Diesel effects on some population attributes of Orthonychiurus folsomi Schäffer 1900 (Collembola: Onychiuridae) under laboratory conditions.

Soil contamination by hydrocarbons and its effects on population health and welfare is a growing concern, especially in urban environments with industrial activity. Indicator species complement the information obtained from the measurement of environment quality by using physicochemical variables. The objective of this study was to evaluate the response of a springtail species that could be potentially used as a bioindicator of hydrocarbon contaminated sites. We studied the effects of seven diesel concentrations on survival and other population parameters of Orthonychiurus folsomi under laboratory conditions; we evaluated the springtails response on survival, fecundity, population size, hatching and development time. Survival and fertility were analyzed by using generalized linear models (GLM). An ANOVA test was used to analyze the final population size and a Kruskal-Wallis test for oviposition, hatching, and development times. Results showed that diesel has negative effects on some population parameters. The most evident effects were recorded above 500 mg/kg concentrations. A significant decrease in survival, fertility, and population size was recorded in function of diesel concentration increase. The estimated LC50 for survival was 955 mg/kg. Oviposition and hatching time increased significantly when diesel concentrations were above 500 mg/kg, while development time increased slightly at low diesel concentrations but decreased at concentrations above 500 mg/kg. Population final size decreased as soil diesel concentrations increased. Due to the sensitive and rapid response of O. folsomi, it could be useful to detect diesel-contaminated soil, mainly in urban areas.

Soil microarthropods and their relationship to higher trophic levels in the Pedregal de San Angel Ecological Reserve, Mexico.

Soil fauna is essential for ecosystem dynamics as it is involved in biogeochemical processes, promotes nutrient availability, and affects the animal communities associated with plants. In this study, we examine the possible relationship between the soil microarthropod community on foliage production and quality of the shrub Pittocaulon praecox. We also examine the arthropods associated to its foliage, particularly the size of the main herbivores and of their natural enemies, at two sites with contrasting vegetation cover and productivity. The diversity of soil microarthropods was assessed from soil samples collected monthly under P. praecox individuals over 13 mo. Specimens collected were identified to species or morphospecies. Shrub foliage productivity was evaluated through the amount of litter produced. Resource quality was assessed by the mean content (percentage by weight) of N, C, S, and P of 30 leaves from each shrub. The mean size of herbivores and their natural enemies were determined by measuring 20 adult specimens of each of the most abundant species. We found a higher species richness of soil microarthropods and foliar arthropods in the open site, although the diversity of foliage arthropods was lower in the closed site. Shrubs growing in the closed site tend to produce more, larger, and nutritionally poorer (lower nitrogen content) leaves than open site. Herbivores and their natural enemies were also larger in the closed site. We found a significant positive relationship between the diversity and species richness of foliar arthropods and the nitrogen content of leaves. In general, species richness and diversity of both the foliar and soil fauna, as well as the size of organisms belonging to higher trophic levels, were affected by vegetation cover and primary productivity at each site. These findings highlight the need to simultaneously consider at least four trophic levels (soil organisms, plants, herbivores, and natural enemies) to better understand the functioning of these systems and their responses to environmental changes.

First record of the genus Australonura Cassagnau 1980 (Collembola: Neanuridae) in the New World, with description of a new species from Paraguay.

The genus Australonura Cassagnau 1980 is newly recorded from South America. The Patagonian species Paleonura limnophila (Cassagnau & Rapoport, 1962) and Paleonura friasica Cassagnau & Oliveira, 1990 are redescribed from type material and recombined in Australonura. A new species, A. paraguayensis sp. nov., is described from Paraguay and assigned to Australonura for its head tubercle arrangement. It differs from other species of the genus by its adjacent but separate dorso-internal tubercles of Abd. V.

A new Mexican species of the Cryptopygus complex (Collembola, Isotomidae) associated with the hermit crab Coenobitaclypeatus (Crustacea, Coenobitidae).

A new species of Cryptopygus Willem, 1901 associated with hermit crabs living on seashores of Quintana Roo State, Mexico, is described and illustrated. It is blind, with 9-11 postlabial setae, unguis with a pair of lateral teeth, empodial appendix lanceolate and almost as long as unguis, tenaculum with 4 + 4 teeth and 3-4 setae on corpus, manubrium with 11-14 pairs of manubrial setae on anterior surface and 17-18 pairs on posterior surface, and mucro bidentate. An updated key for the identification of 29 American species of Cryptopygus complex is included.

Study on the genus Morulina (Collembola: Neanuridae) with description of a new species from Northwest China.

A new species of Morulina from China is described and illustrated. It is close to M. orientis Tanaka from Japan and M. himalayana Cassagnau from Nepal. There are 12 tubercles on the head of all three species, but they can be separated by a number of chaetotaxic characters. A key for identification of all the species in the genus is given.

The subfamily Pachyotominae in Mexico (Collembola: Isotomidae) with description of a new Pachyotoma species.

Pachyotoma primamexicana sp. nov, from Popocatépetl, Mexico is described; it is similar to Pachyotoma alpa (Christiansen & Bellinger, 1980) and P. muskegis (Guthrier, 1903). It can be distinguished from all other the members of the genus by the small size of PAO (about half the size of closest eye) and the formula (2,3,3) of the slightly capitate tenent hairs. An identification key for Nearctic Pachyotominae and a table with diagnostic morphological characters to the Nearctic species of the genus with integument clearly granulated is given. Three new records of species from Mexico are listed: Pachyotoma crassicauda (Tullberg, 1871), Coloburella octogenaria (Mills & Schmidt, 1957) and Bonetrura boneti (Yosii, 1962). A discussion on the distribution of the subfamily Pachyotominae and some notes on the biogeography of the subfamily are provided.

Complete mitochondrial genome of the Mexican marine littoral hygrophilous Spinactaletes boneti (Collembola: Actaletidae) and its phylogenetic placement.

Spinactaletes boneti mitochondrial genome was assembled and annotated. It has 14,766 bp in length, all 37 genes are present and the gene order is the same as the Pancrustacean ancestral gene order. Phylogenetic analyses based on maximum likelihood placed the species as a sister group of the remaining Entomobryomorpha, not closely related to the Isotomoidea superfamily, contradicting the actual systematics of the group.

Comparison of traditional and DNA metabarcoding samples for monitoring tropical soil arthropods (Formicidae, Collembola and Isoptera).

The soil fauna of the tropics remains one of the least known components of the biosphere. Long-term monitoring of this fauna is hampered by the lack of taxonomic expertise and funding. These obstacles may potentially be lifted with DNA metabarcoding. To validate this approach, we studied the ants, springtails and termites of 100 paired soil samples from Barro Colorado Island, Panama. The fauna was extracted with Berlese-Tullgren funnels and then either sorted with traditional taxonomy and known, individual DNA barcodes ("traditional samples") or processed with metabarcoding ("metabarcoding samples"). We detected 49 ant, 37 springtail and 34 termite species with 3.46 million reads of the COI gene, at a mean sequence length of 233 bp. Traditional identification yielded 80, 111 and 15 species of ants, springtails and termites, respectively; 98%, 37% and 100% of these species had a Barcode Index Number (BIN) allowing for direct comparison with metabarcoding. Ants were best surveyed through traditional methods, termites were better detected by metabarcoding, and springtails were equally well detected by both techniques. Species richness was underestimated, and faunal composition was different in metabarcoding samples, mostly because 37% of ant species were not detected. The prevalence of species in metabarcoding samples increased with their abundance in traditional samples, and seasonal shifts in species prevalence and faunal composition were similar between traditional and metabarcoding samples. Probable false positive and negative species records were reasonably low (13-18% of common species). We conclude that metabarcoding of samples extracted with Berlese-Tullgren funnels appear suitable for the long-term monitoring of termites and springtails in tropical rainforests. For ants, metabarcoding schemes should be complemented by additional samples of alates from Malaise or light traps.

[Distribution and diversity of springtails (Hexapoda: Collembola) on the altitudinal gradient of a temperate forest in Mexico]. / Distribución y diversidad de colémbolos (Hexapoda: Collembola) en el gradiente altitudinal de un bosque templado en México.

Mountain ecosystems have shown slow mineralization activity due to weather conditions, and to some groups with arthropods with special roles. The Collembola is an important group for litter fragmentation, showing different distribution patterns. The objective of the present study was to determine the diversity of Collembola along a volcano altitudinal gradient. For this, four sampling expeditions evaluated four altitudinal levels (I = 2 753, II = 3 015, III = 3 250 and IV = 3 687 masl) in Iztaccihuatl Volcano, from November 2003, and March, June and August 2004. Shannon diversity (H'), Pielou evenness (J') and Simpson dominance (1/lambda) indices were calculated. The similarity between the associations of springtails between the sampling sites was evaluated by a cluster analysis using the Pearson correlation coefficient, as distance and the unpaired arithmetic averages (UPGMA) as amalgamation method. A total of 24 075 springtails, distributed in 12 families, 46 genera and 86 species was collected. The higher species abundance was found at the altitudinal area II. The lowest diversity value was recorded in IV, while the higher diversity values were found in III. Significant differences between Shannon indices were found between zones II-III (t(0.01, 187) = 4.11, p < 0.05) and between III-IV (t(0.01, 187) = 3.8, p < 0.05) according to modified t-test. When considering sampling dates, no significant differences were found. The dendrogram showed that in composition the level I is more homogeneous throughout the year. In conclusion, a statistically significant seasonal variation in springtail abundances was not found, but it was observed that, the lower altitude (I) resulted more homogeneous along the studied period, followed by level II and III. There is a particular assemblage of springtails community in each altitudinal area studied; in general, the sites with low slope resulted more diverse in Collembola communities. These results show that there are important factors such as altitude, vegetation type and microhabitat heterogeneity that may affect the distribution of springtails communities along an altitudinal gradient.

Four new species of Parajapyx (Diplura: Parajapygidae) from Mexico with redescription of Parajapyx isabellae aztecus Silvestri.

Four new Mexican Parajapyx species are described: P. silvestrii sp. nov. differs from P. adisi Pagés by the presence of one ma macroseta on mesoscutum, metascutum and abdominal scutum I; P. pagesi sp. nov. differs from P. grassianus Silvestri in the arrangement and number of macrosetae on all abdominal scuta; P. brunocondei sp. nov. is characterized by the unique feature of 50 glandular setae on the subcoxal organs and femur with one macroseta; P. yunyanorum sp. nov. differs from P. reymi Pagés by having some reduced macrosetae on the mesoscutum and metascutum and one lp macroseta lacking on abdominal II to VII scuta. A redescription of P. isabellae aztecus Silvestri, 1948 is presented including additional characters not previously reported, such as complete body chaetotaxy and descriptions of leg III, antennae and cercus. An identification key is presented for Mexican species of Parajapyx.

Two New Species of Sminthurides Börner, 1900 (Collembola: Sminthurididae) from Mexico with Comments on the Genus and a Key to the Members from the Americas.

A survey of Sminthurides Börner, 1900 with specimens from the Americas was performed and two new species from Mexico are described and illustrated (drawings and SEM photographs), including a detailed study of body chaetotaxy. Sminthurides cihuatlensis sp. nov. is part of the Aquaticus group by the presence of ciliate seta B1 on Ant. II; it has a narrow mucro and lives in soil from the slopes of Iztaccíhuatl volcano. Sminthurides fridakahloae sp. nov. belongs to the Penicillifer group by the presence of Tra-2 on the Ant. II; it has a broad, trilamellate mucro, dens with plurichaetosis, and lives on surface freshwater from Colima and Morelos states. In addition, a key for the species is provided.

Biological activity of the mite Sancassania sp. (Acari: Acaridae) from bat guano associated with the pathogenic fungus Histoplasma capsulatum.

Mites and the mammal pathogenic fungus Histoplasma capsulatum are the major components of bat guano microbiota. Interactions between mites and H. capsulatum were evaluated under laboratory conditions. Acarid mites, mainly Sancassania sp., were the most abundant microarthropod in the sampled guano of the Mexican bat Tadarida brasiliensis mexicana and, based on its morphology, Sancassania sp. was similar to the cosmopolitan species Sancassania sphaerogaster. The mycophagous and vectoring activities of this mite were tested for H. capsulatum and two other fungal species, Sporothrix schenckii (pathogenic) and Aspergillus sclerotiorum (non-pathogenic). S. ca. sphaerogaster was able to reproduce in H. capsulatum and S. schenckii colonies, multiplying in great numbers under controlled fungal mycelial-phase culture conditions. H. capsulatum colonies were completely destroyed after 14 days of in vitro interaction with mites. In contrast, S. ca. sphaerogaster did not reproduce in A. sclerotiorum cultures. S. ca. sphaerogaster was found vectoring H. capsulatum, but not the two other fungal species studied.

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.

New records of Collembola from marine littoral sand of Hainan Island, China, with description of a new Oudemansia species (Neanuridae: Pseudachorutinae).

One new species of springtail, Oudemansia chenorum sp. nov., is described and illustrated. Pseudanurida sawayai Schuster, 1965 is reported from Hainan Island for the first time. An identification key for the species of Oudemansia Schött, 1893 is provided and remarks are made on its peculiar morphology as well as that of close related genera. The presence of pseudocelli is further confirmed on members of the genus Oudemansia.

A new species of Odontella from Tierra del Fuego and notes on Afrodontella Deharveng, 1981 (Collembola: Odontellidae).

Odontella rapoporti sp. nov., from Tierra del Fuego is described, as the third species of the Odontella lobata group, which has a subantarctic distribution. The new species is similar to O. lobata and O. setosa, but can be distinguished from them by the number of chaetae on the dens (6 or 7 chaetae in O. setosa vs. 5 chaetae in the other species) and the number of chaetae in the distal whorl of the tibiotarsus (9 chaetae in O. lobata vs. 11 in the other species). The closely related monotypic genus Afrodontella Deharveng, 1981, and its type species (A. septemlobata) are described.

A new species of the genus Neotropiella Handschin, 1942 (Collembola: Neanuridae) from Peru.

BACKGROUND: Neotropiella is a genus of springtails which can be of medium size (2 mm) or relatively long (5 mm). These springtails live in leaf litter, under the bark of dead trees or in decomposing wood, mainly in the Neotropical Region and are often collected by litter samples on Berlese funnels or by pitfall traps. Most species have been described, based on relatively few specimens and chaetotaxy of several species is incomplete. NEW INFORMATION: A new species within Neotropiella was discovered in recent pitfall trap collections from Peru. Neotropiella peruana sp. n. was taxonomically treated and studied under both phase contrast and scanning electron microscopy. It is similar to N. insularis from Brazil, but smaller with only 4 mandibular teeth (vs. 5) and with well-developed unguis lateral teeth. Intraspecific variation of the new species is provided. We also present the first DNA barcodes for the genus.

New species of Furculanurida (Collembola, Neanuridae, Pseudachorutinae) from the Luquillo Mountains, Puerto Rico.

A new species of Furculanurida is described and illustrated. Furculanurida bistribus sp. nov. differs from other species of the genus by the presence of three eyes, three setae on the dens, and the white and purple coloration pattern. A key for identification of the world species of the genus is included.

A new Caribbean species of Hylaeanura Arlé, 1966 (Collembola, Neanuridae, Pseudachorutinae).

We here describe a new Collembola species, Hylaeanura emiliae sp. nov., from the Luquillo Experimental Forest in Puerto Rico. We describe H. emiliae sp. nov. as a distinct species based on the enlarged sensilla s3 in antennal segment IV, the absence of modified sensorial setae in abdominal segment IV and the presence of four setae on each dens. An updated key with illustrations for the identification of worldwide species of the genus is included.

An extraordinary new genus and species of Pseudachorutinae (Collembola: Neanuridae) from Colombia.

A new genus of springtail, Sernatropiella gen. nov., from Cundinamarca province, Colombia, was found at an altitude close to 3.000 m above sea level. It is the largest Neanuridae known in the Northern part of the South American Transition Zone. It is characterized by the presence of a strong hypertrichosis, five eyes per side, very small moruliform postantennal organ and a long buccal beak. Mouth parts very thin and slender. Body with paratergal areas different from other Pseudachorutinae of the region. Thorax and abdominal segments I and II with pre- and post-segmental tergites with setae, and most remarkable is the presence of pseudocelli on head, thorax and abdomen of the type species Sernatropiella pinzonae gen. et sp. nov. A new combination for Neotropiella malkini Arlé, 1981 as Sernatropiella malkini (Arlé, 1981) comb. nov. is given and is considered as a member of the new genus.

First Mexican species of the genus Cosberella (Collembola, Hypogastruridae).

A new species of Cosberella is described and illustrated from a temperate forest of Citlaltépetl formation, Veracruz State. It is characterized by the following combination of characters: Th I with 2 + 2 dorsal setae; 2 + 2 axial setae on Th II-III; two capitate tenent hairs on each leg; unguiculus half the length of unguis; unguis with tooth; six dental setae and Abd VI without anal spines. A key for the species of the genus is included.