Search results for "Opilio"

2017

By the possession of unique exocrine scent glands, Opiliones (harvestmen) arise as a perfect model for studies on the evolutionary history of secretion chemistry. Among gland compounds of harvestmen, it is the quinones that represent recurring elements across the secretions of all suborders. Reliable data on quinone-distribution, however, is only known for Laniatores (benzoquinones) and Cyphophthalmi (naphthoquinones). We here unraveled the quinone-distribution across scent gland secretions of the third large harvestman suborder, the Palpatores (= Eu- and Dyspnoi): Naphthoquinones were found in phalangiid Eupnoi across all subfamilies as well as in nemastomatid (and at least one ischyropsal…

Cover crop differentially affects arthropods, but not diseases, occurring on grape leaves in vineyards

2017

Background and Aims Cover crop has become a common management practice in viticulture. It improves the structure and protects the soil, enhances natural enemy populations and also reduces the vigour of the vine. Here, we investigated the effect of cover crop in vineyards on grapevine diseases and arthropods present on leaves. Methods and Results We measured the presence of the pathogens Plasmopara viticola, Uncinula necator and Guignardia bidwellii and monitored six common beneficial/pest arthropods: Panonychus ulmi, Orthotydeus lambi, Typhlodromus pyri, Scaphoideus titanus and Phalangium opilio in vineyards with cover crop or bare soil in 2014 and 2015. The density of the two pests P. ulmi…

The Leiobunum rupestre species group: resolving the taxonomy of four widespread European taxa (Opiliones: Sclerosomatidae)

2016

Within the central European opilionid fauna the widely used species names Leiobunum rupestre Herbst, 1799 and Leiobunum tisciae Avram, 1968 pose taxonomic and distributional problems. In addition, Nelima apenninica Martens, 1969 is close to L. tisciae in terms of external and genital morphology, but is specifically distinct. While coxal denticulation is largely lacking in N. apenninica, the validity of the genus Nelima Roewer, 1910 is questioned again. In addition, Leiobunum subalpinum Komposch, 1998, a recently described novelty from the eastern Alps, is closely related to L. rupestre. The four species are combined as the morphologically defined Leiobunum rupestre species group. Except for…

A mysterious dwarf: Suthepiidae nov. fam., a new harvestman family from mountains of northern Thailand (Arachnida: Opiliones: Laniatores)

2020

A new family of laniatorean harvestmen from northern Thailand is proposed, Suthepiidae fam. nov., which comprises one new genus and one new species, Suthepia inermis sp. nov. This family stands out by characters hitherto unknown or rarely recorded for Opiliones, and close relatives of this taxon are presently not discernible. Important characters are a short and compact penis with a massively enlarged distal part with a rich armament of sclerites and membranes which can be moved and everted by hemolymph pressure during mating; the pedipalp of males and females is without raptorial adaptations, i.e. elevated sockets (= apophyses) carrying strong distal spines are completely absent, therefore…

Sexually dimorphic tegumental gland openings in Laniatores (Arachnida, Opiliones), with new data on 23 species

2009

International audience; Sexually dimorphic glands often release sexual pheromones both in vertebrates and invertebrates. Species of Laniatores (Arachnida, Opiliones) seem to depend on chemical communication but few studies have addressed this topic. In this study, we review the literature for the Phalangida and present new data for 23 species of Laniatores. In 16 taxa, we found previously undescribed sexually dimorphic glandular openings on the femur, patella, metatarsus, and tarsus of legs I and metatarsus of legs III and IV. For the other species, we provide scanning electron micrographs of previously undescribed sexually dimorphic setae and pegs located on swollen regions of the legs. We…

The arthropod community of boreal Norway spruce forests responds variably to stump harvesting

2016

Forest fuel harvesting increases the need to collect not just logging residues but also tree stumps from harvested stands. This biomass removal has raised concern over forest biodiversity. Here, the effects of stump harvesting on spiders, ants, harvestmen, ground beetles and epiedaphic springtails occupying boreal Norway spruce (Picea abies) forest floor were studied two and five years after harvesting by comparing pitfall trap samples from clear-cut sites with and without subsequent stump harvesting and from unharvested mature forests in central Finland. At harvested sites, traps were placed both on intact and exposed mineral soil surface. Open-habitat and generalist ground beetles benefit…

<p><strong><em>Sinostoma</em> <em>yunnanicum</em>, the first nemastomatine harvestman in China (Arachnida: Opilio…

2016

The easternmost Nemastomatinae species, Sinostoma yunnanicum n. gen., n. sp., from northern Yunnan, China is described. It extends the geographic distribution of Nemastomatinae by roughly 3000 km southeastwards. Within Nemastomatinae Sinostoma displays plesiomorphic characters, including the long, basic bulb of the truncus shaft and the extremely short glans of penis, armed with short robust spines. Sinostoma may represent a relict line in the early evolution of nemastomatine harvestmen.

The evolution of pedipalps and glandular hairs as predatory devices in harvestmen (Arachnida, Opiliones)

2016

Pedipalps are the most versatile appendages of arachnids. They can be equipped with spines (Amblypygi), chelae (Scorpiones), or adhesive pads (Solifugae), all of which are modifications to grasp and handle fast-moving prey. Harvestmen (Opiliones) show a high diversity of pedipalpal morphologies. Some are obviously related to prey capture, like the enlargement and heavy spination of Laniatores pedipalps. Many Dyspnoi, by contrast, exhibit thin, thread-like pedipalps that are covered with complex glandular setae (clavate setae). These extrude viscoelastic glue that is used to immobilize prey items. Comparable setae (plumose setae) have previously been found in representatives of both Eupnoi a…

An Enigmatic European Harvestman (Opiliones): New Record and Redescription of Dicranopalpus larvatus (Canestrini, 1874)

2019

Dicranopalpus larvatus is redescribed based on type material. Recent first findings of this rare species on Sardinia enable to provide the essential morphological characters. Original drawings are presented with emphasis on penial and pedipalpal morphology. Dicranopalpus larvatus is a small, short-legged, ground-dwelling species endemic to Italy that matures in autumn and winter and has completed its life cycle in April. Additional information on phenology, life cycle, ecology, distribution and systematic position is given.

A harvestman with elaborate palpal pliers, Thunbergia gretae n. gen. n. sp. from China (Opiliones: Sclerosomatidae: Gagrellinae)

2020

Abstract Based on the unusual characteristics of the male pedipalp and male genital morphology, a new genus and new species of Gagrellinae harvestmen, Thunbergia gretae n. gen. n. sp. (male and female) from Shaanxi Province, China, is proposed. The tibia and tarsus of the pedipalp form elaborate palpal claws, resembling gaspipe pliers, probably used to grasp the legs or the pedipalps of the female during courtship. There is no comparable modification of the pedipalp in the female. The penis lacks wing or sac-like (saccate) elements normally present in Gagrellinae, and the penis base is markedly inflated to form a bulb-like structure harbouring the penis muscle. Two or three opisthosomal ter…