Is there a downside to plant ecological services in the city? Influences of particulate matter on the two-spotted spider mite (Tetranychus urticae) foraging on the small-leaved lime in urban conditions

The aim of this research was to examine how particulate matter (PM) pollution affects the life history of the two-spotted spider mite (TSSM), Tetranychus urticae (Trombidiformes: Tetranychidae), in modelled urban conditions. For this purpose, experimental populations of TSSM were cultured on the foliage of small-leaved lime (Tilia cordata) contaminated with PM at intensities corresponding to differing city zones such as a park, a busy road and an industrial area. The control samples in the study were washed, unpolluted leaves. The spider mite was selected as a model organism due to its cosmopolitan distribution, broad host spectrum, resistance to a variety of pesticides and food-intake mode involving cell-content sucking, while T. cordata is widely planted in cities and has demonstrated a considerable capability for PM capture. Data on the longevity and mortality of particular instars and on female fecundity at different pollution levels were collected and statistically evaluated. Concentrations of PM typical for roads and industrial city zones significantly reduced total female fecundity (avg. 53.9 and 55.9 eggs/female, respectively, vs 79.2 in control), which entailed a slower population increase, while the survival rate of particular developmental instars (P = 0.52) and fertility curves (P = 0.19) remained unchanged. The presence of PM caused physiological effects in the mites, despite the lack of direct consumption of the pollutant by adult and juvenile instars. Considering the incomparable resilience of TSSM to unfavourable environmental factors, it is predicted that the detrimental influence of PM on other representatives of urban arthropods may be even more severe. The results suggest that there is a need for further investigations into the ecological ramifications of air purification provided by urban green spaces.

Accumulation of Plastics and Trace Elements in the Mangrove Forests of Bima City Bay, Indonesia

Pollution with microplastics (MPs), nanoplastics (NPs) and trace elements (TEs) remains a considerable threat for mangrove biomes due to their capability to capture pollutants suspended in the water. This study investigated the abundance and composition of plastics and TEs contained in the soil and pneumatophores of Avicennia alba sampled in experimental areas (hotel, market, river mouth, port, and rural areas) differentiated in anthropopressure, located in Bima Bay, Indonesia. Polymers were extracted and analyzed with the use of a modified sediment isolation method and Fourier transform infrared spectroscopy. Trace elements were detected by inductively coupled plasma optical emission spectrometry. The lowest and highest quantities of MPs in soil were recorded in rural and hotel areas, respectively. The rural site was characterized by distinct MP composition. The amounts of sediment-trapped MPs in the tested localities should be considered as high, and the recognized polymers partly corresponded with local human activity. Concentrations of seven plastic types found in plant tissues did not entirely reflect sediment pollution with nine types, suggesting a selective accumulation (particularly of polyamides and vinylidene chloride) and substance migration from other areas. Very low concentrations of non-biogenic TEs were observed, both in sediments and pneumatophores. The results highlight the relevance of environmental contamination with plastics.

Not Only Leptotrombidium spp. an Annotated Checklist of Chigger Mites (Actinotrichida: Trombiculidae) Associated with Bacterial Pathogens

Mites of the family Trombiculidae are known for playing a role in maintaining and spreading the scrub typhus etiologic agent, an intracellular Gram-negative bacterium, Orientia tsutsugamushi. Species of the genus Leptotrombidium are investigated most thoroughly, particularly in SE Asia, and a few are proven vectors for the pathogen. The mentioned association, however, is not the only one among trombiculids. Here, we present a list of chiggers indicated in the literature as positive for bacterial pathogens, tested throughout almost 100 years of research. Taxonomic identities of trombiculids follow recent revisions and checklists. Results point at 100 species, from 28 genera, evidenced for association with 31 bacterial taxa. Pathogen-positive mites constitute around 3.3% of the total number of species comprising the family. Discussed arachnids inhabit six biogeographic realms and represent free-living instars as well as external and internal parasites of rodents, soricomorphs, scadents, lagomorphs, peramelemorphs, bats, passerine birds, reptiles and humans. A variety of so far detected bacteria, including novel species, along with the mites’ vast geographical distribution and parasitism on differentiated hosts, indicate that revealing of more cases of Trombiculidae-pathogens association is highly probable, especially utilizing the newest techniques enabling a large-scale bacterial communities survey.

Timing Is Everything. Temporal and Spatial Niche Segregation in Curculio spp. (Coleoptera: Curculionidae) Associated with Oak Trees

Oak seed predatory weevils occurring in Poland are prone to increased interspecific competition due to the limited number of Quercus species, compared to southern Europe, in which they can develop. Therefore, analyses on the preferences of three weevil species for acorn sizes chosen for reproduction, as well as on reproductive period duration, were performed. Cafeteria-type experiments were set for females of three species associated with one oak species. Females were allowed to choose and oviposit in acorns of different sizes and growth stages. Research revealed statistically significant differences between the masses of acorns chosen for oviposition by females of Curculio glandium (the biggest), C. pellitus (medium), and C. venosus (the smallest). Studied weevils also differed in terms of the beginning of the reproductive period, which corresponded with the increasing mass of growing acorns. Moreover, C. glandium was observed to be the only species to perform radial egg galleries and lay a considerably higher and varied number of eggs. The results support the hypothesis of a strategy aimed at reducing interspecific competition between Curculio spp. in terms of limited host plant species number.

Evidence for co-invasion events: different chigger species (Actinotrichida, Trombidioidea: trombiculidae) share a host

Cases of co-invasion of various chigger species parasitizing murids and cricetids in various habitats were analysed using morphological and molecular approaches. Here we provide evidence for 25 new cases of co-parasitism of chigger mites on rodent hosts (Myodes glareolus, Apodemus flavicollis, Apodemus agrarius) accounting for 8.6% of all host-parasite associations observed in this study. The results confirm higher incidence of co-parasitism in vertebrate-associated Parasitengona mites compared to arthropod-associated ones. Among factors influencing the occurrence of co-parasitism in Trombiculidae the body constitution and year-round availability of hosts associated with lower host specificity of larvae should be considered.

Host-parasite association in trombiculid mites (Actinotrichida: Trombiculidae) of temperate zone - the case of Hirsutiella zachvatkini (Schluger, 1948); are we dealing with prolonged contact with the host?

Background

The time-extended contact of trombiculid larvae with hosts poses a question of its ecological determinants. The phenomenon, which may facilitate the overwintering of larvae in the temperate zone, was previously observed in few parasitengone taxa, but not confirmed for mammal-associated trombiculids. The study aims at tracing the phenology of larvae of Hirsutiella zachvatkini and at verifying the hypothesis of contact with the host, extending beyond the parasitic phase.

Methods

Apodemus agrarius, Apodemus flavicollis and Myodes glareolus, trapped during 2-year studies, were checked for the presence of trombiculid larvae. Larvae of H. zachvatkini served for the studies. The degree of mites’ engorgement was checked over time in order to estimate the duration of feeding phase and to measure the maximum size increase. The experimental rearing aimed at ascertaining the relations between the level of engorgement and successful transformation of larva into subsequent instar.

Results

The mass appearance of larvae on hosts fell on autumn and winter, with a decrease observed in spring, leading to an almost total absence in early and mid summer. The highest intensity, attained in late autumn or in winter, was not followed by further increase in the number of host-associated larvae. The percentage of unengorged larvae on hosts was disproportionately small, irrespective of the season. The size increase of larva was 12.6-fold at maximum. Engorged or partly engorged larvae, observed from the beginning of mass appearance over the entire period of host-parasite association in the field, transformed into subsequent instar when removed from host.

Conclusions

An increase in intensity observed from the onset of appearance of larvae on hosts, through autumn and winter months, at rarity of observations of unengorged larvae and absence of engorged larvae off-host, indicates a prolonged contact with hosts, aimed at synchronisation of life cycle, conditioned by food resources available for active postlarval forms and constitutes a strategy enabling larvae to survive the unfavourable winter conditions. The proportion of engorged and partly engorged vs. unfed larvae, observed over the survey, along with their ability to transform into subsequent instars, indicates a relatively short feeding phase. The lack of continuous increase in abundance and intensity towards spring and summer suggests a gradual detachment of partly and fully engorged larvae which attained the readiness to subsequent development. The size increase of larvae during their parasitic phase does not corroborate the neosomy in H. zachvatkini. Host-associated differences in topic preferences of the chiggers become less obvious at maximum infection rates. Quantitative descriptors of parasite population place M. glareolus among the most infected hosts of H. zachvatkini in contrast to Apodemus mice collected in the same habitat.

Host-associated differences in morphometric traits of parasitic larvae Hirsutiella zachvatkini (Actinotrichida: Trombiculidae)

Examination of host-associated variation in the chigger mite Hirsutiella zachvatkini (Schluger) revealed morphological differences among larvae infesting sympatric hosts: Apodemus agrarius, Apodemus flavicollis and Myodes glareolus. The analysis included 61 variables of larvae obtained from their gnathosoma, idiosoma and legs (measurements and counts). Statistically significant differences were observed for metric characters of the legs as opposed to the scutum. In view of the conspecificity of the mites, supported by comparison of COI gene products obtained from larvae and laboratory-reared deutonymphs, the observed variation is attributed to phenotypic plasticity. The knowledge of larval morphology, including intraspecific variation of metric characters, supported by molecular and host range data, places H. zachvatkini among the most comprehensively defined members of Trombiculidae.

Planthopper (Hemiptera: Flatidae) parasitized by larval erythraeid mite (Trombidiformes: Erythraeidae)-a description of two new species from western Madagascar

Descriptions of Dambullaeus adonis Mąkol et Moniuszko SP NOV: (Trombidiformes: Erythraeidae, Callidosomatinae) and Latois nigrolineata Świerczewski et Stroiński SP NOV: (Hemiptera: Fulgoromorpha, Flatidae) from Madagascar are provided. The first host record for ectoparasitic larvae of Dambullaeus Haitlinger, 2001 and the first evidence on host-parasite association between flatid adult and erythraeid larvae are given. Genus Dambullaeus, known exclusively from larvae and now comprising two species of Gondwanan distribution, is critically reappraised.

Chigger mites (Actinotrichida: Parasitengona, Trombiculidae) of Poland. An updated distribution and hosts

The existing body of knowledge regarding the Trombiculidae of Poland is summarized and supplemented with the results of our recent studies. Although around 3000 nominal species are known worldwide, only 18 have been recorded in Poland. Due to the medical and veterinary importance of parasitic larvae, and the complex life cycle which presents difficulties in finding habitats occupied by postlarval forms, most species have been described exclusively from their larvae. This review provides updated information on the host spectrum and distribution of all the trombiculid species hitherto recorded in Poland, supplemented with data on their general distribution and biology.