Arthropoda

A new species of gall crab collected from elegance coral, Catalaphyllia jardinei, is described in this paper. The male holotype was collected from a reef tank in Germany in 2016, and it is described here using integrative taxonomy. This species, named Lithoscaptus aquarius sp. nov., is the thirteenth assigned to the genus. It is morphologically and phylogenetically closest to Lithoscaptus semperi, a cryptochirid associated with Trachyphyllia geoffroyi. Like L. semperi, it has a large, broad W-shaped depression on the anterior half of the carapace, but the carapace surface of L. aquarius sp. nov. is smooth overall, lacking spines or tubercles. This new species is so named because it was found in a reef tank after searching in vain for material during fieldwork campaigns over the course of several years. Full article

Typical orb webs with glue droplets are renewed regularly, sometimes multiple times per night. Such behaviour, however, is rarely found with cribellate spiders. The adhesive portion of their capture threads consist of nanofibres instead of glue, and the fibres interact with the cuticular hydrocarbons (CHCs) of their insect prey for adhesion. Many of these spiders often only add new threads to their existing webs instead of completely reconstructing them. In testing the adhesion force of aged capture threads of three different cribellate species, we indeed did not observe an overall decline in adhesion force, even after a period of over a year. This is in line with the (formulated but so far never tested) hypothesis that when comparing gluey capture threads to nanofibrous ones, one of the benefits of cribellate capture threads could be their notable resistance to drying out or other ageing processes. Full article

The genus Linothele (Araneae: Dipluridae) from Ecuador is reviewed. A total of 38 new species are described; from the Andes: L. alausi n. sp. (♀), L. anabellecitae n. sp. (♀♂), L. angamarca n. sp. (♀♂), L. banos n. sp. (♀♂), L. canirasi n. sp. (♀), L. carchi n. sp. (♀), L. cayambe n. sp. (♀♂), L. cuencana n. sp. (♀♂), L. guacamayos n. sp. (♀), L. gualaquiza n. sp. (♀), L. guallupe n. sp. (♀), L. ilinizas n. sp. (♀♂), L. ireneae n. sp. (♀), L. jarrini n. sp. (♀), L. javieri n. sp. (♀), L. kaysi n. sp. (♀), L. lacocha n. sp. (♀), L. lloa n. sp. (♀♂), L. milleri n. sp. (♀♂), L. molleturo n. sp. (♀), L. otokiki n. sp. (♀), L. peguche n. sp. (♀♂), L. podocarpus n. sp. (♀), L. pomona n. sp. (♀), L. pristirana n. sp. (♀♂), L. pseudoquori n. sp. (♀♂), L. rionegro n. sp. (♀♂), L. sigchila n. sp. (♀♂), L. uvalino n. sp. (♀), L. victoria n. sp. (♀), L. yunguilla n. sp. (♀♂); from the Pacific region: L. costenita n. sp. (♀♂), L. troncal n. sp. (♀); and, from the Amazonian region: L. amazonica n. sp. (♀), L. archidona n. sp. (♀), L. condor n. sp. (♀♂), L. jatunsacha n. sp. (♀), L. otoyacu n. sp. (♀♂). All previously known Ecuadorian species are re-illustrated, and the males of L. cavicola, L. pukachumpi, and L. tsachilas are described for the first time. The geographical distribution of the genus Linothele through mainland Ecuador is discussed, and short-range endemic species are proposed. Distribution maps are provided for all species found in Ecuador. Finally, the synonymy of L. megatheloides under L. sericata is rejected. Full article

The jorō spider (Trichonephila clavata, originally from east Asia) has been introduced in the southeastern United States, and is rapidly expanding this range, leading to questions about what facilitates this spread. Meanwhile, its cousin, the golden silk spider (T. clavipes), already has a range that covers most of the southeast. In an ongoing effort to understand the behavior of jorō spiders in their introduced range, we undertook the current project to evaluate how they react to perceived threats, which can inform us on how a species interacts with conspecifics, or how well it can tolerate anthropogenic disturbances. We collected mature females of both Trichonephila species, plus three locally common orb-weaving species in Georgia, and we evaluated the time spent immobile after experiencing a mild disturbance (a brief puff of air). We also collected similar “air puff response” data for five other North American species from the published literature. Collectively, the dataset totaled 453 observations of freezing behavior across 10 spider species. Comparing these data across species revealed that most spiders remained immobile for under a minute after the stimulus. Meanwhile, both Trichonephila spiders remained immobile for over an hour, which appears to be unprecedented, and suggests that spiders in this genus are the “shyest” ever documented. This reaction could also allow Trichonephila spiders to tolerate urban environments by remaining motionless throughout each disturbance instead of fleeing. Full article

Many sand scorpions are faithful to the burrows they dig; however, it is unknown how these animals get back home after hunting excursions. Of the many mechanisms of homing that exist, path integration (PI) is one of the more common tools used by arachnids. In PI, an animal integrates its distance and direction while leaving its home, enabling it to compute an approximate homebound vector for the return trip. The objective of our study was to test whether scorpions use PI to return home under absolute darkness in the lab. We first allowed the animals to establish burrows in homing arenas. Then, after they left their burrow, we recorded the scorpion’s location in the homing arena before we transferred it to the center of the testing arena. We used overhead IR cameras to record its movements in the testing arena. If scorpions exhibited PI, we predicted they would follow a vector in the test arena that approximated the same angle and distance from the capture point to their burrow in their home arena. However, under the conditions of this experiment, we found no evidence that scorpions moved along such homebound vectors. We speculated that scorpions may need a reliable reference cue to accommodate path integration. Full article

Monitoring of peatlands is an important conservation issue. We investigated communities of soil mites (Acari: Oribatida, Mesostigmata) inhabiting a relatively undisturbed European boreal mire characterized by a mosaic of oligotrophic and meso-eutrophic areas. We assess the potential of using remote sensing approach as a mapping and predictive tool for monitoring productivity and arthropod biodiversity in a peat bog. In georeferenced plots, Acari biodiversity, water table level, water pH and plot productivity class on the oligotrophic-eutrophic gradient were recorded. Data from the Landsat 8 OLI sensor were used to calculate several spectral indices known to represent productivity and surface moisture gradients in terrestrial ecosystems. We then explored the relationship between spectral indices, environmental gradients and biodiversity of mites. We found that several spectral indices were significantly and consistently correlated with local environmental variables and biodiversity of soil mites. The Excess Green Index performed best as a predictor of plot trophic class on the oligotrophic-eutrophic gradient and showed significant relationship with Oribatida diversity in 2016. However, following hot summer in 2019, there was no significant relationship between abundance and species richness of Oribatida and remotely sensed data; there was a weak correlation between abundance of Mesostigmata and spectral indices which represent surface moisture gradient (e.g., Normalised Difference Moisture Index). We discuss advantages and challenges of using spectral indices derived from remote sensing imagery to map biodiversity gradients in a peatland. Full article

Drosophila suzukii (Diptera: Drosophilidae) is a major invasive pest of caneberries (e.g., blackberries and raspberries) and other thin-skinned fruit crops. In recent years, it has been reported as an economically important fruit pest in many countries. In caneberries, the timely detection and management of invasive insect pests such as D. suzukii is important to maintain profitability and avoid fruit export restriction. Invasions by such new pest species in commercial crop production often changes pesticide use patterns and frequency as growers try to control pest populations on their farms. In this study, we examined the seasonal population of D. suzukii and pesticide use patterns before and after D. suzukii invasion in primocane-fruiting raspberry and floricane-fruiting blackberry crop production in Pennsylvania. The results of seasonal monitoring conducted over two years showed higher populations of D. suzukii fruit flies during the settle period. The evaluation of crop-specific pesticide programs showed an increase in pesticide use frequency compared to the crop season before D. suzukii invasion in the blackberry planting. Similarly, over a five-fold increase in pesticide application was recorded in the raspberry planting in the year following invasion. The implications of increased pesticide use patterns in blackberry and raspberry production are discussed. Full article

The modification of landscapes surrounding water bodies leads to changes in limnological characteristics and decreased aquatic biodiversity, such as fish and macroinvertebrates. Aquatic insects are sensitive to changes in aquatic ecosystems and quickly respond to those changes. The aim of this paper was to evaluate the relationship between the compositions of aquatic and semi-aquatic Heteroptera with environmental variables along an environmental gradient in streams at the headwaters of the Xingu River, Brazil. We collected samples from 12 streams belonging to the Suiá-Miçú river basin and tributaries of the Xingu River, in September (dry season), 2008. The Suiá-Miçú river is one of the tributaries on the right bank of the Xingu River, and it is located in the ecotone between the Cerrado and the Amazon rainforest in the area characterized as the “arc of deforestation’’. Insects were sampled in fixed 100 m transections and divided into 20 segments of 5 meters each. To assess the habitat integrity in each stream, the habitat integrity index (HII) was applied. The following environmental variables were measured: electrical conductivity, turbidity, depth, and the normalized difference vegetation index (NDVI). The ordering of species composition was performed with the principal coordinate analysis (PCoA), and the relationship between environmental variables and composition was performed using a Mantel test. Of the 263 individuals collected, distributed in 8 families, there were 20 genera, of these, 12 were from Nepomorpha and 8 from Gerromorpha. The most abundant genera were Limnocoris (n = 121) and Rhagovelia (n = 32). Naucoridae was the most diverse family. Together, the environmental variables explained ~50% of the species distribution (r = 0.49; p = 0.001). These results reinforce the efficacy of aquatic Heteroptera to monitor environmental conditions. Here, in particular, the responses of this group to variations in landscape metrics, environmental integrity, and water variables together demonstrate that it can be useful to indicate the quality of habitat in streams. Full article

The complete mitogenome of Triatoma boliviana Martínez, Chávez, Sossa, Aranda, Vargas and Vidaurre, 2007 was assembled using next generation sequencing data. The 16,719 bp long genome contains 13 protein coding genes, 22 transfer RNAs, two ribosomal RNAs, and a control region. This mitogenome showed similar nucleotide composition, gene order and orientation than other triatomines. Molecular phylogenetic analyses based on available complete mitogenomes from Reduviidae supported that Triatominae is a monophyletic group and that T. boliviana is basal to the two main Triatomini clades: North and South American. In addition, the analysis of a fragment of the 16S mitochondrial gene among Triatomini species, including species of the dispar lineage, supports the inclusion of T. boliviana in this group. Full article