A new species of Dixella, the first Mexican record of Dixella shannoni, and a summary of dixid records from Mexico (Diptera: Dixidae)

We describe a new species of the genus Dixella Dyar & Shannon of Mexico. Specimens were collected in Lagunas de Santo Domingo, Municipality of Huatusco, Veracruz, a small vegetation-lined lake within an increasingly relictual mountain cloud forest. This species is most closely related to Dixella cumbrica Peters & Cook, 1966, based upon the shape of the apical lobe of the gonocoxite and flattened gonostylus. Also, we include the first record of Dixella shannoni (Lane, 1942), in Mexico, based upon specimens collected in Santiago Yaveo, Oaxaca. Additionally, we present a list of all localities in which dixids have been collected in Mexico.

A new genus and species of groundwater isopod of the family Protojaniridae (Isopoda: Asellota: Gnathostenetroidoidea) from southern Chile

A new asellotan isopod of the family Protojaniridae Fresi, Idato & Scipione, 1980 is described from freshwater springs in the Osorno province, Los Lagos region, southern Chile. Wiyufiloides osornoensis gen. & sp. n. is the third South American protojanirid species and the first known groundwater isopod in Chile. The new genus and species is principally characterized by the presence of a vestigial antennal scale, a strongly subchelate pereiopod I and the absence of an apical lobe on the protopod of pleopod II. The new taxon is described in detail and figures are given.

Two new species of Octomeria (Pleurothallidinae) from Cordillera del Cóndor, Zamora Chichinpe, Ecuador

Two new species of orchids, Octomeria pacii, and O. panguiensis are described and illustrated from Cordillera del Cóndor, Ecuador; likewise, information is provided on their distribution, habitat, and conservation status. These species differ from other species in the genus by their floral and vegetative characteristics and their apparent reproductive strategy of cleistogamy. Octomeria pacii is similar to Octomeria deceptrix, but differs in the caespitose habit, the ramicauls compressed along their entire length, the narrowly elliptical leaves, the autogamous flowers, the translucent white sepals suffused with magenta and the obovate, white lip, marked with magenta. Octomeria panguiensisis similar to O. werneri, but differs by the larger, shortly repent plants with lanceolate leaves, the cleistogamous flowers, the translucent white-colored sepals, the 5-veined lateral sepals and the oblong-trilobed lip with the apical lobe tridentate Keywords: self-compatibility, self-pollination, cleistogamy, Octomeria deceptrix, Octomeria werneri

Subdomain cryo-EM structure of nodaviral replication protein A crown complex provides mechanistic insights into RNA genome replication

For positive-strand RNA [(+)RNA] viruses, the major target for antiviral therapies is genomic RNA replication, which occurs at poorly understood membrane-bound viral RNA replication complexes. Recent cryoelectron microscopy (cryo-EM) of nodavirus RNA replication complexes revealed that the viral double-stranded RNA replication template is coiled inside a 30- to 90-nm invagination of the outer mitochondrial membrane, whose necked aperture to the cytoplasm is gated by a 12-fold symmetric, 35-nm diameter “crown” complex that contains multifunctional viral RNA replication protein A. Here we report optimizing cryo-EM tomography and image processing to improve crown resolution from 33 to 8.5 Å. This resolves the crown into 12 distinct vertical segments, each with 3 major subdomains: A membrane-connected basal lobe and an apical lobe that together comprise the ∼19-nm-diameter central turret, and a leg emerging from the basal lobe that connects to the membrane at ∼35-nm diameter. Despite widely varying replication vesicle diameters, the resulting two rings of membrane interaction sites constrain the vesicle neck to a highly uniform shape. Labeling protein A with a His-tag that binds 5-nm Ni-nanogold allowed cryo-EM tomography mapping of the C terminus of protein A to the apical lobe, which correlates well with the predicted structure of the C-proximal polymerase domain of protein A. These and other results indicate that the crown contains 12 copies of protein A arranged basally to apically in an N-to-C orientation. Moreover, the apical polymerase localization has significant mechanistic implications for template RNA recruitment and (−) and (+)RNA synthesis.

Tanaella quintanai, a new deep-water tanaellid (Crustacea: Peracarida: Tanaidacea) from the Colombian Caribbean Coast, with a key to the species of the genus Tanaella Norman & Stebbing, 1886

A new tanaidacean, Tanaella quintanai sp. nov., is described based on specimens collected from depths of 1,598 to 2,853 m during 2014–2015. The new species appears to be most closely related to the western Atlantic species, T. kroyeri and T. mclellandi. Tanaella quintanai can be separated from the two former, as well as from the other members of the genus by a combination of characters, including (1) a labium with apical lobe bearing one blunt seta (2) a cheliped with the inner margin of the dactylus bearing a sub-proximal bipinnate seta, (3) pereopods 1−3 with basis having sub-dorsoproximal and sub-ventroproximal margins setulose, (4) pereopods 4−6 with basis having ventroproximal margin setulose, (5) pereopods 4−6 with unguis bearing two parallel rows of small setules, and (6) a pleotelson as long as pleonites 1–5 combined. A key separating the currently recognized species of Tanaella is presented.

Four new species of Actinopus (Mygalomorphae: Actinopodidae) from Uruguay

Actinopus specimens from different localities in Uruguay that did not match any of the previously species present in the country were examined, and four new species are described: A. coboi sp. nov., from Colonia province; A. fernandezi sp. nov., from Salto province; A. simoi sp. nov., from Maldonado province; and A. uruguayense sp. nov., from Colonia and Cerro Largo provinces. The record of the species A. longipalpis for Montevideo is rejected and A. liodon is considered “species inquirenda”. Actinopus coboi has spermathecae with an apical lobe diagonally directed; A. fernandezi is characterized by a stylized copulatory bulb and its greater number of retrolateral thorns on tibia II. Actinopus simoi can be distinguished from A. uruguayense by its carapace with a dark coloration; a reddish coloration in the palpal tibia and the shape of its spermathecae and copulatory bulb. With the presence of the Argentinian species—A. gerschiapelliarum, A. puelche and A. insignis—the number of species known in the country is increased to nine. All new species are diagnosed and illustrated; a dichotomous key to all species of Actinopus from Uruguay is also provided.

First records of Gnathia Leach, 1814 and Tachaea Schioedte & Meinert, 1879 from South Korea, with descriptions of two new species (Isopoda, Cymothoida, Cymothooidea)

Two new species of cymothoid isopods,Gnathiakoreanasp. n.andTachaeakoreaensissp. n., are described from South Korea. The generaGnathiaLeach, 1814 andTachaeaSchioedte & Meinert, 1879 are recorded for the first time in South Korea.Gnathiakoreanasp. n.is distinguished from its congeners by having the smooth dorsal surface of the pereon, the strongly ridged unornamented paraocular ornamentation, the strong bifid mediofrontal process, and the serrated superior frontolateral process.Tachaeakoreaensissp. n.is distinguished from its congeners by having the expanded propodus with serrated inferior margins in pereopods 1–3, the propodus with serrated inferodistal margins in pereopods 4–7, one seta on the apical lobe of the maxilla, and ten robust setae on the posterior margin of the pleotelson.

Description of a new neotropical species of Xiqilliba Kramer (Hemiptera: Cicadellidae: Neocoelidiinae)

Xiqilliba Kramer is revised, and a new species, Xiqilliba sakakibarai sp. nov. is described and illustrated. The type species of the genus, Xiqilliba bellator Kramer, is redescribed. The new species can be differentiated from X. bellator by the morphology of the male genitalia, especially by: (1) shorter quadrangular pygofer with bifurcated apical lobe; (2) long and slender style with strong basal curvature; (3) enlarged aedeagus with two pairs of apical processes; and (4) anal tube with pair of short processes of rounded apices. A generic diagnosis and redescription are provided, as well as illustrations of Xiqilliba species.

An ancient FMRFamide-related peptide–receptor pair induces defence behaviour in a brachiopod larva

Animal behaviour often comprises spatially separated sub-reactions and even ciliated larvae are able to coordinate sub-reactions of complex behaviours (metamorphosis, feeding). How these sub-reactions are coordinated is currently not well understood. Neuropeptides are potential candidates for triggering larval behaviour. However, although their immunoreactivity has been widely analysed, their function in trochozoan larvae has only been studied for a few cases. Here, we investigate the role of neuropeptides in the defence behaviour of brachiopod larvae. When mechanically disturbed, the planktonic larvae of Terebratalia transversa protrude their stiff chaetae and sink down slowly. We identified endogenous FLRFamide-type neuropeptides (AFLRFamide and DFLRFamide) in T. transversa larvae and show that the protrusion of the chaetae as well as the sinking reaction can both be induced by each of these peptides. This also correlates with the presence of FLRFamidergic neurons in the apical lobe and adjacent to the trunk musculature. We deorphanized the AFLRFamide/DFLRFamide receptor and detected its expression in the same tissues. Furthermore, the ability of native and modified FLRFamide-type peptides to activate this receptor was found to correspond with their ability to trigger behavioural responses. Our results show how FLRFamide-type neuropeptides can induce two coherent sub-reactions in a larva with a simple nervous system.

Three new species of Nilothauma Kieffer (Diptera: Chironomidae) from Brazil

Three new species of Nilothauma from Brazil are described and illustrated based on adult males. Nilothauma paucisetis sp. nov. is similar to Nilothauma aripuanense Mendes & Andersen, 2009, but can be distinguished by the number of dorsal setae on tergite IX and by the shape of anal point. Nilothauma anamariae sp. nov. is easily recognized by having the inferior volsella L-shaped, with a long simple lateral bristle and an apical lobe directed inwards, bearing 10–12 apically split setae. Nilothauma jaquei sp. nov. is distinguished from all others congeneric species by the superior volsella without microtrichia, with one apical seta and a lateral spine.