Pardosa Species Research Articles

Relevance of ddRADseq method for species and population delimitation of closely related and widely distributed wolf spiders (Araneae, Lycosidae)

Although species delimitation is often controversial, emerging DNA-based and classical morphology-based methods are rarely compared using large-scale samplings, even less in the case of widely distributed species that have distant, allopatric populations. In the current study, we examined species boundaries within two wolf spider species of the genus Pardosa (Araneae, Lycosidae), P. riparia and P. palustris. Wolf spiders constitute an excellent model for testing the relevance of traditional vs. modern methods in species and population delimitation because several closely related species are distributed over cross-continental geographic ranges. Allopatric populations of the two Pardosa species were sampled across Europe to Far East Russia (latitudinal range > 150°) and several dozen individuals were studied using morphological characters (morphometry of three measures for both sexes, plus five in males only and two in females only), DNA barcoding (COI sequencing) and double-digest restriction site associated DNA sequencing (ddRADseq). The results obtained allow for changing the taxonomic status of two Far East Russian populations to subspecies and ddRADseq proved to be a powerful tool for taxonomic research despite scarce sampling and inherent subjectivity of species delimitation in allopatry. Overall, this study pleads for both multi-criteria and more population-based studies in taxonomy.

Prey identity but not prey quality affects spider performance.

Increasing host plant quality affects higher trophic level predators, but whether such changes are simply a result of prey density or are also affected by changes in prey quality remain uncertain. Moreover, whether changes in prey quality affect measures of predator performance is understudied. Using a combination of field and greenhouse mesocosm experiments, we demonstrate that the survival and body size of a hunting spider (Pardosa littoralis Araneae: Lycosidae) is affected more by prey species identity than the trophic level of the prey. Furthermore, increasing host plant quality does not necessarily propagate through the food web by altering prey quality. While changes in plant quality affected spider body mass, they did so in opposite ways for spiders feeding on Prokelisia (Hemiptera: Delphacodes) herbivores relative to Tytthus (Hemiptera: Miridae) egg predators, and had no impact on spider body mass for two additional species of intraguild prey. These changes in body mass were important because greater body mass increased spider egg production. To examine the generality of this pattern, we reviewed the literature and found a consistent positive relationship between female body size and egg production for Pardosa species, indicating that body size is a reliable proxy for fitness. While many studies emphasize the importance of nitrogen to arthropod diets, this focus may be driven largely by our understanding of herbivore diets rather than predator diets. Thus, the positive impact of host plant quality on higher trophic level predators appears to be driven more by altering prey composition, density, and availability rather than simply providing predators with more nutritious prey.

A new primer for metabarcoding of spider gut contents

AbstractAs a key predator group, spiders have received a lot of attention by food web ecologists. The difficulty involved in studying their diet has led to the use of new technologies such as metabarcoding of gut contents. The amplification of a broad range of spider prey without amplifying spiders themselves is challenging. Until now, an efficient universal primer for this purpose was not available. We developed a novel forward primer (NoSpi2) targeting the COI gene. The primer was designed not to amplify spiders ofPardosagenus while amplifying most other invertebrates. NoSpi2 was tested together with the reverse primer BR2 in silico, in vitro on single specimens of prey and spiders, on mock and malaise trap communities, and in an ecological application. In silico evaluation predicted high primer bias forPardosaspecies and more generally for spiders of the oval calamistrum clade (Lycosidae and closely related species) and low bias for other invertebrates. These results were confirmed by in vitro tests. Additionally, some spider families were not amplified contrary to our expectations. We demonstrated a high efficiency for the primer pair NoSpi2/BR2 which recovered 94% of taxa in the mock community and 85% of the taxa detected by the best invertebrate primer pair known for the malaise trap community. The field experiment showed that Lycosidae (Hygrolycosa,Pardosa,Piratula,Trochosa) DNA is not amplified by NoSpi2/BR2. It demonstrated a broad range of detectable prey species (12 orders, 67 families, 117 species). The ability of NoSpi2/BR2 primer to reliably amplify prey species, without amplifying any predator DNA, makes it an ideal choice for gut content analysis for lycosid species and related species, even enabling the homogenization of entire specimens without dissection. Given that the detected prey species included other spiders and carabid beetles, this primer could be also used to study intraguild predation.

Niche differentiation of two sibling wolf spider species, Pardosa lugubris and Pardosa alacris, along a canopy openness gradient

Phylogenetic niche conservatism can cause strong interspecific competition among closely related species leading to competitive exclusion from local communities or meta-communities. However, the coexistence of close relatives is often reported. One of the most frequent mechanisms mediating such coexistence is resource partitioning. Here, we investigated the niche differentiation of two sibling spider species, Pardosa alacris C.L. Koch, 1833 and P. lugubris Walckenaer, 1802, along a canopy openness gradient. We further investigated differences in body size as an additional axis for niche partitioning. We explored niche partitioning along the canopy openness gradient at eight locations. In each afforested location, 60-m-long transects were established consisting of five pitfall traps placed at regular 15-m intervals along the gradient. We measured the body size of individuals of both species collected at the gradient's extremes. We found that the two Pardosa species occurred syntopically but had clearly differentiated spatial niches along the canopy openness gradient. Pardosa lugubris displayed a preference for closed canopies in dense forest habitats and its abundance gradually decreased as the canopy opened while the opposite was the case for P. alacris. The two species also differed in body size. Each species was larger at its preferred gradient extreme than was the other species. The coexistence of the two Pardosa species was mediated mainly by spatial niche partitioning. Body size differences may represent another axis for niche partitioning.

The study of lifecycle of threePardosaspecies viz., P.birmanica, P. leucopalpis and P. oakleyiunder laboratory conditions

The lifecycle of three Pardosa species (P. birmanica, P. leucopalpis and P. oakleyi) was studied under laboratory conditions. The spiders were reared in clear perplex cages on artificial diet. The cotton swab was soaked in modified diet and kept in the cage. The diet was changed after regular interval (24 hours). After mating ten female spiders were selected for research in separate cages. On hatching newly born spiders lings were climbed on the mother back for 4 days after that they were separated from the mother’s back. A group of seventy spider’s lings was separated randomly from all the cages for research and each spider-ling was introduced into a cage to prevent cannibalism. The diet was given to these spiders lings under same laboratory conditions. Daily observations were noted on each cage to study the developmental stages of Pardosa species. The first molting stage was spent on the mother’s back. The selected Pardosa species exhibited eight instars to become adult. The total length of male and female was observed at adult stage. The feeding of man-made diet by the ground spiders is an indication that the mass rearing of these spiders could be utilized against to control the various insects’ pest species.

A survey of East Palaearctic-Lycosidae (Araneae). 10. Three new Pardosa species from the mountains of Central Asia.

Three new species of Pardosa, P. svatoni sp. n. (dy, SE Kazakhstan), P. fengisp. n. (male female, Central Xinjiang) and P lii sp. n. (male female, Central Xinjiang) are described and illustrated. The two former species cannot be placed in any species group. Pardosa lii sp. n. belongs to the P. wagleri species group. It is compared with P. italica Tongiorgi, 1966, whose embolic division has not previously been illustrated.

Life History Adaptation to Changeable Agricultural Habitats: Developmental Plasticity Leads to Cohort Splitting in an Agrobiont Wolf Spider

The wolf spider, Pardosa agrestis Westring (Araneae: Lycosidae), is a dominant arthropod predator in central European agricultural areas. Recent studies have indicated that this spider has a unique phenology among Pardosa species. Three years of systematic field monitoring of a P. agrestis population in Hungary confirmed that an early summer peak (P1) of adults typical of the Pardosa genus is followed by a second late summer peak (P2) that does not occur among congenerics. Rearing experiments conducted outdoors revealed that offspring from P1 can reach maturity in ≈2 mo time, well before the end of summer. Thus, P2 adults represent a second generation of the species, with a chance for a potentially successful reproduction. However, the speed of development was variable among P1 offspring; individuals, which proved to be slower developers, did not mature during P2; rather they overwintered as juveniles and matured during the following year P1 period. Thus, members of the P1 cohort followed different developmental pathways; this corresponds to a cohort-splitting strategy. Splitting occurred even among spiderlings originating from the same clutch (cocoon) at the beginning of P1. In contrast, spiderlings born at the end of P1 uniformly matured by next spring. Splitting among offspring spreads the mother’s reproductive success between risk averse slow-developing and risk prone fast-developing offspring. The facultative bivoltine life cycle arising through cohort splitting may allow P. agrestis to adapt to predictably ephemeral agricultural habitats by flexibly producing the most dispersive juvenile stages in synchrony with the appearance of vacated habitats.

Physiological tolerances of three sympatric riparian wolf spiders (Araneae: Lycosidae) correspond with microhabitat distributions

Coexisting species from the same ecological guild often exhibit different adaptations to discontinuous, abiotic environmental factors. In the laboratory, we compared tolerance to thermal and desiccation stress among three sympatric wolf spiders (Pirata sedentarius Montgomery, 1904, Pardosa lapidicina Emerton, 1885, and Pardosa fuscula Thorell, 1875). In the field, we examined spatial structure across a microhabitat (moisture) gradient in a streamside cobble habitat where these three species are abundant. Female P. sedentarius succumbed more quickly to desiccation stress than females of either Pardosa species. In the absence of thermal stress, desiccation tolerance was high for both Pardosa species. However, P. fuscula appears to be more resistant to combined thermal and desiccation stress than P. lapidicina. These findings correspond with the results of the field survey; the distribution of P. sedentarius was the most restricted (by proximity to the shoreline) among the three species. Contingency analyses also revealed greater relative abundance of P. fuscula than P. lapidicina farther away from the creek. Further examination of spatial structure suggests that neither of these two species was restricted by proximity to the shoreline within the sampling grid.

A REVIEW OF THE SPIDER GENERA PARDOSA AND ACANTHOLYCOSA (ARANEAE, LYCOSIDAE) OF THE 48 CONTIGUOUS UNITED STATES

In the 48 contiguous United States, the wolf spider subfamily Pardosinae is represented by 65 species of Pardosa and 1 species of Acantholycosa. This study provides a comprehensive account of all species of Pardosinae in the USA including keys, some of which are new, for their identification. Based on genital morphology, the species of Pardosa in the USA can be divided into 14 species groups containing from one to 17 species. The male of P. ourayensis Gertsch 1933 is illustrated for the first time. Difficulties arise in the identification of some sister species which are both morphologically and geographically close; and also many of the species in the sternalis group which can be identified only by their distribution.

Occurrence of Parasitoid Wasps, <em>Baeus</em> sp. and <em>Gelis</em> sp., in the Egg Sacs of the Wolf Spiders <em>Pardosa moesta</em> and <em>Pardosa sternalis</em> (Araneae, Lycosidae) in Southeastern Idaho

Egg sacs of the wolf spiders Pardosa moesta and Pardosa sternalis were sampled for two years during June to September in southeastern Idaho. Parasitoid wasps, Baeus sp. (Sceleonidae) and Gelis sp. (Ichneumonidae), were observed in the egg sacs of both Pardosa species. Of 322 egg sacs examined, 14.6% were parasitized. Parasitism of egg sacs occurred throughout most of the Pardosa egg sac-carrying season.

ON THE USE OF AMPULLATE GLAND SILKS BY WOLF SPIDERS (ARANEAE, LYCOSIDAE) FOR ATTACHING THE EGG SAC TO THE SPINNERETS AND A PROPOSAL FOR DEFINING NUBBINS AND TARTIPORES

Abstract The means by which female wolf spiders attach an egg sac to their spinnerets was investigated using scanning electron microscopy. In four Pardosa species, we observed that silk fibers emerging from ampullate gland spigots had been affixed to the surface of the egg sac. More specifically, primary (1°) and secondary (2°) major ampullate (MaA) glands and 1° and 2° minor ampullate (MiA) glands all contributed fibers for this purpose. The diameters of the 2° MaA and 2° MiA fibers were greater than those of the 1° MaA and 1° MiA fibers and, correspondingly, the widths of the 2° ampullate spigots were clearly greater than those of the 1° ampullate spigots. Larger 2° ampullate spigots were also observed in adult females of species from three other lycosid genera. Thus, 2° ampullate glands, which in araneoids function only in juveniles during proecdysis, are not only functional in adult female lycosids (and adult females of several other families), but they appear to play a greater role than the 1° ampull...

COMPARISON OF AUTUMN AND WINTER DEVELOPMENT OF TWO WOLF SPIDER SPECIES (PARDOSA, LYCOSIDAE, ARANEAE) HAVING DIFFERENT LIFE HISTORY PATTERNS

Abstract Pardosa species do not overwinter in the adult stage in the Holarctic region, therefore penultimate instars should avoid precocious maturation in autumn. We tested how artificially increased temperature and/or lengthened light regime would affect the pre-overwintering development of two common species with different phenological patterns. Juvenile instars of Pardosa agrestis (Westring 1861) and P. hortensis (Thorell 1872) were collected in autumn from the field. The experimental spiders were held either indoor at 26 °C or outdoors at ambient temperature and were exposed either to short or to long daylength. Molting events were monitored for five months. At outdoor temperatures no spiders reached adulthood and molts of younger instars occurred more frequently at long daylength. In the indoor temperature groups all P. hortensis and the majority of P. agrestis individuals reached adulthood during the experiment. Long daylength treatment enhanced the effect of increased temperature by almost halving ...

LIFE-CYCLES OF FOUR SPECIES OF PARDOSA (ARANEAE, LYCOSIDAE) FROM THE ISLAND OF NEWFOUNDLAND, CANADA

Populations of four species of Pardosa, P. fuscula, P. groenlandica, P. hyperboreaand P. moesta, were sampled during summer 1997 on the west coast of the Island of Newfoundland, Canada. Measurements of carapace width indicated that all four species fit a biennial life-cycle model where new individuals join the population in summer, live through the following winter, grow throughout the next year, live through the next winter, and then mature, breed and die in the year following their second winter. All species showed only one defined recruitment of new spiderlings during the sampling period, but at least two species may have extended periods of recruitment and some individuals may have an extended life-cycle.

LIFE HISTORY OF PARDOSA MOESTA AND PARDOSA MACKENZIANA (ARANEAE, LYCOSIDAE) IN CENTRAL ALBERTA, CANADA

Abstract The density, fecundity, and life-cycle of Pardosa moesta Banks 1892 and Pardosa mackenziana (Keyserling 1877) were studied in a deciduous forest in central Alberta, Canada. Density estimates were lower than reported for other Pardosa species; they ranged from 0.46 per m2 for male P. mackenziana to 2.99 per m2 for immature P. mackenziana. Adult female densities were below 1 per m2 for both species. Clutch sizes were highly variable and averaged (± SE) 33.06 ± 1.29 for P. moesta and 48.37 ± 1.67 for P. mackenziana. Although clutch size was positively related to female size, little of the variation was adequately explained by female size alone. Several lines of evidence suggest that P. moesta and P. mackenziana require two years to mature in central Alberta, with a peak reproductive period in May and June. Females carry egg sacs into the summer months and immature spiders overwinter following the first growing season when they are still less than 5 mg in weight. After a second summer of growth, sub-...

A STUDY OF EGG PRODUCTION IN THREE SPECIES OF WOLF SPIDERS (ARANEAE, LYCOSIDAE), PARDOSA AMENTATA,P. PALUSTRIS, AND P. PULLATA IN THE FIELD

Egg production by three species of Pardosa was studied over a 3-year period in a grassland, a fallow field, and a meadow in Northumberland (England).Differences in egg production were found to be related to the size of the female spiders and habitat structures. Influence of localities and egg production in subsequent years are discussed.

A Study on the Diel Activity of Pardosa Spiders (Araneae, Lycosidae) Sampled by the Time-sorting Pitfall Trap in Different Habitats

In this study, the diel activity of Pardosa amentata (Clerck), P. pullata (Clerck), P. palustris (Linnaeus) and P. nigriceps (Thorell) (Araneae, Lycosidae) was determined using the time-sorting pitfall trap in grassland and fallow field in Northumberland - England. In spite of some captures of Pardosa species during the day-time and night, most were caught in the afternoons and mornings. The least lycosids were collected at midnight and sunrise periods. The running activity of the species was found to be temperature-dependent. During sunny and hot periods, these spiders were more active and visible. In May and June, the males of Pardosa were more active than the females. The females with egg sacs preferred mostly the afternoon and morning periods. Like the adults, immuture spiders were caught in all periods, but they were more active in the afternoons.

Studies on species of Holarctic Pardosa groups (Araneae, Lycosidae). IV. Redescription of Pardosa tetonensis Gertsch and descriptions of two new species from the western United States

Three North American Pardosa species assigned to the modica group are treated and illustrated. P. tetonensis Gertsch (Wyoming, Montana) is redescribed. P. confusa sp. n. is described on material from Colorado, Utah, and ?Oregon. It is morphologically very close to P. tetonensis and the two species have not yet been found in sympatry. P. crassistyla sp. n. is described on material from Wyoming, Colorado, Utah, Idaho, Oregon and California; it shows considerable geographic variation in size.

Studies on species of Holarctic Pardosa groups (Araneae, Lycosidae). III. Redescriptions of Pardosa algens (Kulczynski), P. septentrionalis (Westring), and P. sodalis Holm

AbstractThree Pardosa species assigned to the modica group are redcscribed and illustrated: P. algens (Kulczynski) (with P. johanseni Gertsch and P. townsendi Gertsch placed as junior synonyms) from northern Siberia and arctic North America; P. septentrionalis (Westring) from Scandinavia and northern Euro-Russia into NW Siberia; and P. sodalis Holm (with P. bargusinensis Šternbergs placed as junior synonym) from widely separated localities in Siberia and NW North America (Alaska, Yukon). Geographical variation is noted in P. algens but infraspecific taxa are not formally adopted. Some reflections on the distribution of wolf spiders in arctic Nearctic are presented.

Contiguous Allotopy of Pardosa ramulosa and Pardosa tuoba (Araneae: Lycosidae) in the San Francisco Bay Region, and Its Implications for Patterns of Resource Partitioning in the Genus

Two Pardosa species are contiguously allotopic in the San Francisco Bay Region, with P. tuoba restricted to coastal prairie and coastal scrub habitats and P. ramulosa inhabiting adjacent salt marshes as well as the borders of bodies of standing fresh water within the habitat of P. tuoba. Pardosa ramulosa appears to be a specialist on open water habitats, where it feeds preferentially on insects of the surface film. Coexistence in these two species, and in other sets of sympatric Pardosa species, is made possible by partitioning of the array of essentially two-dimensional habitats with lowgrowing vegetation.

Two new species of the genus Pardosa C. KOCH from Japan. (Araneae: Lycosidae)

In this paper are given the descriptions of two new species of the genus Pardosa C. KOCH found in Japan. These species resemble each other morphologically and ecologically, inhabiting riversides and seashores.