Research Article |
Corresponding author: Piluca Álvarez Fidalgo ( pilucaaf@gmail.com ) Academic editor: Torsten Dikow
© 2023 Reinoud van den Broek, Piluca Álvarez Fidalgo, John Smit.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
van den Broek R, Álvarez Fidalgo P, Smit J (2023) A new species of the genus Conosiphon Becker, 1923 and the first records of this genus for Europe (Diptera, Asilidae). ZooKeys 1181: 59-79. https://doi.org/10.3897/zookeys.1181.105663
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A new species of Conosiphon Becker, 1923, Conosiphon ianus Álvarez Fidalgo & van den Broek, sp. nov., is described from Spain, representing the first record of this genus for Europe. It is illustrated in high-resolution photographs and the first ecological information is provided, as well as a key to all species tentatively placed in this genus.
Almería, Asilinae, endemic, Iberian Peninsula, identification key, Spain
In this paper we describe a new, possibly endemic, species of the genus Conosiphon Becker, 1923 from Almería, part of the Mediterranean area of Spain. The Mediterranean Basin is one of 25 well known biodiversity hotspots in the World, which contain both significant reservoirs of biodiversity and/or endemic species, and are threatened due to the loss of their original pristine habitat (
Almería is the easternmost province of Andalusia and is located in the southeast of Spain. The most pronounced characteristic of its natural landscape is its dryness, typical of the Mediterranean Basin, which is increased due to its geographical position and due to the relief of the landscape, which prevents the humid air masses from the Atlantic from penetrating (
The new species of Conosiphon described here is the first record of this genus from Europe, which is otherwise known from the Mediterranean part of Africa. Nothing has previously been reported on the ecology of this genus; therefore, we provide the first ecological information on the genus Conosiphon.
The terminology used to designate the morphology follows
The 52 specimens of the new species studied in this work come mainly from captures carried out by Francisco Rodríguez Luque using entomological nets, and regulated by capture authorisations issued by Consejería de Medio Ambiente y Ordenación del Territorio de Almería. The holotype and 11 paratypes are stored at
Morphological study of all the pinned specimens was performed with an Olympus X-Tr, an Olympus VB 454, and a Leica M80 binocular microscope. The genitalia of some male specimens were first detached from the abdomen and then macerated for 24 hours in a cold solution of approximately 20% KOH; afterwards, they were dissected and prepared on glycerine in order to be photographed. High-resolution photographs of the genitalia were taken using a Nikon D810 camera equipped with a Cnscope 4X Achromatic Microscope Objective Lens with extension tube; Zerene Stacker 1.04 software was used in order to obtain fully focused images, and afterwards the Adobe Photoshop CC 2015 program was used to improve the lighting and contrast. Based on these photographs, the drawings were performed. The male holotype and one female paratype were photographed in high resolution with a Nikon D810 camera and a Nikon Nikkor 105 mm macro lens with a Kenko 36 mm extension tube and using the stacking technique of the Helicon Focus v. 7.6.4 software. The maps were created by using the software program QGIS 3.4. Field images were taken using reflex cameras (Nikon D5300 and Canon EOS 600D) fitted with macro lenses (Nikon 60 mm and Tamron 180 mm).
DNA extraction was conducted on single legs, using the NucleoMag 96 Tissue kit by Macherey-Nagel on a Thermo Scientific KingFisher Flex magnetic bead extraction robot, with a final elution volume of 150 µl. The standard COI barcoding fragment (
Dysmachus pauper Becker, 1907 (by original designation); type locality: Algeria.
This Palearctic genus was originally proposed by
Seven species have been assigned to the genus Conosiphon at some point in history but four of these are now considered to belong to other genera. Two of them were treated as such by
After the diagnosis based on
Type material. Holotype Almería, Spain • 1 ♂; Cabo de Gata; 36°49.3'N, 2°15.4'W, 20 m a.s.l.; 02.I.2022; F. Rodríguez leg.; MNCN_Ent 344922; pinned. Paratypes Almería, Spain • 2 ♂; same collection data as for holotype • 5 ♀♀; same collection data as for holotype; pinned. The holotype, 1 ♂ paratype and 4 ♀♀, are stored in
Head proportionally large; facial protuberance strong and prominent, occupying most of the face, its upper margin very well developed, more than in any other species of Conosiphon; ventral macrosetae of fore femora absent, only long and thin setae present; macrosetae of mystax very dense and at least as long as the antennae, or longer; legs entirely dark, only basal part of the tibiae narrowly pale coloured; acrostichal macrosetae long and abundant. Hypopygium with a small and pointy epandrial lobe on the dorsal inner side, just before the apex. Hypandrium with a blunt projection on hind margin.
Male (Figs
Conosiphon ianus Álvarez Fidalgo & van den Broek, sp. nov., male holotype (MNCN_Ent 344922) A habitus in dorsal view B habitus in lateral view Male paratype of the clear-winged form (PAFC) C wing. Male paratype of the dark-winged form (PAFC) D wing. Scale bars: 5 mm (A, B); 3 mm (C, D). Photographs: PÁF.
Antenna black, covered with grey tomentum. Ratio scape: pedicel: flagellum, 2:1:5. Scape ~ 5× longer than broad, cylindrical in lateral view and bearing some stiff white seta-like macrosetae dorsally; more and longer mainly black ones ventrally. Pedicel much shorter (~ 1/2 the length of the scape), conical (narrower on the base and broader apically) in lateral view, bearing only short and stiff black macrosetae on the apical area, both dorsally and ventrally. Flagellum bare and nearly as long as the two basal antennal segments together. Postpedicel ~ 3× the length of the pedicel. Style three-segmented (1:4:1), bare and nearly half as long as the postpedicel, last segment very narrow.
Thorax. Antepronotal macrosetae pale, well developed and mixed with numerous pale setae. Postpronotal lobe with some longish white setae. Scutum, scutellum, and pleurae black, covered with dense brownish grey tomentum. Dusting less dense along the median line of the scutum, giving the appearance of having a dark middle band along the mesonotum. Mesonotal setae very thin, scattered, and black, some pale ones hardly noticeable. On the mesonotal line, five pairs of presutural dorsocentrals, and six or seven pairs of post-sutural ones. The post-sutural macrosetae are thinner in the prescutellar area, here similar to acrostical macrosetae. The acrostical macrosetae are black, slightly shorter and stouter than dorsocentral ones and more abundant than mesonotal setae. All macrosetae located over the mesonotal middle line from the pronotal area to the prescutellar area. Scutellar surface bearing several long and soft white setae; scutellar margin with four stout and very long black macrosetae (and a fifth central thick seta that might be considered a macroseta). Notopleural, supraalar, and postalar macrosetae long and black. Anepisternum and katepisternum almost bare, with only some isolated thin pale setae, and a few dark macrosetae-like setae on dorsal area of anepisternum. Anepimeron with a set of seven or eight pale dorsal macrosetae and katatergite with a row of seven or eight long pale macrosetae. Halteres brown.
Legs. Coxae heavily grey tomentose, with several long macrosetae and setae. Legs shiny black and thin, covered with short pale setae. Only the area of connection of femora and tibiae pale, with apex of femora and basal part of the tibiae both narrowly yellowish. No ventral macrosetae on fore femur, but long, thin, black and white setae are present. Macrosetae on femora, tibiae, and tarsi stout, predominantly pale on fore and mid legs, and predominantly black on the hind legs. Claws black. Pulvilli brownish yellow.
Wing. Hyaline, slightly darkened in the apical area. Costa with black fine setae. Veins dark brown, only pale brown on the basal area.
Abdomen. Abdomen black, covered with dense brownish grey tomentum, like the mesonotum; tomentum less dense on the dorsal area of each tergite, giving an appearance of having dark patches. Tergal setae whitish, except on the dorsal area of the tergites, where they are longer, thicker, and black. Tergite I with dorsal setae particularly longer, pale, and more erect on the basal part, black and more adpressed on the marginal area. Tergites II and III with shorter black setae dorsally and more adpressed than those on tergite I. Dorsal black setae even shorter and more adpressed on tergites IV-VIII. Tergites I-VI with two or three thick, very long, pale marginal macrosetae laterally. Sternite I with very long, erect and dense whitish filiform setae, sternite II bare, the remaining sternites with long, thin, erect white setae, but shorter than those on sternite I. Sternites IV-VII with a pair of long true macrosetae, not as strong as those on terga, directed outwards and placed near the margin of the sternites; on the remaining sternites, macrosetae thinner and hardly differentiated from the true setae.
Terminalia
(Fig.
Female (Figs
Conosiphon ianus Álvarez Fidalgo & van den Broek, sp. nov. Female paratype (MNCN_Ent 344924) A habitus in dorsal view B habitus in lateral view Female paratype from Aguadulce in PAFC C Ovipositor, dorsal view D ovipositor, lateral view. Scale bars: 5 mm (A, B); 1 mm (C, D). Photographs: PÁF.
The main variation involves the colouration of the wings of the males (Figs
The number of dorsocentral macrosetae vary greatly, both in male and female, from 4–6 pairs of presutural, and six or seven pairs of postsutural ones, some thicker, some thinner, but always thinner on the prescutellar area, where they are approximately the same length or slightly shorter than the dorsocentrals (as mentioned in the description). It is remarkable that the number and position of the dorsocentral macrosetae are not even symmetrical within one single specimen.
The number of marginal scutellar macrosetae is very variable too in both sexes (2–6, sometimes 3 or 5, usually 4), and frequently some of them are slightly thinner and it is doubtful whether they can be considered macrosetae or not. Rarely one or two can be pale instead of black. Also, leg macrosetae are variable in colouration and in some specimens, occasionally the number of pale macrosetae on hind legs is higher than usual. Legs are entirely black or at most the knees are narrowly pale. There is no correlation between the dark-winged form and the darker colouration of the legs, nor for the clear-winged form and the lighter knees.
Length of the body: 8.5–9.5 mm, length of the wing: 6.0–6.5 mm.
Type specimen of Conosiphon pauper (Becker, 1907). Holotype Algeria • 1 ♂ (Fig.
The new species is named after the Roman deity Janus for two reasons: on the one hand, because Janus gives the name to the month of January, the peculiar flight period (mainly December and January) of this robber fly, and on the other hand, because Janus is represented showing two faces, expressed in C. ianus by the presence of two colour forms (clear-winged and dark-winged). The name ianus should be treated as a noun in apposition (
The first evidence of the presence of this species dates back to the winter of 2009 (Fig.
Copulas were frequently observed, taking place always on the ground. Also, as occurs in other species of Asilidae, cannibalism was sometimes observed. Due to the limited number of hunting observations, little is known about their main prey. However, observations preserved in photographs exist of C. ianus feeding on Coleoptera, Diptera (Bibio sp. (presumably Bibio gineri Gil Collado, 1932), Coenosinae, Musca sp., and Sarcophagidae), Heteroptera, and Hymenoptera.
Up to this date, C. ianus Álvarez Fidalgo & van den Broek sp. nov. is only known from the province of Almería, southeastern Spain. It seems to be present in several coastal areas of the south of the province, being much more local in the east coast and in the semi-desertic interior of the province In order to provide a clearer view of the known distribution of this species, all available records were gathered and then located in a 5 × 5 km grid map of the province of Almería (Fig.
As can be seen from all the available records, this is a winter species. The earliest date it was found was 8 November and the latest 6 February. However, usually the first adults start to be seen in the third week of November. Normally, the peak of abundance occurs in December and the species is found still in good numbers till middle January. Numbers decline rapidly in the third week of January and the species is rarely seen during the first week of February. Fig.
Due to presence of two distinct morphological forms within the range of C. ianus sp. nov. (e.g., the colouration of the wings in the male), we analysed 12 specimens, including nine males: four clear-winged forms and five dark-winged forms. All specimens clearly group together in one clade, separate from other taxa in all analyses executed: Neighbour-Joining, Minimum Evolution and Maximum Likelihood. The results are presented in a Neighbour-Joining tree (Fig.
Holotype (male) of Conosiphon pauper (Becker, 1907) A fore femora, showing macrosetae present on ventral side C terminalia in lateral view. Photos: E. Wolff, courtesy of J. Pohl,
This key is provided for all species tentatively placed in the genus Conosiphon.
1 | Macrosetae present on ventral side of front femora (Fig. |
2 |
– | Macrosetae absent on ventral side of front femora, only filiform setae present (Fig. |
3 |
2 | Medium sized species, 13–14 mm. On ventral side of fore femora a double row of macrosetae, yellow and black in male, all black in female. Style of antennae ~ 1/2 as long as postpedicel. Known distribution: Algeria. Flight period: unknown | Conosiphon alter Becker |
– | Smaller species, 10–11 mm. On ventral side of fore femur a single row of strong black macrosetae (Fig. |
Conosiphon pauper Becker |
3 | Facial protuberance well developed but sloped in the upper margin; distance between dorsal ridge and antennal socket approximately equal to the length of the scape (Fig. |
Conosiphon similis Becker |
– | Facial protuberance very large in both sexes, upper ledge very well developed; distance between dorsal ridge and antennal socket clearly shorter than the length of the scape (Fig. |
Conosiphon ianus Álvarez Fidalgo & van den Broek |
As previously commented, we treat the new species as Conosiphon after
The most important fact is that a new species of robber fly of an unknown genus in Europe has been found in Almería, Spain. For the first time a species of Conosiphon has been described in detail, illustrated, and its ecological information provided. Regarding the problem of making sure C. ianus is truly a valid species but not being able to examine the types directly, high resolution images turned out to be a very useful tool. The descriptions by Becker were concise enough but some important details were not mentioned, for example, the shape of the hypandrium of the males. However, these doubts were solved thanks to the photographs. The macrosetae of the ventral side of the fore femora are as strong as they should be (Fig.
Dealing with C. similis was much more difficult as the male is unknown and only females could be compared. Despite difficulties, there are clear differences in the shape of the facial protuberance, which is, as in the male, very well developed in the female of C. ianus. In the female of C. similis, as in the male of C. pauper, it slopes from the upper side. The mystax of the type specimen studied of C. similis is somewhat damaged (Fig.
Unfortunately, the type material of C. alter seems to be lost as the specimens used by
It is also important to comment about the status of the new species. Between 2009 and 2014 it was observed regularly but never in high numbers. However, in 2014 the species seemed to go through a burst in population size, and it was common in several areas. It was found in good numbers until 2018–2019 but seems to be severely declining in recent years. Its decline in Roquetas de Mar and El Ejido might well be related to habitat destruction and human activities. However, these factors did not happen yet in other areas of the province where it was previously found. In our opinion, this species might be affected by the lack of rain as Almería is going through a severe drought in recent years. Effectively, the years when the species was common did concur with somewhat rainy November months. A few weeks later, the imagoes started to be observed, usually the first week of December. Nevertheless, November in 2019–2022 has been much drier than usual, particularly 2021–2022, when imagoes were hardly seen.
Therefore, the province of Almería, as part of the Mediterranean Basin, is an exceptional hotspot of biological diversity that still is providing unexpected new species to science in spite of the current biodiversity and climate crisis. But even species that were common not long ago are being severely affected by human pressure and climate change. C. ianus sp. nov. seems to be a good example of this.
We want to sincerely thank Francisco Rodríguez Luque (Roquetas de Mar, Spain) for his field work that allowed him to discover this new species, for capturing the specimens necessary for its description, and for his photo of C. ianus in its natural habitat. Thanks to the Consejería de Medio Ambiente y Ordenación del Territorio de Almería, for granting him the necessary permits for collecting specimens in the province of Almería. We are also extremely grateful to Fritz Geller-Grimm (Wiesbaden, Germany), who first identified the genus of the new species, and also for his priceless help and the information provided at the beginning of this work. Very special thanks also go to Alberto Javier Narro Martín (Madrid, Spain) for photographing the terminalia of C. ianus, to Marina Trillo Camprodón (Estación Biológica de Doñana, Sevilla, Spain) for the fine drawings of the terminalia based on Alberto’s photos, to Vicenta Llorente del Moral (Madrid, Spain) for her invaluable help translating
The authors have declared that no competing interests exist.
No ethical statement was reported.
The research was funded by the project TED2021-130795B-I00 (MCIU/ACI/UE – projects oriented towards the Ecological and Digital Transition) and by a work contract as technical staff for the second author funded by the Ministerio de Ciencia e Innovación of Spain (reference: PTA2020-018923-I).
Conceptualization: RB. Data curation: PÁF, RB, JS. Formal analysis: JS. Investigation: PÁF, RB. Methodology: JS, RB. Resources: JS, PÁF. Supervision: PÁF. Validation: RB, JS, PÁF. Writing – original draft: PÁF. Writing – review and editing: PÁF.
Reinoud van den Broek https://orcid.org/0009-0000-0970-9356
Piluca Álvarez Fidalgo https://orcid.org/0000-0002-5330-3078
John Smit https://orcid.org/0000-0002-1568-5183
All of the data that support the findings of this study are available in the main text or Supplementary Information.
Data compilation of live specimens of Conosiphon ianus Álvarez Fidalgo & van den Broek, sp. nov.
Data type: xlsx
Explanation note: Identified from photographs available in the public website BiodiversidadVirtual.org. The images were taken by F. Rodríguez Luque.
Full details of the specimens of Conosiphon ianus Álvarez Fidalgo & van den Broek, sp. nov. used for DNA barcoding
Data type: xlsx