Generic diversity of the predaceous fungus gnats (Diptera: Keroplatidae) from Colombia

Keroplatidae is a family of Diptera that is poorly known and with scarce previous studies in Colombia, with only five species in four genera, and another five genera with non-identified species. This paper provides an extensive revision of the Keroplatidae from Colombia, with specimens collected along different altitudinal gradients, from Amazonian areas to Andean mountains. We found 17 genera, nine of these represent new records for Colombia ( Cerotelion , Heteropterna , Placoceratias , Platyroptilon , Lapyruta , Micrapemon , Plautyra , Pyrtaula and Xenoplatyura ) . Additionally, the distribution in Co-lombia is extended for the genera Isoneuromyia, Keroplatus, Lyprauta, Macrocera, Neoceroplatus, Neoditomyia, Neoplatyura and Proceroplatus . For each genus we present a diagnosis, annotations of their biology based on literature and new field observations


INTRODUCTION
Keroplatidae is a dipterous family with small to medium size (3-15 mm), that can be recognized by their cylindrical or modified antennae (dorsoventrally flattened or lamellated), regularly composed of fourteen flagellomeres, although they can reach of several times the length of their body (Macrocerinae), and by their wing venation, with presence of a short R 4 vein ending in R 1 or C; and with veins R and M in contact or briefly fused, resulting in the absence of the transverse vein r-m (Vockeroth 2009, Falaschi 2016).This group has cosmopolitan distribution comprising seven subfamilies: the classically known Arachnocampinae, Macrocerinae, Keroplatinae, and Sciarokeroplatinae (Matile 1990, Ševčík et al. 2015, Mantič et al. 2020), and three new subfamilies recently established based on molecular phylogenetic results and fossil records: Platyurinae, Lygistorrhininae, and Adamacrocerinae (Mantič et al. 2020(Mantič et al. , Ševčík et al. 2020)).There are 92 genera and approximately 1000 described species in the family (Evenhuis 2006, Ševčík 2009, 2012, Mantič et al. 2020).The highest species richness is for the Palearctic region with 243 species in 30 genera, having the Neotropics 204 species in 31 genera (Papavero 1978, Evenhuis 2006, Falaschi et al. 2019, Mantič et al. 2020).In Colombia, studies are very scarce, with records of only five described species in four genera and two subfamilies (Macrocerinae and Keroplatinae), and five more genera with undescribed species (Falaschi 2016).
According to their ecology, they are mainly reported in humid tropical forests at low altitudes, in places such as caves and slippery holes in banks, under rocks or fallen logs, banks of streams in forests, as well as in understorey vegetation and on fungi (Meyer-Rochow 1999, 2007, Evenhuis 2006).The five Keroplatidae species recorded in Colombia by Falaschi (2016) have been found mainly in high altitude ecosystems such as Macrocera matilei Papavero, 1978, at 3000 meters above sea level (m.a.s.l.); Neoditomyia colombiana Lane and Sturm, 1958, between 1600-2000 m.a.s.l.; and Neoditomyia andina Lane and Sturm, 1958, found in low altitudes between 400 -500 m.a.s.l.; finally, Paramacrocera lanei Matile, 1990 and Lyprauta zetekyi Lane, 1950 which lack specific locality data.Additionally, Falaschi (2016) reported five other genera with undescribed species, between 130 -1960 m.a.s.l.(Isoneuromyia Brunetti, 1912;Neoceroplatus Edwards, 1941; Procero-platus Edwards, 1925;Keroplatus Bosc, 1792;and Neoplatyura Malloch, 1928) from three localities in Colombia.This study aims to update the generic Keroplatidae records from Colombia by studying specimens from fieldwork and biological collections, providing for each genus a diagnosis, remarks, information about its biology, and an updated distribution in Colombia.

Sampling
The study was based on specimens collected between 2016 and 2019 in the peri-urban High Andean Forest at 2000 m.a.s.l., and in two paramo complexes from the high Central Andes between 2720 -3400 m.a.s.l.(Fig. 1) in three vegetation types (paramo, forest, and grassland).The specimens are deposited in the Colección Entomológica Universidad de Antioquia (CEUA), Medellín.In addition, we examined specimens from the Instituto de Investigaciones Biológicas Alexander von Humboldt (IAvH), Villa de Leyva.These specimens were collected in National Natural Parks (PNN), Fauna and Flora Sanctuaries (SFF), and Natural Reserves (RN) distributed in 20 departments of Colombia, which were sampled with Malaise traps, except for a couple done with canopy Malaise and emergence traps.

Taxon treatments
The specimens were identified at the generic level following keys available for subfamilies, tribes, and genera (Edwards 1929, Lane 1950, Freeman, 1951, Vockeroth 1981, Matile 1990, Vockeroth 2009, Ševčík et al. 2015).Photographs of the habitus and wings representing the subfamilies, tribes, and genera, were taken with a Moticam 5MP digital camera adapted to an Olympus SZx7 stereomicroscope.The photos were taken at different focal levels, and then combined by stacking into a single image using Helicon Focus 6.7.2 software and were edited with Adobe Photoshop CS6.
Distribution maps of the genera were made with QGis 3.12.3software, with the Colombian departments and the terrestrial ecoregions of the world (Olson et al., 2001) to determine the ecological characteristics of the areas inhabited by the specimens.
Biology.The biology of this genus is predatory (Matile 1990).Specimens were mainly found in forest with closed canopies and paramo vegetation types, rocky soil forming small cavities and next to small streams (Fig. 1).Additionally, in the field, three specimens were associated with Alpinia Roxb, 1810 (Zingiberaceae) in one locality of the municipality of Envigado, Antioquia at 1700 m.a.s.l.
Remarks.Before this work, only one female of M. matilei Papavero, 1978 was recorded from Colombia without a specific locality (Papavero 1978).In this work we recorded three more unidentified species, being the first records with specific localities in the country for Antioquia and Santander departments (Fig. 4b).

Subfamily
Tribe Genus World distribution (species number) Neotropical distribution (species number)
Biology.Specimens were collected and associated with well-preserved forested areas, particularly in high mountain cloud forests dominated by Quercus humboldtii Bonpl., and with wet transitional habitats between these forests and dry forests of lowlands.
Remarks.This is the first record of this genus from Colombia (Fig. 4a), with one undescribed species.
Biology.The specimens were associated mainly with well-preserved closed forested areas and rocky soil forming small cavities (Fig. 1b), principally in montane forests in the Central and Oriental Andes, and with the piedmont dry forests and the Llanos grasslands of the Orinoco basin, as well as with the forests of the isolated Santa Marta Mountain, which is also a transitional habitat between dry forests and the peaks of the Andes.They were also recorded in areas of anthropogenic activity, such as grasslands.
Remarks: this is the first record of this genus in Colombia (Fig. 4a), with three undetermined species.Until recently, the specimens with pectinate antennae were grou-ped within the genus Ctenoceridion Matile, 1972, however, Mantič et al. (2020) proposed Ctenoceridion as a junior synonym of Heteropterna based on phylogenetic analyses and similarities in the structures of the male genitalia.The current taxonomy is followed here.Neoceroplatus Edwards, 1941 (Figs. 2f, 3f) Diagnosis.Slender and long terminal palpomere; flagellum with flagellomeres compressed, more wider than long; last flagellomere with an apical process, light in color and usually long; setose anepisternum and laterotergite; triangular and narrow membranous area of mediotergite (isosceles triangle), with the top of the triangle extending and dividing the mediotergite (Y form); R 2+3 ending in R 1 ; tibial trichia in regular rows, at least in the apical third (Matile 1990, Vockeroth 2009, Ševčík et al. 2015).
Biology.Data about the biology of this genus were provided by Falaschi et al. (2019), when describing a new species from Brazil, Neoceroplatus betaryiensis, reporting for the first time bioluminiscense in the larvae of this genus.The larvae are very active, especially at night, and are usually found on fallen branches or tree trunks.Some larvae were also spotted in association with mycelium of polyporaceous fungi.Pupae are also bioluminescent.In the same study, the authors report a case of parasitoidism by an ichneumonid wasp emerged from a pupa (Falaschi et al. 2019).The examined specimens from Colombia were primarily associated with dense canopy forests and rocky soils forming small cavities (Figs.1a-b), inhabiting mainly montane forests of the Colombian Andes, with just a few records in paramo areas.However, there are also records in moist forests of the Chocó-Darien and Amazon regions.

Examined
Biology.The examined specimens were associated mainly with dense canopy forests in protected areas, with one re-cord in an urbanized intervening area surrounded by forest habitats.These forests correspond to moist forests of the Chocó-Darien region and moist evergreen tropical rain forests of the Amazon region.
Remarks.This is the first record of the genus from Colombia (Fig. 4a), with two undetermined species.(Matile 1990;Ševčík et al. 2015).
Biology.Specimens were associated mainly with forested areas, some with rocky soils forming small cavities (Fig. 1b), others in paramo habitats and grasslands disturbed by anthropogenic activities.The type of forest where they were mostly found corresponds to montane and cloud forests with a wet climate, some of them surrounding the Magdalena Valley, containing transitional habitats between dry forests and high mountains of the north of the Andes.
Remarks.This is the first record for the genus in Colombia (Fig. 4b), with two undetermined species.
xii.2016, A.L. Montoya and J. Torres-Toro (CEUA: 97162).One male, Envigado, Loma del Escobero, Parcelación  Biology.Specimens found were associated exclusively with preserved forest habitats with dense canopies, some with rocky soils forming small cavities (Fig. 1b), mainly in montane forests of the northern and northwestern Andes, having the influence of the piedmont dry forests and Orinoco basin, and with associations with the Santa Marta Mountains, and some records in the moist forest of the Amazon.
Remarks.Before this work, two males of an undescribed species were recorded for one locality in the department of Valle del Cauca (Falaschi 2016).Here, we recorded three more unidentified species, extending the distribution of the genus to Antioquia, Cundinamarca, Meta, and Putumayo (Fig. 4b).Lapyruta Edwards, 1929 (Figs. 2j, 3j) Diagnosis.Three ocelli; setose pleurotergites; laterotergite with very fine, short and pale hairs above (pilose); bare spiracles; uniformly setose scutum; C produced at least two-fifths of distance from R 4+5 to M 1 ; vein CuP not reaching wing margin; tibial setae in regular rows, except sometimes at the base; meso and metatibia with two apical spurs; in males the inner spur of hind tibia become swollen at the apex, just before the acuminate tip, in females both hind tibial spurs are normal (Edwards 1929, Lane 1950).

Examined
Biology.The specimens found were associated exclusively with preserved forest habitats with dense canopies, mainly in the Amazon region's moist evergreen tropical rain forests.

Examined
Lyprauta Edwards, 1931 (Figs. 2k, 3k) Diagnosis.Three ocelli; bare pleurotergites; uniformly setose scutum; C produced at least two-fifths of distance from R 4+5 to M 1 ; branches of M and Cu bare above; vein M 2 incomplete, interrupted at base; R+M shorter than the stem of M fork; reduced vein CuP, not exceeding the apex of basal cell (br+bm); tibial setae in regular rows; meso and metatibia with two apical spurs (Lane 1950, Vockeroth 2009).
Biology.The examined specimens were associated mainly with forested environments, with one record in cultivated areas product of anthropogenic activities.The forest types correspond mainly to montane forests in the Magdalena Valley, with few records in moist forests of the Chocó and Amazon regions.

Examined
Biology.The specimen recorded in this work was found associated with moist evergreen tropical rain forest habitats with dense canopies in the Amazon region.
Remarks.This is the first record of the genus for Colombia (Fig. 4c), with an unidentified species.
Biology.Specimens were found associated with wellpreserved and continuous forest habitats with dense canopies in protected areas, mainly with montane forests dominated by Cecropia obtusifolia Bertol., of the western slope of the Western Andes and moist forests of Western Amazonia.
Examined material.COLOMBIA.Neoplatyura Malloch, 1928 (Figs. 2n, 3n) Diagnosis.Sub-rectangular flagellomeres, slightly compressed; three ocelli; bare pleurotergites, but sometimes anepisternum with a few hairs in the upper half; anterior spiracle with a fringe of hairs (sometimes not visible); setose scutum with bare stripes; C projected at least two fifths of distance from R 4+5 to M 1 ; branches of M and Cu with a row of fine dorsal setae (denser towards the apex); tibial setae irregular in the basal half and regular at apex (Vockeroth 2009).
Biology.Specimens were found associated mainly with closed-canopy forests, with a few records in paramo ecosystems, grasslands with little or no forest cover, and areas near bodies of water, such as streams and lakes.They are distributed throughout the Andean mountain range.
Remarks.Before this work, two males of an undescribed species were recorded for a locality in the department of Nariño (Falaschi 2016).We recorded three more unidentified species, extending the distribution of the genus to An-tioquia, Boyacá, Cundinamarca, La Guajira, Meta, Norte de Santander, Risaralda, and Valle del Cauca (Fig. 4d).Plautyra Edwards, 1941 (Figs. 2o, 3o) Diagnosis.Sub-rectangular flagellomeres, slightly compressed; three ocelli; bare katepisternum and laterotergite; setose metepisternum; uniformly setose scutum; fusion of R and M at least five times as long as the stem of M; C projected at most one-fifth of distance between R 4+5 and M 1 ; branches of M and Cu bare above; well-developed vein CuP, ending near wing margin; tibial setae in regular rows throughout the entire tibia (Vockeroth 2009).

Examined
Biology.The specimens were associated with forest environments with dense canopies and rocky soils forming small cavities (Figs.1a-b), mainly with montane forests dominated by Quercus humboldtii Bonl. in central and eastern Andes, with a few records in moist and dry forests of the Chocó and Llanos regions, respectively.
Remarks.This is the first record of the genus for Colombia (Fig. 4b), with two undetermined species.
Proceroplatus Edwards, 1925 (Figs. 2p, 3p) Diagnosis.Compressed flagellomeres, sometimes pectinate; three ocelli; setose laterotergite; bare metepisternum; bare anterior and posterior spiracles; wing with irregularly arranged dark spot patterns; two tibial spurs, the outer one-fifth to one-eighth as long as the inner and the latter about four times as long as apical tibial diameter (Vockeroth 2009).
Biology.Specimens found were associated mainly with continuous forest ecosystems dominated by Quercus humboldtii Bonpl., Wienmania sp., Schefflera trianae (Planch.and Linden ex Marchal) Harms, Drimys granadensis L.f. and Cecropia obtusifolia Bertol.; in paramo ecosystems and habitats near small streams, with some records in grasslands produced by anthropogenic activity.
Remarks.Before this work, two males of an undescribed species were recorded for a locality in the department of Cauca (Falaschi 2016).We recorded four more unidentified species, extending the distribution of the genus to Amazonas, Antioquia, Boyacá, Caldas, Chocó, Cundinamarca, Meta, Norte de Santander, Putumayo, Valle del Cauca, and Vaupés (Fig. 4c).

DISCUSSION
The generic review of the Keroplatidae present in Colombia shows that the family is widely distributed covering va-rious ecosystems at different altitudinal ranges in the country.The greatest diversity of the family is concentrated in the Andean mountains, and this could be explained due to the increased sampling efforts carried out in these ecosystems during the last 10 years to uncover the diversity and ecology of some groups of paramo dipterans (e.g., Montoya and Wolff 2020, Henao-Sepúlveda et al. 2019, 2020, 2023).).Other groups were found to be more associated with low altitudes and warm climates, such as the genus Neoditomyia, with two species known for the country before this work, which were found in Huila (Garzón) and Villavicencio between 400 and 500 m.a.s.l.(Lane and Sturm 1958).These altitudinal ranges are shared with other species of the genus recorded for Belize (Jackson 1974), Dominica, Cuba (Matile 1977(Matile , 1982)), Jamaica, and Brazil (Coher 1996).Nevertheless, in this work, two specimens are reported between 700 and 1900 m.a.s.l., extending the altitudinal range of distribution for this genus.
The specimens studied here were found associated with three different vegetation covers: forest areas, paramos, and areas for livestock and agriculture.All the genera were found in forest areas, exhibiting their greatest diversity in these ecosystems.We highlight the genera Cerotelion, Heteropterna, Isoneuromyia, Keroplatus, Lapyruta, Micrapemon, Neoditomyia, Plautyra, and Xenoplatyura that were collected exclusively in these habitats.This high richness and abundance found in the forests was expected and corresponds to what is mentioned in the literature since keroplatids prefer environments with low brightness and high humidity (Evenhuis 2006), characteristics present in forest areas.In the case of paramo ecosystems, although the abundance and richness found does not compare with that of forests for most genera, it is clear that paramo habitats present microhabitats with differential conditions compared to forested areas, promoting the emergence of unique taxa in these environments.For most of the genera present in the paramo ecosystem, we found a species diversity that potentially has not yet been described.It is worth highlighting the genus Pyrtaula, whose greatest abundance was found in paramo areas, in contrast to the other genera.
We found that some specimens of Heteropterna, Lyprauta, Macrocera, Neoplatyura, Placoceratias, Platyroptilon, Proceroplatus, and Pyrtaula were associated with disturbed environments, however, abundances in this habitat in general were extremely low, with less than five individuals reported for each of the mentioned genera.Specimens associated with these areas probably correspond to widespread distributed species that exhibit some degree of tolerance to disturbance and that were able to continue to occupy these niches after forest degradation.
In this work, the genera Macrocera (three morphospecies) and Proceroplatus (four morphospecies) were found in all ecosystems and abundant in the Malaise traps (Matile 1990) and well represented in the Neotropical region (Bechev 2000).To date, only one species has been recorded for Macrocera in the country (Papavero, 1978), likewise Proceroplatus has a record of an undescribed species (Falaschi 2016), which could suggest that most of the species reviewed in this work may be new records or new species.
The genera Isoneuromyia (three morphospecies), Neoceroplatus (three morphospecies), and Neoplatyura (three morphospecies) show high diversity of species described for Brazil (Bechev 2000), but completely unknown for the Colombian regions, especially for the Andean regions of the country.While the genera that have one or two representatives, such as Cerotelion (one morphospecies), Lapyruta (one morphospecies) and Micrapemon (one morphospecies), groups that we consider rare and scarce in traps.The lack of knowledge of the taxonomic determination at the species level of the representatives of the family Keroplatidae in Colombia, is largely due to the lack of studies that focus on providing information that embraces its diversity at both generic and species levels.

CONCLUSIONS
This work greatly increases the knowledge of the generic diversity and life histories of Keroplatidae for Colombia, mainly in high mountain ecosystems, with a total of 17 genera identified, nine of which are recorded for the first time for the country.These results demonstrate the enormous potential of finding high hidden diversity in these poorly studied groups, which is relevant, not only for the general knowledge of these groups, but also to propose and implement effective actions for their conservation.We hope that this work will not only serve as a basis for future studies of Keroplatidae in Colombia but will also encourage the study of other unknown groups, in order to continue increasing the knowledge of the Colombian entomofauna and its overwhelming diversity.

AUTHORS' CONTRIBUTIONS
JSV, JVS and CHS revised the entomological material and literature, analyzed the data and prepared the draft and the illustrations.MW and CHS revised the entomological material and literature, designed the investigation, acquired the funding, contributed to the writing of the text and made critical revisions.All authors actively participated in the discussion of the results and approved the final manuscript.

Figure 4 .
Figure 4. Geographic distribution of Keroplatidae genera found in Colombia.

Table 1 .
Keroplatidae subfamilies, tribes and genera identified from Colombia, with world distribution (based on Specimens were found associated only with forested habitats of closed canopies in protected areas, mainly with montane forests of the Cauca Valley and Northern Andes, highly diverse areas that are important centers of endemism, with the last one having the influence of the piedmont dry forests and the Llanos grasslands of the Orinoco basin, and with species associations shared with the Santa Marta mountains.Additionally, one specimen was recorded in moist forests of the Chocó-Darien region.Remarks.Keroplatus is similar to the genus Neoceroplatus, but they differ most obviously by the size of the palps, which in Keroplatus are shorter than the length of the face and the clypeus together, whereas in Neoceroplatus the palps are slender and longer than the length of the face and the clypeus.Before this work, two males of an undescribed species were recorded in the PNN Gorgona (Falaschi 2016), here, we recorded two additional non-identified species, being the first records of the genus for Antioquia, Norte de Santander and Risaralda (Fig.4a).
(Pizano andepresentatives of the family found in tropical lowland forests might be explained because of the lesser exploration efforts carried out in the country(Pizano and García 2014, Parrado-Rosselli et al. 2015).