亡率,取食偏好采用白蚁取食率,即每克白蚁每天取食量(mg)评价。试验数据采用多因素方差分析。【结果】方差分析结果表明,白蚁种类和不同木材对白蚁取食率和死亡率均影响显著。在供试的7种木材中,黑胸散白蚁最喜食垂柳和马尾松,其取食率分别为31.46和30.59 mg;台湾乳白蚁最喜食马尾松、水杉和银杏,其取食率分别为26.53、21.82和21.81 mg。两种白蚁对银杏、垂柳、广玉兰这3种木材的取食率有显著差异,而对其他4种木材的取食率差异不显著。【结论】白蚁取食率和死亡率受白蚁种类和木材品种影响明显。7种供试木材中,两种白蚁都对马尾松显示出明显偏好,且死亡率最低。     

用低放射性强度131I与198Au标记家白蚁的试验

近十多年来,利用放射性同位素~(131)I、~(198)Au标记法研究白蚁的活动规律、危害范围以及示踪探巢等多有报道,但一般使用的放射性强度比较大,为数个至十多个毫居里(mc),弊病较多。为此开展了用低放射性强度微居里(μc)级的~(131)I和~(198)Au标记家白蚁(Coptotermes formosanus Shiraki)的试验研究。结果表明,使用放射性同位素~(131)I和~(198)Au5O—150μc标记诱集箱内的白蚁,即可达到上述研究和防治家白蚁的目的。     

成都市白蚁天敌资源——蚂蚁种类调查研究

部分蚂蚁种类是白蚁的重要天敌。为了探明成都市白蚁天敌——蚂蚁的常见种类及其生境,2011—2015年通过对成都市房屋建筑、园林树木、古建筑以及安装在住宅小区绿地的地下型白蚁监测装置等生境中调查白蚁与蚂蚁种类及数量,共鉴定白蚁9种,隶属于3科4属,黑胸散白蚁Reticulitermes chinensis占比最高(83.9%);蚂蚁29种,隶属于4亚科15属,中国短猛蚁Brachyponera chinensis占比最高(38.2%)。相关性分析表明,黑毛蚁Lasius niger与尖唇散白蚁R.aculabialis、新中华散白蚁R.neochinensis之间,莱曼氏蚁Formica lemani与黑胸散白蚁、尖唇散白蚁之间,敏捷扁头猛蚁Pachycondyla astuta、铺道蚁Tetramorium caesputum与尖唇散白蚁之间均呈显著负相关。黑毛蚁、莱曼氏蚁、敏捷扁头猛蚁、铺道蚁的种群数量大,在白蚁生物防治中具有一定的应用潜力。鉴于蚂蚁对白蚁的控制作用受环境、人为等多种因素的影响,建议进一步加强蚂蚁对白蚁自然控制作用的系统研究。     

黑胸散白蚁多对脱翅成虫群养的产卵及孵化行为

采用室内多对脱翅成虫群养的方法对黑胸散白蚁群Reticulitermes chinensis Snyder体产卵及孵化行为进行观察。结果表明:多对脱翅成虫群养,黑胸散白蚁表现出群居行为,会共同产卵、护卵;1～5对脱翅成虫群养的产卵历期分别为9.00,8.25,8.17,7.33,7.13d;孵化历期分别为36.67,39.33,31.33,35.88,36.33d;经分析差异均不显著。在1～4对脱翅成虫群养范围内,群体产卵成功率随原始脱翅成虫配对数量的增加而升高;4～5对产卵成功率比1～2对的显著要高(P<0.05)。     

黑胸散白蚁不同群体在形态分类特征上的差异性研究

【目的】研究黑胸散白蚁Reticulitermes chinensis Snyder形态分类特征显著差异性。【方法】利用SPSS19.0对黑胸散白蚁兵蚁和成虫不同的量度特征进行差异单因素分析(ANOVA)、多重比较Duncan’s(P0.05)和主成分分析。【结果】兵蚁头长至上颚端、头阔指数、前胸背板中区毛、前胸背板长、后颏狭、后颏宽、右触角最短节数、左触角节数和右触角节数9个指标在6个不同群体间变异较小,具有相对稳定性;成虫前翅宽、单复眼间距、复眼距头下缘、左触角最短节数、右触角节数、头长至上颚端和前Cu脉分支数7个指标在6个不同群体间变异较小,具有相对稳定性;显著性分析结果显示主成分分析选出的兵蚁的9个指标和成虫的6个指标在不同群体间存在显著性差异;不同种类白蚁的特征值测量指标亦存在一定程度重叠区。【结论】白蚁形态分类鉴定最好结合兵蚁和成虫的多个形态指标进行判断;种内形态指标的差异显著性及种间形态指标存在重叠,容易导致白蚁同物异名;白蚁形态分类学需要将形态分类学方法和现代分子生物学技术等多种技术有机结合。     

白蚁活动对中亚热带次生林和人工林的危害差异

中亚热带地区是中国南方重要的木材生产基地, 大量的地带性常绿阔叶林被转换成以杉木(Cunninghamia lanceolata)为代表的人工林。白蚁是森林中最主要的社会性昆虫之一, 其取食行为既对森林类型转换后林中的树木产生危害, 也对林间枯枝落叶的分解具有十分重要的意义, 但对二者缺乏统一的认识。本文以中亚热带典型的米槠(Castanopsis carlesii)次生林、米槠人工林和杉木人工林为研究对象, 调查了不同林分白蚁的活动特点及其范围。结果表明, 米槠次生林与杉木、米槠人工林中均普遍存在白蚁取食现象, 但白蚁对次生林的取食高度和面积均远低于人工林。白蚁对生物多样性较高的米槠次生林树干韧皮部的取食面积仅分别为米槠人工林的1.65%和杉木人工林的0.59‰, 取食高度的11.1%和1.2%。同时, 白蚁对杉木韧皮部的取食显著大于米槠, 对杉木的取食面积和高度分别是米槠的27.7倍和9.2倍。每隔0.5 m为一个统计区间, 白蚁对杉木树干2 m以下韧皮部取食面积比例由低往高为4 : 3 : 2 : 1, 对米槠1 m以下高度部位的取食面积比为99 : 1。此外, 白蚁对次生林地表覆盖的凋落枝和凋落叶的平均取食面积分别为51.7%和46.1%, 而人工林对应均值分别为17.5%和29.4%, 均表现为次生林高于人工林。这些结果表明白蚁对生物多样性较高的次生林危害小于杉木人工林, 且在人工林中可见危害主要体现在白蚁对韧皮部的取食, 在次生林主要体现在白蚁对凋落物残体的分解作用, 这为区域森林经营管理提供理论支撑。     

鼠类对山杏和辽东栎种子的贮藏

在北京市东灵山地区,选择灌丛生境,人工释放山杏和辽东栎种子,对两种种子在释放处被鼠类就地取食、存留动态、种子被搬运和贮藏的距离、位置、状态、微生境等进行了分析比较。采用活捕饲喂和咬痕比较的方法,对野外取食山杏和辽东栎种子的鼠类进行了鉴定。结果表明：1)取食山杏和辽东栎种子的鼠类主要是大林姬鼠和岩松鼠;2)山杏种子被鼠类搬运的平均距离大于辽东栎种子,两种种子大多数被搬运至21m之内,在9m之内最为集中;3)山杏种子的中位存留时间较辽东栎种子长;4)在释放处,鼠类对辽东栎种子的就地取食强度(54．83％)大于对山杏种子的取食(0．17％);5)在搬运之后,大部分山杏种子被埋藏起来,仅有3粒被取食;而辽东栎种子大部分被取食;6)鼠类趋向于把种子搬运到灌丛下方或灌丛边缘进行贮藏或取食。山杏种子在贮藏点的数量为1—3粒,而辽东栎种子在贮藏点的数量均为1粒。     

Estimating the population size and colony boundary of subterranean termites by using the density functions of directionally averaged capture probability

Marked termites were released in a linear-connected foraging arena, and the spatial heterogeneity of their capture probabilities was averaged for both directions at distance r from release point to obtain a symmetrical distribution, from which the density function of directionally averaged capture probability P(x) was derived. We hypothesized that as marked termites move into the population and given sufficient time, the directionally averaged capture probability may reach an equilibrium P(e) over the distance r and thus satisfy the equal mixing assumption of the mark-recapture protocol. The equilibrium capture probability P(e) was used to estimate the population size N. The hypothesis was tested in a 50-m extended foraging arena to simulate the distance factor of field colonies of subterranean termites. Over the 42-d test period, the density functions of directionally averaged capture probability P(x) exhibited four phases: exponential decline phase, linear decline phase, equilibrium phase, and postequilibrium phase. The equilibrium capture probability P(e), derived as the intercept of the linear regression during the equilibrium phase, correctly projected N estimates that were not significantly different from the known number of workers in the arena. Because the area beneath the probability density function is a constant (50% in this study), preequilibrium regression parameters and P(e) were used to estimate the population boundary distance 1, which is the distance between the release point and the boundary beyond which the population is absent.     

Estimating population density of the Formosan subterranean termite, Coptotermes formosanus(Isoptera: Rhinotermitidae) using the effective sampling area of in-ground monitoring stations

The effective sampling area of a monitoring station, alpha, was calculated for several Coptotermes formosanus Shiraki colonies in Broward County, Florida, USA. A simple mark-recapture protocol provided data on termite station catch within a foraging range of a colony. Average recapture probability was 0.005 close to the release point (< 5 m) and declined to 0.0008 at a distance of 51 to 60 m. The relation between the log % termites recaptured was fitted with log distance, to determine P(x), the average proportion of captured termites that started at distance x from the release point. The effective sampling area was estimated by using P(x) and the equation, alpha 2 pi integral [ x P(x)] dx. Integrating this equation, an average estimate alpha that ranged from 0.607 to 14.5 m2 was obtained. Factors influencing the variation of alpha among the colonies are discussed. The effective sampling area estimated should be taken as a reliable estimator that translates subterranean termite catches into termite population density.     

Foraging populations and distances of the desert subterranean termite, Heterotermes aureus (Isoptera: Rhinotermitidae), associated with structures in southern Arizona

Mark-release-recapture studies were conducted on foraging populations of Heterotermes aureus (Snyder) (Isoptera: Rhinotermitidae) associated with three structures in Tucson, AZ. Foraging population estimates ranged from 64,913 to 307,284 termites by using the Lincoln Index and from 75,501 to 313,251 termites using the weighted mean model. The maximum distance between monitors ranged from 26 to 65 m, with minimum total foraging distance ranging between 297 and 2,427 m. Characterizations of the cuticular hydrocarbons of foraging groups were qualitatively identical. Quantitative similarities within sites and differences among sites suggested that each site was occupied by a single colony during the sampling period. The colony at each site had a proportion of soldiers (0.135, 0.069, and 0.040) that was significantly different from the colonies at each of the other sites. From this study, we question the assumption of equal mixing of marked H. aureus foragers throughout the occupied collars around structures.     

白蚁采食行为中的信息交流

白蚁作为社会性昆虫, 其采食个体间依赖各种信息交流机制进行联系与协作, 其中包括踪迹、 警戒、 食物信息、 同伴识别和助食等。通常的联系信号为挥发性或半挥发性化学物质或者一定频谱和功率的机械振动波。其中踪迹信息素、 蚁源烃类、 警戒信息素、 助食素和机械振动信号等都在白蚁采食过程中起着重要作用。白蚁采食过程中食物定向和食物品质信息的传达主要依靠腹板腺分泌的踪迹信息素, 已发现有十二碳烯醇类、 降碳倍半萜类和大环二萜类。蚁源的机械振动也在食物品质表达方面起到一定作用, 但食物品质的表达机制还不明确。白蚁采食协作的基础是同伴识别, 蚁源烃类（C21~C35）是同伴识别的主要信息物质, 采食个体分泌的助食素则可促成共同取食。警戒信息素传递白蚁采食的安全信息, 通常为一些兵蚁源的萜类物质, 但得到功能鉴定的结构还不多。近来研究还发现特殊的蚁源机械振动也可起到示警作用。已初步证实各种信息交流机制间存在交互作用, 但交互作用的机理有待进一步解析。生物物理因素在白蚁采食行为中的作用值得更多重视。本文以白蚁的采食行为为线索, 评述白蚁采食个体间信息交流机制的研究进展及利用问题, 并对今后的研究提出展望。     

Spatial ecology of a range‐expanding bumble bee pollinator

Molecular methods have greatly increased our understanding of the previously cryptic spatial ecology of bumble bees (Bombus spp.), with knowledge of the spatial ecology of these bees being central to conserving their essential pollination services. Bombus hypnorum, the Tree Bumble Bee, is unusual in that it has recently rapidly expanded its range, having colonized much of the UK mainland since 2001. However, the spatial ecology of B. hypnorum has not previously been investigated. To address this issue, and to investigate whether specific features of the spatial ecology of B. hypnorum are associated with its rapid range expansion, we used 14 microsatellite markers to estimate worker foraging distance, nest density, between‐year lineage survival rate and isolation by distance in a representative UK B. hypnorum population. After assigning workers to colonies based on full or half sibship, we estimated the mean colony‐specific worker foraging distance as 103.6 m, considerably less than values reported from most other bumble bee populations. Estimated nest density was notably high (2.56 and 0.72 colonies ha^?1 in 2014 and 2015, respectively), estimated between‐year lineage survival rate was 0.07, and there was no evidence of fine‐scale isolation by distance. In addition, genotyping stored sperm dissected from sampled queens confirmed polyandry in this population (mean minimum mating frequency of 1.7 males per queen). Overall, our findings establish critical spatial ecological parameters and the mating system of this unusual bumble bee population and suggest that short worker foraging distances and high nest densities are associated with its rapid range expansion.     

Conservation genetics,foraging distance and nest density of the scarce Great Yellow Bumblebee (Bombus distinguendus)

The conservation genetics of bees is of particular interest because many bee species are in decline, so jeopardizing the essential ecosystem service of plant pollination that they provide. In addition, as social haplodiploids, inbred bees may be vulnerable to the extra genetic load represented by the production of sterile diploid males. Using microsatellite markers, we investigated the genetic structure of populations of the Great Yellow Bumblebee (Bombus distinguendus Morawitz) in the UK, where this species has undergone a precipitous decline. By means of a mixture of analytical methods and simulation, we also extended—and then applied—genetic methods for estimating foraging distance and nest density in wild bees. B. distinguendus populations were characterized by low expected heterozygosity and allelic richness, inbreeding coefficients not significantly different from zero, absence of detected diploid males, absence of substantial demographic bottlenecking, and population substructuring at large (c. 100+ km) but not small (10s of km) spatial scales. The minimum average effective population size at our sampling sites was low (c. 25). In coastal grassland (machair), the estimated modal foraging distance of workers was 391 m, with 95% of foraging activity occurring within 955 m of the nest, and estimated nest density was 19.3 nests km^‐2. These findings show that B. distinguendus exhibits some genetic features of scarce, declining or fragmented populations. Moreover, B. distinguendus workers appear to forage over above‐average distances and nests remain thinly distributed even in current strongholds. These considerations should inform future conservation actions for this and similar species.     

Response of the Formosan subterranean termites (Isoptera: Rhinotermitidae) to baits or nonrepellent termiticides in extended foraging arenas

Distance effects of three treatments, noviflumuron, fipronil, and thiamethoxam, against laboratory populations of the Formosan subterranean termite, Coptotermesformosanus Shiraki, were tested in extended foraging arenas with foraging distances of 50 m. The results showed that during the 10-wk test period, all termites were killed by noviflumuron baits, whereas the nonrepellent termiticides fipronil and thiamethoxam divided the laboratory populations into two groups after causing 25-35% worker mortality. The horizontal transfer of lethal effects of fipronil was < or = 5 m. For thiamethoxam, the distance of transfer was substantially shorter. Because of their dose-dependent lethal time, the nonrepellent termiticides did not fulfill the requirements of a liquid bait model.     

Experimental manipulation of termites (Isoptera,Macrotermitinae) foraging patterns in a Sahelo-Sudanese savanna: effect of litter quality

Summary The foraging pattern of four sympatric fungus-growing termite species was followed for five months of the dry season in a semi-arid savanna (Senegal). Experimental plots were established with and without termites (exclusion with insecticide) and amended with different litter quality: Acacia leaves, millet canes, ground millet (<500 µm), Combretum wood and cattle manure. Results showed different foraging patterns between the fungus-growing species. Odontotermes nilensis, for example, rapidly developed its foraging activity on the litter. In contrast, Macrotermes subhyalinus delayed its foraging activity but, extensively collected the food after its discovery. Differences in food preference were evident between the termite species: Odonto-termes nilensis foraged preferentially on millet, canes and Acacia leaves, Macrotermes subhyalinus preferred cane and ground millet. Ancistrotermes guineensis selected the millet, and Microtermes sp. was mostly recorded foraging on pieces of dead wood. Relationships between different foraging parameters were established to assess the relative intensity of this activity over the dry season. The comparison between untreated plots and plots treated with Fipronil® (Aventis) clearly demonstrated that the exclusion of termites from part of the savanna is possible and that this possibility can be used to study their role on the soil and organic matter cycle in situ.     

Minimizing moving distance in deposition behavior of the subterranean termite

Subterranean termite nests are located underground and termites forage out by constructing tunnels to reach food resources, and tunneling behavior is critical in order to maximize the foraging efficiency. Excavation, transportation, and deposition behavior are involved in the tunneling, and termites have to move back and forth to do this. Although there are three sequential behaviors, excavation has been the focus of most previous studies. In this study, we investigated the deposition behavior of the Formosan subterranean termite, Coptotermes formosanus Shiraki, in experimental arenas having different widths (2, 3, and 4 mm), and characterized the function of deposited particles. We also simulated moving distance of the termites in different functions. Our results showed that total amounts of deposited particles were significantly higher in broad (4 mm width) than narrow (2 mm) tunnels and most deposited particles were observed near the tip of the tunnel regardless of tunnel widths. In addition, we found that deposited particles followed a quadratic decrease function, and simulation results showed that moving distance of termites in this function was the shortest. The quadratic decrease function of deposited particles in both experiment and simulation suggested that short moving distance in the decrease quadratic function is a strategy to minimize moving distance during the deposition behavior.