A symbiotic balancing act: arbuscular mycorrhizal specificity and specialist fungus gnat pollination in the mycoheterotrophic genus Thismia (Thismiaceae).

BACKGROUND AND AIMS: Mycorrhizal associations in mycoheterotrophic plants are generally more specialized than in autotrophs. Mycoheterotrophs typically bear small, inconspicuous flowers that often self-pollinate to maximize seed set, although some have structurally complex flowers indicative of xenogamy. A trade-off has previously been proposed between specialization in these above- and below-ground symbioses, although empirical data are lacking. METHODS: We used next-generation DNA sequencing to compare the mycorrhizal communities from the roots of a mycoheterotrophic species, Thismia tentaculata (Thismiaceae), and its neighbouring autotrophs. We furthermore conducted detailed assessments of floral phenology and pollination ecology, and performed artificial pollination experiments to determine the breeding system. KEY RESULTS: Thismia tentaculata maintains a symbiotic association with a single arbuscular mycorrhizal Rhizophagus species. The flowers are pollinated by a single species of fungus gnats (Corynoptera, Sciaridae), which are attracted by the yellow pigments and are temporarily restrained within the perianth chamber before departing via apertures between the anthers. The plants are self-compatible but predominantly xenogamous. CONCLUSIONS: Our findings demonstrate that T. tentaculata maintains highly specialized associations with pollinators and mycorrhizal fungi, both of which are widely distributed. We suggest that specialization in multiple symbiotic interactions is possible in mycoheterotrophs if redundant selective pressures are not exerted to further restrict an already constrained suite of life-history traits.

The number of Estonian black fungus gnats (Diptera, Sciaridae) doubled: the first records of 64 species.

Background: Adult sciarid flies are small to medium-sized, delicate insects, typically black in colour and belonging to the superfamily Sciaroidea within the order Diptera. They exhibit a uniform appearance. Distinguishing them from other families of Sciaroidea is primarily achieved through their typical wing venation. Sciaridae are common in both natural and semi-natural ecosystems, where they play a significant role in decomposition during their larval stage. Prior to the current study, only one specific research project had been conducted on Sciaridae in Estonia. The number of sciarid species identified in Estonia was set at 67. New information: This research, conducted in north-eastern Estonia during 2015 and 2016, presents a comprehensive overview of Sciaridae diversity, shedding light on previously understudied aspects of Estonia's biodiversity. A total of 1038 specimens were identified, representing 91 species, amongst which 64 were previously unknown to Estonia. Notably, Corynopterawinnertzi (Mohrig, 1993) emerged as the most abundant species, followed by Corynopterairmgardis (Lengersdorf, 1930), Corynopteracrassistylata (Frey, 1948) and Bradysiatrivittata (Staeger, 1840). The genus Corynoptera Winnertz, 1867 exhibited the highest diversity, consistent with findings from broader European studies. This study underscores the importance of ongoing surveys for better understanding the distribution and composition of Sciaridae species in Estonia, emphasising the need for further research to delve into the intricate ecology and biology of these insects.

New species and other new records of the family Mycetophilidae (Insecta, Diptera) from Morocco.

Twelve species in nine genera of Mycetophilidae are newly recorded from Morocco and from North Africa. Five species are described as new to science: Rymosiaebejerisp. nov., Leiaarcanasp. nov., Megophthalmidiaamsemlilisp. nov., Mycomyamirasp. nov., and Phthiniasnibbypinsaesp. nov. Three species are newly recorded from Gibraltar.

Fungus gnat pollination in Arisaema urashima: the interplay of lethal traps and mutualistic nurseries.

While most flowering plants engage in mutualistic interactions with their pollinators, Arisaema species employ a unique, seemingly antagonistic strategy by imprisoning and causing the pollinators to perish within their spathes. Recent studies have revealed that Arisaema thunbergii primarily relies on a fungus gnat, Leia ishitanii, with some individuals possibly escaping female spathes after oviposition. We investigated interactions between A. urashima and its pollinating fungus gnats, given that A. urashima is closely related to A. thunbergii. Specifically, we tested whether decaying A. urashima serve as brood-sites for some pollinators and whether these pollinators can escape seemingly lethal floral traps. We retrieved A. urashima spathes together with adult insect corpses trapped within the spathes and incubated the spathes to see if conspecific insects emerged. In addition, under laboratory conditions, we observed the escape behaviour of Sciophila yokoyamai, whose next-generation adults most frequently emerge from the decaying spathes. Our findings indicate that S. yokoyamai almost always escapes from the female spathe after oviposition while using the inflorescence as a nursery. In contrast, other pollinators of A. urashima, including Mycetophila spp., remain trapped and perished within the spathes. This study demonstrates that A. urashima spathes can function both as lethal traps and mutualistic nurseries, with outcomes differing among pollinator species. Our results also suggest that the contribution of certain pollinators to Arisaema reproduction is underestimated or even neglected, given that information on their pollinator assemblages has been based on floral visitors trapped within the inflorescences.

Review of the Genus Sciara Meigen, 1803 (Diptera, Sciaridae) in Ukraine.

On the territory of Ukraine during the field seasons 2015-2022, we collected eight Sciara species-S. analis Schiner, 1864, S. flavimana Zetterstedt, 1851, S. hebes (Loew, 1869), S. helvola Winnertz, 1867, S. hemerobioides (Scopoli, 1763), S. humeralis Zetterstedt, 1851, S. incerta Winnertz, 1867 and S. ruficauda Meigen, 1818. All specimens are kept in the collections of the Schmalhausen Institute of Zoology NAS of Ukraine (SIZK). According to the results of our research, the four species S. flavimana, S. hebes, S. helvola and S. incerta are being registered for the first time in Ukraine. New localities are given for S. analis, S. hemerobioides, S. humeralis and S. ruficauda. The distribution, morphological peculiarities, ecology and phenology of registered species are also briefly discussed. A key to 12 European Sciara species is given.

The Genus Spinopygina gen. nov. (Diptera, Sciaridae) from Western North America: Preliminary Molecular Phylogeny and Description of Seven New Species.

The genus Spinopygina gen. nov. (type species Camptochaeta uniceps Hippa & Vilkamaa, 1994) from western North America is described. The genus includes the following eight species: Spinopygina acerfalx sp. nov.; S. aurifera sp. nov.; S. camura sp. nov.; S. edura sp. nov.; S. peltata sp. nov.; S. plena sp. nov.; S. quadracantha sp. nov.; and S. uniceps (Hippa & Vilkamaa, 1994) comb. nov., transferred from Corynoptera Winnertz. The new species are described and Spinopygina uniceps is re-diagnosed. The species are keyed and illustrated. In the maximum-likelihood phylogenetic hypothesis based on four gene fragments (28S, 18S, 16S and COI), Spinopygina gen. nov. appears as the sister group of Claustropyga Hippa, Vilkamaa & Mohrig, 2003. In the same analysis, a remarkable, undescribed species is placed within Camptochaeta Hippa & Vilkamaa clade.

New faunistic records of the families Bolitophilidae and Keroplatidae (Diptera, Sciaroidea) from Morocco.

The family Bolitophilidae is recorded for the first time from Morocco with one species Bolitophila (Bolitophila) saundersii (Curtis, 1836). Ten new species are added to the Moroccan fauna of Keroplatidae, known until now by only two species, raising the number of species currently known in Morocco to 12.

Biological Activity of Insecticides Against Bradysia ocellaris Larvae (Diptera: Sciaridae): A New Pest of Strawberry Crops.

Black fungus gnat larvae are one of the primary insect pests in greenhouse and nursery crops, and Bradysia ocellaris (Comstock) (Diptera: Sciaridae) is one common pest species. This pest is difficult to control in Brazil because of the absence of registered insecticides. The aim of this work was to evaluate the effects of some insecticides on B. ocellaris larvae. We also verified that the insect growth regulator novaluron caused the deformation of B. ocellaris. Of the insecticides evaluated, malationa, and thiamethoxam showed high mortality rate (96 and 86 % respectively). Further, bioassays with acetamiprid (78 %) and novaluron (44 %) showed that the lethal concentrations (LC50) were 19.18 mg a.i.L-1 at 48h to acetamiprid and 1.24 mg a.i.L-1 at 120 h to novaluron. When larvae were fed on potato pieces treated with novaluron, independently of the dose, the mortality rate was 100 %, since no larvae could complete the development cycle. Among all evaluated insecticides, only acetamiprid and novaluron were considered effective tools for control of B. ocellaris larvae under laboratory conditions.

Revision of the Exechiaparva group (Diptera: Mycetophilidae).

BACKGROUND: Exechia is a diverse genus of small fungus gnats, widespread in the Holarctic Region, while the fauna is largely unknown elsewhere, such as in the Afrotropical and Oriental Region. Members of Exechia can be arranged into several species groups, based on homologies in the male and female terminalia. The Exechiaparva group is delimited, based on male terminalia possessing a pair of gonocoxal lobes on the apicoventral gonocoxal margin. Eight previously-described species can be placed in this group, of which six are from the Holarctic Region, while one is recorded each from the Oriental and the Afrotropical Regions. NEW INFORMATION: The Exechiaparva group was reviewed and found to include 33 species, of which 24 were described as new to science and six were re-described. Identification keys to 32 species for males and nine species for females are provided together with illustrations and photos of male and female terminalia. Species delimitations were based on morphological examination of 94 male and female specimens, as well as DNA barcodes obtained from 124 specimens. Molecular and morphological species delimitations were mostly congruent, except in two cases where two species were delimited within a single Barcode Index Number (BIN). We found that each species is only known from a single zoogeographical region and that several species complexes are largely congruent with zoogeographical divisions, indicating that intercontinental barriers may have a strong impact on the species diversity of the group.

Effects of Climatic Change on the Potential Distribution of Lycoriella Species (Diptera: Sciaridae) of Economic Importance.

Lycoriella species (Sciaridae) are responsible for significant economic losses in greenhouse production (e.g., mushrooms, strawberries, and nurseries). The current distributions of species in the genus are restricted to cold-climate countries. Three species of Lycoriella are of particular economic concern in view of their ability to invade areas in countries across the Northern Hemisphere. We used ecological niche models to determine the potential for range expansion under future climate change scenarios (RCP 4.5 and RCP 8.5) in the distribution of these three species of Lycoriella. Stable environmental suitability under climate change was a dominant theme in these species; however, potential range increases were noted in key countries (e.g., USA, Brazil, and China). Our results illustrate the potential for range expansion in these species in the Southern Hemisphere, including some of the highest greenhouse production areas in the world.

Every Single Specimen Counts: A New Docosia Winnertz (Diptera: Mycetophilidae) Species Described from a Singleton.

A new species-Docosia caucasica sp. n.-has been described from material collected from the Lesser Caucasus Mountains in Georgia (Sakartvelo). The new species belongs to a group of Palaearctic species characterized by distinct posterolateral processes of gonocoxites and apically modified setae at the posteroventral margin of the gonocoxites medially. Within the group, D. caucasica sp. n. is most similar to D. landrocki Lastovka and Sevcík, 2006 in having a similar outline of the medial process of posteroventral margin of the gonocoxites and the gonostylus. There is also a marked difference within the partial cytochrome c oxidase subunit 1 gene (COI) sequence of D. caucasica sp. n. and other Docosia spp. available in public databases. As the new species is described from a single male specimen only, the adequacy and code compliance of that are discussed.

A contribution towards checklist of fungus gnats (Diptera, Diadocidiidae, Ditomyiidae, Bolitophilidae, Keroplatidae, Mycetophilidae) in Georgia, Transcaucasia.

The fungus gnats of Georgia are studied based on 2682 specimens collected from 57 localities during 2011-2019. Altogether, 245 species are recorded including four species of Bolitophilidae, three species of Diadocidiidae, two species of Ditomyiidae, 34 species of Keroplatidae and 202 species of Mycetophilidae. 230 and 188 species are recorded from Georgia and the whole of Transcaucasia for the first time, respectively. Three new species - Sciophila georgei sp. nov., Leia katae sp. nov. and Anatella metae sp. nov. - are described including detailed illustrations of the male terminalia. Photographs are provided for an additional 38 species to highlight a variability of their general facies. Combined with earlier published data, the number of fungus gnat species in Georgia is set at 246. The estimated diversity of fungus gnats in Georgia is calculated using non-parametric methods and discussed with respect to other Western Palaearctic regions.

Additions to the knowledge of Manota Williston (Diptera: Mycetophilidae) from the Neotropical region, with description of four new species.

The Neotropical species of the genus Manota Williston are studied, based on material of 146 specimens from French Guiana, Ecuador, Nicaragua, Dominica and the Dominican Republic. Four new species are described, viz. M. corniculata sp. n. (French Guiana), M. pseudocavata sp. n. (French Guiana), M. truuverki sp. n. (French Guiana) and M. vladi sp. n. (Dominican Republic). Manota defecta Williston, 1896, the type species of the genus, is listed from Dominica, representing the first record since its description more than a century ago from a Southern Caribbean Island, St. Vincent. New records of 13 additional species are provided: M. acutistylus Jaschhof Hippa, 2005 (Dominica), M. aligera Hippa, Kurina Sääksjärvi, 2017 (French Guiana), M. digitata Hippa, Kurina Sääksjärvi, 2017 (French Guiana), M. iota Hippa Kurina, 2013 (French Guiana), M. micula Hippa Kurina, 2013 (French Guiana), M. nordestina Kurina, Hippa Amorim, 2018 (French Guiana), M. parva Jaschhof Hippa, 2005 (Nicaragua), M. pauloides Hippa, Kurina Sääksjärvi, 2017 (Ecuador), M. perplexa Kurina, Hippa Amorim, 2017 (Nicaragua), M. rotundistylus Jaschhof Hippa, 2005 (Ecuador), M. serrulata Hippa, Kurina Sääksjärvi, 2017 (French Guiana), M. spinosa Jaschhof Hippa, 2005 (French Guiana), M. subaristata Kurina, Hippa Amorim, 2017 (Ecuador). The number of Neotropical Manota species has risen to 96.

Enhanced Control of the Fungus Gnat Bradysia odoriphaga (Diptera: Sciaridae) by Co-Application of Clothianidin and Hexaflumuron.

The fungus gnat is a major pest of chive in China. Its control has been relied heavily on the application of clothianidin. Due to the intensive application, its control efficacy become reduced. The present study was intended to evaluate co-drenching of clothianidin with hexaflumuron on absorption and dissipation of clothianidin in chive plants and soils and determine the effect of such application on control efficacies. Chive production fields in Guangdong and Hubei Provinces were drenched with clothianidin alone and a mixture of clothianidin and hexaflumuron at low application rates. Concentrations of clothianidin in chive plants and soils were analyzed by HPLC. Results showed that co-application had higher control efficacies against the fungus gnat than clothianidin alone. The co-application enhanced clothianidin absorption and dissipation and extended the half-lives of clothianidin in chive. It was likely that hexaflumuron protected chive roots from larva damage, and healthy roots absorbed more clothianidin, resulting in the extension of the half-lives. Additionally, the terminal residues of clothianidin in chive after 14 days of application were lower than the maximum residue limit in chive set by the Codex Alimentarius Commission. This study for the first time documented that co-application of clothianidin and hexaflumuron improved chive plants in absorption and dissipation of clothianidin and enhanced fungus gnat control efficacies.

Just a Fragment of Undescribed Diversity: Twenty New Oriental and Palearctic Species of Sciaroidea (Diptera), including DNA Sequence Data and Two New Fossil Genera.

The following 17 extant new species of Sciaroidea (Diptera: Bibionomorpha) are described: Bolitophila nikolae Sevcík sp. nov. (Bolitophilidae, Taiwan), Catocha jingfui sp. nov. (Cecidomyiidae, Taiwan), Catocha manmiaoe sp. nov. (Cecidomyiidae, Taiwan), Catocha shengfengi sp. nov. (Cecidomyiidae, Taiwan), Planetella taiwanensis sp. nov. (Cecidomyiidae, Taiwan), Diadocidia pseudospinusola sp. nov. (Diadocidiidae, Taiwan), Asioditomyia bruneicola sp. nov. (Ditomyiidae, Brunei), Asioditomyia lacii sp. nov. (Ditomyiidae, Taiwan), Ditomyia asiatica sp. nov. (Ditomyiidae, Thailand), Chetoneura davidi sp. nov. (Keroplatidae, Brunei), Euceroplatus mantici sp. nov. (Keroplatidae, Thailand), Setostylus fangshuoi sp. nov. (Keroplatidae, Taiwan), Platyceridion yunfui sp. nov. (Keroplatidae, Hainan), Terocelion adami sp. nov. (Keroplatidae, Taiwan), Hadroneura martini sp. nov. (Mycetophilidae, Taiwan), Paratinia furcata sp. nov. (Mycetophilidae, Czech Republic, Slovakia), and Nepaletricha sikorai sp. nov. (Sciaroidea incertae sedis, Thailand). Two new genera are described from the mid-Cretaceous Burmese amber, Burmasymmerus gen. nov. (Ditomyiidae, type species Burmasymmerus korneliae sp. nov., including also B. wieslawi sp. nov.), representing the first record of the family Ditomyiidae from the Mesozoic, and Burmatricha gen. nov. (Sciaroidea incertae sedis, type species Burmatricha mesozoica sp. nov.). Molecular phylogeny of Ditomyiidae, based on two DNA markers (28S, COI), as well as that of Catocha Haliday, 1833, based on the mitochondrial COI and 16S fragments, are also presented.

Contribution to the molecular phylogeny of Sciaridae (Diptera) with special attention to the genera emBradysia/em and emCorynoptera/em.

The systematics of the dipteran family Sciaridae is based mainly on morphological characters and has remained quite controversial. In this study, we used two mitochondrial DNA markers (CO1, 16S) and a nuclear one (28S) to take a glimpse into phylogenetic relationships of part of the North and Central European Sciaridae. A total of 91 species from 19 genera were analysed using Maximum Likelihood based phylogenetics (depending on the availability of valid sequences, 50-70 per gene). We strengthen the suggestion of the Chaetosciara group as an independent subfamily. Within the subfamily Megalosphyinae, two separate Bradysia clades were identified, suggesting a close relation between the genera Zygoneura, Austrosciara, and Scatopsciara. The genus Alpinosciara gen. n. is established to place the species of the former Corynoptera crassistylata group inside the subfamily Megalosphyinae. This new genus now includes 22 species.

Revision of the Nearctic species of Ditomyia Winnertz and a new species from the Neotropical Region (Diptera: Ditomyiidae).

The Nearctic species of Ditomyia Winnertz (Diptera: Ditomyiidae) are revised and four species are recognized: D. euzona Loew and D. potomaca Fisher from the eastern Nearctic and D. sohnsi n. sp. and D. elongata n. sp. from the western Nearctic. All species are figured and a key provided. Additionally, the first known Neotropical Ditomyia is described and the generic limits of Ditomyia discussed.

Hidden in Plain Sight: Comprehensive Molecular Phylogeny of Keroplatidae and Lygistorrhinidae (Diptera) Reveals Parallel Evolution and Leads to a Revised Family Classification.

We provide the first molecular phylogeny of Keroplatidae and Lygistorrhinidae, families of fungus gnats (Diptera: Bibionomorpha: Sciaroidea). Phylogenies reconstructed by Maximum Likelihood and Bayesian methods, based on four nuclear and four mitochondrial gene markers (5106 base pairs) sequenced for 75 genera and 105 species, show Keroplatidae as monophyletic only with the family Lygistorrhinidae included, herewith treated as the subfamily Lygistorrhininae stat. nov. The subfamily Arachnocampinae is retained in the family, although lowering its overall support. An early branching clade, comprising species of Platyura Meigen, 1803 and Paleoplatyura melanderi Fisher, 1941, forms subfamily Platyurinae Loew, 1850 stat. nov. The subfamilies Sciarokeroplatinae and Macrocerinae grouped together with three genera considered here as Keroplatidae incertae sedis. Subfamily Lygistorrhininae forms a sister clade to subfamily Keroplatinae, both retained monophyletic with high support. The traditional division of the subfamily Keroplatinae into the tribes Orfeliini and Keroplatini appears as outdated, resting largely on adaptive characters prone to parallel evolution. We find support for an alternative tribe corresponding to the Cloeophoromyia-Asindulum genus group, but a tribal reclassification of the Keroplatinae is left for future studies. The genus Heteropterna Skuse, 1888 is considered as identical with Ctenoceridion Matile, 1972 syn. nov.

A new species of Stenophragma Skuse from Borneo (Diptera: Mycetophilidae: Sciophilinae).

Stenophragma borneense sp. n. from Borneo is described and illustrated. In the new species, a variability in the presence/absence and location of R4+5, including between left and right wings of the same specimen, is observed. The cell between Rs and R4+5, if present, can be triangular, trapeziform or almost squared. An identification key to the extant species of the genus is also provided.

Three new species and new records of Clastobasis Skuse (Diptera: Mycetophilidae) from Japan and the Kuril Islands.

Three new Clastobasis Skuse species are described: C. ainuorum sp. n. (Kuril Islands, Iturup), C. kanabo sp. n. (Japan, Honshu) and C. menguali sp. n. (Japan, Honshu). The new species are figured, photographed and their systematics discussed. New records are provided for C. loici Chandler and C. subalternans Zaitzev, both from Japan (Honshu). The number of Palaearctic Clastobasis species is set up at eight including six of them restricted only to the Eastern Palaearctic. Clastobasis loici, previously known only from Europe, is described to have a Trans-Palaearctic distribution. A key to the Palearctic species of Clastobasis is provided and the distribution shortly discussed.