This paper presents results of a study of the Syrphidae fauna of Cameroon, based largely on an expedition to that country conducted in May 2006. Sixty-three species of Syrphidae were collected during the Expedition, 49 of which are newly recorded for the country, including some undescribed species. A preliminary checklist of the Syrphidae of Cameroon is provided, indicating that the Cameroonian Syrphidae fauna now comprises 96 species in total.
The flower flies (Syrphidae) fauna of Cameroon has not been the subject of a dedicated study and remains poorly understood as a result. The little that is known is largely based on historical records, as summarised in Dirickx (1998), supplemented by a few additions in the genera Syritta Le Peletier & Serville, 1828 (Lyneborg & Barkemeyer 2005), Paragus Latreille, 1804 (Kassebeer 1998, 2000) and some more recent publications (e.g., Ngamo et al. 2005).
An entomological expedition to Cameroon was undertaken from 2–26 May 2006, with sampling conducted in the south-western region around Limbe and Kumba (Mount Cameroon area); in the south, in the coastal region around Kribi; in Adamoua Province around Ngaounderé; and in the North Province, in the vicinity of Poli (Fig. 1; Appendix I) (Ssymank et al. 2011). This contribution provides results of the collecting effort.
The article is also dedicated to the late Brian Roy Stuckenberg (1930–2009). Brian's interest in the Diptera began with his Master's thesis, for which he revised Afrotropical species of the syrphid genus Paragus (Stuckenberg 1954a, b), describing six new species and one new subspecies. The standard of Brian's work remains an inspiration for future generations of entomologists.
MATERIAL AND METHODS
Field sampling for Syrphidae in Cameroon was conducted from 5–25 May 2006, usually following standardised field protocols of at least half an hour of observation time in smaller habitats of 100 m2, sometimes up to 200 m2 for regular habitats, and at least 15 min for linear habitats on transects of 10 m, up to a maximum of 100 m. Observation time, weather conditions, habitat type, and as far as possible, the names of flowering plants were recorded. Details of the protocol adopted are outlined in Ssymank (1999). During some field excursions additional individuals were counted, or activities of some syrphids, especially flower-visiting, recorded without voucher specimens being retained, if their identification was not in doubt, although at least one voucher specimens of each species from each locality is retained in the author's collection. As syrphid densities were often low and individuals widely dispersed, sampling was often conducted at a number of different sampling stations during the same excursion.
Sampling coordinates and dates (Appendix I), were captured with a Garmin 45 GPS device. Geographical coordinates are provided in the World Geodetic System 1984, in degrees, minutes and seconds; the numbers of localities refer to the author's database (available upon request). “CAM” numbers refer to Ssymank et al. (2011). Details of plot size, sampling time, sunshine conditions, percentage cloud cover and wind conditions are further provided. If “excursion” is indicated this implies sampling along a track, trail or roadside margin of >500 m in length. Plot sizes are either sampling areas given in square metres, or the length of linear transects in metres. Temperature was not measured regularly, but it usually exceeded 35 °C on cloudless days at noon, sometimes reaching 41 °C in the shade.
Determinations were done using all available keys, as listed by Whittington (2003), especially Bezzi (1915), Curran (1938a, b, 1939a, b), Lyneborg and Barkemeyer (2005) for Syritta and Stuckenberg (1954a, b) for Paragus. Original descriptions were consulted and museum material was studied, both to ensure correct identification and to exclude species for which description was inadequate. The studied type material of Syrphidae is kept in the following institutions: Natural History Museum, London, UK (BMNH); Naturhistorisches Museum, Basel, Switzerland (NHMB); Muséum national d'Histoire naturelle, Paris, France (MNHN), Musée Royal de l'Afrique Centrale, Tervuren, Belgium (MRAC).
A preliminary checklist of the flower flies of Cameroon is presented in Appendix II. Most historic records had been summarised in the catalogue by Dirickx (1998) and these, together with additional records in Kassebeer (1998, 2000), Lyneborg and Barkemeyer (2005) and Wakkie (2011), indicated that a total of 47 species was known from Cameroon prior to the onset of this study.
During a 3.5-week period of intensive sampling, over 40 localities were visited, 36 of which yielded Syrphidae (Appendix I). In total, 881 syrphids were collected or observed during that period, representing 63 species altogether (Table 1, Figs 2–7).
The preliminary checklist includes 96 species, 63 of which were recorded during the 2006 Expedition, 49 being new records to the fauna of Cameroon. This indicates that Cameroon may host more syrphid species than it is currently recorded.
Of 96 listed species, 86 have been assigned to known specific names. Sixteen species (17%) were originally described from Cameroon. Many of these species are still only known from a single male or female type specimen and have not been recorded since their original discovery.
The Syrphidae fauna of the Afrotropical Region as a whole remains poorly known, Cameroon being no exception. In the most recent estimation, Kirk-Spriggs and Stuckenberg (2009: 186) concluded that 30% of Syrphidae species occurring in the Afrotropical Region remain undescribed.
Since the publication of Dirickx's (1998) catalogue of the Syrphidae of the Afrotropical Region, a critical assessment of the Afrotropical Syrphidae has been published by Whittington (2003), in which he concluded that for many genera the majority of available keys probably cover only 30–60% of species occurring in the region. He further pointed out that at least nine genera of Syrphidae are in need of complete taxonomic revision. Since Dirickx's (1998) catalogue some genera have been revised, however, at least in part, viz. Graptomyza Wiedemann, 1820 (Whittington 1992, 1994), Melanostoma Schiner, 1860 (Dirickx 2001), Allobaccha Curran, 1928 (Dirickx 2010) and Paragus Latreille, 1804 (e.g., Kassebeer 1998, 1999a, b, 2000, 2001). A full revision of the genus Syritta by Lyneborg and Barkemeyer (2005) listed 41 Afrotropical species, and included the description of 26 new species. Only one additional species has been added subsequently, i.e., Syritta lyneborgi (Steenis 2010). Thus, species of Syritta are readily identifiable thanks to this revision, with one female representing an undescribed species (Syritta sp. in Table 1).
Species identification remains problematic in some genera, with some species, e.g., Paragus borbonicus Macquart, possibly representing complexes of sibling species. Specimens that could not be reliably determined are indicated as ‘cf.’ or ‘aff.’.
Records of the genus Paragus comprise about 44% of the total number of Syrphidae sampled during the Cameroon Expedition 2006. Preparation of the male terminalia is essential for determination, and numerous historical museum specimens awaiting detailed study. Many African species are still only known from a single type specimen or type locality. This is partly due to rapidly depleting primary habitats, such as forest and natural wetlands, or to poor sampling in the Afrotropical Region in general. Identification of Paragus certainly poses one of the greatest challenges, due to the large number of species described by Kassebeer (1998, 1999a, b, 2000, 2001) and to the fact that type specimens are currently unavailable for study. Another problem is the morphological variability, which is especially apparent in the “longiventris-group” of the subgenus Pandasyopthalmus (e.g., Vujic et al. 2008). The revision and keys provided by Stuckenberg (1954a, b) therefore remain the only comprehensive works on the genus. Some species of Paragus can be easily separated, i.e., in the subgenera Serratoparagus Vujic & Radenkovic, 2008 and Afroparagus Vujic & Radenkovic, 2008, but only a few species of the remaining subgenus, Pandasyopthalmus Stuckenberg, 1954, e.g., P. minutus Hull and P. dolichocerus Bezzi, have distinct and easily discernable morphological characters. Cameroonian material of P. aff. minutus differs slightly as compared to the BMNH material in having the bases of the femora darker, and these specimens may represent a closely related new species. There is a degree of the intra-specific variation in the terminalia of material assigned to P. longiventris, still they are entirely different in some specimens and best fit the descriptions and illustrations of P. boyesi Kassebeer, 1999, known only from Madagascar. As the types of the latter could not be studied and a longer series is unavailable, the specimens on hand may equally represent a yet undescribed closely related new species from the Afrotropical mainland.
While males of Asarkina angustata Becker could be reliably identified, some females could not and are labelled as A. cf. angustata. One female is labelled Allobaccha aff. brevis (Karsch), as its characters differ slightly and no sufficient material is available to assess variability. A single specimen, labelled Ceriana (Monoceromyia) aff. neavei (Bezzi), has been compared to the type material, but found to be slightly different, indicating that it may represent a closely-related new species, which description is premature because of insufficient material available.
The genus Eristalinus Rondani, 1845 is in desperate need of revision and no key enabling reliable determinations is currently available. Both E. cf. vicarians (Bezzi) and E. cf. xanthopus (Bezzi) are only represented by a single female specimen each, and cannot be identified with certainty.
L. Lyneborg's unpublished revision of Eumerus Meigen, 1822, the largest Afrotropical genus, includes descriptions of many new species, but his key does also facilitate identification of the described species. Eumerus cf. serratus Bezzi and E. cf. capensis (Curran) (Appendix II) are only represented by females and their true identity remains uncertain.
Melanostoma cf. infuscatum Becker is represented by a single female in poor condition and its determination is not unequivocal.
Dedicated studies of the Syrphidae fauna have not been conducted in countries around Cameroon, and no reliable checklists have been published. Wakkie (2011), however, records three species from in the Central African Republic, three species in Chad, five species in the Democratic Republic of the Congo, 17 species in Gabon, and 82 species in Nigeria. The source and voucher material of the Cameroonian species reported exclusively by Wakkie (2011) (see Appendix II) could not be traced and the identity of the four species remains unconfirmed. No species are listed for Equatorial Guinea by Wakkie (2011), although several are listed by Dirickx (1998). Nigeria is the best studied neighbouring country and is comparable to Cameroon in terms of the habitat diversity; although 43 species recorded from Nigeria are unknown from Cameroon, but most of these may occur there. Typical examples will include widespread West African species of Eristalinus, Eumerus, Microdon Meigen, 1803, Mesembrius Rondani, 1857, Rhingia Scopoli, 1763, Phytomia Guérin-Méneville, 1834 and Syritta, as well as species described from localities close to Cameroon, e.g., Milesia prolixa Hippa, 1990. Montane Chasmomma species may also occur in Cameroon. Based on figures for surrounding countries, it can be estimated that at least 130 species occur in Cameroon.
The majority of previous (‘historical’) records from Cameroon could not be confirmed during this survey due to several factors: (1) many such records were based on single specimens, and if a species is very rare then the total recorded number of Syrphidae may be too low to allow for its re-collection; (2) the present survey did not specifically target ‘historical’ localities and local endemics are expected to be excluded from the record; (3) it was impossible to undertake a survey at higher elevations in Cameroon's mountainous regions at this time; (4) some Syrphidae species may be seasonally abundant and were not active during the period of sampling; (5) Cameroon had been subjected to land use change and rapidly diminishing primary forests cover (e.g., Mbatu 2011), which in turn reduced the diversity of flower flies. Thus, it has been impossible to assess the conservation status of the Syrphidae in Cameroon in its entirety.
Syrphids are important pollinators of both wild plants and cultivated crops, still very few studies have been conducted in the Afrotropical Region, aside from the African Pollinators Initiative, the Biota Africa project and its successor. A major proportion of syrphid species are aphidophagous at larval stage and, therefore, are of great importance in biological control of plant pests. The genera Allobaccha, Allograpta Osten Sacken, 1875, Asarkina Macquart, 1842, Betasyrphus Matsumura in Matsumura & Adachi, 1917, Episyrphus Matsumura in Matsumura & Adachi, 1917, Melanostoma, Paragus and Syritta appear to be the main players in this field.
F.Ch. Thompson (pers. comm.) is currently preparing a catalogue and bibliography of Afrotropical flower flies, and the forthcoming Manual of Afrotropical Diptera ( http://afrotropicalmanual.net) will include a generic key to Syrphidae of the region. This will largely improve the situation and encourage more entomologists to work on this family. However, many genera still require urgent revisionary work before reliable keys for species will become available.
Syrphidae (Diptera) recorded during the Cameroon Expedition (2–26 May 2006). Notes: * — only observed in the field, no voucher specimen retained; ** — Asarkina angustata 1♂ and several ♀ cf. angustata; *** — Allobaccha sp. includes 2♀, possibly of two species that could not be associated with ♂; † = Syritta sp. n. (1♀).
I thank other participants of the Cameroon Expedition 2006, especially F. Menzel, who was largely responsible for its organisation, as well as our colleagues D. Achu-Kwi (Institut de Recherche Agricole pour le Developpement, IRAD) and E.N. Nukenine (University of Ngaoundéré), who assisted me in Cameroon and accompanied us on several occasions. R. and J. Oehlke and my wife B. Lechner-Ssymank also assisted with the collection of Syrphidae specimens in the field. Permits for collecting and exporting insect material were issued by the Ministry of Scientific Research and Innovation (Autorisation de recherche No. 091/IRAD/DG/DGA/CSPAH/04/2006). D. Burkhardt and M. Brancucci (NHMB), C. Daugeron (MNHN), M. de Meyer (MRAC) and N. Wyatt (BMNH) kindly made museum specimens available for comparative purposes. Eumerus species identifications were checked by D. Doczkal (Gaggenau), and Syritta species determinations by W. Barkemeyer (Oldenburg). M. de Meyer (RCMA) kindly checked the French abstract and two anonymous referees are thanked for their useful suggestions and improvements to the manuscript.
Collecting localities (stations) from the Cameroon Expedition (2–26 May 2006). Abbreviations: Dép. — Department; Prov. — Province.
(CAM01): Guidjiba, N Mbe, close to Bénoué N.P., almost dry temporary river (Mayo Sala) with adjacent bush savanna, grazed by Zebu-cattle; Prov. Nord; Dép. Mayo-Rey; 08°20′58″N 13°41′29″E; 348–360 m a.s.l.; 5.v.2006 (excursion ca 12:30, full sun, 0% clouds, wind 0).
Gombo Village, SW Poli, Vallée des Rôniers, small seeping source at the village, bush savanna, Zebu-grazed, just at the beginning of leaf emergence; Prov. Nord, Dép. Faro; 08°30′32″N 13°07′16″E; 505 m a.s.l.; 6.v.2006 (10 m2, 09:30–11.00, full sun, 0 % clouds, wind 0).
(CAM04): Gombo Village, SW Poli, Vallée des Rôniers, source of the river Mayo Zapsuré, eutrophic limnocrene with in addition 2–3 remnant water-filled holes in the otherwise dry riverbed; Prov. Nord, Dép. Faro; 08°29′57″N 13°06′52″E; 455 m a.s.l.; 6.v.2006 (10 m2,11:45–12:00, diffuse light, partly shaded, 0% clouds, wind 0), again visited on 7.v.2006 (No. 6393a, 10 m2, 16:00–17:00, diffuse light, 30% clouds, wind 0–1).
Gombo Village, SW Poli, Vallée des Rôniers, small remnant water filled holes in the otherwise dry riverbed of the Mayo Zapsuré, small remnant of alluvial forest, single flowers of Scadoxus multiflorus; Prov. Nord, Dép. Faro; 08°29′50″N 13°06′29″E; 450 m a.s.l.; 6.v.2006 (10 m2, 12:00–12:15, full sun, 0% clouds, wind 0–1).
(CAM09): Ouro-Bai village, Mayo Bai west of Poli (on the way to Campo des Hippopotames), sandy riverbed with drinking places for donkeys and Zebus, grazed and therefore riverside partly dominated by grasses; Prov. Nord, Dép. Faro; 08°29′18″N 13°02′14″E; 340 m a.s.l.; 7.v.2006 (100 m2, 11:00–11:30, diffuse light, clouds 0%, wind 0).
(CAM12): Lake “Lac de Bini”, northwest of Ngaoundéré, eutrophic shallow lake with a few single bushes along its shore, Zebu-droppings and decaying fruit on the banks; Prov. Adamaoua, Dép. Vina; 07°25′38″N 13°29′45″E; 1085 m a.s.l.; 9.v.2006 (100 m, 10:30–12:00, full sun, 60% clouds, wind 0).
(CAM 13): University Lake of Ngaoundéré, Campus of the University of Ngaoundéré, on the banks of the lake with sedge beds, adjacent a cornfield with scattered banana plants; Prov. Adamaoua, Dép. Vina; 07°25′22″N 13°32′39″E; 1080 m a.s.l.; 9.v.2006 (100 m, 12:30–13:30, partly shady, 70% clouds, wind 0–2).
(CAM14): Waterfall of the Mayo Vina (Chutes de la Vina), between Wakwa and Dibi, SW of Ngaoundéré, not far from the bridge of the street, steep river bank with bushes, adjacent abandoned crops; Prov. Adamaoua, Dép. Vina; 07°12′36″N 13°35′10″E; 1060 m a.s.l.; 9.v.2006 (excursion 15:30–16:00, partly in the shade).
(CAM 17): Ranch de Ngaoundaba, south of Dibi, SE of Ngaoundéré, crater-lake with abundant bush and herb vegetation in the small swamp (Impatiens spp., Tradescantia spp. etc.; Prov. Adamaoua, Dép. Vina; 07°07′57″N 13°41′40″E; 1155 m a.s.l.; 10.v.2006 (100 m2, 10:00–10:30, full sun, 0% clouds, wind 0–1).
Ranch de Ngaoundaba, south of Dibi, SE of Ngaoundéré, trail along the banks round the crater lake, excursion around the lake; Prov. Adamaoua, Dép. Vina; 07°07′57″N 13°41′40″E; 1155 m a.s.l.; 12.v.2006 (excursion 14:00–16:00, partly shady, 60% clouds, wind 0–2).
Lake “Lac de Tizon”, SE of Ngaoundéré, hut on the rim of the crater, about 2 m deep hole dug in the ground for waste, mainly filled with decaying mango fruit on the bottom, several flies hovering in the shade; Prov. Adamaoua, Dép. Vina; 07°15′17″N 13°34′35″E; 1200m a.s.l.; 10.v.2006(1 m2, 13:00–13:15, full sun, 10% clouds, wind 0–2).
Ranch de Ngaoundaba, S of Dibi, SE of Ngaoundéré, grassland around the huts of the ranch, and trail round the crater lake; Prov. Adamaoua, Dép. Vina; 07°08′01″N 13°41′45″E; 1195 m a.s.l.; 11.v.2006 (excursion 09:00–10:30, mostly shade, 95% clouds, wind 1–3).
Ranch de Ngaoundaba, S of Dibi, SE of Ngaoundéré, Chemin des Crêtes, trail along the crater rim/hill tops of the rim, single flowering tree (Phyllanthus discoideus, Euphorbiaceae) on a hill top; Prov. Adamaoua, Dép. Vina; 07°07′46″N 13°41′44″E; 1265 m a.s.l.; 11.v.2006 (10 m2, 17:15–17:30, last evening sun, slight mist, wind 1–2), revisited on 12. v. 2006 (10 m2, 10:00–12:00, full sun, 60 % clouds, wind 1–4).
(CAM25): Bakingili, 5 km NW of Limbe, Seme New Beach Hotel, garden of the hotel on ornamental plants; Prov. Sud-Ouest, Dép. Fako; 04°03′23″N 09°03′09″E; 5–10 m a.s.l.; 13.v.2006 (10m2,10:00–10:30, diffuse light, 100% clouds, wind 0–1) revisited on 14.v. (10 m2, 08:00–08:50, shady, 100% clouds, wind 0–1), 15.v. (single observation, ca. 09:00) and 16.v.2006 (100 m, 09:15–09:45, shady, 100% clouds, wind 0–1).
(CAM23): Liongo-Muea (between Buea and Kumba), banana plantation, humid ruderal vegetation along a small river over volcanic lava; Prov. Sud-Ouest, Dép. Fako; 04°11′43″N 09°19′31 “E; 470–475 m a.s.l.; 14.v.2006 (100 m2, 13:00–14:00, shady, clouds 100%, wind 0–1).
(CAM24): Idenau near Limbe, small brook with wild Guinea Yam (Dioscorea sp.) and adjacent corn and maniok fields on a small hill; Prov. Sud-Ouest, Dép. Fako; 04°02′23″N 09°05′40″E; 60 m a.s.l.; 14.v.2006 (excursion 17:30–17:45, diffuse light, 100% clouds, wind 0–1).
(CAM26): Idenau near Limbe, SE of Debundscha; tall herb vegetation along the banks of a small river passing through oil palm plantations with abundant epiphytic ferns; Prov. Sud-Ouest, Dép. Fako; 04°10′39″N 09°00′01″E; 8 m a.s.l.; 15.v.2006 (100 m2, 10:30–11:00, rain, 100% clouds, wind 0–2).
(CAM27): Mt Cameroon, NW of Buea, mountain rainforest of the lower mountain zone with interspersed small cultures of Guinea Yam, manioc, corn and bananas; Prov. Sud-Ouest, Dép. Fako; 04°07′50″N 09°12′47″E; 990–1070 m a.s.l.; 15.v.2006 (excursion 13:00–15:00, drizzle, 100% clouds, wind 0–1).
Bakingili, 5 km NW of Limbe, harvested cornfield above the Seme New Beach Hotel on the border of the rainforest; Prov. Sud-Ouest, Dép. Fako; 04°03′45″N 09°03′17″E; 70 m a.s.l.; 16.v.2006 (100 m2, 11:30–12:00, shady, 100% clouds, wind 0).
Bakingili, 5 km NW of Limbe, roadside margins on the road close to the Seme New Beach Hotel and hotel surroundings; Prov. Sud-Ouest, Dép. Fako; 04°03′23″N 09°03′09″E; 5–15 m a.s.l.; 16.v.2006 (excursion 09:30–12:00, diffuse light, 100% clouds, wind 0–1).
(CAM29): Malende Mukuya (S of Kumba), cocoa-plantation with a small brook, a few white flowers of lianas; Prov. Sud-Ouest, Dép. Fako; 04°21′25″N 09°25′58″E; 30–55 m a.s.l.; 17.v.2006 (10 m2, shady, 90% clouds, wind 0, very sticky).
(CAM30): On the way from Balangi to Ediki, SW of Kumba, river bank of a fast-flowing stream, remnants of secondary semi-natural rainforest, adjacent corn and melon crops; Prov. Sud-Ouest, Dép. Meme; 04°30′32″N 09°27′40″E; 35–50 m a.s.l.; 17.v.2006 (100 m, 14:00–14:30, partly shady, 60% clouds, wind 0).
(CAM31): Kindongi Camp, Ediki, SW of Kumba, secondary rainforest with closed canopy, small clearing with a wooden hut and melon culture; Prov. Sud-Ouest, Dép. Même; 04°32′25″N 09°25′17″E; 120–137 m a.s.l.; 18.v.2006 (100 m2, 10:30–12:00, partly shady, 10% clouds, wind 0–2).
(CAM32): Lake Barombi Mbo, NW of Kumba, shores of the crater lake, steep crater sides with rainforest; Prov. Sud-Ouest, Dép. Meme; 04°39′05″N 09°24′34″E; 303–340 m a.s.l.; 18.v.2006 (excursion 14:00–15:00, partly shady, 80% clouds, wind 0).
River Mongo, margin of a cornfield close to the road bridge (road Kumba to Doula); Prov. Sud-Ouest; 04°44′05″N 09°34′08″E; 140 m a.s.l.; 19.v.2006 (excursion 08:15–08:45, full sun, 20% clouds, wind 0–2).
(CAM33): Mbanga, humid gravel surface with sparse vegetation of Cyperaceae and Cassia mimosifolia (extra-floral nectar glands), street margin of the road from Kumba to Douala; Prov. Littoral, Dép. Mungo; 04°33′53″N 09°38′04″E; 100 m a.s.l.; 19.v.2006 (100 m2, 10:45–11:45, full sun, 40% clouds, wind 0–1).
(CAM34): Bissiang (NE of Kribi), forest margins along the track; Prov. Sud, Dép. Océan; 02°58′59″N 09°58′43″E; 30 m a.s.l.; 21.v.2006 (100 m, 12:00–13:00, mostly shady, 90% clouds, wind 0–1).
(CAM35): Bissiang (NE of Kribi), secondary rainforest with a small swamp; Prov. Sud, Dép. Océan; 03°00′21″N 10°02′58″E; 30 m a.s.l.; 21.v.2006 (100 m, 14:30–15:00, mostly shady, 90% clouds, wind 0).
(CAM37): River Lobe, SW of Kribi, vicinity of the water falls of the river mouth, roadside margin and riparian vegetation; Prov. Sud, Dép. Océan; 02°52′35″N 09°54′02″E; 20 m a.s.l.; 22.v.2006, collection twice in the morning and late afternoon of the same day (excursion 10:30–11:00, shady, 100% clouds, wind 0 and 100 m2, 15:00–16:00, shady, 100% clouds, wind 0).
(CAM36): Waterfalls of the Lobe River (Chutes de la Lobé), SW of Kribi, fallows and cultures with manioc and peanuts — close to remnant of secondary rainforest along the river; Prov. Sud, Dép. Océan; 02°53′55″E 09°53′55″E; 10 m a.s.l.; 22.v.2006 (100 m2, 11:00–12:45, shady, 95% clouds, wind 0) revisited on 24.05.2006 (16:00–16:45, shady, 90% clouds, wind 0).
(CAM36): Close to the waterfalls of the Lobe River (Chutes de la Lobé), SW of Kribi, cultures with Maniok and peanut, riparian zone and adjacent secondary rainforest; Prov. Sud, Dép. Océan; 02°52′57″N 09°53′57″E; 16 m a.s.l.; 22.v.2006 (100 m2, 13:30–14:00, full sun, 3 % clouds, wind 0–1).
(CAM39): Nkó Long, Akom II (District de Niete), SE of Kribi, clear cuttings in the secondary rainforest with melon cultures, small river partly with riparian Chinese bamboo thickets; Prov. Sud, Dép. Océan; 02°51′13″N 10°02′03″E; 20–36 m a.s.l.; 23.v.2006 (100 m2, 10:15–11:30, full sun, 0 % clouds, wind 0).
Close to “Rocher du Loup”, road from Kribi to Campo, small brook ca. 50 m from the coastline; Prov. Sud, Dép. Océan; 02°46′41″N 09°52′59″E; 30 m a.s.l.; 24.v.2006 (100 m2, 11:00–11:50, full sun, 0% clouds, wind 0–1).
(CAM41): Close to “Rocher du Loup”, N of Ebodje, SW of Kribi on the road to Campo, another small brook and roadside margin in aprimary rainforest stand; Prov. Sud, Dép. Océan; 02°35′25″N 09°50′55″E; 45 m a.s.l.; 24.v.2006 (100 m2, 12:00–13:30, full sun, 0% clouds, wind 0–1).
(CAM43): On the way from Kribi to Edea, Lokoundje River, SW of Fifinda, riparian tall herbs and bush vegetation at the bridge; Prov. Sud, Dép. Océan; 03°10′41″N 10°01′40″E; 6 m a.s.l.; 25.v.2006 (100 m, 10:00–11:00, mostly shady, 90% clouds, wind 0–1).
(CAM44): Elabi, NE of Kribi, cornfield along the forest margin, with a small swamp; Prov. Sud, Dép. Océan; 02°59′39″N 09°56′5″E; 18–20 m a.s.l.; 25.v.2006 (100 m2, 11:30–12:30, full sun, 60% clouds, wind 0).
Preliminary checklist of the Syrphidae of Cameroon. Abbreviations: Ssy — Ssymank pers. obs. (see also Table 1); Hist — historical records, catalogue citations and other recently published sources; Cam — complete list of recorded species from Cameroon; TL — type locality.