Corresponding author: Tolotra Ranarilalatiana (
Academic editor: Mariano Michat
Diving beetles are generally aquatic and live submerged in water during larval and adult stages. A few groups have colonised hygropetric habitats and fewer species still can possibly be referred to as terrestrial. Here we describe six new Copelatine species that were mainly found in dry shallow forest floor depressions in the eastern and northeastern lowland humid forests of Madagascar. Three new species are described in each of the two genera
Ranarilalatiana T, Bergsten J (2019) Discovery of a specialist Copelatinae fauna on Madagascar: highly ephemeral tropical forest floor depressions as an overlooked habitat for diving beetles (Coleoptera, Dytiscidae). ZooKeys 871: 89–118.
Diving beetles are typically 0.8–48 mm long streamlined aquatic beetles with advanced synchronous hind-leg stroke swimming. They are typical of a variety of water bodies ranging from large rivers to small streams, ponds, marshes, mires, bogs and lakes, forest pools, rock pools, ditches, and canals (
Even fewer diving beetle species have only been found by sifting litter from terrestrial habitats. Their morphology is notably characterised by the absence, or strong reduction, of natatorial setae on legs and they are therefore tentatively referred to as terrestrial (
While adult dytiscids are typically aquatic, all, as far as known, leave water for pupation and many also leave water for dispersal flights (
However, in our most recent experience of searching dry forest floor depressions in lowland humid forests of northeastern Madagascar, we came across a handful of
Madagascar is one of the world’s most important biodiversity hotspots (
We describe six new species below and note that forest floor depressions and flat pans in tropical humid regions could be an overlooked habitat for specialist diving beetle communities. We provide photos of habitus and of male genitalia, as well as distribution maps for each species. The unusual terrestrial localities are richly illustrated with photos. For one species we also provide
New collecting efforts of
We targeted shallow forest floor depressions or flat pans that bore signs of occasionally having water by being more moist or with a more clayish soil than sourrounding forest floor. Several sites were directly on paths in the forest. None, except one site in Marojejy NP and one in Masoala NP had any connection or was in proximity of running water. Specimens were sampled with sieves, white pans and by hand searching through the clay, soil and leaf litter. Material was collected into plastic tubes with 95% ethanol for conservation.
Each locality was given a collecting event code and associated metadata included geographic name(s), forest type, locality type, habitat description, eventual disturbance, collecting date and collectors. Altitude, latitude and longitude were recorded with a handheld GPS (Garmin). Each locality was also documented with photographs using a compact Panasonic digital camera.
Specimens were examined under dissection microscopes from Leica (M165C and MZ12.5). Genitalia were extracted with a fine forceps or pin from the tip of the abdomen and glued on cards on the same pin as the specimen. Photos of habitus were taken with a Canon EOS 5D Mark II DSLR camera equipped with a MP-E 65 mm 1-5X super macrolens and mounted on a motorised rail (Stackshot) from Cognisys. The system was operated using Canon EOS Utility and Zerene Stacker (Zerene Systems) softwares, the latter also used for stacking the Z-stack of captured images with the PMax or DMap algorithm. Photos of genitalia were taken with a Canon EOS 7D DSLR camera mounted on a BALPRO 1 Universal bellow from Novoflex with a long working distance 10X Plano apochromatic microscope objective from Mitutoyo. The system was mounted on a motorised rail (Stackshot) from Cognisys and operated with the same softwares given above. Photo and video recording of one species in the field was done with a Panasonic Lumix DMC-TZ100 compact camera on a gorillapod.
Label data are given as written and separated by “//” if on separate labels and “|” if on different rows on the same label. All examined specimens (individual mounted specimens, or single alcohol tubes with multiple specimens) have been given unique catalogue numbers and these are listed first, starting with “
All specimens examined in this study are registered in the Swedish Museum of Natural History, Stockholm, Sweden (
Twenty-five species of
Masoala National Park [15.6713S; 49.9672E] (Madagascar, Analanjirofo region, Maroantsetra)
-3♂ GP, 5♀, 42 ex. (Alc.) (
-1♂ GP, 2♀ (
A small species with medially infuscated testaceous elytra and oblong-oval body shape. Penis in lateral view with low ventral ”hump”, apical blade with acute apex and somewhat curved non-straight ventral margin, in ventral view apical blade is left-angled (Fig.
Body length: 4.6–5.4 mm (♀: 4.6–5 mm, ♂: 4.8–5.4 mm).
Body shape oval (Fig.
Habitus, dorsal view.
Head rufotestaceous with a rather weak v-shaped infuscation between eyes. Pronotum dark brown medially and testaceous laterally. Elytra testaceous brown, variably with darker infuscation medially especially along the striae (Fig.
Elytra with ten discal and one submarginal striae. Ninth striae avbreviated anteriorly. Submarginal striae present posteriorly only, starting at about middle. Posteriorly every second striae abbreviated (2nd, 4th, 6th, 8th, and 10th). Pronotum striolated laterally and basally. Lateral margin of pronotum with a narrow bead, not reaching anterior corner. Head, pronotum and elytra with same type of microreticulation and micropunctures.
Ventral side rufotestaceous except metacoxal plate infuscated brown. Abdominal sternites with vague testaceous spots laterally. Metacoxal plate with coarse strioles, abdominal sternites II–IV with finer strioles. Metacoxal lines anteriorly diverging and ending well before metaventral suture. Prosternal process lanceolate, short, and anterior metaventral process rather broad.
Male protibia modified, angled at base and expanding distally. Pro and mesotarsal segments I–III dilated and ventrally equipped with adhesive discs (constellation I:3 (row 1), 4 (row 2), II:4, III:4). Longer metatibial spur apically slightly more curved than in female.
Male genitalia as in Figure
Male genitalia. From left to right aedeagus in right lateral, ventral, left lateral views, and left paramere.
Dorsal structures of females not significantly different from male, but body size on average smaller.
The northeastern humid forest from Marojejy NP to Masoala NP including the island of Nosy Mangabe (Fig.
The Latin adjective amphibius comes from the ancient Greek word “amphibios” and means capable of living both in water and on land.
Masoala National Park [15.6703S; 49.9715E] (Madagascar, Analanjirofo region, Maroantsetra)
-5♂ GP, 5♀, 13 ex. (Alc.) (
-4♂ GP, 6♀, 6 ex. (Alc.) (
-6♂ GP, 4♀, 97 ex. (Alc.) (
Habitus very similar to
Very similar in all respects to
Body length: 4.4–5 mm (♀: 4.4–4.8 mm, ♂: 4.7–5 mm).
On average slightly smaller and elytra less infuscated and therefore appearing more unicolorous lighter testaceous, but variation overlap between the species both in infuscation and body size (Fig.
Ventral side slightly lighter testaceous and therefore infuscation on metacoxal plate more contrasting.
Male genitalia as in Figure
Only known from Masoala National Park, northeastern Madagascar (Fig.
Latinisation of the Malagasy word “zana-tany” litterally translated to “child of the land”, with the meaning to be native of a country. The new species is endemic and a native of Madagascar.
Betampona Réserve Naturelle Intégrale (RNI) [
-3♂ GP, 24 ex. (Alc.) (
-3♂ GP, 3♀ (
A slightly smaller species than preceding two and in fact the smallest of all known species of the
Body length: 4.2–4.8 mm (♀: 4.2–4.6 mm, ♂: 4.6–4.8 mm).
Very similar in all respects to the two preceding species and only differences noted below.
Slightly smaller than both preceding species and somewhat less elongate (Fig.
The lightest testaceous species of all three. Elytra with very faint to no infuscation medially and infuscation between eyes on head essentially lacking (faint traces present).
Possibly more extensive striolation on pronotum, but individual variation likely to overlap between the species.
Metacoxal lines projecting anteriorly longer than in preceding two species but does not reach metaventral suture.
Male genitalia as in Figure
Only known from Betampona RNI, eastern lowland Madagascar (Fig.
Named after the type locality and protected area where it was found, Betampona Réserve Naturelle Intégrale. The epithet is a noun in apposition.
Betampona Réserve Naturelle Intégrale (RNI) [
-2♀, 1♂ GP, 4♀ (Alc.) (
-2♀, 4♀ (Alc.) (
-1♂ GP (
A small
Male genitalia. From left to right aedeagus in right lateral, ventral, left lateral views, and left paramere.
Body length: 3.7–4.2 mm (♀: 3.7–4.2 mm, ♂: 3.9–4.1 mm).
Body shape broadly oval with a continuous outline laterally between pronotum and elytra (Fig.
Head and pronotum rufous, infuscated inside eyes and vaguely medially on pronotum. Elytra infuscated medially but with testaceous sections basally, laterally and apically. Appendages testaceous except metatarsus rufotestaceous.
Elytra and pronotum covered with fine punctures, much finer than in
Ventral side rufotestaceous, metacoxal plate and abdominal sternites II–IV with few fine strioles laterally. Metacoxal lines absent. Anterior metaventral process broad.
Male pro and mesotarsal segments I–III dilated and ventrally equipped with adhesive discs (constellation I:3, 4, II:4, III:4). Anterodistal angle of protarsal segment IV with a modified stout seta.
Penis bilobed with ventral lobe extending to near, but stops before, apex of dorsal lobe. Penis straight, short and pointed with a thin apex in ventral view, straight and evenly tapering towards apex in lateral view (Fig.
Female similar to male.
Known from Betampona RNI and at Analalava reserve, eastern lowland Madagascar (Fig.
Maps of Madagascar with species distributions and administrative divisions.
The species was found in Betampona RNI and collected under the same circumstances as
Habitat photo of locality MAD18-66, Betampona RNI. The three new species
Habitat photo of locality MAD18-43, Masoala NP where
“Semifactus” means half-done or half-finished here referring to that this species is possibly less modified to spending time on land compared to next two
Analalava Reserve [
-3♀, 4♀ (Alc.) (
-1♂ GP, 4♀, 1♂ (Alc.), 8♀ (Alc.), (
-1♀, 1♀ (Alc.) (
-1♂ GP, 1♀, 1♀ (Alc.) (
-1♂ (Alc.) (
-1 ♂ GP (
A small, elongate but rather robust
Body length: 3.9–4.8 mm (♀: 3.9–4.5 mm, ♂: 4.2–4.8 mm).
Body shape elongate, subparallell and rather convex. Lateral outline non-continuous between pronotum and elytra. Head broad with small eyes creating a wide interocular distance (Fig.
Pronotum and head rufotestaceous, infuscated inside eyes and slightly medially on pronotum. Elytra infuscated but with basal and apical testaceous spots. All appendages testaceous.
Elytra with longitudinal subugosity formed by shorter and longer strioles, sometimes connected to form longer continuous lines. Pronotum densely covered with large punctures and with a narrow lateral bead not reaching anterior corners. Head covered with finer punctation. Head, pronotum and elytra with same type of microreticulation and micropunctures.
Ventral side entirely testaceous, metacoxal lines absent but suggested ridge present in their place, metacoxal plate and abdominal sternites II–IV with fine strioles. Anterior metaventral process narrow.
Male pro and mesotarsal segments I–III broadly dilated and ventrally equipped with adhesive discs (constellation I:5 (row 1), 4 (row 2), II:4, III:4). Anterodistal angle of protarsal segment IV with a modified stout seta.
Bilobed penis with an apical knob visible in both lateral and ventral views, ventral lobe ending on right side well before apical knob of dorsal lobe. In lateral view apex not upturned (Fig.
Female with similar dorsal subrugosity as in male.
Known from Analalava reserve and Betampona RNI, eastern lowland Madagascar (Fig.
Analalava reserve is managed through collaboration between a local people NGO (Velonala) and Missouri Botanical Garden (MBG) since 2004. In 2015, it was designated as a new protected area. It covers 225 ha of typical littoral humid forest and represents one of few remaining forest fragment on the lowland central east coast of Madagascar. One specimen was collected in the same terrestrial habitat as
The Malagasy word “kelimaso” means small eyes (keli = small, maso = eye), a characteristic of this species and seemingly an adaptation to spending significant amount of time out of water in the ground litter layer (three of five terrestrial dytiscid species are eyeless).
Nosy Mangabe Special Reserve, part of Masoala National Park [
-4♂ GP, 10♀ (
-1♂, 2♀ (
-3♂ GP, 2♀ (
-1♂, 1♀ (
-3♂, 2♀, 14 ex. (6♂, 8♀) (Alc.) (
A small and robust reddish
Body length: 3.7–4.5 mm (♀: 3.7–4.3 mm, ♂: 3.8–4.5 mm).
Body shape subparallell, robust and rather convex anteriorly. A broader body shape compared with
Body with a rather uniform reddish coloration, only head partly infuscated between eyes. All appendages testaceous except metatarsus rufotestaceous.
Elytra and pronotum densely covered with large punctures, puncturation reduced posteriorly and towards lateral margins of elytra. Pronotum with a narrow lateral bead not reaching anterior corners. Head covered with finer punctation. Head, pronotum and elytra with same type of microreticulation and micropunctures.
Ventral side entirely testaceous, metacoxal lines absent, suggestion of ridge in their place less distinct compared with
Male pro and mesotarsal segments I–III dilated and ventrally equipped with adhesive discs (constellation I:3, 4, II:4, III:4). Segments less dilated than in
Bilobed penis short and robust with rather blunt apex in ventral view. Ventral lobe twisted around right side of dorsal lobe to a position dorsal of it at apex (Fig.
Female with similar dorsal puncturation as in male.
Masoala NP including the island of Nosy Mangabe (Fig.
The species was found in humid forests at low-altitude between (50–360 m) in dry shallow forest floor depression with dead leaves and soil. In one out of five localities it was collected from a rainwater-filled pit full of dead leaves, the other four places from dry forest floor depressions (Figs
Habitat photos of locality MAD18-45, Masoala NP. The two new species
Habitat photo of locality MAD18-58, Nosy Mangabe, where the new species
Habitat photo of locality MAD18-63, Nosy Mangabe, one of several similar localities where
Habitat photo of locality MAD18-57, Nosy Mangabe, near where
Habitat photo of locality MAD17-08, Analalava reserve, where the new species
Menalamba in Malagasy means red clothes and the word is associated with the revolt and anti-colonianism movement in Madagascar’s history of independence. Here it refers to the characteristic reddish coloration of the species (Fig.
At one locality on Nosy Mangabe (MAD18-57) we videorecorded the terrestrial locomotion and behaviour of this species in the field (Suppl. material
The knowledge of Malagasy
We are grateful to Madagascar National Parks and Ministère de l’Environment, d’Ecologie et des Forets for permits and support to carry out this fieldwork. We thank Brian Fisher at Californian Academy of Science/Madagascar Biodiversity Center Tsimbazaza, for organising the Marojejy expedition 2018, and to all IPSIO participants. Our sincere thanks to Virginia Rodriguez Ponga and Jean Noël (Madagascar Fauna and Flora Group, Toamasina, Betampona) for supporting the fieldwork in Betampona. Special thanks go to Desiré Razafimahatratra (Guide at Marojejy NP), Jao Aridy (MNP agent and guide at Masoala NP) and Doxi (Guide at Betampona RNI) for great guiding and assistance during fieldwork. Stella Papadopoulou kindly helped with video editing. Meteorologie Madagascar generously provided precipitation data from weather stations. Finally, we are grateful to David Bilton and Lars Hendrich for very useful comments that improved the manuscript.
Movie 1 showing terrestrial locomotion of
video
It was filmed at locality MAD18-57 on Nosy Mangabe Island, part of Masola NP, 18 February 2018.