Spine-like Setae Research Articles

Ngan mayla gen. et sp. nov, a new blind potamid cave crab from Borneo, Kalimantan (Crustacea: Decapoda: Brachyura: Potamoidea, Potamidae), and three other unidentified cave crabs from the same region.

We here report on freshwater cave crabs of the families Potamidae and Gecarcinucidae in East Kalimantan, Sarawak, Indonesia in Borneo. A new genus and species of potamid crab, Ngan mayla, is described from Lubang Gedung Cave in the Merabu Karst. With its bullet-shaped eyes, Ngan mayla gen. et sp. nov. is totally blind and also displays the characters associated with an obligate cave-dwelling life, namely that it is dolichopod and fully depigmented. The closest genus and species is Cerberusa caeca Holthuis, 1979, from northern Sarawak. Highly modified, Ngan mayla gen. et sp. nov. proves to be among the most troglobitic of the known subterranean potamids, of which there were currently only seven in the Old World, with only four simultaneously being completely blind, entirely depigmented and dolichopod (Cerberusa caeca Holthuis, 1979, Diyutamon cereum Huang, Shih & Ng, 2017 and Phasmon typhlops Huang, Ahyong & Shih, 2020, to which must be added today Ngan mayla gen. et sp. nov.). Ngan mayla gen. et sp. nov. is easily distinguished from other potamid genera by its chelipeds bearing numerous acute teeth, spines (some horn-tipped) and short simple setae or spine-like setae on all articles. Two young female crabs collected in 2010 at the same area (Merabu Karst) but from a different cave, the Lubang Tebot Cave, could not be identified to specific level: an Isolapotamon sp., and a gecarcinucid with very long legs, pale colouration and slightly modified but black-pigmented eyes, close to Balssiathelphusa Bott, 1969, could possibly belong to a new genus. Some information on New World troglobitic crabs is provided.

New species of the long-horned caddisfly Oecetis McLachlan, 1877 (Trichoptera: Leptoceridae) from the Atlantic Forest, Brazil and their evolutionary relationship

Asymmetrical genitalia are reported from majorTrichoptera subgroups and evolved multiple times independently. In Oecetis, it is a characteristic of the insconpicua group. However, certain species in other species groups also evolved an asymmetrical spiny projection on the phallotheca. Here, two new species with an asymmetric projection are described in the falicia group from the Brazilian Atlantic Forest, Espírito Santo state. Their phylogenetic relationships were investigated through a Bayesian analysis combining COI and morphological data. Additionally, we provide new records of Oecetis connata, O. inconspicua and O. paranensis from the Espírito Santo state, and O. connata and O. flinti from Minas Gerais state. Oecetis capixaba sp. nov. is placed with low support as the sister species of O. acanthostema, both presenting stout spine-like setae on the inner surface of the inferior appendage; the new species is diagnosed by the long spine-like setae on the inferior appendage, the narrow dorsolateral process of segment IX, and the phallic apparatus without apical projections. Oecetis ruschii sp. nov. is placed as a sister group of the clade including O. facilia and O. furcata, both presenting forked dorsolateral processes of segment IX; the new species is diagnosed by the dorsolateral process of segment IX with a lateral branching and the apex of inferior appendage wide and triangular. While the phylogenetic results should be considered preliminary and interpreted with caution, they indicate that the asymmetric projection evolved multiple times convergently in the avara, punctata, and falicia groups. The asymmetric genitalia in the falicia group seems to have evolved only in males since no correspondent asymmetry is described for females. The function of the asymmetrical projection remains unknown.

Armoured Lepidopteran Caterpillars Preserved in Non-Fossil Resins and What They Tell Us about the Fossil Preservation of Caterpillars.

Resin is a plastic-like product of trees. Older occurrences of such resin are referred to as amber and are considered fossil resin. Younger resins are termed copals. Even younger ones have been dubbed defaunation resins. Non-fossil resins remain in a terminological limbo, often referred to as "sub-fossils". We report two lepidopteran caterpillars preserved in non-fossil resin: one from Madagascar, one from Brazil. Prominent hairs (=setae) and spines (=spine-like setae) of the specimens make it likely that they represent larvae of Erebidae (e.g., tussock moths and others). So far, most known caterpillars preserved in resins are either "naked" or bear protective cases; only few are armoured with spines or hairs. In particular, long-haired caterpillars such as the ones reported here are so far almost absent. Only one specimen with comparable setae has been reported from 15-million-year-old Dominican amber, but no significant details of this specimen are accessible. We briefly also review the record of caterpillars known from the Holocene, recognising that it is very sparse. The new specimens demonstrate that very hairy caterpillars can readily be preserved in resins in fine detail. Furthermore, the specimens increase the known size range of caterpillars preserved in resins, with one measuring more than 12 mm.

New species of Neomachilellus Wygodzinsky 1953 (Insecta: Archaeognatha: Meinertellidae) from Madre de Dios, Peru.

This study describes a new species of jumping bristletail, Neomachilellus mercurialis sp. nov., discovered during a research expedition at the Los Amigos Biological Station in Madre de Dios, Peru. The specimens could not be morphologically assigned to any known species within the genus Neomachilellus s. str. Wygodzinsky 1953. Morphological examination revealed distinct differences in various characters, morphometric measurements, and pigmentation patterns compared to other species. The new species exhibits submedian, widened, oval-shaped ocelli, pigmentation on articles I‒VII of the maxillary palpi, and strong pigment on the femora, tibiae, and tarsi of the legs. Notably, femora and tibiae lack spines or prominent spiniform setae, while the tarsi feature spine-like setae characteristic of the nominal subgenus. The newly discovered species shares a close relationship with other taxa of Neomachilellus, specifically belonging to the muticus-group of species. Urgent taxonomic revision and molecular studies are warranted for this genus, emphasizing the ongoing challenges in understanding Archaeognatha.

A new species of Petalocladius Sublette & Wirth, 1972 (Diptera, Chironomidae, Orthocladiinae) from the Dominican Republic, with an emended generic diagnosis

Petalocladius dominiensis Andersen & Baranov sp. n. is described and figured based on an adult male collected in the Ebano Verde Scientific Reserve in the Dominican Republic. The new species can be separated from its only congener, P. setosus Sublette & Wirth, 1972 from Jamaica, as it is slightly smaller with about 115 dorsocentrals compared to 56 in P. setosus. The inferior volsella is broadly subtriangular, while more lingulate in P. setosus, and the gonostylus has a small, but distinct megaseta and a subapical brush of spine-like seta, which apparently lack in P. setosus. The generic diagnosis is emended including the new species, and the systematic position is briefly discussed.

Revision of the Neotropical genera Sumichrastia Townsend, 1916 and Myioscotiptera Giglio-Tos, 1893, with a new junior synonym proposal (Tachinidae: Dexiinae: Dexiini)

ABSTRACT Sumichrastia Townsend, 1916, and Myioscotiptera Giglio-Tos, 1893, monotypic genera of Dexiini restricted to the Neotropical Region, are revised. A redescription and photographs of the female holotype of Sumichrastia aurea (Giglio-Tos, 1893), in addition to the first recognition, description and photographs of the male are given. This genus belongs to the group of Dexiini with spine-like setae on the abdomen. Furthermore, a redescription and photographs of male holotype are given for Myioscotiptera cincta Giglio-Tos, 1893, in addition to a new specific synonym: Oberonomyia palpalis Reinhard, 1964 new junior synonym of M. cincta. Updated diagnoses are given for Sumichrastia and Myioscotiptera to help differentiate them from the other Dexiini genera. Finally, a brief biography of the collector of both holotypes, the Swiss naturalist François Sumichrast, is given. http://www.zoobank.org/urn:lsid:zoobank.org:pub:D7147DE5-BA93-4B32-9D16-0C53CB80D2F5

A new, widespread genus of Baetidae from South Asia (Insecta, Ephemeroptera).

Material collected on different islands across South Asia revealed a new genus of Baetidae with a widespread distribution, Arcobaetisgen. nov. The larvae present important similarities with Nigrobaetis, but have paraglossae dorsally with an arc of long, spine-like setae in distal area; long, slightly feathered setae between prostheca and mola of both mandibles; and very slender legs with row of short setae at dorsal margin of femur. The male imago has an extraordinarily small 3rd (apical) segment of gonostylus, which is much narrower than the apex of the 2nd segment. The new genus includes five species: A.sumbawensissp. nov. is described from Sumbawa (Indonesia) based on larvae, A.sumatrensissp. nov. from Sumatra (Indonesia) based on larvae, A.bornensissp. nov. from Borneo (Brunei) based on larvae, and A.sripadaisp. nov. (type species) is described from Sri Lanka based on a reared male imago with its larval and subimaginal exuviae; A.gracilentus (Chang & Yang, 1994), comb. nov. from Taiwan, formerly described in Margobaetis Kang & Yang, 1994, a subgenus of Baetis Leach, 1815, and subsequently transferred to the genus Nigrobaetis Kazlauskas (in Novikova & Kluge), 1987, is transferred to the new genus. A key to the larvae of all species is provided. Morphological similarities and the relationship of the new genus to other genera of Baetidae are discussed.

Xiphocentronidae (Trichoptera: Psychomyioidea) from the Andean foothills: first species of Machairocentron and Xiphocentron described in the Peruvian Amazon

Neotropical Xiphocentronidae may have arrived in South America from Central America in the late Miocene or via the Greater Antilles land bridge during the Oligocene. This would give from 10 to 30 Mya of diversification of the family in South America. However, only 11 species were previously known from the Andean foothills. In this study, five new species are described from Peru, four of Xiphocentron (X. ashaninka sp. nov., X. harakbut sp. nov., X. matsigenka sp. nov., X. yine sp. nov.) and one of Machairocentron (M. amahuaca sp. nov.). The new species are most similar to species described from the Yungas of Argentina, and the Pacific dominion of Colombia and Venezuela. The association with species from the Pacific may suggest a species divergences prior to the major Andean uplift and the Amazon basin formation. The spine-like setae on the basal region of the inferior appendage of Xiphocentron were recognized as topologically homologous to the setal brushes on the ventral projection of Caenocentron. Furthermore, based on the morphology of male and female genitalia of Machairocentron, a mating position different from that described for Psychomyiidae is inferred.

Mangrovomyia, a new genus of long-legged flies from Iranian mangroves (Diptera: Dolichopodidae: Hydrophorinae)

The genus Mangrovomyia Grichanov et Gilasian gen. nov. is described from Iran, including two new species, M. naserzadehae Grichanov et Gilasian sp. nov. and M. mofidii Grichanov et Gilasian sp. nov. The new genus is believed to be most closely related to the genera Hydrophorus Fallén, Epithalassius Mik and Paraliptus Bezzi in the subfamily Hydrophorinae, differing in peculiar characters of body setation, antenna, wing and male genitalia. The most distinct synapomorphies appear to be the very short and thick arista-like stylus; trapezoidal postpedicel with oblique transverse furrow; frons, face and clypeus covered with numerous setae, and anterior half of mesonotum covered with a field of numerous short setae and devoid of strong bristles. Mangrovomyia mofidii sp. nov. differs from M. naserzadehae sp. nov. in femora yellow (vs. black), fore tibia with thick and golden-brown (vs. thin and black) apical spine-like setae, katepisternum entirely covered with numerous setae (vs. without setae), and other features. Mangrove habitats of the new species are briefly discussed.

A new species of the oribatid mite genus Epilohmannia (Acari: Oribatida: Epilohmanniidae), with a key to known species from Iran

During investigations of oribatid mites from Shiraz, Fars Province in southern Iran, a new species of Epilohmannia (Acari: Oribatida: Epilohmanniidae) was found from soils under oak and willow trees. Epilohmannia rotundistriata sp. nov. is distinguishable from other species by the broadly rounded rostrum with longitudinal striations; bothridial seta with long, finely barbed stalk and strongly swollen, fusiform head bearing many distinct barbs; anterior margin of notogaster concave; notogastral setae c1 and c2 situated transversely nearly at the same level; anal and adanal setae thickened, barbed, ad3 distinctly shorter than the other two adanal setae; all apodemes well developed; tarsi of leg IV with three thick spine-like setae (a″, s and tc′). A key for identifying known species of Epilohmannia in Iran, is provided.

Igaponera curiosa, a new ponerine genus (Hymenoptera: Formicidae) from the Amazon

The monotypic ant genus Igaponera gen. nov. is proposed to include its type species I. curiosa (Mackay & Mackay, 2010). Igaponera gen. nov. is described and phylogenetically compared with other ponerine genera based on external morphology. The type species is known from a single gyne originally described in the genus Pachycondyla Smith, 1858. Igaponera curiosa is easily diagnosed by: costate sculpture on head, mesosoma, and petiole; short, robust, triangular mandibles with blunt apex; relatively large eyes set at mid-length on sides of head; lack of stridulitrum; and presence of distinct but relatively small arolia. Putative apomorphies of the new genus are: cuticular flange concealing metapleural gland opening; vertically standing hypostomal tooth with recessed base; stout mandibular shape with blunt apex; absence of stout spine-like setae on meso- and metatibial apices. Our phylogenetic results based on morphology suggest that Neoponera Emery, 1901 and Pachycondyla are the closest lineages to Igaponera, which shows intermediate characteristics as compared to those genera. The genus is apparently arboreal, known only from a seasonally flooded Igapó forest near Manaus, Brazil. Despite the collection site being frequented by researchers, no other specimens of this genus have been collected in over 40 years prior to this study.

It is a mess! How many species are in Rivudiva trichobasis Lugo-Ortiz & McCafferty, 1998 (Ephemeroptera: Baetidae)?

The original description of Rivudiva trichobasis Lugo-Ortiz & McCafferty, 1998 is short, with few illustrations. The lack of information resulted in a broad specific diagnosis, with emphasis on the spine-like setae on the antenna. Our hypothesis is that the lack of information resulted in many species being hidden behind R. trichobasis name. We evaluated the species R. coveloae (Traver, 1971) and R. venezuelensis (Traver, 1943) considering the new evidence. After analyzing the paratype of R. trichobasis and records of the species in Brazil, the hidden-species hypothesis was corroborated. Five new species were identified among the published records of R. trichobasis of which four are described here: R. amazona sp. nov. (Roraima State), R. oxum sp. nov. (Rondônia State), R. uiara sp. nov. (Amazonas State), R. naia sp. nov. (Roraima State). The fifth species, Rivudiva sp. X from Maranhão State, could not be described due to the poor conservation of the specimen and is therefore left in open nomenclature. Records from Espírito Santo State (Brazil) and from Paraguay are treated as putative and must be evaluated considering the new evidence. Rivudiva venezuelensis and Rivudiva coveloae are diagnosed and illustrated based on type material. After analyzing these two species, we hypothesize that only R. coveloae likely belongs to the genus Rivudiva. However, information on the nymphal stage is needed to corroborate this hypothesis.

A 100-million-year-old ensiferan with unusual mouthparts and comments on the evolution of raptorial appendages within Polyneoptera

Myanmar amber is known to provide fossils of the group Insecta with surprising morphologies. Here we present fossils of the new species Gryllobencain patrickmuelleri n. gen., n. sp. from Myanmar amber that possess an overall “orthopteroid” morphology, hence resemble crickets. Unlike in most crickets, thorax appendages 1 and 2 (“legs”) are large and prominent, even in comparison to thorax appendage 3. Furthermore, thorax appendages 1 and 2 are able to fold against themselves and are armed with prominent spine-like setae, indicating that these legs were originally used for grasping prey. Most prominent is a large spine on the tibia of both appendages distantly reminding of the tibial spur or claw of praying mantises. Comparable prey-catching apparatuses have evolved repeatedly in the group Polyneoptera: gladiators (Mantophasmatodea), three ingroups of bush-crickets (Saginae, Austrosaginae, Listroscelidinae) as well as one species of fossil mantises (Santanmantis axelrodi Grimaldi, 2003) appear to have used thorax appendages 1 and 2 for prey catching. The new fossils do not seem to be closely related to any of these groups. They differ especially by prominent cerci equipped with numerous, probably mechano-sensorial setae. In the other five groups, the cerci are significantly smaller, often indistinct. The fossils furthermore have prominent maxillae with sickle-shaped proximal parts and well-armed large palps, indicating that the maxillae played an important role in processing the prey. While the thorax appendages hence represent a case of clear convergent evolution, the uniqueness of the feeding apparatus leads us to recognise the fossils as a highly specialised new species.

A new genus and species of the family Cormopsocidae (Psocodea: Trogiomorpha) from mid-Cretaceous amber of Myanmar

A new genus Stimulopsocus gen. nov. with one new species Stimulopsocus jiewenae sp. nov. is described from the mid-Cretaceous Burmese amber. This new genus is assigned to the family Cormopsocidae according to the following characters: forewing anterior and posterior margins almost parallel; dark quadrangular pterostigma present; forewing with crossvein r-rs and only one A. Some characters in Stimulopsocus gen nov. differ from the other genera of Cormopsocidae, i.e., a length of Sc appearing as a crossvein-like veinlet at middle of forewing; all tibiae with spine-like setae. Remarkably, the forewing Sc of Stimulopsocus is more similar to Permopsocida than to Psocodea.

A new genus of Laelapidae (Acari: Mesostigmata) from South America

Hypoaceus gen. nov., a new genus of the family Laelapidae Berlese, is erected and described to accommodate Hypoaceus eugenitalis (Karg) comb. nov. and Hypoaceus pycnosis (Karg) comb. nov. that have been collected from Chile and Argentina. Important morphological characters of the above-mentioned species are presented and redescribed based on the type species. Some of the important morphological characters of the new genus are as follows: setae st4 absent; genitiventral shield well expanded posterior to coxae IV with two-three pairs of setae including st5 and bears numerous pore-like structures on the surface; interior appendages of internal malae elongate and scarcely barbed; epistome with fair denticles anteriorly; supralabral process long and style like; straight spermadactyl is about of twice of movable digit length; apotele two tined; male holoventral shield bearing numerous pore-like structures on the surface. Tarsus II both in male and female bearing strong spur or spine-like setae (av1 and pv1); male with strong spur-like seta (pv1) on femur II.

A new genus of the pseudoscorpion family Chernetidae (Pseudoscorpiones) from southern Australia with Gondwanan affinities

A new genus of pseudoscorpions of the family Chernetidae, Austinochernes, is described for two new Australian species, A. andrewaustini (type species) from South Australia and Victoria, and A. zigzag from Tasmania. They are most similar to species of the Neotropical genus PseudopilanusBeier, 1957 in the possession of a spine-like seta on the prolateral face of the chelal hand at the base of the fingers, but differ by the presence of acuminate setae on the male pedipalpal trochanter. The suspected relationship between Austinochernes and Pseudopilanus suggests that their distribution is the result of Gondwanan vicariance.

Living on a sticky trap: natural history and morphology of Bactrodes assassin bugs (Insecta: Hemiptera: Reduviidae: Bactrodinae)

ABSTRACT Plants with glandular trichomes have been shown to attract specialist, mutualistic predatory insects. Despite recent advances in understanding the plant component in this association, few sticky plant specialist insects are well documented and their adaptations to the sticky plant environment are understudied. We here describe and illustrate, for the first time, aspects of the natural history and morphology of a small clade of predatory hemipteran insects, the Bactrodinae (Reduviidae). Our study suggests that these insects are exclusively associated with plant species with glandular trichomes. The relationship is not specific as one species of Bactrodes Stål may be associated with multiple species, genera or even families of plants. We document a unique clamp-like structure formed by one of the pretarsal claws and opposing tarsal spine-like setae that enables Bactrodinae to grasp trichomes and walk on leaves densely covered with trichomes. We further present observations of Bactrodes species scavenging on insects entrapped on leaves. Bactrodinae also oviposit on their host plants, and females engage in behaviours that we interpret as maternal egg guarding, a life history strategy that is rare in predatory true bugs. We speculate that instead of or in addition to decreasing egg predation or egg parasitism, female egg guarding may be a response to the limited availability of sticky plants and a strategy against cannibalism.

Philibaetis gen. nov., a new genus from the Philippines (Ephemeroptera, Baetidae)

Investigations of type material and new material from the Philippines (Luzon) revealed that Baetis luzonensis Müller-Liebenau, 1982 and B. realonae Müller-Liebenau, 1982 do not belong to Baetis Leach, 1815. A new genus, Philibaetisgen. nov., is described to accommodate both species and both are re-described based on larvae. The new genus is characterised by having a rectangular labrum with a submarginal row of long, simple setae on the dorsal surface and ventrally on lateral margins long, simple, spine-like setae, on anterolateral margins long, feathered setae and medially long, bifid setae and a partial, submarginal row of lanceolate setae. Both mandibles have blade-like incisors and dorsally, a mediolateral patch of long, spine-like setae; additionally, the left mandible has a tuft of long, partly branched setae at the base of the subtriangular process. Philibaetisgen. nov. is further characterised by a hypopharynx with a medial tuft of stout setae and anterolaterally, two smaller tufts of stout setae, a galea-lacinia with the distal denti-seta tooth-like and directed against canines, a fore femur apically with stout setae, both on anterior and posterior side and without a femoral patch and a claw with one row of denticles and two or three subapical setae. The protogonostyli under the cuticle of male last instar larvae are folded in the Labiobaetis type, excluding their affiliation to the genus Baetis. COI sequences were obtained from both species. The genetic distance (Kimura 2-parameter) between them is 17.5% on average. Very limited genetic distances of 0% to 3% (0.75% on average) were found between specimens of P. luzonensiscomb. nov.

Ontogenetic and morphological studies on Tetranychus canadensis (Acari: Tetranychidae).

Tetranychus canadensis (McGregor) is redescribed based on type specimens and American non-type specimens. The ontogenetic development of leg chaetotaxy is provided, which is the typical additional pattern for Tetranychus. The variation of pregenital striae and shape of aedeagi are discussed. Low temperature scanning electron microscopic photos show the supracoxal setae on palpfemur (ep) and leg coxae I (el) are eupathidia; lateral and ventral lips bear modified leaf-like adoral setae (or2 and or3) and the dorsal lips bearing a pair of spine-like dorsal adoral setae (or1); dorsal seta on tibia I (db) is a trichobothrium with a cup-shaped base and broken striae on the inner integument. Confocal scanning shows a thin, long ejaculatory duct and a thicker duct connecting the aedeagus to a cup-shaped seminal vesicle; the aedeagus is hollow where the ejaculatory duct passes through.

A new genus and species of Katiannidae (Collembola: Symphypleona) from Bolivia.

The new genus Borgesminthurinus gen. nov. from Bolivia shares with Sminthurinus the presence of antennal segment IV undivided, antennal segment III with one papilla; sacs of ventral tube smooth; each tenacular rami with 3 teeth and a basal appendix. They also have dens with ventral chaetotaxy reduced and lack mucronal seta; but new genus clearly differs in having thick and barbulate setae on head and body, lacking neosminthuroid setae on abdomen and the presence of seta a0 on Abd. VI acuminate. The new genus differs from Katianna which has divided antennal segment IV, vertex of head with spine-like setae and setae of the body long and smooth.