Biogeographical variation in the harvestman Mitopus morio (Opiliones, Arachnida)

The taxonomic status of three forms of the harvestman Mitopus morio in Britain have been examined. These have been identified by previous workers as a small, upland M, morio cinerascens , a larger, lowland M. morio morio , and a northern M. morio borealis. In this paper, the delimitation of trinomials has been found to be inappropriate for M. morio. since all three forms have been shown to lie at different points on a continuum of phenotypic variation within the species M. morio. It is suggested that this phenotypic variation is mediated by the variation in temperature regimes between different localities.     

Seasonal habitat selection and temporal activity patterns determine the structure of bat assemblages in Dhana Biosphere Reserve,Jordan (Mammalia: Chiroptera)

We measured species richness, diversity, and diel activity patterns of insectivorous bats at four sites within Dhana Biosphere Reserve. A total of seven species belonging to five families at varying species compositions were recorded. Four to six species were present at these sites and total diversity ranged between 0.32 at Ain Lahtha and 0.65 at Al Khararah. Overall frequency of passes was highest at Shaq Kalbeh. The Common Pipistrelle, Pipistrellus pipistrellus, was the most prevalent at three sites, followed by the Arabian Horseshoe Bat, Rhinolophus clivosus, and Botta’s Serotine, Eptesicus bottae. Natterer’s Bat, Myotis nattereri, and the European Free-tailed Bat, Tadarida teniotis, occurred at low abundance. The Lesser Horseshoe Bat, Rhinolophus hipposideros, occurred at a higher abundance within Finan site (arid site at lower altitude), whereas the Egyptian Mouse-tailed Bat, Rhinopoma cystops, was restricted to Finan. The overall mean number of bat passes was not significantly different between sites. Average seasonal species diversity was low during winter (none at Ain Lahtha and Shaq Kalbeh) and highest during summer (0.68 at Al Kharrarah). Seasonal activity patterns for each site in terms of frequencies of bat passes on an hourly basis are given.     

External ultrastructure of sensory organs in the subfamily lrumuinae (Arachnida, Opiliones, Assamiidae)

The external ultrastructure of sensory organs in edaphic reprerentatives of the subfamily Irumuinae is described. The types of receptor are either bristle-shaped or bulbiform. The bristle-shaped receptors occur on the ventral side of the coxae and displace sensory hairs there. The bulbiform ones are distributed over the scute and on proximal joints (femur, trochanter) of legs. These structures are considered as adaptations to the soil environment.     

Influence of environmental factors on number dynamics and spatial structure of the tur (Capra caucasica) population in the Caucasian Reserve

The number and structure of the tur (Capra caucasica Guldenstaedt et Pallas 1783) population on the territory of Caucasian Reserve (Western Caucasus), as well as peculiarities of the effect of natural and anthropogenic factors on the population, were studied based on ideas of meta-population species dynamics. Fourteen local tur groupings were united into three groups by the similarity of long-term number dynamics. A negative effect of winter, which deviated from the average long-term winter by the level of snowiness, on the tur population was detected. Snowy winters damage not only males (that frequently die in avalanches), but also affect the birth rate subsequently; the portion of females, in spite of the male death, decreases anyway two years after winter, as well as the portion of underyearlings. It was demonstrated that the snowy winter effect is manifested only when the animal density is rather high. The following tendency was detected for the tur population: the greater the density before the winter, the larger the decrease in the animal density after it (and this tendency weakens one year after the winter). Wolf predation has no negative effect on the tur population in the reserve. A maximal association between the tur density and wolf density was found at a tur density up to 50 individuals/1000 hectares. With a further increase in the victim density, the wolf density changes independently of the tur density. Turs in the reserve are not easily accessible to poachers due to habitat peculiarities, and therefore, the role of poaching in the dynamics of their numbers is not significant.     

Electron microscope study on the meiotic cycle of Acanthopachylus aculeatus (Arachnida; Opiliones)

Summary The primary spermatocytes of an Opilionid, Acanthopachylus aculeatus show (at least as a rule) two bodies which in longitudinal sections appear as integrated of up to 12 dark bands each about 300 Å wide, interlaced with one another by a curtain of thin filaments. The same bodies appear in transversal sections as formed by an hexagonal lattice the nodal points of which are the cross sections of the dark bands. The study of spermatocytes at early prophase demonstrated that at the inception these bodies are formed by association of several structures comparable to those observed in the axis of paired autosomes and called synaptinemal complexes.The findings in this species are compared with their similar in other species, particularly with species of Gryllidae.This investigation was supported by United States Public Health Service Research Grant GM 08337 from the Research Grants Branch, Division of Medical Sciences, and partly by Grant RF 61034 from The Rockefeller Foundation.     

Harvestmen of the BOS Arthropod Collection of the University of Oviedo (Spain) (Arachnida,Opiliones)

There are significant gaps in accessible knowledge about the distribution and phenology of Iberian harvestmen (Arachnida: Opiliones). Harvestmen accessible datasets in Iberian Peninsula are unknown, an only two other datasets available in GBIF are composed exclusively of harvestmen records. Moreover, only a few harvestmen data from Iberian Peninsula are available in GBIF network (or in any network that allows public retrieval or use these data). This paper describes the data associated with the Opiliones kept in the BOS Arthropod Collection of the University of Oviedo, Spain (hosted in the Department of Biología de Organismos y Sistemas), filling some of those gaps. The specimens were mainly collected from the northern third of the Iberian Peninsula. The earliest specimen deposited in the collection, dating back to the early 20^th century, belongs to the P. Franganillo Collection. The dataset documents the collection of 16,455 specimens, preserved in 3,772 vials. Approximately 38% of the specimens belong to the family Sclerosomatidae, and 26% to Phalangidae; six other families with fewer specimens are also included. Data quality control was incorporated at several steps of digitisation process to facilitate reuse and improve accuracy. The complete dataset is also provided in Darwin Core Archive format, allowing public retrieval, use and combination with other biological, biodiversity of geographical variables datasets.     

Costs and benefits of freezing behaviour in the harvestman Eumesosoma roeweri (Arachnida, Opiliones)

Animals present an enormous variety of behavioural defensive mechanisms, which increase their survival, but often at a cost. Several animal taxa reduce their chances of being detected and/or recognized as prey items by freezing (remaining completely motionless) in the presence of a predator. We studied costs and benefits of freezing in immature Eumesosoma roeweri (Opiliones, Sclerosomatidae). Preliminary observations showed that these individuals often freeze in the presence of the syntopic predatory spider Schizocosa ocreata (Araneae, Lycosidae). We verified that harvestmen paired with predators spent more time freezing than when alone or when paired with a conspecific. Then, we determined that predator chemical cues alone did not elicit freezing behaviour. Next, we examined predator behaviour towards moving/non-moving prey and found that spiders attacked moving prey significantly more, suggesting an advantage of freezing in the presence of a predator. Finally, as measure of the foraging costs of freezing, we found that individuals paired with a predator for 2 h gained significantly less weight than individuals paired with a conspecific or left alone. Taken together, our results suggest that freezing may protect E. roeweri harvestmen from predatory attacks by wolf spiders, but at the cost of reduced food and/or water intake.     

Maternal care, defensive behavior, and sociality in neotropical Goniosoma harvestmen (Arachnida, Opiliones)

Summary: Goniosoma includes large and conspicuous species of harvestmen that occur exclusively in the Brazilian Atlantic forest. This paper reports on the parental activities, defensive behavior, and gregariousness of five species of Goniosoma, and also summarizes the published biological data for the genus. The behavioral patterns within the genus are discussed and a hypothesis for the emergence of gregariousness in the group is presented. Several Goniosoma live inside caves, mainly as trogloxenes. Although species of the genus comprise only 5% of the harvestmen fauna in Brazil, they account for 20.6% of all harvestmen species recorded in Brazilian caves. In addition to several morphological and physiological features that may favor the occupation of caves, species of Goniosoma also present subsocial behavior, which may confer a special advantage in this particular environment. Female protection is crucial for egg survival since predators may consume entire batches in a single night. Most species of Goniosoma form dense diurnal aggregations ranging from three to 200 individuals (mainly subadults and adults of both sexes). In a hypothetical scenario for the evolution of sociality in the Goniosoma, physiological constraints acting on individual harvestmen would lead to a behavioral response for the selection of sites with appropriate microclimatic conditions. The lack of cannibalism among adults and subadults may favor tolerance towards conspecifics, and may represent a pre-adaptation to gregariousness. The derived functions of gregarious behavior may include strengthening of the defensive signal through the collective release of a repugnant secretion, the dilution effect, and promptness in fleeing a predator attack as a consequence of the additional alarm role of scent gland secretions. These defensive functions may overcome the costs of group living and may be responsible for the maintenance of gregariousness in Goniosoma.     

Evolution of hyperflexible joints in sticky prey capture appendages of harvestmen (Arachnida,Opiliones)

The rigid leg segments of arthropods are flexibly connected by joints, which usually consist of two ball-and-bowl hinges, permitting a uniaxial pivoting up to 140°. Here, we report the occurrence of hyperflexible joints (range of movements?=?160–200°) in the pedipalps (second pair of appendages) of some harvestmen (Sabaconidae and Nemastomatidae), representing some of the most flexible leg joints among arthropods. Hyperflexion is achieved by a reduction of hinges and a strong constriction of the joint region. We demonstrate that hyperflexion occurs during prey capture and is used to clamp appendages of the prey, in addition to attachment by glue secreted by specialized setae. By means of high-speed video recordings, we found that in the Sabaconidae the tibiotarsal joint of the pedipalp can flex extremely rapidly (<5 ms), limiting prey escape. This is the fastest reported predatory strike in arachnids and caused both by leverage and a click mechanism. By comparative analysis of different related taxa, we retraced joint evolution and found that hyperflexion has independently evolved in Sabaconidae and Nemastomatidae, with totally different joint kinematics. We hypothesize that (rapid) hyperflexion evolved to enhance the efficiency of the pedipalp as a means of prey capture, because in springtails detachable scales limit the action of the sticky secretion of pedipalpal setae.     

Spatial distribution, population structure, and fecundity ofCeratozamia matudai lundell (Zamiaceae) in El Triunfo Biosphere Reserve, Chiapas, Mexico

We describe the spatial distribution, population structure, and fecundity ofCeratozamia matudai in two populations in the El Triunfo Biosphere Reserve, in Chiapas, Mexico. Three random plots of 20 × 20 m were laid out in a cypress forest habitat of the cycad and six plots in a cloud forest habitat on Mount Ovando. The aggregated spatial pattern ofC. matudai showed a clumped local distribution on shallow soils on steep slopes. Individuals between the sites showed differences in leaf production, trunk diameter, height, and growth pattern. A population structure with an inverse “J” curve was obtained in both sites. Emergence of male and female cones appears to be synchronous in both populations, with a predominance of male cones recorded.     

An exquisitely preserved harvestman (Arthropoda,Arachnida, Opiliones) from the Middle Jurassic of China

Sclerosomatids constitute the largest family of the arachnid order Opiliones, and one of the two families commonly found in the temperate regions of the northern Hemisphere. Harvestmen have a sparse fossil record in the Mesozoic, with only two species known from the Jurassic, one of them poorly preserved and none with precise phylogenetic placement. Here we report a new fossil, Mesobunus dunlopi sp. nov., from the Middle Jurassic (approx. 165 Mya) of Daohugou, Inner Mongolia, China. The new species is related to another genus of the same formation, but the preservation quality and details of the penis and pedipalps allow us to place them in the extant sclerosomatid subfamilies Gagrellinae or Leiobuninae. The first recognisable fossil in this subfamily highlights morphological stasis over ca. 165 Mya and the finding of this species along with lacustrine insects suggests a life mode similar to that of some modern sclerosomatids, and a possible connection between morphological and ecological stasis.     

Chemical and behavioral defenses of the neotropical harvestman Camarana flavipalpi (Arachnida: Opiliones)

The defensive secretion of the harvestman Camarana flavipalpi (Gonyleptidae) was chemically characterized, revealing the presence of a single, highly volatile component (2-methyl-5-ethyl-phenol). Individuals do not frequently use chemical defenses and rely mainly on thanatosis as defense. Two types of emission of secretions were recorded: a globule at the gland opening without liquid displacement and liquid displacement along the lateral margins of the dorsal scute with accumulation of fluid at the lateroposterior area of the body. The anterior opening of the ozopore is covered by an integumentary dome that faces the laterodorsal area of the scute. The lateral channel is well defined near the opening of the ozopore and along the lateral margin of the dorsal scute as rows of small granules. The ozopore morphology of C. flavipalpi is similar to closely related species and simplified when compared with other species that promptly release chemical secretions.     

Comparative Density of Hair Sensilla on the Legs of Cavernicolous and Epigean Harvestmen (Arachnida: Opiliones)

To allow an animal to behave appropriately, the location of sensorial structures is expected to be related to their function. As the different leg pairs of arachnids may have different functions (probing x supporting the body), one could expect them to have a different density of sensilla. Moreover, different regions of the same leg (dorsal, lateral, and ventral) would also be expected to have different densities of sensilla, according to the use of each region (e.g., the ventral part is often in contact with the substrate while the dorsal part is not). As cavernicolous animals are expected to be more sensitive than their epigean relatives, one could also expect a different density of sensilla when comparing cavernicolous and epigean animals. Using three epigean and three cavernicolous species of harvestmen (Arachnida, Opiliones), this study aimed at describing the morphology of hair sensilla on the legs and answering three questions: (1) Are there differences in the density of hair sensilla between the dorsal, lateral and ventral regions of each leg pair of the same individual? (2) Are there differences in the density of hair sensilla between the leg pairs of the same individual? (3) Are there differences in the density of hair sensilla when comparing the leg pairs of individuals of cavernicolous and non-cavernicolous species? The tarsi and metatarsi of all right legs of the six studied species were analyzed under a scanning electron microscope. The results (P < 0.05) showed that, in general: the ventral region of the tarsus was denser in sensilla trichodea than the lateral and dorsal regions, particularly on legs I and II; the density of sensilla chaetica did not differ on legs III and IV, but was greater on the dorsal region of legs I and II; the ventral part of legs I had the higher density of sensilla trichodea of the four pairs, whereas the second pair had the lower density; Holcobunus citrinus (Eupnoi) was the species with higher density of sensilla trichodea, on all legs; the cavernicolous species had a lower density of sensilla than the epigean species. The results are tentatively related to harvestmen behavior.     

Neotropical harvestmen (Arachnida,Opiliones) use sexually dimorphic glands to spread chemicals in the environment

Sexually dimorphic glands have convergently appeared in animals and are often responsible for the production of pheromones. In the suborder Laniatores of the order Opiliones (Arachnida), glands of such type are widespread, but there is not a single paper on how they are used. Using Scanning Electron Microscopy and a behavioral approach, we describe glandular openings and how these glands are used, in the harvestmen Gryne perlata and Gryne coccinelloides (Cosmetidae). Males of these two species have glandular openings on the metatarsi of legs I and on the metatarsi IV. Males were shown rubbing the glands of the metatarsi I against their other legs, whereas glands on the metatarsi IV are gently touched on the substrate or rubbed either against other legs, or against the substrate. Not all behaviors were seen in both species.     

Dormant stages and their participation in adjustment and regulation of life cycles of harvestmen (Arachnida,Opiliones)

Information on seasonal adaptations in the life cycles of harvestmen (order Opiliones) summarized in this review reveals a great diversity of these arachnids with respect to duration, voltinism, and phenology of their life cycles, as well as to the number and ontogenetic position of the dormant stages required for survival during the winter season and also for synchronizing development with seasonal climate rhythms. Most harvestmen have stenochronous development with univoltine life cycles synchronized by arrest of development in hibernating eggs or (rarely) diapausing nymphs and adults. The number and arrangement of dormant stages represent stable species-specific traits, with some rare cases of interpopulation differences (e.g., in Phalangium opilio). Eurychronous harvestmen exhibit the year-round occurrence of main ontogenetic stages which show equal abilities for either active development or quiescence (depending upon the external factors). Two alternative types of development arrest are common in univoltine opilionids: (1) diapause induced at the early stage of embryogenesis and terminated during cooling (in Opilio parietinus and eleven other species) with transformation into postdiapause quiescence; (2) cold quiescence enforced by low temperatures at the last stage of egg development just before hatching (in Phalangium opilio and four other species). In conclusion, the systems of seasonal adaptations in Opiliones are compared with those in other arachnids, insects, and crustaceans. Some promising directions in the study of seasonal adaptations in opilionid life cycles are suggested.     

Seasonal aspects of the life cycle of solifuges (Arachnida, Solifugae) as compared with pseudoscorpions (Arachnida, Pseudoscorpiones)

Solifuges (order Solifugae) and pseudoscorpions (order Pseudoscorpiones) united into the superorder Haplocnemata (Shultz, 2007) are nevertheless characterized by essential differences both in morphological and biological characters. Analysis of available information on the biology and life cycles of these arachnids revealed a clear difference between the daily rhythms of activity: their presence in solifuges and their absence in pseudoscorpions. However, this concerning the seasonal adaptations in the two orders is not simple since they demonstrate not only differences but also a lot of similarities. All the studied solifuges are characterized by the seasonally timed stenochronous (heterodynamic) type of development which is characteristic of species with uni-, bi-, and semi-voltine development (i.e., to life cycles completed within a year, half a year, and several years), as well as to species combining different forms of voltinism. This type of development is not only prevalent in solifuges (as in pseudoscorpions and other arachnids) but appears to be the only one, since no cases of eurychronous (homodynamic) development have been found in solifuges; whereas pseudoscorpions and other arachnids develop both steno- and eurychronously. The initial ontogenetic stages remain in underground shelters (brood burrows in solifuges and brood chambers in pseudoscorpions). The first nymphal stages (I instar nymphs in solifuges, protonymphs in pseudoscorpions) are embryonized; active life outside the brood burrows starts with II instar nymphs in solifuges and with deutonymphs in pseudoscorpions.     

Geographic and seasonal variations of the number of B chromosomes and external morphology in Psathyropus tenuipes (Arachnida: Opiliones)

Psathyropus tenuipes (= Metagagrella tenuipes) is a harvestman that harbors B chromosomes with extremely high frequency (individuals without Bs are only 1% of the total number of specimens so far examined) and high numbers (mean number of Bs per individual is about 4). Geographic variations of the number of Bs and external morphology of the species and the relationship between them were studied. A northward increase in the number of Bs was detected throughout the Japanese Islands, though the number also varied considerably locally. Latitudinal gradients were also found in some external characters, while there were no correlations between those external morphologies and the number of Bs. Principal component analysis using eight morphological data for 21 populations revealed four geographical groups that reflect actual location of the populations. Populations along the Seto Inland Sea were characterized by a lower number of Bs than those in other areas. Seasonal change was also found in a population (Yatsukami in western Honshu) in both 1994 and 1995 for the number of Bs, though the number in the same population was stable at least throughout later postembryonic stages in both 1997 and 1998. Embryos contained fewer numbers of Bs than adults, suggesting that females of the species tend to lay eggs with fewer numbers of Bs.     

Blackflies (Diptera, Simuliidae) of the Lapland State Biosphere Nature Reserve, with description of a new species of the genus Argentisimulium Rubzov et Yankovsky, 1982

Eleven blackfly species were collected in the southern part of the Lapland State Biosphere Nature Reserve. Among these, six species, Prosimulium macropyga (Lundström, 1911), Boreosimulium annulus (Lundström, 1911), Schoenbaneria pusilla (Fries, 1824), Odagmia rotundata Rubzov, 1956, Archesimulium tuberosum (Lundström, 1911), and Argentisimulium noelleri (Friederichs, 1920) are common in this region; Archesimulium polare (Rubzov, 1940) is recorded from the Kola Peninsula for the first time; Gnus decimatum (Dorogostajsky et al., 1935) is recorded from the northern part of European Russia for the first time. A new species, Argentisimulium tshuni sp. n., is described from the male, larva, and pupa. The diagnostic characters of the new species are as follows. The male differs from those of the all other species in the presence of a conical projection in the distal part of the gonostylus, absence of an apical spine, presence of one very large spine in the parameres, and shorter gonostylus. In addition, the male differs from most of the congeners in the obsolete basal wrinkled part of the gonofurca. The larva differs from those of the majority of the related species in the presence of only one row of the inner mandibular spines. Records of two species, Helodon ferrugineus (Wahlberg, 1844) and Stegopterna trigonia (Lundström, 1911), identified from a few early-instar larvae, need confirmation. The type material of the new species is deposited at the Zoological Institute, Russian Academy of Sciences, St. Petersburg.