Joanna Mąkol

Correlation of heteromorphic life instars in terrestrial Parasitengona mites and its impact on taxonomy – the case of Leptus molochinus (C. L. Koch, 1837) and Leptus ignotus (Oudemans, 1903) (Acari: Trombidiformes: Prostigmata: Erythraeidae)

Leptus molochinus (C. L. Koch, 1837) is redescribed based on adults, deutonymphs and larvae. Larvae of hitherto distinguished Leptus ignotus (Oudemans, 1903), syn. nov., redescribed as Leptus ignotus ignotus, were obtained by experimental rearing from females of L. molochinus (C. L. Koch, 1837). The previous conjectures on “Leptus ignotus” as a compound taxon were not confirmed. Leptus ignotus danelli Southcott, 1992 is regarded as a distinct species, L. danelli Southcott, 1992 stat. nov. Data on larvae obtained by experimental rearing and those collected in the wild are compared with literature data on field-collected larvae. Information on development of eggs into larvae and on host spectrum is summarised. A female, from which larvae have been obtained by experimental rearing, is designated as neotype. Backgrounds for synonymisation of species known from different life instars are discussed.

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?

BackgroundThe 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.MethodsApodemus 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.ResultsThe 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.ConclusionsAn 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–parasite interactions within terrestrial Parasitengona (Acari, Trombidiformes, Prostigmata)

Published data on larvae of terrestrial Parasitengona that exploit members of the same group as hosts are summarized, and new, hitherto unpublished, records are provided. Larvae of 11 species have been recorded as parasitizing post-larval forms of 23 species assigned to the same cohort of mites. Of the 30 records involving different host [H] and parasite [P] sets, 10 apply to new observations. The members of the following families were found to enter within-cohort [H]–[P] interactions: Erythraeidae [H]–Erythraeidae [P]; Trombidiidae [H]–Erythraeidae [P]; Erythraeidae [H]–Trombidiidae [P]; Smarididae [H]–Trombidiidae [P]; Chyzeriidae [H]–Chyzeriidae [P]; Calyptostomatidae [H]–Johnstonianidae [P]; Trombidiidae [H]–Johnstonianidae [P]; Microtrombidiidae [H]–Johnstonianidae [P]; Johnstonianidae [H]–Johnstonianidae [P]. Hyperparasitism has been confirmed for members of Erythraeus cinereus (Dugès, 1834). Johnstoniana parva Wendt, Wohltmann, Eggers & Otto, 1994 remains the only species known to exclusively parasitize other Parasitengona. Of larvae that we tried to rear in laboratory, only J. parva was able to develop to the deutonymphal stage after parasitizing other Parasitengona. We argue that based on current evidence, terrestrial Parasitengona, except for J. parva, should be regarded as accidental parasites of members of the same cohort.

A redescription of Neothrombium neglectum (Bruyant, 1909) with revision of Neothrombium (Acari: Neothrombiidae) and notes on the biology of species

ABSTRACT Neothrombium neglectum (Bruyant, 1909), the type species of Neothrombium Oudemans, 1909, is redescribed based on adult, deutonymph, and larva. A lectotype was designated from the type series of larvae studied by Bruyant. Falsivalgothrombium Zhang and Xin, 1989, a genus hitherto known exclusively from adults, is considered a junior synonym of Neothrombium Oudemans, 1909. A new combination, Neothrombium longitarsis (Zhang and Xin, 1989) n. comb., is proposed. A critical review of the five hitherto described members of Neothrombium known from larvae has resulted in the proposal of synonymization of Neothrombium danangensis Haitlinger, 1998 n. syn. and Neothrombium mojdehii Saboori and Ostovan, 2001 n. syn. with Neothrombium neglectum (Bruyant, 1909). Complementary data on morphology and biology of N. neglectum are given. The second longest duration of association with a host was recorded among larvae representing terrestrial parasitengone mites. A contribution to the phenology of N. neglectum and time intervals between the development of larvae, protonymphs, deutonymphs, tritonymphs, and adults are provided.

Towards resolving the double classification in Erythraeus (Actinotrichida: Erythraeidae): matching larvae with adults using 28S sequence data and experimental rearing

The taxonomy of free-living adults and heteromorphic parasitic larvae of Parasitengona mites has in the past been treated independently resulting in a double classification. Correct linkage of names still remains unknown for many species. A holistic understanding of species is imperative for understanding their role in ecosystems. This is particularly true for groups like parasitengone mites with a radically altered lifestyle during development—parasitic to predatory. Here, we infer linkages of three nominal species of Erythraeus, using matching with 28S DNA sequence data from field-collected specimens and through laboratory rearing. The general mixed Yule coalescent method (GMYC) was used to explicitly test if field-collected specimens representing heteromorphic life instars were conspecific. The field-collected larvae were allocated to adults of Erythraeus cinereus and Erythraeus regalis, respectively. Laboratory rearing of the same two species confirmed the matching done by DNA. Rearing was also successful for Erythraeus phalangoides after eggs were treated to an imitated winter diapause. This integrative taxonomic approach of molecular, morphological, and rearing data resulted in the following synonyms: E. phalangoides (De Geer, 1778) [= Erythraeus adrastus (Southcott, 1961), syn. nov.], E. cinereus (Dugès, 1834) [= Erythraeus jowitae Haitlinger, 1987, syn. nov.], and E. regalis (C.L. Koch, 1837) [= Erythraeus kuyperi (Oudemans, 1910), syn. nov., = Erythraeus gertrudae Haitlinger, 1987, syn. nov.]. The molecular evidence confirmed the separate identity of three further members of the genus. We provide redescriptions of E. phalangoides, E. cinereus, and E. regalis after modern standards, and neotypes are designated.

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.

ABSTRACT. 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.

Redescription of Erythraeus tonsus (L. Koch, 1879) (Acari: Trombidiformes: Erythraeoidea) with record on an unusual case of polymely in adult Erythraeidae collected in Alaska (USA).

ABSTRACT Erythraeus tonsus (L. Koch, 1879) (Acari: Erythraeidae) is redescribed based on adult specimens from Kenai Peninsula, Alaska (USA). A female has been designated a neotype. The monstrosity, regarded as polymely, is reported for the first time in terrestrial parasitengone mites. Larvae and deutonymphs of E. tonsus remain unknown.

The first description of a microtrombidiid mite (Actinotrichida: Prostigmata, Microtrombidiidae) from Baltic amber, with notes on related extant genera and species

Discovery of parasitengone mites (Acari) in the Gulf of Gdańsk deposits of Baltic amber (“Blue Earth” sediment) resulted in the first description of a fossil representative of Microtrombidiidae. The new species, based on larvae, displays affinity to recent members of Montenegtrombium Saboori and Pešić, 2006, Persianthrombium Sedghi, Saboori and Hakimitabar (in Sedghi et al. 2010) and Porttrombidium Haitlinger, 2000, known from the southwestern Palaearctic. A comparison with related genera and species places the newly described taxon in Porttrombidium (as Porttrombidium gedanense sp. nov.). Montenegtrombium is regarded as a junior synonym of Porttrombidium.KurzfassungDie Entdeckung von Milben aus der Gruppe der Parasitengona (Acari) in Baltischem Bernstein aus der “Blauen Erde” der Danziger Bucht führt zur ersten Beschreibung eines fossilen Vertreters der Microtrombidiidae. Die Milbe ist als Larve konserviert und ähnelt rezenten Arten der Gattungen Montenegtrombium Saboori & Pešić, 2006, Persianthrombium Sedghi, Saboori & Hakimitabar (in Sedghi et al. 2010) und Porttrombidium Haitlinger, 2000, alle bekannt aus der südwestlichen Paläarktis. Ein Vergleich mit Arten dieser Gattungen zeigt, dass die neu nachgewiesene Bernstein-Larve als neue Art von Porttrombidium zu betrachten ist – Porttrombidium gedanense sp. nov. Bei der Gattung Montenegtrombium handelt es sich um ein jüngeres Synonym von Porttrombidium.

Abalakeus Southcott, 1994 is a junior synonym of "plume-footed" Eatoniana Cambridge, 1898 (Trombidiformes, Erythraeidae)—evidence from experimental rearing

Eatoniana Cambridge, 1898 was previously known exclusively from active postlarval forms. In the course of experimental rearing, larvae showing a strong affinity to members of Abalakeus jahromiensis Sedghi, Saboori et Hakimitabar, 2010, were obtained from a field-collected female of Eatoniana plumipes (L. Koch, 1856). Studies of all members of Abalakeus compared with newly obtained larvae of Eatoniana, resulted in synonymisation of Abalakeus Southcott, 1994 with Eatoniana and of A. jahromiensis with E. plumipes. Complementary data to the previous diagnosis of Eatoniana and information on the biology of E. plumipes are provided. A female of E. plumipes was selected as the neotype. A key to Eatoniana spp. known from larvae is provided.