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A protonymph of the snout mite genus Odontoscirus Thor, 1913, O. cretacico sp. nov., is described and illustrated from Cretaceous amber of Myanmar is described and illustrated, constituting the earliest fossil species described of the family Bdellidae (ca. 99 Ma). After reexamining the literature and recollected specimens from type localities, we conclude that the following five recent species do not belong to the genus Biscirus and should be transferred to Odontoscirus: O. anomalicornis (Berlese 1916) comb. nov., O. symmetricus (Kramer 1898) comb. nov., O. uncinatus (Kramer 1898) comb. nov., O. norvegicus (Thor 1905) comb. nov., and O. insularis (Willmann 1939) comb. nov. The implications of the fossil record of the family is discussed.

The laniatorean family Phalangodidae has been largely reduced to a core of Holarctic species; however, many taxa were never formally transferred to other families. We examined a group of harvestmen related to Beloniscus Thorell, 1891, from South-east Asia and determined the nature of the relationships of the ‘Beloniscus-like harvestmen’, herein described as the new family Beloniscidae, fam. nov., in the broad context of Laniatores. Based on a molecular phylogenetic analysis of a broad representative laniatorean Sanger-sequences dataset we found support for our taxonomic hypotheses that (1) inclusion of Beloniscidae, fam. nov. in Phalangodidae would render the family non-monophyletic, and (2) Beloniscidae, fam. nov. represents a lineage that is morphologically and genetically distinct from all other known laniatorean families. The new family Beloniscidae is endemic to South-east Asia and comprises 37 species in two new subfamilies: Beloniscinae, subfam. nov. and Buparinae, subfam. nov. Beloniscinae includes the genera Beloniscellus Roewer, 1931, Beloniscops Roewer, 1949, Belonisculus Roewer, 1923, Beloniscus (type genus) and Kendengus Roewer, 1949. Buparinae includes the genera Buparellus Roewer, 1949, Bupares Thorell, 1889 (type genus) and Buparomma Roewer, 1949. Members of Beloniscidae are relatively homogeneous in their external morphology, but are recognised by well marked genitalic features. Male genitalia are described for exemplar species, and the morphology is compared with that of Epedanidae. Names are given to two new genitalic structures: sella curulis and pseudocalyx. http://zoobank.org/urn:lsid:zoobank.org:act:540BCE49-6F2E-4372-BFD4-D3C6068F045D http://zoobank.org/urn:lsid:zoobank.org:act:FE8B011B-AA6D-4E6C-A321-123542A0563F http://zoobank.org/urn:lsid:zoobank.org:act:E4A559CD-170A-40F2-924A-541C22974344

The harvestmen family Cosmetidae contains more than 700 described species distributed from Argentina to the USA. The monophyly of the family remains undisputed; however, the majority of cosmetid genera are poorly defined and have not been revised using modern systematic approaches. This can be partially attributed to the paucity of information regarding genitalic morphology for most cosmetid species. A better understanding of the diversity of genitalic forms in this family will facilitate more in-depth systematic studies and taxonomic revisions within the family. In this study, we describe two distinct forms of genitalia exhibited by members of the genus Erginulus, compare these forms to the common genitalic morphology of other cosmetid harvestmen, and briefly discuss the systematic implications to be addressed in a subsequent revisionary study.

In its first twenty years of existence Zootaxa has been widely utilized among researchers of Opiliones, mainly those coming from Latin American countries, principally Brazil. During 2003–2020, a total of 141 papers on Opiliones were published in Zootaxa (no papers were published on Opiliones in the first two years, 2001–2002). The journal has greatly facilitated the dissemination of knowledge on Opiliones, especially with respect to the taxonomy and systematics of harvestmen from the Neotropical Realm. Those 141 papers in Zootaxa include almost a quarter (191) of the new species of Opiliones described between 2001 and 2020, as well as 112 new synonymies. Additionally, 27 of those papers proposed 182 new or restored combinations. A total of 108 authors working in 25 countries have contributed papers to Zootaxa focusing on Opiliones. There is clearly a predominance for collaborative contributions with more than twice as many papers authored by two or more authors compared to single-author publications. In general, the majority of papers deal within the local biogeographic realm (where the lead author resides). Studies of harvestmen from seven of the eight biogeographic realms were published in Zootaxa during 2003–2020. The largest portion of these contributions were by far focused on the Neotropical opiliofauna, but Australasian, Nearctic, Indomalayan, Palearctic, Afrotropical and Antarctic opiliofauna are covered as well. No papers on Opiliones have been published in Zootaxa by authors representing countries in Africa. We also recognize a strong gender bias in authorship and the current composition of Opiliones subject editors. We will strive to create an inclusive environment and aim to promote diversity of scientists who study Opiliones. Fil: Pérez González, Abel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; Argentina Fil: Acosta, Luis Eduardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Diversidad y Ecología Animal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto de Diversidad y Ecología Animal; Argentina Fil: Proud, Daniel Nathan. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; Argentina. Moravian College; Estados Unidos Fil: Shultz, Jeffrey W.. University of Maryland; Estados Unidos

Procheiridium judsoni n. gen. et n. sp. is described from Burmese cretaceous amber. This species represents the earliest record of the pseudoscorpion subfamily Pycnocheiridiinae and the first fossil taxon of the subfamily to be recorded. The phylogenetic position of the new genus in the superfamily Cheiridioidea is discussed.

Procaeculus coineaui sp. nov. from Cretaceous Burmese amber is described and its phylogenetic position discussed. This fossil taxon is the first caeculid mite known from Burmese amber and constitutes the earliest record of the family. The genus Procaeculus is redefined to include the new fossil species and internal relationships between genera of the family are discussed based on a phylogenetic hypothesis. Fil: Porta, Andrés Osvaldo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; Argentina Fil: Proud, Daniel N.. Moravian College; Estados Unidos Fil: Franchi, Ezequiel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; Argentina Fil: Lourenco Porto, Willians. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; Argentina Fil: Epele, María Bernarda. YPF - Tecnología; Argentina Fil: Michalik, Peter. University of Greifswald; Alemania

In many species of scorpions (Order Scorpiones) and spiders (Order Araneae), mating plugs (gel-like or sclerotized) are deposited in the female reproductive tract, minimizing the possibilities of further matings. Although harvestmen (Order Opiliones) have direct sperm transfer via copulatory organs (penis or spermatopositor in the male and ovipositor in the female), prior studies of the reproductive anatomy of these arachnids have not reported the occurrence of these structures. With the aid of scanning electron microscopy, we observed distinct masses of amorphous, gel-like material in the distal openings of the ovipositors of six different specimens including representatives of the families Cosmetidae (Cynorta marginalis and Flirtea picta), Gonyleptidae (Discocyrtulus bresslaui and Geraeocormobius sylvarum), Kimulidae (Kimula sp.) and Metasarcidae (Metasarcus clavifemur). Dissection of one of these structures from a specimen of the cosmetid harvestman C. marginalis revealed a detailed endocast of the internal surfaces of the female reproductive tract. Considerable interspecific variation in the relative sizes and shapes (smooth and rough) of the amorphous gel-like structures were observed, but evidence of sclerotized components (i.e., parts of the male genitalia) was not found. The location and morphology of the gel-like structures are consistent with observations of mating plugs in other arachnids. The composition, source (male, female or both) and function of these amorphous gel-like structures (i.e. effective matting plug) requires additional study. Fil: Townsend, Victor Robert. Virginia Wesleyan University; Estados Unidos Fil: Pérez González, Abel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; Argentina Fil: Proud, Daniel Nathan. Moravian College; Estados Unidos. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; Argentina

Psilodercidae contains some 200 known extant species of small spiders that live in tropical rainforests and caves and is mainly restricted to the Oriental biogeographic realm. Interestingly, at least ten different fossil species have been described from inclusions in Upper Cretaceous Burmese amber. This suggests the family has been diversifying in the region for at least ~100 million years. In this paper, we revise the taxonomy of fossil species of this family and the closely related Ochyroceratidae, based on the re-examination of type specimens of described species. We find that ten Cretaceous species described in the psilodercid genera Priscaleclercera and Aculeatosoma are valid, and present new illustrations of their type material. The genus Propterpsiloderces apparently does not belong to Psilodercidae, but rather to a family representing a stem lineage within Scytodoidea. Ochyroceratidae is represented in the fossil record by a single ochyroceratine genus from Miocene Dominican amber, Arachnolithulus. The original combination of the extant species Leclercera spinata Deeleman-Reinhold, 1995 is reinstated by transferring it from Priscaleclercera, leaving this latter genus as a strictly fossil taxon. Finally, we present the description of a hitherto unknown species of Priscaleclercera from mid-Cretaceous Burmese amber, Priscaleclercera christae sp. nov., bringing the total number of congeners to ten. By studying its morphological features, we argue that Priscaleclercera is a crown-group Psilodercidae, closely related to the Althepus–Leclercera lineage. The high species diversity of Priscaleclercera indicates that Psilodercidae was already a diverse component of the Oriental tropical forests during the Cretaceous.

Most species descriptions of harvestmen from Central America that belong to the suborder Eupnoi are based on characters such as total body length, relative size of leg segments, coloration of the body and legs, and armature of the eye mound and dorsal scutum. Characters based on reproductive morphology and microanatomical structures are generally absent from most taxonomic works. Not surprisingly, the taxonomy of these harvestmen from this region requires extensive revision. In an effort to identify novel characters, we used scanning electron microscopy to compare the morphology of somatic and reproductive structures of Prionostemma vittatum (Roewer, 1910), Metopilio niger (Goodnight and Goodnight, 1942), and Metopilio ornatipes (Banks, 1909). Specifically, we investigated the morphology of the ocularium, ozopore, dorsal scutum, genital plate, pedipalp, spiracular opening on tibia II, ovipositor, and penis. We compared the morphology of these Neotropical taxa with that of a temperate sclerosomatid species, Leiobunum formosum (Wood, 1870). In general, we observed interspecific variation in the surface texture of the cuticle and the distribution of setae on the body and appendages. Potentially informative characters include cuticular structures associated with the ocularium, anterior propeltidium, meso- and metapeltidium, dorsal scutum, genital plate, pedipalp, and penis. We also observed intersexual variation with respect to morphology of Spicer's tarsal organ and the claw of the pedipalp.

In at least four closely related families of the diverse harvestmen lineage Gonyleptoidea, males may possess sexually dimorphic tarsal glands in the swollen tarsomeres of the basitarsus and/or metatarsus of leg I. The first histological and ultrastructural examination of the sexually dimorphic tarsal glands in leg I focused only on Manaosbiidae. In this study, we examine the morphology and ultrastructure of the sexually dimorphic glands, and their associated glandular openings, found in the basitarsus and/or metatarsus of leg I of males representing Cosmetidae, Gonyleptidae, and Cranaidae (glandular openings only). In cosmetids and gonyleptids, the tarsal glands are made up of 20–60 glandular units that form distinct groups within the prolateral and retrolateral half of the tarsomere. Each glandular unit consists of a pair of terminal secretory cells, an intercalary cell wrapped around the receiving canal, and a canal cell tightly wrapped around the length of the conducting canal. Cosmetidae, Gonyleptidae, and Cranaidae exhibit remarkably similar tarsal glands and gland openings although the location of the glands in the leg differs slightly among them. Males of these three families exhibit markedly different glands and glandular openings compared to males of the family Manaosbiidae. The sexually dimorphic tarsal glands may provide an important morphological character for determining phylogenetic relationships among gonyleptoid families. Finally, we provide morphological and ultrastructural data for the common tegumental glands. These data indicate that the sexually dimorphic tarsal glands are strikingly similar to, and may possibly be derived from, the tegumental glands. J. Morphol. 274:1203–1215, 2013. © 2013 Wiley Periodicals, Inc.

The tarsal flexor system, a novel system of retinacular structures, is described for the first time based on morphological and ultrastructural examinations of several Neotropical harvestmen (Opiliones: Laniatores). The tarsal flexor system is made up of many individual pulleys that function to maintain close apposition between the tendon and internal ventral surface of the cuticle in the tarsus. Pulley cells are specialized tendinous cells that form the semi-circular, retinacular pulley system in the tarsus; these cells contain parallel arrays of microtubules that attach to cuticular fibers extending from deep within the cuticle (i.e., tonofibrillae). The tarsal flexor system is hypothesized to provide mechanical advantage for tarsal flexion and other movements of the tarsus. This system is discussed with regards to other lineages of Opiliones, especially those that exhibit prehensility of the tarsus (i.e., Eupnoi). Comparing tarsal morphology of laniatorid harvestmen to other well-studied arachnids, we review some literature that may indicate the presence of similar tarsal structures in several arachnid orders. The general internal organization of the tarsus is described, and ultrastructural data are presented for a number of tarsal structures, including sensilla chaetica and the tarsal perforated organ. Sensilla chaetica possess an internal lumen with dendritic processes in the center and exhibit micropores at the distal tip. With respect to the tarsal perforated organ, we found no ultrastructural evidence for a sensory or secretory function, and we argue that this structure is the result of a large pulley attachment site on the internal surface of the cuticle. A small, previously undocumented muscle located in the basitarsus is also reported. J. Morphol. 274:1216–1229, 2013. © 2013 Wiley Periodicals, Inc.

Descriptions of defensive behaviors used by Neotropical harvestmen are rarely based upon direct observations of encounters between individuals and syntopic predators. In this study, we investigated the defensive responses exhibited by five harvestman species from Costa Rica in interactions with ctenid spiders (Cupiennius spp.), whip spiders (Phrynus pseudoparvulus), onychophorans (Epiperipatus sp.), and centipedes (Scolopendra sp.). We also observed interactions between harvestmen and a non-predatory invertebrate, the millipede Nyssodesmus python. In 64 encounters, ctenid spiders consumed 11 harvestmen, including eight Prionostemma sp., two Cynorta marginalis, and one Eupoecilaema magnum. The most frequent defensive behavior exhibited by harvestmen was fleeing. Other behaviors included aggression (striking with leg II), bobbing, leg autotomy, lying flat, and thanatosis. Prionostemma exhibited the most variable responses, especially in the presence of ctenid spiders. In addition to the lab-based e...

Cavernicolous species that exhibit a high degree of troglomorphism often provide some of the most intriguing evolutionary riddles. For such taxa, the correct systematic arrangement is difficult to determine and becomes problematic when based solely on highly convergent external morphological characters, leading to exaggerated support of spurious relationships. For the arachnid order Opiliones, examination of male genitalia morphology often aids in determining the family to which a particular taxon belongs. However, many taxa described prior to the 1990s lack detailed descriptions or drawings of this important character and, for highly-derived species, it is may still be necessary to seek support from additional sources of characters (e.g. molecular data) to accurately assess systematic placement. The enigmatic species Stygnomma pecki Goodnight & Goodnight, from a cave in Belize proved to be especially difficult to place based on morphological characters alone. Thus, using a previously published dataset for laniatorean harvestmen, we carried out a robust phylogenetic analysis aiming to determine the evolutionary relationship of this Neotropical troglomophic species. Informed by the results of the molecular phylogenetic analysis of 88 terminals representing Laniatores, we describe Jarmilana gen. nov. and provide a redescription of the type species Jarmilana pecki (Goodnight & Goodnight,) comb. nov. Morphological evidence, including male genitalia morphology, supports the inclusion of J. pecki in the family Pyramidopidae. This represents the first record for the family Pyramidopidae in the New World, raising the question of whether this represents transoceanic dispersal or a relict of an ancient widespread tropical Gondwanan distribution. Fil: Cruz López, Jesús A.. Universidad Nacional Autónoma de México; México Fil: Proud, Daniel Nathan. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales “Bernardino Rivadavia”; Argentina Fil: Pérez González, Abel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales “Bernardino Rivadavia”; Argentina

The type specimens of Fijicolana tuberculata Roewer, 1963 were re-examined and the male genital morphology is illustrated and described for the first time. Despite the presence of several morphological features that are typical of Samoidae, such as the presence of scopulae on legs III and IV, genital morphology unambiguously indicates that this species belongs to the Zalmoxidae rather than to the Samoidae. Fijicolana Roewer, 1963 is newly synonymized with Zalmoxis Sørensen, 1886. However, the newly implied combination is preoccupied by Z. tuberculatus GoodnightGoodnight, 1948 thus the replacement name Zalmoxis roeweri nom. nov. is proposed to avoid secondary homonymy. The definition of Z. roeweri nom. nov. is amended, and the morphology of this species is compared with other representatives of Zalmoxidae and Samoidae. We conclude that the presence of scopulae alone is not a sufficiently diagnostic characteristic for Samoidae and, therefore, correctly placing taxa into families within Samooidea + Zalmoxoidea requires additional morphological evidence (e.g. genital morphology). In light of this result, we point out that the "scopulated" Australasian samoids Badessania metatarsalis Roewer, 1949, Sawaiellus berlandi Roewer, 1949 and Parasamoa gressitti GoodnightGoodnight, 1957 require re-examination in order to detect potential errors in their family placement.

Relatively little is known about factors that contribute to microhabitat selection among Central American harvestmen. In this study, we compared walking and climbing speeds for five common species from Costa Rica representing the families Cosmetidae (3 species), Gonyleptidae (1 species) and Sclerosomatidae (1 species). Our sample included two arboreal species, two species that infrequently occupy perches in the vegetation, and one species that rarely climbs. Our analyses revealed no significant interspecific differences in climbing speed, although species with relatively long legs walked significantly faster than species with shorter legs. An arboreal habit did not correlate with increased climbing speed, and all species walked significantly faster than they climbed.

In tropical rain forests, harvestmen assemblages are extremely diverse, with richness often exceeding 25 species. In the neotropics, there are published accounts of harvestmen faunas in South America rainforests (especially Amazonia), but relatively little is known about the community ecology of harvestmen in tropical forests of Central America. In this paper, we provide the first insights into the diverse assemblage of harvestmen inhabiting a wet forest at La Selva Biological Station, Costa Rica. Over five field seasons, we recorded 38 species. During our 2009 field season, we examined variation in species abundance, richness, and composition between adjacent successional forests (young secondary, mature secondary, and primary forests) as well as between distinct habitats (ground/litter layer and shrub/tree layer). Based on night samples (but not day), our results indicate that there are only minor differences in species composition and relative abundance between the forest ages, but no differences in richness. The ground/litter layer and shrub/tree layer habitats differed markedly in species composition, species richness, and relative abundance of several species. Our analysis of covariance supports the hypothesis that leg length is related to climbing behavior for several species belonging to Eupnoi and Laniatores.

In encounters with predators, sclerosomatid harvestmen may employ a variety of defensive tactics including the voluntary detachment of legs (autotomy). The long-term costs of this evasive defense are not fully understood, but prior studies have documented negative consequences for terrestrial locomotion and foraging. In this study, we investigated the impact of leg loss upon locomotion in adult harvestmen (Leiobunum spp.). In southeastern Virginia, these harvestmen regularly climb vegetation and occupy perches on tree trunks, branches, and leaves that are often 1–2 m or more above the ground. In our study, we measured walking and climbing speeds for individuals with 5, 6, 7, and 8 legs. The results of our field surveys conducted over three seasons revealed relatively high frequencies (36–63%) of leg loss. We also found that individuals with six legs occupied perches that were significantly lower in the understory than those with eight legs. In the lab, we observed significantly slower walking spe...

Natural history studies serve as important foundations for future investigations of behavioral ecology and provide biologists with critical information needed for the development of empirical research programs. Relatively little is known about the biology of most species of Neotropical harvestmen in Central America. In this field study, we investigated the activity patterns of two common species Cynorta marginalis (Cosmetidae) and Prionostemma sp. (Sclerosomatidae) in a wet tropical forest in Costa Rica. We used visual encounter surveys along randomly selected transects to compare the relative abundance of these species during morning, afternoon, evening, and late night sampling periods. To generate ethograms, we observed up to three individuals of each species for 10 min along each transect, generating 69 behavioral observations for C. marginalis and 51 for Prionostemma. Both species occupy perches on vegetation and are generally nocturnal with respect to activity. After dusk, individuals of C. marginalis actively climb, interact with conspecifics, and forage on the surfaces of small and large trees. During the day, adult Prionostemma form relatively inactive clusters of up to 40 individuals on arboreal perches and descend to the leaf litter after dusk to forage.

In Central America, the family Manaosbiidae is recorded only from Panama and Costa Rica. Four species occur in this region: Barrona williamsi Goodnight & Goodnight 1942, Bugabitia triacantha Roewer 1915, Poassa limbata Roewer 1943, and Zygopachylus albomarginis Chamberlin 1925. In this paper, we describe Barrona felgenhaueri new species (Cocle Province, Panama) and Bugabitia akini new species (Cocle Province, Panama) and report a new record for B. williamsi (Cocle Province, Panama). We used SEM to examine the penis morphology of Barrona Goodnight & Goodnight 1942 and the Caribbean species Cranellus montgomeryi Goodnight & Goodnight 1947 and Rhopalocranaus albilineatus Roewer 1932. We compared genital morphology of these species with published descriptions for Manaosbiidae from South America. With respect to genital morphology, we found that the most variable characters were the number and relative sizes of the setae that occur on the lateral margins of the ventral plate. Other features that exhib...

In July and August 2005, we investigated the use of two distinct microhabitats by harvestmen (Arachnida: Opiliones) in crappo-cocorite seasonal forest, lower montane rain forest, and upper montane rain forest of the Northern Range of Trinidad, West Indies. In addition to new locality records, geographic distributions, and microhabitat use, this article provides a preliminary understanding of the species diversity, compositional similarity, and relative harvestmen abundance among forest stands located within three types of rain forest of different altitudes found in Trinidad. We collected harvestmen inhabiting the space within and underneath decaying logs as well as the leaf litter associated with the logs. In upper montane rain forest, in addition to logs, we sampled the sheaths of palm (Euterpe broadwayi Becc. ex Broadway) fronds, another shelter commonly used by harvestmen that was especially abundant at the higher elevations. We collected 173 individuals representing eight families and 14 species. The number of harvestmen per shelter varied from 3.2 individuals per log in crappo-cocorite forest to 0.8 individual per log or palm frond sheath in upper montane rain forest. In the crappo-cocorite seasonal forest, cosmetids, sclerosomatids and stygnids were most abundant. In upper montane rain forest, cranaids and manaosbiids were the most abundant taxa, whereas cosmetids and sclerosomatids were relatively rare. Crappo-cocorite and lower montane forests were very similar in species composition but differed greatly from upper montane forest. The cosmetids Paecilaema ingleiGoodnight and Goodnight 1947, Cynortula granulata Roewer 1912, and the stygnid Stygnoplus clavotibialis (Goodnight and Goodnight 1947) were found to be strongly correlated with the crappo-cocorite and lower montane forests, whereas in upper montane forests Santinezia serratotibialisRoewer 1932 and Cranellus montgomeryiGoodnight and Goodnight 1947 were closely correlated.

Morphological changes during postem- bryonic development in the Cranaidae are described on the basis of the examination of an incomplete series of larvae, nymphs, and adults of Phareicranaus calcarife- rus and Santinezia serratotibialis. The life histories of these species are hypothesized to consist of six nymphal stages, featuring the appearance of secondary male sex- ual characteristics in the antepenultimate nymph (N5). Color and body shape change dramatically during devel- opment. Growth rates for nymphs based upon leg mea- surements were similar for both species. In S. serratoti- bialis, the greatest increase in leg size occurred from larva to 1st nymph. The tarsomeres of legs I-IV varied by 1-2 segments per leg for each nymph stage, with the number of tarsal segments increased by 1-2 segments at each stage. Adults had nearly twice as many tarsomeres on leg II than other legs. Ontogenetic changes were observed in the armature of the proximal cheliceral seg- ment, ocularium, pedipalp, opisthosoma, distitarsus III and IV, and leg IV. Morphological changes in postem- bryonic development in cranaid harvestmen are similar to those reported for other Laniatores. J. Morphol. 270:1055-1068, 2009. 2009 Wiley-Liss, Inc.

Larval erythraeid mites are common ectoparasites of harvestmen (Opiliones). However, interactions between these mites and hosts in tropical environments have received little attention. In this study, we examined the prevalence and intensity of mite infestations for Neotropical harvestmen from the Caribbean island of Trinidad. Overall, the prevalence of infestation was 9.9%, with significant interspecific variation in the intensity of mite infestation and significant differences in parasitism of hosts between habitats. Harvestmen collected from lowland, crappo-cocorite forest exhibited the highest infestation rates. In our samples, the intensity of infestation varied from 1 to 17 mites per host. Examination by scanning electron microscopy revealed that harvestmen were infested by two taxa of mites, a species of Leptus and another unidentified erythraeid species. Our observations represent the first host records for erythraeid mites parasitizing harvestmen from the families Cranaidae and Manaosbiidae. Mites were found to attach preferentially to the tibia and femur of the leg (175 of 178 observations). In general, the harvestmen of Trinidad exhibited mite parasitism in a fashion similar to temperate species with respect to site of attachment and prevalence and intensity of mite infestation. In the field, we also collected an adult Cynortula sp. (Cosmetidae) that was transporting 30 gravid adults of an oribatid mite (Acariformes, Oribatida, Mixonomata). Cases of mite phoresy upon harvestmen are rare, with our observation representing the first report of phoresy by an oribatid mite upon a harvestman and the first documentation of mite phoresy upon harvestmen in the Caribbean.

We describe multiple observations of epizoic cyanobacteria occurring on external surfaces of a species of sclerosomatid harvestman (Prionostemma sp.) in Costa Rica. In the field we collected four adults (three males, one female) that had green films growing upon the dorsal surfaces of the carapace and abdominal scutum. Examination by SEM revealed dense clusters of what appeared to be small prokaryotic cells (1–5 µm in diameter) covering the external surfaces of the carapace, abdominal scutum and coxae. We extracted DNA from the films of two specimens. The DNA was used as a template to amplify the intergenic spacer region (IGS) between the beta and alpha phycocyanin subunits (a signature DNA sequence, unique to cyanobacteria) by PCR. We successfully amplified an approximately 700 base pair product using DNA extracted from the film and did not obtain any product from the harvestman lacking the film. Our observation represents the second confirmed occurrence of epizoic cyanobacteria on Neotropical h...

A new troglobitic harvestman, Relictopiolus galadriel gen. nov et sp. nov., is described from Olhos d’Água cave, Itacarambi, Minas Gerais State, Brazil. Morphological characters, including male genitalia and exomorphology, suggest that this species belongs to the family Kimulidae, and it appears to share the greatest similarities with Tegipiolus pachypus. Bayesian inference analyses of a molecular dataset strongly support the inclusion of this species in Kimulidae and confirm the hypothesized sister-group relationship between R. galadriel and T. pachypus. A time calibrated phylogeny indicates that these sister-taxa diverged from a common ancestor approximately 40 Mya, during the Paleogene. The current range of Kimulidae illustrates a remarkable disjunct distribution, and leads us to hypothesize that the ancestral distribution of Kimulidae was once much more widespread across eastern Brazil. This may be attributed to the Eocene radiation associated with the warming (and humidifying) events in the Cenozoic when the best conditions for evergreen tropical vegetation in South America were established and followed by the extinction of kimulid epigean populations together with the retraction of rain forests during the Oligocene to Miocene cooling. The discovery of this relictual troglobite indicates that the Olhos d’Água cave was a stable refugium for this ancient lineage of kimulids and acted as a "museum" of biodiversity. Our findings, considered collectively with the diverse troglofauna of the Olhos d’Água cave, highlight it as one of the most important hotspots of troglobite diversity and endemism in the Neotropics. Given the ecological stresses on this habitat, the cavernicolous fauna are at risk of extinction and we emphasize the urgent need for appropriate conservation actions. Finally, we propose the transfer of Acanthominua, Euminua, Euminuoides and Pseudominua from Kimulidae to Zalmoxidae, resulting in two new synonymies and 13 new combinations. Fil: Pérez González, Abel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; Argentina Fil: Ceccarelli, Fadia Sara. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; Argentina Fil: Monte, Bruno G. O.. Universidade Federal do São Carlos; Brasil Fil: Proud, Daniel Nathan. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; Argentina Fil: DaSilva, Márcio Bernardino. Universidade Federal da Paraíba; Brasil Fil: Bichuette, Maria E.. Universidade Federal do São Carlos; Brasil

Although relatively rare among harvestmen in the superfamily Gonyleptoidea, paternal care has been observed in the families Manaosbiidae and Gonyleptidae, but not previously in the Cosmetidae. In this study, we describe multiple observations of egg guarding by adult males of an undescribed species of cosmetid harvestman from Volcan Cacao, Guanacaste Province, Costa Rica. Observations were made from 26–28 July 2010, during the wet season. In this species, males only guard eggs after dusk, leaving eggs unattended during the day. Based upon differences in color and size, males guarded eggs through several stages of development. When guarding, males contacted the first two pairs of legs with the eggs. Oviposition sites consisted of the undersides of leaves of small plants, with eggs closely packed together in a single layer covered by abundant, transparent mucus. The largest, darkest eggs were located near the distal tip of the leaf.

Parental care in harvestmen may take several forms including egg hiding, egg guarding, egg transport and young guarding. In most species, one adult, usually the female, performs guarding of the young. From 9 July–3 August 2005, we made observations of parental care by adults of the Neotropical cranaid harvestman Phareicranaus calcariferus (Simon 1879) in northern and central Trinidad. Nine observations involved an adult female and young while three appeared to include both an adult female and male with young. The number of young present was inversely related to the size of the young, indicating that parental care in this species may occur over an extended period of time.

We recorded the number of ectoparasitic erythraeid mite larvae (Leptus sp. Latreille 1796) that were attached to 1241 Leiobunum formosum Wood 1870 from a population in southeastern Virginia. The prevalence of infestation (percent of individuals parasitized) exhibited significant annual and seasonal variation, ranging from 0.5% to 20.3%. The mean intensity of infestation (number of mites per parasitized individual) varied from 1.0 to 1.3, with a maximum observed intensity of 3 mites/individual. This study provides the first description of annual and seasonal variation in mite infestation of harvestmen.

In at least four closely related families of the diverse harvestmen lineage Gonyleptoidea, males may possess sexually dimorphic tarsal glands in the swollen tarsomeres of the basitarsus and/or metatarsus of leg I. The first histological and ultrastructural examination of the sexually dimorphic tarsal glands in leg I focused only on Manaosbiidae. In this study, we examine the morphology and ultrastructure of the sexually dimorphic glands, and their associated glandular openings, found in the basitarsus and/or metatarsus of leg I of males representing Cosmetidae, Gonyleptidae, and Cranaidae (glandular openings only). In cosmetids and gonyleptids, the tarsal glands are made up of 20–60 glandular units that form distinct groups within the prolateral and retrolateral half of the tarsomere. Each glandular unit consists of a pair of terminal secretory cells, an intercalary cell wrapped around the receiving canal, and a canal cell tightly wrapped around the length of the conducting canal. Cosmetidae, Gonyleptidae, and Cranaidae exhibit remarkably similar tarsal glands and gland openings although the location of the glands in the leg differs slightly among them. Males of these three families exhibit markedly different glands and glandular openings compared to males of the family Manaosbiidae. The sexually dimorphic tarsal glands may provide an important morphological character for determining phylogenetic relationships among gonyleptoid families. Finally, we provide morphological and ultrastructural data for the common tegumental glands. These data indicate that the sexually dimorphic tarsal glands are strikingly similar to, and may possibly be derived from, the tegumental glands.

The type specimens of Fijicolana tuberculata Roewer, 1963 were re-examined and the male genital morphology is illustrated and described for the first time. Despite the presence of several morphological features that are typical of Samoidae, such as the presence of scopulae on legs III and IV, genital morphology unambiguously indicates that this species belongs to the Zalmoxidae rather than to the Samoidae. Fijicolana Roewer, 1963 is newly synonymized with Zalmoxis Sorensen, 1886. However, the newly implied combination is preoccupied by Z. tuberculatus Goodnight & Goodnight, 1948 thus the replacement name Zalmoxis roeweri nom. nov. is proposed to avoid secondary homonymy. The definition of Z. roeweri nom. nov. is amended, and the morphology of this species is compared with other representatives of Zalmoxidae and Samoidae. We conclude that the presence of scopulae alone is not a sufficiently diagnostic characteristic for Samoidae and, therefore, correctly placing taxa into families within Samooidea + Zalmoxoidea requires additional morphological evidence ( e.g. genital morphology). In light of this result, we point out that the "scopulated" Australasian samoids Badessania metatarsalis Roewer, 1949 , Sawaiellus berlandi Roewer, 1949 and Parasamoa gressitti Goodnight & Goodnight, 1957 require re-examination in order to detect potential errors in their family placement.

The tarsal flexor system, a novel system of retinacular structures, is described for the first time based on morphological and ultrastructural examinations of several Neotropical harvestmen (Opiliones: Laniatores). The tarsal flexor system is made up of many individual pulleys that function to maintain close apposition between the tendon and internal ventral surface of the cuticle in the tarsus. Pulley cells are specialized tendinous cells that form the semi-circular, retinacular pulley system in the tarsus; these cells contain parallel arrays of microtubules that attach to cuticular fibers extending from deep within the cuticle (i.e., tonofibrillae). The tarsal flexor system is hypothesized to provide mechanical advantage for tarsal flexion and other movements of the tarsus. This system is discussed with regards to other lineages of Opiliones, especially those that exhibit prehensility of the tarsus (i.e., Eupnoi). Comparing tarsal morphology of laniatorid harvestmen to other well-studied arachnids, we review some literature that may indicate the presence of similar tarsal structures in several arachnid orders. The general internal organization of the tarsus is described, and ultrastructural data are presented for a number of tarsal structures, including sensilla chaetica and the tarsal perforated organ. Sensilla chaetica possess an internal lumen with dendritic processes in the center and exhibit micropores at the distal tip. With respect to the tarsal perforated organ, we found no ultrastructural evidence for a sensory or secretory function, and we argue that this structure is the result of a large pulley attachment site on the internal surface of the cuticle. A small, previously undocumented muscle located in the basitarsus is also reported.

To facilitate identification of harvestmen of the family Cosmetidae in Central America, we developed dichotomous keys that distinguish the 33 known genera and the 133 described species for this region. Couplets are based upon characters found in the literature and examinations of museum specimens. Important characters include the number of tarsomeres on leg I, armature of the dorsal scutum, free tergites and legs, as well as the coloration and relative length of the body and legs. In addition, we provide a summary of sexually dimorphic features and comment on the potential usefulness of penis morphology and coloration as characters for distinguishing taxa.