The biocontrol nematode Phasmarhabditis hermaphrodita infects and increases mortality of Monadenia fidelis, a non-target terrestrial gastropod species endemic to the Pacific Northwest of North America, in laboratory conditions

Inundative biological control (biocontrol) efforts in pest management lead to the mass distribution of commercialized biocontrol agents. Many 'biocontrol gone awry' incidents have resulted in disastrous biodiversity impacts, leading to increased scrutiny of biocontrol efforts. The nematode Phasmarhabditis hermaphrodita is sold as a biocontrol agent on three continents and targets pest gastropods such as Deroceras reticulatum, the Grey Field Slug; P. hermaphrodita is not presently approved for use in the United States. Investigations into the potential for P. hermaphrodita to infect non-target gastropod species of conservation relevance, however, are limited. We examined the effects of three strains of P. hermaphrodita on mortality in Monadenia fidelis, the Pacific Sideband, a snail species endemic to the Pacific Northwest of North America, in laboratory conditions. Across a 71-day laboratory infectivity assay, snails exposed to each of the three nematode strains, each analyzed at two doses, experienced a mean 50% mortality by days 20-42. All nematode-treated snails were dead by the end of the study. By contrast, 30/30 water-control snails experienced no mortality. Nematodes killed smaller, juvenile-stage snails significantly faster than those in larger and more developmentally advanced hosts. Our results provide direct evidence that the biocontrol nematode P. hermaphrodita infects and kills M. fidelis, a non-target gastropod species endemic to the Pacific Northwest, in laboratory conditions. This study suggests that introduction of P. hermaphrodita to new ecosystems might negatively impact endemic gastropod biodiversity and advocates for further investigation of non-target effects, including in conditions closer to the natural environments of non-target species.

Pestiferous slugs and their associated nematodes in agricultural fields, greenhouses, and nurseries in Alberta, Canada

Some slug species are considered a nuisance in agriculture and horticulture worldwide, causing economic losses to growers. Phasmarhabditis is a genus of bacteria-feeding nematodes that can parasitize slugs and snails and thus potentially serve as a biological control agent. Canada had no record of Phasmarhabditis until a survey conducted in 2019 reported a Canadian strain of Phasmarhabditis californica from a single Arion rufus slug. To build on this discovery, we surveyed three major agricultural sites, ten greenhouses, and nurseries in Alberta from June to September 2021 to collect pest slug species and investigate their associated nematodes, specifically P. californica. Slugs were collected from the field and returned to the laboratory to check for emerging nematodes on White traps. We collected 1331 slugs belonging to nine species, with Deroceras reticulatum being the most common. Only 45 (3.38%) slug samples were positive for nematodes, and the majority were identified to species level: Alloionema appendiculatum, Caenorhabditis briggsae, Caenorhabditis elegans, Panagrolaimus subelongatus, and Mesorhabditis spiculigera. We did not isolate P. californica from any of the slugs collected from these survey sites, which included the original site where P. californica was discovered. However, four D. reticulatum slugs retrieved from a residential garden sample were infected with P. californica. These findings suggest the possibility of a fragmented distribution of P. californica across Alberta. Future research should focus on extensively surveying agriculture and horticulture sites and residential gardens in different provinces across Canada.

Gosodesmine, a 7-Substituted Hexahydroindolizine from the Millipede Gosodesmus claremontus

Millipedes (Diplopoda) are well known for their toxic or repellent defensive secretions. Here we describe gosodesmine (1), 7-(4-methylpent-3-en-1-yl)-1,2,3,5,8,8a-hexahydroindolizine, a unique alkaloid with some terpene character found in the chemical defense secretions of the millipede Gosodesmus claremontus Chamberlin (Colobognatha, Platydesmida, Andrognathidae). The structure of 1 was suggested by its mass spectra and GC-FTIR spectra and established from its ¹H, ¹³C, and 2D NMR spectra and 1D NOE studies. The 7-substituted indolizidine carbon skeleton of 1 was confirmed by unambiguous synthesis. This is the first report of an alkaloid from a platydesmid millipede and the first report of a 7-substituted indolizidine from an arthropod.

Assessment of volunteered geographic information for vegetation mapping

Vegetation mapping requires extensive field data for training and validation. Volunteered geographic information in the form of geotagged photos of identified plants has the potential to serve as a supplemental data source for vegetation mapping projects. In this study, we compare the locations of specific taxa from the iNaturalist platform to locations identified on both a fine-scale vegetation map and high-resolution ortho-imagery in open-canopy shrubland in San Clemente Island, CA. Due to positional uncertainty associated with the iNaturalist observations, as well as the presence-only nature of the data, it was not possible to perform a traditional accuracy assessment. We instead measured the distance between the location recorded by an iNaturalist observer for a given taxon and the closest mapped individual of that taxon. This distance was within 10 m for a majority of the observations (64%). When comparing the iNaturalist location to the closest individual detected through image interpretation, 87% of the observations were within 10 m. The discrepancy in agreement between the vegetation map and imagery is likely due to mapping errors. While iNaturalist data come with important limitations, the platform is an excellent resource for supporting vegetation mapping and other ecological applications.

The millipede family Conotylidae in northwestern North America, with a complete bibliography of the family (Diplopoda, Chordeumatida, Heterochordeumatidea, Conotyloidea)

The center of diversity for the chordeumatidan millipede family Conotylidae is northwestern North America, where five of six subfamilies and ten of fourteen previously described genera occur; in this paper, seven additional new genera and 33 new species from the region are described. New species in the genus Taiyutyla Chamberlin, 1952 are: Taiyutyla tillamook, Taiyutyla acuphora, and Taiyutyla amicitia; in the genus Bollmanella Chamberlin, 1941: Bollmanella bombus, Bollmanella washingtonensis and Bollmanella leonardi; in the genus Brunsonia Loomis Schmitt, 1971: Brunsonia pulchra, Brunsonia digitata, Brunsonia wenatchee, Brunsonia chelanoparva, Brunsonia chelanomagna, Brunsonia selwayana and Brunsonia benewah. Vancouvereuma n. gen. is described with the type species Taiyutyla shawi Shear 2004. Calityla n. gen. includes the new species Calityla siskiyou, Calityla ubicki, Calityla trinitaria, Calityla essigi, and Calityla humboldtensis. Ovaskella, n. gen. includes the new species Ovaskella ovaskae and Ovaskella sinuosa. Karagama, n. gen. includes the new species Karagama ladybird. Complicatella, n. gen. includes the new species Complicatella pectenifera and Complicatella neili. Bifurcatella n. gen. includes the new species Bifurcatella olympiana, Bifurcatella hoh, Bifurcatella angulata, Bifurcatella pacifica, Bifurcatella germania, Bifurcatella uniclada, Bifurcatella inflata and Bifurcatella hobo. Loomisiella, n. gen. includes the new species Loomisiella evergreen and Loomisiella pylei. New distribution records are provided for numerous previously described species of conotylids. A complete bibliography of the family Conotylidae of the world is also included.

A new monster from southwest Oregon forests: Cryptomaster behemoth sp. n. (Opiliones, Laniatores, Travunioidea)

The monotypic genus Cryptomaster Briggs, 1969 was described based on individuals from a single locality in southwestern Oregon. The described species Cryptomasterleviathan Briggs, 1969 was named for its large body size compared to most travunioid Laniatores. However, as the generic name suggests, Cryptomaster are notoriously difficult to find, and few subsequent collections have been recorded for this genus. Here, we increase sampling of Cryptomaster to 15 localities, extending their known range from the Coast Range northeast to the western Cascade Mountains of southern Oregon. Phylogenetic analyses of mitochondrial and nuclear DNA sequence data reveal deep phylogenetic breaks consistent with independently evolving lineages. We use discovery and validation species delimitation approaches to generate and test species hypotheses, including a coalescent species delimitation method to test multi-species hypotheses. For delimited species, we use light microscopy and SEM to discover diagnostic morphological characters. Although Cryptomaster has a small geographic distribution, this taxon is consistent with other short-range endemics in having deep phylogenetic breaks indicative of species level divergences. Herein we describe Cryptomasterbehemothsp. n., and provide morphological diagnostic characters for identifying Cryptomasterleviathan and Cryptomasterbehemoth.

Phylogenomic analyses resolve an ancient trichotomy at the base of Ischyropsalidoidea (Arachnida, Opiliones) despite high levels of gene tree conflict and unequal minority resolution frequencies

Phylogenetic resolution of ancient rapid radiations has remained problematic despite major advances in statistical approaches and DNA sequencing technologies. Here we report on a combined phylogenetic approach utilizing transcriptome data in conjunction with Sanger sequence data to investigate a tandem of ancient divergences in the harvestmen superfamily Ischyropsalidoidea (Arachnida, Opiliones, Dyspnoi). We rely on Sanger sequences to resolve nodes within and between closely related genera, and use RNA-seq data from a subset of taxa to resolve a short and ancient internal branch. We use several analytical approaches to explore this succession of ancient diversification events, including concatenated and coalescent-based analyses and maximum likelihood gene trees for each locus. We evaluate the robustness of phylogenetic inferences using a randomized locus sub-sampling approach, and find congruence across these methods despite considerable incongruence across gene trees. Incongruent gene trees are not recovered in frequencies expected from a simple multispecies coalescent model, and we reject incomplete lineage sorting as the sole contributor to gene tree conflict. Using these approaches we attain robust support for higher-level phylogenetic relationships within Ischyropsalidoidea.

Three new species in the harvestmen genus Acuclavella (Opiliones, Dyspnoi, Ischyropsalidoidea), including description of male Acuclavella quattuor Shear, 1986

In Shear's (1986) cladistic analysis of the Ischyropsalidoidea, he described the new genus Acuclavella including four new species from the Pacific Northwest states of Washington and Idaho. Several of these species descriptions were based on very limited sample sizes. Our recent field work has increased by more than an order of magnitude both the number of specimens and known localities for Acuclavella. We use this new material to interpret species limits in Acuclavella using morphometric analyses and DNA sequence data from four gene regions. We sequence for the first time the protein-coding homolog of the Wnt2 gene for phylogenetic reconstruction in Opiliones. Our multi-locus phylogeny corroborates a sister relationship between Acuclavella and Ceratolasma, as hypothesized using morphology by Shear (1986). Within Acuclavella, morphometric clusters and reciprocal allelic monophyly allows recognition of three additional species: Acuclavella leonardi sp. n., Acuclavella sheari sp. n., and Acuclavella makah sp. n. This work also describes the previously unknown male of Acuclavella quattuor, from specimens collected at the type locality. Our research identifies a number of novel morphologies for Acuclavella, including females with four pairs of spines, individuals with three pairs of spines on scute areas I-III, and a population with two pairs of spines disjunct from Acuclavella quattuor, which was diagnosed with this spination character. We were unable to assign these populations to existing species, and conservatively do not yet recognize them as new. Intrageneric morphometrics and phylogenetic inference in Acuclavella were often concordant. However, we demonstrate that species delimitation signal would not be detected if only a single line of evidence were utilized.