Radio-telemetric evidence of migration in the gregarious but not the solitary morph of the Mormon cricket (Anabrus simplex: Orthoptera: Tettigoniidae)

 The Mormon cricket, Anabrus simplex, is one of just a few species of katydids (or bushcrickets, Orthoptera: Tettigoniidae) that, like migratory locusts, appear to have solitary and migratory morphs. Using radio telemetry we studied movements of individuals of two morphs of this flightless species. Individuals within each migratory band had similar rates of movements along similar directional headings whereas solitary individuals moved little and showed little evidence of directionality in movement. Our results also add to other recent radio-telemetry studies showing that flightless insects of 1–2 g in mass can be tracked successfully using these methods. Received: 28 February 2000 / Accepted in revised form: 19 June 2000     

Effects of Serotonergic and Opioidergic Drugs on Escape Behaviors and Social Status of Male Crickets

 We examined the effects of selective serotonin depletion and opioid ligands on social rank and related escape behavior of the cricket Gryllus bimaculatus. Establishment of social rank in a pair of males affected their escape reactions. Losers showed a lower and dominants a higher percentage of jumps in response to tactile cercal stimulation than before a fight. The serotonin-depleting drug α-methyltryptophan (AMTP) caused an activation of the escape reactivity in socially naive crickets. AMTP-treated animals also showed a lower ability to become dominants. With an initial 51.6±3.6% of wins in the AMTP group, the percentage decreased to 26±1.6% on day 5 after injection. The opiate receptor antagonist naloxone affected fight and escape similarly as AMTP. In contrast to naloxone, the opioid agonist [d-Ala², N-Me-Phe⁴, Gly⁵-ol]-enkephalin decreased escape responsiveness to cercal stimulation in naive and subordinate crickets. We suggest that serotonergic and opioid systems are involved in the dominance induced depression of escape behavior. Received: 27 July 1998 / Accepted in revised form: 31 March 1999     

Male antenna morphology and its effect on scramble competition in false garden mantids

Well-developed antennae are crucial for many insects, but especially for scramble competitors, who race to find their mates using female sex cues. In these systems, the ability of males to locate females quickly is thought to be under strong selection. A rarely tested assumption is that males with more sensory structures are able to locate females faster. In the present study, we used the false garden mantid Pseudomantis albofimbriata to investigate male antennal morphology and its effect on male efficiency in finding a mate. We used scanning electron microscopy to describe the major sensilla types and their arrangement along the length of male antennae. We also conducted field enclosure trials relating male antennal morphology to scramble competition in this system. We identified six different types of antennal sensilla (cheatic, trichoid, basiconic, grooved peg, ceolocapitular and campaniform) on male P. albofimbriata antennae. As expected, males who had more trichoid sensilla located females quicker than did males with fewer sensilla. Results of the current study suggest that antenna morphology plays a significant role in mate location and hence scramble competition in the P. albofimbriata mating system.     

Evolution of a new sense for wind in flying phasmids? Afferents and interneurons

The evolution of winged stick insects (phasmids) from secondarily wingless ancestors was proposed in recent studies. We explored the cuticle of flying phasmids for wind sensors that could be involved in their flight control, comparable to those known for locusts. Surprisingly, wind-sensitive hairs (wsH) occur on the palps of mouthparts and on the antennae of the winged phasmid Sipyloidea sipylus which can fly in tethered position only when air currents blow over the mouthparts. The present study describes the morphology and major functional properties of these “new” wsH with soft and bulging hair bases which are different from the beaker-like hair bases of the wsH on the cerci of phasmids and the wsH described in other insects. The most sensitive wsH of antennae and palps respond with phasic-tonic afferents to air currents exceeding 0.2 ms⁻¹. The fields of wsH on one side of the animal respond mainly to ventral, lateral, and frontal wind on the ipsilateral side of the head. Afferent inputs from the wsH converge but also diverge to a group of specific interneurons at their branches in the suboesophageal ganglion and can send their integrated input from wsH fields of the palps and antennae to the thoracic central nervous system. Response types of individual wsH-interneurons are either phasic or phasic-tonic to air puffs or constant air currents and also, the receptive fields of individual interneurons differ. We conclude that the “new” wsH system and its interneurons mainly serve to maintain flight activity in airborne phasmids and also, the “new” wsH must have emerged together with the integrating interneurons during the evolution from wingless to the recent winged forms of phasmids.     

Olfaction in the female sheep botfly

The nasal botfly Oestrus ovis (Diptera, Cyclorrhapha: Oestridae) is a myiasis-causing insect species, which affects the health of sheep, goats and humans. Gravid females are viviparous and larviposit into the animal’s nostrils. Host-searching and larvipositing flies are visually guided and influenced by climatic conditions, whereas olfaction seemed to play no role in this process. However, here, we show that the antennae of adult O. ovis female flies are relatively small but well developed and inhabited by several types of olfactory sensilla. Further, we show that the antennal lobes of this species receive input from antennal afferents and consist of a clearly defined glomerular organisation. We also give the first evidence of the fly’s ability to detect several synthetic odour compounds. Our findings provide a morpho-functional basis for future investigations on olfactory-mediated behaviour of this insect pest.     

Irresistible bouquet of death—how are burying beetles (Coleoptera: Silphidae: Nicrophorus) attracted by carcasses

Chemical composition of volatiles emitted from fresh mouse carcasses (laboratory mice, Mus musculus) was studied using solid sample injection technique (solid-phase micro-extraction), two-dimensional gas chromatography with time of flight mass spectrometric detection and gas chromatography with electroantennographic detection. Electroantennography (EAG) and laboratory olfactometric behavioural observations were used to study the antennal sensitivity to identified infochemicals and their attractiveness for burying beetles Nicrophorus vespillo and Nicrophorus vespilloides (Silphidae: Nicrophorinae). Chemical analysis showed that immediately after death, emitted volatiles did not differ from those emitted by a living organism. However, in the course of time, sulphur-containing chemicals, specifically methanethiol, methyl thiolacetate, dimethyl sulphide, dimethyl disulphide and dimethyl trisulphide appear. EAG measurements revealed antennal sensitivity to these compounds. Behavioural tests in laboratory olfactometer showed that dimethyl sulphide, dimethyl disulphide and dimethyl trisulphide are highly attractive to both studied species. The data suggest that sulphur-containing chemicals are involved in mediating the fresh carcass attractiveness for N. vespillo and N. vespilloides.     

Optical Imaging of Odor-Evoked Glomerular Activity Patterns in the Antennal Lobes of the Ant Camponotus rufipes

 Ants have a well developed olfactory sense, which they need both for the perception of environmental chemicals, and for a highly sophisticated intraspecific communication system based on pheromones. The question arises therefore as to how different odors are coded in the antennal lobe, the first central neuropil to process olfactory information. We measured odor-evoked activity patterns using in vivo neuropil calcium recording in the antennal lobe of the ant Camponotus rufipes. We found that (a) odors elicit focal activity spots (diameter ca. 20 μm) which most probably represent the olfactory glomeruli; (b) different odors are coded in odor specific patterns of such activated spots, and a particular spot can participate in the pattern for different odors; (c) calcium increased in the activated spots within the 2-s stimulation period and slowly declined thereafter. Received: 10 March 1999 / Accepted in revised form: 5 July 1999     

Polarization-Sensitive Interneurons in the Optic Lobe of the Desert Ant Cataglyphis bicolor

 Desert ants, Cataglyphis bicolor (Hymenoptera), navigate by using compass information provided by skylight polarization. In this study, electrophysiological recordings were made from polarization-sensitive interneurons (POL-neurons) in the optic lobe of Cataglyphis. The POL-neurons exhibit a characteristic polarization opponency. They receive monochromatic input from the UV receptors of the specialized dorsal rim area of the compound eye. Both polarization opponency and monochromacy are features also found in the POL-neurons of crickets (Orthoptera). Received: 29 September 1999 / Accepted in revised form: 13 December 1999     

When males whistle at females: complex FM acoustic signals in cockroaches

Male cockroaches of the species Elliptorhina chopardi expel air through a pair of modified abdominal spiracles during courtship. This air expulsion simultaneously produces air and substrate-borne vibrations. We described and compared in details these two types of vibrations. Our analysis of the air-borne signals shows that males can produce three categories of signals with distinct temporal and frequency parameters. “Pure whistles” consist of two independent harmonic series fast frequency modulated with independent harmonics that can cross each other. “Noisy whistles” also possess two independent voices but include a noisy broad-band frequency part in the middle. Hiss sounds are more noise-like, being made of a broad-band frequency spectrum. All three call types are unusually high in dominant frequency (>5 kHz) for cockroaches. The substrate-borne signals are categorised similarly. Some harmonics of the substrate-borne signals were filtered out, however, making the acoustic energy centered on fewer frequency bands. Our analysis shows that cockroach signals are complex, with fast frequency modulations and two distinct voices. These results also readdress the question of what system could potentially receive and decode the information contained within such complex sounds.Electronic supplementary material  Supplementary material is available for this article at and is accessible for authorized users.     

Fire ant venom alkaloids act as key attractants for the parasitic phorid fly, Pseudacteon tricuspis (Diptera: Phoridae)

The phorid fly, Pseudacteon tricuspis Borgmeier, is an introduced parasitoid of imported fire ants, Solenopsis spp., in the USA. Although the assumption that phorid flies use fire ant alarm pheromones for host location is probably true, we demonstrated in a previous study the possible involvement of other ant semiochemicals in the response of P. tricuspis to fire ants. This study was conducted to determine the glandular sources and identity of the semiochemicals mediating this interaction. First, we tested the electroantennogram response of P. tricuspis to extracts of key body parts and glands of workers of the red imported fire ant, S. invicta Buren. The results confirm that the poison (venom) gland/sac is the key source of compounds which elicited strong antennal activity in P. tricuspis. Follow-up studies were conducted by using a combination of bioassay-guided fractionation and behavioral bioassays to test the hypothesis that attraction of this parasitoid to fire ants is mediated by venom alkaloids. The results confirm the response of P. tricuspis to physiologically relevant amounts of the two venom alkaloid fractions (cis and trans alkaloid fractions) of S. invicta. Further analysis by coupled gas chromatography–electroantennogram detection revealed nine venom alkaloid components including two novel 2,6-dialkylpiperideines that elicited significant antennal activity in P. tricuspis. This is the first demonstration of the role of venom alkaloids of ants as attractants for their natural enemies. We propose a semiochemical-mediated host location mechanism for P. tricuspis involving both alarm pheromones and venom alkaloids. The ecological significance of these findings, including the attraction of male P. tricuspis to fire ant venom alkaloids, possibly for mate location, is discussed.     

Tectonic and lithological constraints on the evolution of the Karoo graben of northern Malawi (East Africa)

The results of a lithostratigraphic, tectonic and kinematic study of the Karoo deposits of northern Malawi are reported. The objective of the lithostratigraphic study is to correlate the deposits of the Karoo basins of northern Malawi with the well-known deposits of southern Tanzania, thus establishing a stratigraphic framework through which the timing of faulting can be constrained. The kinematic analysis of faulting constrains the opening direction for the Karoo graben in this area and provides basic data to discuss the Karoo graben development within the regional tectonic framework of south-eastern Africa. The studied faults are defined by moderately to steeply dipping cataclastic zones with a width of up to 15?m and are characterized by an array of slickensided fault surfaces with different orientations and slip directions. In this study, small faults (offset <10?m) and meso-scale faults (offset >10?m, but generally not exceeding 30–40?m) have been distinguished. Methods used to analyse the kinematic data include the 'pressure tension' (PT) method, which estimates the principal axes for the bulk brittle strain, and the internal rotation axis (IRA) method, which estimates the axis of bulk internal rotation and the overall sense of slip at the faults. A mass balance calculation reveals a volume increase of up to 16% during cataclastic deformation in the fault zones. The PT method shows an approximately east trending extension direction for faults that occur only in the latest Carboniferous (?) and Early Permian strata, whereas the fault kinematics from faults that cut middle Permian to Early Triassic rocks is characterized by a ESE to SE trending extension direction. The small faults yield essentially the same kinematic results as the meso-scale faults. In a transport-parallel cross-sectional view, the principal extension axes are at an acute angle of approximately 60° to the major fault planes. Given the moderate fault density, the relatively high angle between the orientation of the principal extension axis and the fault planes suggest only a moderate amount of horizontal extension across the Karoo graben of northern Malawi. Riedel structures in the fault zones formed within two conjugate sets of localized shear zones; slip on one set was top to the W/NW and, on the other, top to the E/SE. The two conjugate sets of Riedel structures have an acute angle about the regional shortening axes, implying that no pronounced rotation of the strain axes occurred. The internal rotation axes for the Riedel structures reveal a largely bimodal distribution and inferred weakly monoclinic to orthorhombic symmetry. Therefore the overall deformation during Karoo rifting in northern Malawi is interpreted to be close to a coaxial deformation with a limited amount of horizontal extension.     

Male-produced anti-sex pheromone in a plant bug

In plant bugs (Miridae), females produce sex pheromones in the metathoracic scent gland, which in most other true bugs (Heteroptera) is responsible for chemical defense. The possibility that the metathoracic gland secretion of male plant bugs plays a role other than defense has been largely overlooked. Here we show that in a pine-inhabiting mirid, Phytocoris difficilis Knight, hexyl butyrate and (E)-2-hexenyl butyrate are abundantly produced only in males; we demonstrate that these metathoracic gland compounds elicit strong antennal responses in conspecific males, and that these butyrates totally interrupt attraction of males to the female-produced sex pheromone. Our results suggest that in at least some plant bugs the male metathoracic scent gland esters have a natural communicative function as anti-sex pheromones, probably to interrupt further mating attempts by other males.     

Numerical model of flow and pollutant transportation in non-orthogonal curvilinear coordinates

The planar 2D k-ε double equations‘ turbulence model was adopted and transformed into non-orthogonal curvilinear coordinates. The concentration convection-diffusion was introduced to planar 2D SIMPLEC algorithm of flow in non-orthogonal curvilinear coordinates. The numerical model of pollutant transportation in non-orthogonal curvilinear coordinates was constructed. The model was applied to simulate the flow and pollutant concentration fields. In the testing concentration field, two optimal operations of contamination discharging both along bank and in the centerline at the first bend of the meandering channel were adopted. Comparison with available data showed the model developed was successful, was valuable to engineering application.     

Coming of age in an ant colony: cephalic muscle maturation accompanies behavioral development in <Emphasis Type="Italic">Pheidole dentata</Emphasis>

Although several neurobiological and genetic correlates of aging and behavioral development have been identified in social insect workers, little is known about how other age-related physiological processes, such as muscle maturation, contribute to task performance. We examined post-eclosion growth of three major muscles of the head capsule in major and minor workers of the ant Pheidole dentata using workers of different ages with distinct task repertoires. Mandible closer muscle fibers, which provide bite force and are thus critical for the use of the mandibles for biting and load carrying, fill the posterio-lateral portions of the head capsule in mature, older workers of both subcastes. Mandible closer fibers of newly eclosed workers, in contrast, are significantly thinner in both subcastes and grow during at least the next 6 days in minor workers, suggesting this muscle has reduced functionality for a substantial period of adult life and thus constrains task performance capability. Fibers of the antennal muscles and the pharynx dilator, which control antennal movements and food intake, respectively, also increase significantly in thickness with age. However, these fibers are only slightly thinner in newly eclosed workers and attain their maximum thickness over a shorter time span in minors. The different growth rates of these functionally distinct muscles likely have consequences for how adult P. dentata workers, particularly minors, develop their full and diverse task repertoire as they age. Workers may be capable of feeding and interacting socially soon after eclosion, but require a longer period of development to effectively use their mandibles, which enable the efficient performance of tasks ranging from nursing to foraging and defense.     

<Emphasis Type="BoldItalic">Osedax</Emphasis> borings in fossil marine bird bones

The bone-eating marine annelid Osedax consumes mainly whale bones on the deep-sea floor, but recent colonization experiments with cow bones and molecular age estimates suggesting a possible Cretaceous origin of Osedax indicate that this worm might be able grow on a wider range of substrates. The suggested Cretaceous origin was thought to imply that Osedax could colonize marine reptile or fish bones, but there is currently no evidence that Osedax consumes bones other than those of mammals. We provide the first evidence that Osedax was, and most likely still is, able to consume non-mammalian bones, namely bird bones. Borings resembling those produced by living Osedax were found in bones of early Oligocene marine flightless diving birds (family Plotopteridae). The species that produced these boreholes had a branching filiform root that grew to a length of at least 3 mm, and lived in densities of up to 40 individuals per square centimeter. The inclusion of bird bones into the diet of Osedax has interesting implications for the recent suggestion of a Cretaceous origin of this worm because marine birds have existed continuously since the Cretaceous. Bird bones could have enabled this worm to survive times in the Earth’s history when large marine vertebrates other than fish were rare, specifically after the disappearance of large marine reptiles at the end-Cretaceous mass extinction event and before the rise of whales in the Eocene.     

Visual targeting of components of floral colour patterns in flower-naïve bumblebees (Bombus terrestris; Apidae)

Floral colour patterns are contrasting colour patches on flowers, a part of the signalling apparatus that was considered to display shape and colour signals used by flower-visitors to detect flowers and locate the site of floral reward. Here, we show that flower-naïve bumblebees (Bombus terrestris) spontaneously direct their approach towards the outside margin of artificial flowers, which provides contrast between these dummy flowers and the background. If no floral guides are present, the bumblebees continue to approach the margin and finally touch the marginal area of the dummy flower with the tips of their antennae. Whilst approaching dummy flowers that also have a central floral guide, the bumblebees change their direction of flight: Initially, they approach the margin, later they switch to approaching the colour guide, and finally they precisely touch the floral guide with their antennae. Variation of the shape of equally sized dummy flowers did not alter the bumblebees’ preferential orientation towards the guide. Using reciprocal combinations of guide colour and surrounding colour, we showed that the approach from a distance towards the corolla and the antennal contact with the guide are elicited by the same colour parameter: spectral purity. As a consequence, the dummy flowers eliciting the greatest frequency of antennal reactions at the guide are those that combine a floral guide of high spectral purity with a corolla of less spectral purity. Our results support the hypothesis that floral guides direct bumblebees’ approaches to the site of first contact with the flower, which is achieved by the tips of the antennae.Electronic Supplementary Material  Supplementary material is available for this article at     

基于主成分分析和FCM聚类的行驶工况研究

在定义了运动学片段的基础上,对典型道路上采集的大量工况试验数据进行划分,从而获得大量运动学片段.用主成分分析法对12个表征道路运行特征的参数(包括加速比例、减速比例、匀速比例、怠速比例、平均速度、平均运行速度、最大速度、平均加速度、最大加速度、最小加速度、速度标准偏差和加速度标准偏差)进行压缩,得到4个主成分.利用模糊C均值聚类技术对所有运动学片段的第一和第二主成分得分进行分类,根据相关系数的大小及各类别的时间长度比选取合适片段,最终拟合出代表性工况.通过对特征参数和速度、加速度联合概率分布的误差分析可知,所提出的构建方法精度较高,拟合工况能综合反映合肥市实际道路的交通状况.      

The ladybird<Emphasis Type="Italic"> Thalassa saginata</Emphasis>, an obligatory myrmecophile of<Emphasis Type="Italic"> Dolichoderus bidens</Emphasis> ant colonies

The larvae and pupae of the ladybird Thalassa saginata develop inside colonies of the dolichoderine ant Dolichoderus bidens. This association is the first specific and obligatory relationship recorded between ants and ladybirds. The ants provide shelter and protection to the larvae but the diet of the latter remains unclear. The integration of T. saginata larvae into the ant colonies is achieved by mimicking the cuticular patterns of the ants brood. Moreover, the larvae secrete substances from their hairs and anal gland that are likely to enhance their attractiveness.     

20世纪唐代蝗灾研究综述

作为中国古代三大自然灾害之一,蝗灾一直受人类关注。对中国历史上的蝗灾,虽然20世纪前期就开始多学科知识结合研究,但往往因时间跨度太长而不细致,直到90年代之后才开始具体探讨某个朝代的蝗灾情况。对于唐代蝗灾的研究前人已经取得一定成果,但还有某些方面存在不足,了解唐代蝗灾研究状况对我们进一步研究全面蝗灾有很大意义,本文就唐代蝗灾的研究情况作一简要的综述。     

基于斜投影算子的引信抗主瓣干扰方法

目的 利用信号极化域信息滤除干扰信号,解决回波阵列期望信号和主瓣干扰信号的入射角一致导致空域滤波抗干扰失效的问题。方法 由于主瓣干扰信号的极化状态通常是未知的,为此提出基于斜投影的抗主瓣干扰方法。该方法利用极化域–空域联合谱多信号分类算法,估计主瓣干扰信号的极化状态。然后,利用期望信号和主瓣干扰信号极化状态的差异,通过构造斜投影算子,处理阵列接收数据,从而滤除主瓣干扰信号。结果 当主瓣干扰导向矢量失配,或者期望信号与主瓣干扰信号的极化状态满足一定程度的差异时,基于斜投影的抗主瓣干扰方法均取得良好效果。结论 基于斜投影的抗主瓣干扰方法具有稳定性好、鲁棒性强等优点,可应用于雷达、无线电引信等系统对主瓣干扰的抑制,提升雷达、无线电引信等系统适应复杂电磁环境的能力。