Cyathostoma lari is a parasite of the nasal and orbital sinuses of gulls and other hosts in Europe and Canada. Here, we provide an overview of previously published data on the prevalence and infection intensity of C. lari in gulls. Furthermore, based on our data, we analyze the spatiotemporal trends in the prevalence and intensity of infection by C. lari in Chroicocephalus ridibundus in Czechia (central Europe; data from 1964 to 2014) and compare them with those obtained from five species of gulls in Karelia (Northwest Russia; data from 2012–2020). Based on our preliminary observations, we hypothesized that C. lari is subject to a decline in certain regions, but this decline is not necessarily applicable throughout its distribution range. We found that the C. lari population crashed in specific parts of its distribution range. The reasons are unknown, but the observed population changes correspond with the diet switch of their core host in Czechia, C. ridibundus. We previously observed a diet switch in Czech C. ridibundus from earthworms (intermediate hosts of C. lari) to other types of food. This diet switch affected both young and adult birds. Nevertheless, it may not necessarily affect populations in other regions, where they depend less on earthworms collected from agrocenoses affected by agrochemicals and trampling. Correspondingly, we found that these changes were limited only to regions where the gulls feed (or fed) on arable fields. In Karelia, where arable fields are scarce, gulls likely continue to feed on earthworms and still display high infection rates by C. lari. Therefore, C. lari, a parasite of the nasal and orbital sinuses of gulls, nearly disappeared from their central European nesting grounds but is still present in better-preserved parts of its distribution range.

The soil weed seedbank is the source of future weed infestations. Seed predation can result in a large number of seed losses, thus contributing to weed biocontrol. Earthworms are important predators of seeds and seedlings and affect seeds and seedling survival after gut passage. A study was conducted to assess the ability of Pheretima guillelmi (Kinberg) to ingest and digest the seeds and seedlings of 15 main farmland weed species. Pheretima guillelmi ingested the seeds and seedlings of each weed species tested. The percentages of seeds and seedlings ingested were 96.7% to 100% and 21.7% to 94.2%, respectively. Pheretima guillelmi showed greater ingestion of seeds than seedlings for each species and digested the seeds and seedlings of each weed species tested to varying extents. The percentages of seeds and seedlings digested were less than 15% irrespective of the weed species. Passage through the gut of P. guillelmi affected the survival of seeds and seedlings. The germination of large crabgrass [Digitaria sanguinalis (L.) Scop.], green foxtail [Setaria viridis (L.) P. Beauv.], goosegrass [Eleusine indica (L.) Gaertn.], Chinese sprangletop [Leptochloa chinensis (L.) Nees], Malabar sprangletop [Leptochloa fusca (L.) Kunth], redroot pigweed (Amaranthus retroflexus L.), common purslane (Portulaca oleracea L.), barnyardgrass [Echinochloa crus-galli (L.) P. Beauv.], and ricefield flatsedge (Cyperus iria L.) seeds egested by P. guillelmi decreased by 46%, 49%, 47%, 25%, 38%, 26%, 32%, 13%, and 15%, respectively, compared with their respective controls. In contrast to seed ingestion, ingestion of seedlings by P. guillelmi was fatal to individuals of all weed species; no seedlings survived passage through the gut. Our results indicate that predation of weed seeds and seedlings by P. guillelmi probably depletes the soil weed seedbank and that the introduction of P. guillelmi into fields is a potential strategy for weed biocontrol in farmland.

The impact of human activities on biogeochemical cycles in terrestrial environments is nowhere more apparent than in urban landscapes. Trace metals, collected on roadways and transported by storm water, may contaminate soils and sediments associated with storm water management systems. These systems will accumulate metals and associated sediments may reach toxic levels for terrestrial and aquatic organisms using the retention basins as habitat. The fate and bioavailability of these metals once deposited is poorly understood. Here we present results from a dose-response experiment that examines the application of synchrotron X-ray fluorescence methods (μ-SXRF) to test the hypothesis that earthworms will bio-accumulate Zn in a roadway-dust contaminated soil system providing a potential pathway for roadway contaminants into the terrestrial food web, and that the storage and distribution of Zn will change with the level of exposure reflecting the micronutrient status of Zn.

Lumbricus friendi was exposed to Zn-bearing roadway dust amended to a field soil at six target concentrations ranging from background levels (45 mg/kg Zn) to highly contaminated levels (460 mg/ kg Zn) designed to replicate the observed concentration range in storm-water retention basin soils. After a 30 day exposure, Zn storage in the intestine is positively correlated with dose and there is a change in the pattern of Zn storage within the intestine. This relationship is only clear when μ-SXRF Zn map data is coupled with a traditional toxicological approach, and suggests that the gut concentration in L. friendi is a better indicator of Zn bioaccumulation and storage than the total body burden.

A comparative analysis of earthworm populations in seral Khasi pine forest represented by Pinus kesiya 5- and 35-year old stands, and a climax broad-leaved mixed forest represented by a sacred grove was done at altitudes of 1500 m in Meghalaya in north-east India. Tonoscolax horaii occurred under all forest types whereas Amynthas diffringens and Eulyphoeus feslivus were confined to pine forest stands only. Perionyx sp. and Drawida assamensis were restricted to the sacred grove. T. horaii had larger numbers in all three different forest types. This species offers possibilities of vermicullurc for biologically improving soil fertility in manmade ecosystems because of its wide range of tolerance.

Generally earthworm populations were more active during the monsoon season; A. diffringens was however, more active during the winter, thereby conferring an advantage on this species as it was enabled to avoid competition during the monsoon season when other species dominate. Earthworm activity was generally higher in the sacred grove than in the pine forest stands. Population size was significantly correlated with soil moisture, temperature and pH. Wormcasts had a higher pH and nutrient status than the soil.

In the highly leached soils of the humid tropics where there is a large concentration of fine root biomass in the surface soil layers, earthworm activity is beneficial because it helps incorporate detritus into the mineral soil rapidly and locally concentrates nutrients in the surface layers.

Earthworm populations in grassland and plantations in the area of Bulolo, Papua New Guinea were compared with populations in nearby undisturbed rain forest. The grasslands had been maintained by burning for many years. The Pinus plantation had been developed on a burned grassland site and the Araucaria plantation on a site which had been cleared of secondary forest.

The grasslands and the Pinus plantation supported moderate populations of exotic earthworms including Pontoscolex corethrurus, but no indigenous species. The Araucaria site supported a native species, Amynthas zebrus only, which was also found together with two other native species at very low density in rain forest.

Exotic earthworm species widespread throughout the tropics, were present in disturbed soils and formed moderately high density populations in burned grasslands. There was no evidence that they displaced native Megascolecidae in rain forest.

Effects of tobacco genetically modified to express the protease inhibitor bovine spleen trypsin inhibitor (BSTI) were examined in laboratory assays against three earthworm and one collembolan species. BSTI is a serine protease inhibitor that can bind to the digestive trypsins of insects feeding on modified plants, resulting in reduced growth and survival. Protease inhibitors are active against a broad range of insects, so may have a large impact on non-target organisms. Survival and fecundity of the collembolan Folsomia candida were unaffected by consumption of artificial diet containing BSTI-expressing tobacco leaf or powdered freeze-dried BSTI-expressing tobacco leaf that was added to soil. Similarly, mortality and growth of earthworms Aporrectodea caliginosa and Lumbricus rubellus did not differ significantly between soil augmented with BSTI-expressing tobacco leaves or unmodified control leaves. The redworm Eisenia fetida gained less weight when provided with BSTI-expressing leaves in one assay, but when the experiment was repeated, there was no significant difference between treatments. BSTI-expressing tobacco and unmodified control leaves decomposed at the same rate, indicating that the inhibitor had no effect on the overall function of the decomposer community of micro-flora and fauna in soil.

Diets of the Eurasian badger Meles meles were studied by scat analysis in three localities of eastern and central Poland, representing pristine forests and rural landscapes with little wood cover. In spring, earthworms constituted 82–89% of biomass consumed by badgers in all localities. In summer and autumn, the proportion declined to 56% in the pristine forest, and to 24% in the mosaic of forests, fields, and orchards. Supplementary resources at this time were amphibians (in forests) or garden fruits (in a rural landscape). Literature on badger diet composition in Europe showed that earthworms and vegetable matter were the dominant food types of badgers, but their roles changed with latitude. The share of earthworms grew from nil at 37–40°N to 40–70% at 55–63°N; the opposite trend was observed for vegetable food. Also, of two major supplementary resources, vertebrates were taken by badgers more often at northern latitudes, and insects in the south. In consequence, the food niche of badgers was broadest at 45–55°N and became narrow at both lower and higher latitudes. Moreover, in the temperate zone of Europe, the degree of habitat transformation by humans significantly affected badger feeding habits. In forests, badgers relied predominantly on earthworms (on average, 62% in diets). In farmlands and pastures, earthworms and plant material (usually garden fruit and cereals) played equally important roles (34% each). This biogeographical pattern of feeding habits can be explained by variation in abundance and availability of earthworms.

Conventional and organic semidwarf Granny Smith apple production systems were compared during three years of conversion to certified organic management. Because of differences in fruit load with hand thinning compared with chemical thinning, apple tonnage was higher in the organic production system (OPS) in 1989 and 1991. The organic system was higher than the conventional system in number and weight of fruit per tree, but smaller in average fruit size. Using grower-receivedfarmgate premiums of 38% (1990) and 33% (1991) for unsorted, certified organic apples, comparative cost accounting showed greater net return per hectare for the OPS. The OPS required higher material and labor inputs in all years.

Greater terminal growth in the conventional production system (CPS) in 1991 was the only significant difference in growth indicators between systems. N was generally higher in leaf and new wood bark tissues in the CPS. P was generally higher in the leaf and new wood bark tissues in the OPS. No decline in yield was associated with increased weed biomass in the OPS. There was no difference in fruit damage caused by codling moth between production system treatments (codling moth granulosis virus and pheromone-based mating disruption vs. synthetic insecticide). In 1991, secondary lepidopterous pests (apple leafroller and orange tortrix) caused greater fruit scarring in the CPS. In all years, tentiform leafminers caused greater leaf damage in the CPS. Apple leafhopper density and leaf damage were greater in the OPS in 1990 and 1991.

Soil nutrient levels showed few significant changes during conversion to organic management. Soil bulk density and water holding capacity were useful indicators of changes in soil physical characteristics. Potentially mineralizable nitrogen andmicrobial biomass-C were more sensitive indicators of system change than total N or organic C. Two soil biological ratios, the respiratory ratio and biomass-C/total organic-C, were similar in the two production systems. Earthworm biomass and abundance increased in the OPS in the third year. The introduction of Lumbricus terrestris into the OPS greatly increased litter incorporation rates.

Soil physical and biological properties often change when different cropping, tillage, or management systems are imposed. Changes occasionally occur quickly, but usually become evident only after months or years. Infiltration rates are affected by several soil properties and may provide the most sensitive indication of changes in soil properties. To evaluate the use of infiltration measurements for detecting changes in soil properties, we conducted infiltration tests on a cropping systems experiment, a tillage experiment, and two beef cattle grazing experiments. In Pennsylvania, significant changes in infiltration rates did not occur until more than four years after converting from a conventional to a low-input cropping system. Infiltration rates were higher on 14th-year no-till plots compared with moldboard plow and chisel treatments in an Iowa tillage study. Earthworm populations and activity were highest in the no-till treatment. Infiltration rates correlated negatively with increased stocking rates in a long-term beef grazing study in Oklahoma. The number of earthworms did not correlate positively with infiltration in this study, suggesting a complex interaction. A short-term study of overwinter beef corn-stalk grazing in Iowa did not show consistent patterns in infiltration rate or other soil properties with different stocking rates. Infiltration appears to be a good indicator of soil structural changes associated with cropping, tillage, and management systems.

Effects of soil fauna on soil quality are largely unknown. Our objective was to learn whether long-term soil management has significantly affected earthworm species and populations at two Iowa locations. Soil cores were collected in fall 1989, spring 1990, and fall 1990 from a long-term tillage study in Polk County, Iowa, involving monoculture of corn (Zea mays L.) with either no-tillage, fall disking, fall chisel plowing, or fall moldboard plowing. Species found were Lumbricus terrestris (L), Octolasion tyrtaeum (Savigny), Aporrectodea trapezoides (Duges), A. turgida (Eisen), and A. tuberculata (Eisen), with O. tyrtaeum dominant across all treatments. As the amount of tillage increased, the number of earthworms generally decreased. InBoone County, Iowa, we compared the populations of mature and immature earthworms and cocoons on two adjacent fields, one managed conventionally, the other managed with an alternative farming system for more than 20 years. The predominant species was A. tuberculata. Regardless of management practice, the most worms were found in Canisteo soil on the toeslope landscape position.

The combination of several measures (organic matter accumulated, soil porosity, field soil respiration, CO2 evolved during incubation, and mineral N released) shows clearly that soil biological activity was enhanced in the systems that minimized tillage. Surprisingly, the abundance of earthworms, which are considered very sensitive to damage by tillage, did not always follow the same pattern. We do not know the reason for the response of earthworms, but in part it may have been an artifact of the interaction of the collection technique with soil properties such as infiltration rate and temperature. The most dramatic improvement in porosity, organic matter accumulation and N mineralization ability came from five years' continuous growth of grass sod, underscoring the potential role of grass in sustainable cropping systems and the value of grass for soil conservation and improvement.

Invertebrates are an integral part of soils and are important in determining the suitability of soils for the sustainable production of healthy crops or trees. We discuss the importance of the soil invertebrate fauna in relation to terrestrial habitats and global biodiversity as we understand it. We describe the role of the main invertebrate groups in soils, including earthworms, termites, springtails, and nematodes, and how they determine soil quality. Practical problems in dealing with the invertebrate fauna include sampling, taxonomy and availability of biological information on species. Various measures are available that use invertebrates to assess soil quality, each with its advantages and disadvantages. They include abundance, biomass, density, species richness, trophic/guild structure, food web structure, keystone species and ecosystem engineers. We propose the three most useful and practical of these as suitable to be combined with other biological (microbial) and non-biological (hydrological, physical, chemical) criteria into a single index of soil quality that might be used on a regional, if not international basis.

In the fifth year of an agricultural conversion experiment in Pennsylvania, we studied the soil biological community under three treatment regimes planted with corn: organic-manure, organic-legume, and a conventional system. The organic treatments consisted of complex crop rotations, cultivations, and organic matter inputs to control pests and maintain soil fertility. The conventional system consisted of a simple corn/soybean rotation with synthetic fertilizer and pesticide inputs. High rates of CO2 evolution (a measure of potential microbial activity) in the organic plots corresponded with high levels of organic matter input. Soil nematodes were most abundant in organic plots, although seasonal patterns differed between the two organic treatments. Soil microarthropods were dominated by fungivorous Prostigmata mites, which reached peak abundance in organic plots two to five months after organic matter incorporation. Oribatid mites, which were rare throughout the study, followed the same pattern of abundance in each treatment and were probably most influenced by tillage disturbances. Predatory Mesostigmata were generally more abundant in organic plots. Surface-dwelling Collembola were abundant briefly in the spring, but soil-dwelling species dominated numerically throughout the cropping season. Spring tillage appeared to have a strong negative effect on earthworm populations in all plots. Small earthworm species became abundant in organic-manure plots during the summer. Larger earthworm species were abundant in organic-legume and conventional plots after the autumn harvest, when crop residues covered the undisturbed soil The systems-level nature of the Conversion Project experiment makes it difficult to identify cause-effect relationships. The data do suggest that organic amendments tend to enhance soil biological activity, while tillage disturbances tend to disrupt the biotic community.