Wax perception in honeybees: contact is not necessary

In social insects, much progress has been made in identifying variations in the cuticular signatures of sexes, castes, kin and reproductive status. In contrast to this, we still do not know how the receivers perceive these recognition cues. This study was designed to investigate whether honeybees use contact-chemosensory or olfactory sensilla to perceive wax components. To answer this question in a behavioral assay, we combined classical conditioning of the proboscis extension reaction and a recently established method using zinc sulfate to selectively block antennal contact-chemosensory sensilla. Comparison of the responses to sucrose, wax and geraniol before and after antennal zinc sulfate treatment revealed that the sucrose response is lost after treatment but the responses to wax and geraniol are maintained. As sucrose is perceived by the contact-chemosensory sensilla, the retention of the wax response indicates that contact-chemosensory sensilla are not necessary for wax perception.     

A new type of insect infrared organ of low thermal mass

The Australian beetle Acanthocnemus nigricans is attracted by forest fires and has a pair of complex infrared (IR) receptor organs on the first thoracic segment. Each organ consists of a tiny sensory disc (diameter 120-130 µm) which serves as an absorbing structure for IR radiation. The disc is arranged above an air-filled cavity which is located just anteriorly to the coxae of the prothoracic legs. Inside the disc, about 30 multipolar thermoreceptors (warmth receptors) are tightly attached to the cuticle which is directed to the outside. The many dendrites of each multipolar neuron are tightly wrapped around the soma and contain a large number of mitochondria. Absorption of IR radiation by the disc causes an increase in temperature which is measured by the warmth receptors. Therefore, the IR receptors of A. nigricans can be classified as microbolometers with reduced thermal mass and in principle can be compared to the IR organs of pit vipers.     

电化学产电菌的分离及性能评价

利用兼性滚管法分离了折流板空气阴极微生物燃料电池(BAFMFC)A、B两格室的阳极生物膜,共获得19株纯菌.将菌株投加至无菌立方型反应器中,检验其产电特性.利用交流阻抗法测量各纯菌电池的内阻,结果显示38个电池的欧姆内阻为25Ω±5Ω,说明了各电池的产电差异来源于菌株本身的活性.其他运行条件均保持不变,在1000Ω外阻下,7株纯菌电池的输出电压在200mV以上.其中,A格室产电活性最高的菌株(A2)产生的最大电压为328mV,输出的最大功率密度为165.1mW/m2,B格室产电活性最高的菌株(B1)最大电压为241mV,最大功率密度为214.4mW/m2.原子力显微镜和脂肪酸快速鉴定表明,A2为肠杆菌科的杆菌,B1为厚壁菌门的芽孢杆菌.     

The antennal sensilla of Melipona quadrifasciata (Hymenoptera: Apidae: Meliponini): a study of different sexes and castes

The sensilla of insects are integumental units that play a role as sensory structures and are crucial for the perception of stimuli and for communication. In this study, we compared the antennal sensilla of females (workers and queens), males (haploid (n) and diploid (2n)), and queen-like males (QLMs, resulting from 2n males after juvenile hormone (JH) treatment) in the stingless bee Melipona quadrifasciata. Images of the dorsal antenna surfaces were acquired using a scanning electron microscope. As reported for other hymenopterans, this species exhibits a heterogeneous sensillar distribution along the antennae. Thirteen different types of sensilla were found in the antennae of M. quadrifasciata: trichodea (subtypes I to VI), chaetica (subtypes I and II), placodea, basiconica, ampullacea, coeloconica, and coelocapitula. Sensilla trichodea I were the most abundant, followed by sensilla placodea, which might function in olfactory perception. Sensilla basiconica, sensilla chaetica I, sensilla coeloconica, and sensilla ampullacea were found exclusively in females. In terms of the composition and size of the sensilla, the antennae of QLMs most closely resemble those of the 2n male, although QLMs exhibit a queen phenotype. This study represents the first comparative analysis of the antennal sensilla of M. quadrifasciata. The differences found in the type and amount of sensilla between the castes and sexes are discussed based on the presumed sensillary functions.     

A new type of infrared organ in the Australian "fire-beetle" Merimna atrata (Coleoptera: Buprestidae)

 The Australian buprestid beetle Merimna atrata (Coleoptera: Buprestidae) approaches forest fires because its larvae develop in freshly burnt wood. So far nothing is known about possible sensory systems enabling the beetles to detect fires and to cope with the thermal environment close to the flames. We found that M. atrata has two pairs of infrared (IR) organs on the ventrolateral sides of the abdomen. Each IR organ consists of a specialized IR-absorbing area which is innervated by one thermosensitive multipolar neuron. The primary dendritic branches ramify into more than 800 closely packed terminal endings which contain a large number of mitochondria. We called the special morphology of the dendritic region a terminal dendritic mass. The type of IR receptor found in M. atrata is unique in insects and can best be compared with the IR organs of boid snakes. Received: 14 August 2000 / Accepted in revised form: 18 October 2000     

Sugar receptor response of the food-canal taste sensilla in a nectar-feeding swallowtail butterfly, Papilio xuthus

The feeding behavior in nectar-feeding insects is triggered by a sugar-receptor response in contact chemosensilla. The contact chemosensilla are distributed not only on tarsi and the outside of the proboscis but also on the inside of the food canal in Lepidoptera. Although the chemosensilla inside the food canal are assumed to detect sweet taste during the passage of nectar through the food canal, their electrophysiological function has received little attention. In the nectar-feeding Asian swallowtail butterfly, Papilio xuthus (Lepidoptera: Papilionidae), we found 15- to 30-μm-long sensilla neatly lined up along the inside galea wall, which forms the food canal in the proboscis. The receptor neurons of these sensilla responded to sucrose. We hypothesized that starch and sucrose compete with each other for a taste receptor site on the sensilla. When we added starch and sucrose to the food-canal sensilla, the electrophysiological responses of food-canal sensilla were inhibited in parallel with the food-sucking behavior of the butterflies. These results suggest that the food-canal sensilla are involved in the behavioral control of nectar-sucking in this butterfly species.     

阳极位置对新型ABR-BEF系统处理性能及微生物群落的影响

研究了阳极所处位置对新型厌氧折流板-生物电Fenton（ABR-BEF）系统处理中药废水效能与产电能力的影响,并对各格室污泥的疏松胞外聚合物（LB-EPS）及紧密胞外聚合物（TB-EPS）组分情况进行了分析,继而通过高通量测序技术对系统中微生物群落演替进行了探讨.结果表明,当将阳极电极位置由系统的第4格室调整到第3、第2格室后,由于阳极与阴极距离的增大,COD平均去除率由原来的90%分别下降到70%和65%;输出电压由149.8mV降至95.3mV、50.0mV左右,同时最大功率密度由76.78mW/m³减少到55.57mW/m³和52.87mW/m³;但阴极室对邻苯二酚的降解率仍保持在95%左右.改变阳极位置后LB-EPS、TB-EPS中蛋白质含量均下降,TB-EPS尤为明显;而对于多糖而言,阳极在第3号格室时,各组分多糖含量最高.阳极位置由第4格室改为第2格室后,第1到第4格室甲烷丝状菌属（Methanothrix）所占比例分别增大到71.09%、72.47%、58.03%和76.79%;在总细菌纲水平上产电菌所属的d变形菌纲（Deltaproteobacteria）在第1到第4格室中分别减少了2.54%、6.06%、4.40%和4.87%,阳极与阴极距离的增大使得产电菌数量减少,这成为该系统产电能力下降的重要原因.     

Nestmate recognition in ants is possible without tactile interaction

Ants of the genus Camponotus are able to discriminate recognition cues of colony members (nestmates) from recognition cues of workers of a different colony (non-nestmates) from a distance of 1 cm. Free moving, individual Camponotus floridanus workers encountered differently treated dummies on a T-bar and their behavior was recorded. Aggressive behavior was scored as mandibular threat towards dummies. Dummies were treated with hexane extracts of postpharyngeal glands (PPGs) from nestmates or non-nestmates which contain long-chain hydrocarbons in ratios comparable to what is found on the cuticle. The cuticular hydrocarbon profile bears cues which are essential for nestmate recognition. Although workers were prevented from antennating the dummies, they showed significantly less aggressive behavior towards dummies treated with nestmate PPG extracts than towards dummies treated with non-nestmate PPG extracts. In an additional experiment, we show that cis-9-tricosene, an alkene naturally not found in C. floridanus' cuticular profile, is behaviorally active and can interfere with nestmate recognition when presented together with a nestmate PPG extract. Our study demonstrates for the first time that the complex multi-component recognition cues can be perceived and discriminated by ants at close range. We conclude that contact chemosensilla are not crucial for nestmate recognition since tactile interaction is not necessary.     

Maternally inherited architecture in tertiary leaf beetles: paleoichnology of cryptocephaline fecal cases in Dominican and Baltic amber

Complex ethological adaptations and intraspecific interactions leave few fossil traces. We document three Dominican (20 million years old [myo]) and Baltic (45 myo) amber fossils that exhibit firm evidence of highly integrated interactions between mothers and offspring in the diverse camptosomate lineage of beetles (Chrysomelidae, leaf beetles). As in contemporary species, these hard cases were initially constructed by mothers, then inherited and retained by offspring, which then elaborate this protective domicile with an unusual but economical building material, their feces. The three fossils are classified in the Subfamily Cryptocephalinae; two are classified in the tribe Chlamisini based on morphological evidence—the flattened head lacking a sharp keel and long legs with simple recurved untoothed claws. These diagnostic features are not clearly visible in the third specimen to permit more refined identification. These fossils provide more precise paleontological dating of tribal nodes within the cryptocephaline radiation of leaf beetles. These fossils are the first and earliest evidence of mother–offspring interaction, building behavior, and fecal recycling in Camptosomata beetles and of inheritance of architectural structures in beetles.     

Photolysis of a mixture of anthracene and benzo[a]pyrene at ultra-trace levels in natural water with disinfection purposes

The photodegradation of anthracene(AN) and benzo[a]pyrene(BaP),two priority polycyclic aromatic hydrocarbons(PAHs),was examined at ultra-trace levels in surface water to elucidate their behaviour under several irradiance values and types of radiation.The emitting flux and the spectrum of the lamps were found to develop a crucial role in AN and BaP degradation since removal efficiencies of the target contaminants higher than 99%were found after 15 min of irradiation under an ultraviolet C(UVC) irradiance of 0.63 mW/cm~2,corresponding to a fluence of 560.25 mJ/cm~2.On the other hand,although ultraviolet A(UVA) lamps exhibited a higher irradiance compared to that of UVC lamps,they were not efficient for degrading the target PAHs.The removal kinetic studies corroborated these findings,being the AN elimination rate in surface water higher than that in deionized water at optimal operating conditions.Disinfection potential was also measured.A rapid microbial load inactivation,in terms of total coliforms naturally contained in the water matrix studied,was evidenced within 15 min of treatment for the fluence referred.However,after 24 hr in the dark,a regrowth was observed.Additionally,photolysis products more toxic than the parent compounds were found,which were not removed even by extending the treatment time.In this regard,it can be concluded that the individual action of UVC light for removing AN and BaP with disinfection purposes is not an efficient treatment;therefore,the use of radiation in combination with other kinds of treatments is required.     

缓冲液对微生物燃料电池产电性能影响研究

微生物燃料电池(microbial fuel cell,MFC)应用于废水处理是一项非常有潜力的除污产能的绿色技术.但MFC运行过程中采用磷酸盐缓冲液不符合除污产能要求,增加水体富营养化趋势且增加水处理成本.试验采用单极室微生物燃料电池处理模拟生活污水,以投加PBS(phosphate buffer solution)...     

高原地区军用箱式装备内部环境条件试验研究

在高原格尔木地区对箱式装备集装箱内部环境条件如温度、大气温度、太阳辐射强度及风速等数据进行了测试,利用模糊系统分析的方法,建立了非线性数学模型,预测出该地区集装箱内部最恶劣的温度范围,为危险军用物资集装箱安全储运提供了理论依据并提出相应的建议和对策。     

基于柱状发光体悬浆式光催化反应器绝对量子产率的计算方法

与均相体系不同 ,多相光催化体系不能忽略催化剂颗粒对光子的散射 ,但严格求解光辐射传递方程在数学上是很困难的 .通常采用的输入光强计算表观量子产率的方法往往低估了真实的光量子产率 .本文针对带有柱状发光体圆筒形悬浆体系反应器 ,在做出一些合理的简化后 ,提出了一种以二氧化钛为催化剂在近紫外光辐照下多相光催化绝对量子产率的计算方法 .以苯酚为模型化合物 ,应用在典型反应器中光催化降解的实验结果 ,求得局域体积光子吸收速率 (LVRPA)在反应器内的分布 ,计算了绝对光量子产率 .表观量子产率与绝对量子产率相差7.08% ,约有1.1%输入光辐射从反应器筒壁上被淬灭 .本方法可用来评价不同催化剂或同一催化剂不同模型化合物的光催化效率 ,也为光催化反应器的设计提供了依据 .     

Moth pheromone binding proteins contribute to the excitation of olfactory receptor cells

Pheromone binding proteins (PBPs) occur in high concentrations in the sensillum lymph surrounding the sensory dendrites of moth pheromone-sensitive sensilla. They were shown to transport the lipophilic odorants through the aqueous sensillum lymph to the receptor cells. The sensilla trichodea of the silkmoth Antheraea polyphemus are supplied with three types of receptor cells responding specifically to three pheromone components. The sensillum lymph of these sensilla contains three different types of PBPs. In this study, recombinant PBPs in various combinations with pheromone components were applied to the receptor cells via tip-opened sensilla during electrophysiological recordings. The responses of receptor cells were shown to depend on both the pheromone component and the PBP. Pheromone components artificially bound to particular PBPs elicited nerve impulses in receptor cell types which they do not activate under natural conditions. This is the first electrophysiological study to suggest that the PBPs contribute to the activation of receptor molecules.     

Beetle adhesive hairs differ in stiffness and stickiness: in vivo adhesion measurements on individual setae

Leaf beetles are able to climb on smooth and rough surfaces using arrays of micron-sized adhesive hairs (setae) of varying morphology. We report the first in vivo adhesive force measurements of individual setae in the beetle Gastrophysa viridula, using a smooth polystyrene substrate attached to a glass capillary micro-cantilever. The beetles possess three distinct adhesive pads on each leg which differ in function and setal morphology. Visualisation of pull-offs allowed forces to be measured for each tarsal hair type. Male discoidal hairs adhered with the highest forces (919?±?104?nN, mean?±?SE), followed by spatulate (582?±?59?nN) and pointed (127?±?19?nN) hairs. Discoidal hairs were stiffer in the normal direction (0.693?±?0.111?N?m^?1) than spatulate (0.364?±?0.039?N?m^?1) or pointed (0.192?±?0.044?N?m^?1) hairs. The greater adhesion on smooth surfaces and the higher stability of discoidal hairs help male beetles to achieve strong adhesion on the elytra of females during copulation. A comparison of pull-off forces measured for single setae and whole pads (arrays) revealed comparable levels of adhesive stress. This suggests that beetles are able to achieve equal load sharing across their adhesive pads so that detachment through peeling is prevented.     

Decision rules for egg recognition are related to functional roles and chemical cues in the queenless ant Dinoponera quadriceps

The capacity to distinguish colony members from strangers is a key component in social life. In social insects, this extends to the brood and involves discrimination of queen eggs. Chemical substances communicate colony affiliation for both adults and brood; thus, in theory, all colony members should be able to recognize fellow nestmates. In this study, we investigate the ability of Dinoponera quadriceps workers to discriminate nestmate and non-nestmate eggs based on cuticular hydrocarbon composition. We analyzed whether cuticular hydrocarbons present on the eggs provide cues of discrimination. The results show that egg recognition in D. quadriceps is related to both age and the functional role of workers. Brood care workers were able to distinguish nestmate from non-nestmate eggs, while callow and forager workers were unable to do so. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

反硝化生物膜对PBS表面形态及化学组分的影响

PBS是一种新型的可生物降解聚合物(BDPs),可以用做反硝化碳源和生物膜载体,去除饮用水源水中的硝酸盐.利用红外光谱和扫描电子显微镜对反硝化生物膜生长前后PBS颗粒表面形态、化学组成的变化进行了分析.结果表明,PBS仅在微生物作用下降解并为反硝化菌提供碳源.PBS颗粒可以在12 h内使进水中53 mg·L^-1的硝态氮降低到10 mg·L^-1以下(我国饮用水水质标准为:NO₃^--N<15 mg·L^-1).红外光谱表明,反硝化微生物附着生长后其PBS在2 925 cm^-1和2 850 cm^-1附近的吸收带以及3 200 cm^-1～3 410 cm^-1处峰值减弱,说明PBS材料中甲基、羟基官能团比例下降,而其它官能团没有发生明显的变化,PBS的主要单体组分淀粉和乙烯都可以被反硝化微生物用作碳源.扫描电子显微镜观察结果表明,反硝化生物膜附着生长后,PBS颗粒表面会出现空洞,扩大了生物膜生物附着生长的表面积,有利于形成致密的反硝化生物膜,对反硝化菌形成保护作用.     

麦田O3干沉降过程及不同沉降通道分配的模拟

利用涡度相关系统对南京地区冬小麦田和裸土期O₃干沉降过程进行观测的基础上,引入Surfatm-O₃干沉降模型,对其叶片气孔阻力（R_s^leaf）、土壤阻力（R_soil）和表面阻力（R_cut）的公式进行参数化修订和验证,开展了冬小麦主要生育期的总O₃通量（F_O3）、干沉降速率（V_d）及其不同沉降通道分配的模拟,并间接分析了土壤排放的NO与O₃的化学反应对O₃干沉降过程的影响.结果表明：冬小麦田F_O3和V_d的实测值与模拟值趋势相似,平均实测和模拟V_d值分别为0.39和0.37cm/s,模拟值比实测值低估5.3%,其中每一个独立阻力公式的模拟效果均较好.平均非气孔沉降（表面沉降和土壤沉降）是O₃干沉降主要的沉降通道,占总O₃通量的68.8%,表面沉降占非气孔沉降的46.7%;平均绿叶和黄叶气孔沉降分别占总O₃通量的28.6%和2.6%.白天非气孔沉降比例减小至占总O₃通量的58.8%,绿叶和黄叶的气孔沉降比例比值增大,分别占总O₃通量的37.7%和3.5%.夜晚表面沉降和土壤沉降分别占总O₃通量的64.3%和35.7%.土壤排放的NO会与O₃产生化学反应,对O₃干沉降过程产生影响,需要在今后的O₃干沉降模型中考虑.     

Diet-dependent heat emission reveals costs of post-diapause recovery from different nutritional sources in a carnivorous beetle

Restoration of fat stores is metabolic first priority for many insects that emerge from hibernation with depleted fat bodies. To some extent, the animals must be flexible and use whatever foods available irrespective of their nutrient composition. Previously, the carabid beetles Anchomenus dorsalis have been found to refill their fat stores to the same extent over 9 days irrespective of the nutrient composition of their food. However, a higher cost of fat deposition when the food was rich in sugar or protein rather than lipid was indicated by higher total energy consumption. Here, we test the hypothesis of increased metabolic costs of building fat stores from sugar- or protein-rich food than from lipid-rich food by microcalorimetry. We measured the heat emitted from beetles that had fed on sugar-, protein-, or lipid-rich food for 0 (common control), 2, 5, or 10 days. As predicted, heat emission was increased in beetles getting sugar- and protein-rich food compared with those getting lipid-rich food. However, we did not confirm the beetles’ ability to rebuild fat stores from protein-rich food; instead, they increased in lean mass. Overall, sugar-rich food seems to be optimal for post-winter recovery, because it is better than lipid-rich food that allows concurrent rebuilding of fat stores and lean mass, which may benefit preparation for spring migration and reproduction. We propose that overwintered fruits may be highly preferred post-diapause food for these otherwise mostly carnivorous beetles.     

Sorption of 1-naphthol by plant cuticular fractions

The contribution of aliphatic-rich plant biopolymer to sorption of hydrophobic organic compounds is significantly important because of their preservation and accumulation in the soil environment,but sorption mechanism is still not fully understood.In this study, sorption of 1-naphthol by plant cuticular fractions was examined to better understand the contributions of respective fraction.Toward this end,cuticular materials were isolated from the fruits of tomato by chemical method.The tomato cuticle sheet consisted of waxes (6.5 wt%),cuticular monomer (69.5 wt%),and polysaccharide (24.0 wt%).Isotherms of l-naphthol to the cuticular fractions were nonlinear (N value (0.82-0.90)) at the whole tested concentration ranges.The KodKow ratios for bulk cuticle (TC1),dewaxed cuticle (TC2),cutin (TC4),and desugared cuticle (TC5) were larger than unity,suggested that tomato bulk cuticle and cutin are much powerful solption medium.Sorption capability of cutin (TC4) was 2.4 times higher than the nonsaponifiable fraction (TC3).The 1-naphthol interactions with tomato cuticular materials were governed by both hydrophobic-type interactions and polar (H-bonding) interactions. Removal of the wax and polysaccharide materials from the bulk tomato cuticle caused a significant increase in the sorption ability of the cuticular material.There was a linear negative trend between K_(oc) values and the amount of polysaccharides or fraction's polarities ((N O)/C);while a linear positive relationship between K_(oc) values and the content of cutin monomer (linear R~2=0.993) was observed for present in the cuticular fractions.Predominant sorbent of the hydrophobic organic compounds (HOCs) in the plant cuticular fraction was the cutin monomer,contributing to 91.7% of the total sorption of tomato bulk cuticle.