Notes on some little known species of Africophilus Guign. (Coleoptera: Dytiscidae) with the description of three new species

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1 Notes on some little known species of Africophilus Guign. (Coleoptera: Dytiscidae) with the description of three new species by JOYCE OMER-COOPER Rhodes University, Grahamstown The genus Africophilus Guign. was erected by Guignot (1947) to accommodate the species A. inopinatus from the Ivory Coast, West Africa. Unfortunately only the female is known. In subsequent years A. pauliani Legros (1950) and A. nesiotes Guignot (1951) were described from Madagascar and A.jansei O-C (1957) from South Africa. The known distribution of A. nesiotes has since been extended outside Madagascar to West, East and Southern Africa. In this paper three new species are described, two from Nigeria and one from Malawi. The genus belongs to the subfamily Laccophilinae. I ts members range in size from mm and are found in the fine gravel at the sides of mountain streams or in trickles of water running over algal growth down rockfaces. When disturbed they are poor swimmers and easily caught but once out of the water they can, and do, jump like fleas so that, as a rule, more escape than are finally bottled. The species are all very much alike and it is difficult to find clear cut characters upon which to separate them. The difficulty of identification is made greater by the fact that two or more species may occur together in the same habitat. They are all black with dypeus, sides of pronotum, margins of elytra and a lateral preapical elytral spot testaceus; they are all more or less widely oval and flattened; their antennae are short with the last five joints widened and, usually, with the base testaceus and the succeeding joints ringed with, or entirely brown. Antennal colour is not constant within the species. An irregular polygonal reticulation accompanied by a fine punctuation, is common to them all and, with the exception of A. difference, the sides of the pronotum are dearly prolonged backwards to form a sharp point (fig. 5 h). Apart from slight differences in the shape of the apophysis of the prosternal process and in the shape of the last abdominal sternites there seem to be no significant specific differences in the under side. The males have a peculiar structure on the last visible abdominal sternite complemented by a backward projection near the middle of the posterior border of the penultimate segment. The slight asymmetry of the whole apparatus is puzzling. The apical sternite is furnished with a more or less circular shallow pit whose posterior edge of thin chitin extends beyond the posterolateral margins of the segment and whose pattern remains constant within the species but differs slightly in different species (figs. I, 2, 3, 4 and 5a). In the female a corresponding area of thin chitin is

2 462 ]. ent. Soc. sth. Afr. Vol. 32, No.2, 1969 discernible but is not sunk to form a shallow pit nor has it a patterned posterior margin. The course of the posterior margin of this sternite is, however, diagnostic for the species (figs. I, 2, 3, 4 and 5b). The backward projection of the penultimate segment is not present in the female.. The median lobe of the aedeagus is for the most part peculiar and distinctive (figs. lc, 2d, 3d and 4d) accompanied by a small left paramere (figs. 3f and 5f) resembling that found in the genus Laccophilus but with a more developed basal region, and a very poorly chitinised, very small right paramere surmounted by a long hair borne on a narrow projection and characteristic of the genus (figs. 3e and 5e). A. pauliani Legros departs from the norm in the shape of its median lobe (Legros 1950: 54, fig. I) and that of the new species A. differens described here, departs widely from it and more nearly resembles one which might be expected to occur in the genus Laccophilus although the parameres remain typically africophiloid. Tentative species identifications may be made upon size; shape; frequency of irregular, fine, sometimes branching lines superimposed on the irregular polygonal reticulation of the elytra; density of punctuation in the posterior third of the elytra; and shape of the last visible abdominal sternite in both sexes. Since these characters are subject to variation the aedeagus should always be used, when possible. as the final criterion. Apart from the sexual characters of the last visible abdominal sternites, figured hereafter, the following are the main external characters of the African species with the exception of A. inopinatus Guign. Unfortunately I do not have the unique female type of the latter for comparison and have not been able to examine the last abdominal sternite which is missing from the mount. According to Guignot the type is 3.0 mm long, the reticulation of the greater part of the pronotum and first half of the elytra is elongate and the penultimate sternite feebly angled in the middle. This description does not accord with any species known to me. CONSPECTUS OF EXTERNAL CHARACTERS A. nesiotes Guign mm. Rather widely oval but narrowed behind; irregularly directed fine lines superimposed on the polygonal micro-reticulation few, and not easily seen except in the hinder third of the e1ytra. Polygonal mesh of pronotum and elytra not markedly irregular. A. congener spec. nov mm. Widely oval, less narrowed behind than A. nesiotes; polygonal mesh of the micro-reticulation of pronotum and elytra rathu irregular, clearly narrowed in a small region on each side of the disc of the pronotum and in the scutellary region of the elytra; irregularly directed fine lines superimposed on the reticulation rather numerous and evident; the hinder region of the e1ytra densely and coarsely punctured and with the randomly directed lines numerous and well impressed giving the area a wrinkled appearance. A. jonse; o-c mm. Elongate oval; polygonal mesh of the micro-reticulation irregular but not clearly elongate anywhere; superimposed fine lines evident on the e1ytra, more numerous and more impressed in the posterior third which is, however, not very densely punctured. A. josi spec. nov mm. Widely oval, almost oblong; polygonal mesh of the micro-reticulation irregular, sometimes longitudinally elongate sometimes transverse but, apart from a small scutellary region where it is usually elongate, there are no clearly demarcated regions with the different shapes. A high proportion of the fine lines take a longitudinal direction often accompanied by a fine punctuation so that in scme specimens they give the impression of fine supplementary serial rows of punctures. Pcsterior third of the elytra with close, coarse punctures and deeply impressed randomly directed fine lines. A. dijjerens spec. nov. L '5 mm. Shortly and widely oval; serial rows of elytral punctures scarcely visible. Polygonal mesh of the micro-reticulation very irregular, superimposed fine lines present but not very evident except in the posterior third of the elytra.

3 Omer-Cooper; On species d Africophilus 463 Africophilus congener spec. nov. DESCRIPTIONS OF NEW SPECIES L. 2.8 mm. Widely oval, little narrowed behind; brownish black with front of head, sides of pronotum and elytra testaceus. Underside black with front of epipleura and legs testaceus. Head. Brownish black behind, testaceus in front, micro-reticulate and alutaceus. Antennae testaceus with the five last joints brownish. Pronotum. Brownish black with the sides brownish testaceus. Micro-reticulate with the meshes irregularly polygonal but narrowed and elongate in a small area each side of the middle. The reticulation is accompanied by a fine punctuation closer along the anterior border and at the sides giving an alutaceus appearance. The anterior transverse row of large shallow punctures behind the anterior margin does not reach the side margins and leaves a narrow space in the middle unpunctured. The corresponding posterior row has fewer punctures and ends at the sides in a shallow depression. On the centre of the disc in both the male and female types is one large, shallow puncture. Elytra. Brownish black, blacker behind with the margins, wider at the shoulders vaguely testaceus and with a lateral preapical testaceus spot. Micro-reticulate the mesh irregularly polygonal and somewhat elongate in the scutellary region. The reticulation bears very fine punctures, which are denser and slightly larger in the posterior third of the elytra, and is crossed here and there by fine, sometimes branched, lines taking no particular direction, possibly the remains of a large reticulation such as is found in the genus Laccophilus. These lines are more numerous and more impressed in the posterior third of the elytra giving rise, together with the dense punctuation to a wrinkled appearance. The three rows of serial punctures are evident in the anterior two thirds. The inner is slightly irregular and composed of fairly large punctures, the second more regular composed of larger elongate punctures and the outer most irregular composed of fewer, also elongate punctures which become smaller further back. Between the rows are scattered, large, shallow punctures. Underside. Black with the abdominal segments brown and testaceus and epipleura and legs testaceus with the tarsi brownish: apophysis of the prosternal process narrowly rhomboidal with a rather long point; micro-reticulate, the reticulation of the rnetacoxae, as in all the species, elongate, the remainder irregularly polgonal. MALE. First three joints provided beneath with small suckers. Fifth and sixth abdominal sternites as in fig. 2a. Median lobe of the aedeagus as in figs 2c and d, parameres of the usual Africophilus type. LOCALITY. MALAWI, Mountain stream Dedza, 17.1X.1948, o-holotype, 'il-allotype. This species is very close to A. nesiotes Guign. The specimens described here had, in fact, been standing unrecognised amongst my A. nesiotes from Nyasaland since they were collected in The new species differs from nesiotes in that its shape is less narrowed behind, the second serial row of punctures appears to be composed of short lines due to the elongated punctures and their arrangement in short longitudinal groups, the superimposed fine lines are more evident on the elytra, and the posterior third is more strongly and densely punctured. It is wider and shorter than A.jansei but resembles that species in the narrow shape of the apophysis of the prosternum and in the shape of the last visible sternite of the female although in A. jansei the posterior margin is very slightly more sinuate.

4 464 J. ent. Soc. sth. Afr. Vol. 32, No.2, 1969 a b 2 a b a b 4

5 Omer-Cooper: On species of Africophilus 465 Africophilus josi spec. nov. L mm. Broadly oval, almost oblong; black with front of head, sides of pronotum and elytra and a lateral preapical spot testaceus. Underside black with front of epipleura and legs testaceus. Head. Brownish black behind testaceus in front; micro-reticulate and alutaceus. Antennae testaceus or with the last five joints ringed or touched with brown. Pronotum. Black with the sides testaceus. Densely microreticulate, the mesh polygonal, except on each side of the disc where it tends to be narrow and elongate, and finely punctured throughout. The anterior and posterior transverse rows of punctures are slightly irregular and composed of rather fine punctures. The anterior row does not reach the lateral margins of the pronotum and leaves a rather wide space in the middle unpunctured. The posterior row ends in a small depression just before the lateral margin and leaves a wide unpunctured region in the middle. Base of the pronotum slightly more sinuate than in the other species. Elytra. Black with margins and lateral preapical spot testaceus. Micro-reticulate the mesh irregularly polygonal, in some places longitudinally elongate and in others transverse. Fine and very fine punctures are scattered throughout and these become coarser and denser in the posterior third. Superimposed fine, randomly directed lines are evident and a high proportion of these consist of short longitudinally directed ones which, with attendant punctuation, simulate supplementary serial rows. Punctures and lines are coarser and more impressed in the posterior third, giving that region a rough, wrinkled appearance as in congener. The longitudinal serial rows are evident, formed of medium sized shallow punctures, the internal row nearly regular, the second more irregular with the punctures arranged in short longitudinal groups, the outermost very irregular. Between the rows are a few scattered punctures of approximately the same SIze. UNDERSIDE. Black with the prosternum, metacoxal processes, first abdominal segment, epipleura and legs testaceus. Reticulation irregularly polygonal as in the other species. Apophysis of the prostemal process narrowly rhomboidal with a long point. MALE. First three joints of the anterior and meso-tarsi provided beneath with small suckers. Ultimate and penultimate abdominal stemites as in fig. 4a. Median lobe of the aedeagus as in fig. 4e and d. Figs FEMALE. Posterior margin of last visible abdominal sternite as in fig. 4b. EXPLANATION OF FIGURES Africophilus species. 1. A. nesiotes Guign. a. Last visible abdominal sternites of.s. b. Outline of posterior margin of last visible abdominal sternite of <j'. c. Median lobe of aedeagus, right side. d. Left side of basal portion of median lobe. 2. A. congener spec. nov. a. Last visible sternites of o. b. Outline of posterior margin of last visible abdominal sternite of 9. c. Left side of basal portion of median lobe of the aedeagus. d. Median lobe right &ide. 3. A.jansei O-C. a. Last visible abdominal sternites of.s. b. Outline of posterior margin of last visible sternite of Cj? c. Basal portion of median lobe of the aedeagus, left side. d. Median lobe of the aedeagus, right side. e. Right paramere. f. Left paramere. 4. A. josi spec. nov. a. Last visible abdominal sternites of ~. b. Outline of posterior margin of last visible sternite of. c. Basal portion of median lobe of the aedeagus left side. d. Median lobe right side.

6 466 J. ent. Soc. sth. Afr. Vol. 32, No.2, 1969 LOCALITIES. NIGERIA, stream running into the reservoir at Jos, d'-holotype,,!,-allotype and 3 paratypes; River about 14 miles from Jos l3.iv.1963, 14; River at Mango Suspension Bridge near Jos l2.iv.1963, 1,!,. This species is larger than A. nesiotes and the fine randomly directed lines on the elytra are more evident. It is more oblong in shape than A. jansei and can be distinguished from either by the differences in the posterior margins of the last sternite in both males and females. Africophilus dijferens spec. nov. L mm. Widely and shortly oval; black with the front of the head testaceus, sides of the pronotum and the elytra narrowly brownish testaceus and the elytra with a testaceus lateral preapical spot. Head. Black with the front testaceus; micro-reticulate with fine punctures on the network. Antennae testaceus with the last five joints tinged with brown. Pronotum. Black with the sides rather narrowly brownish testaceus. Microreticulate, the mesh irregularly polygonal and micropunctate. The anterior and transverse rows of punctures are rather fine and leave an unpunctured region in the middle. Sides slightly rounded with no more than an indication of the sharp posteriorly directed point of the other species. 9 h e f 5 Fig. 5. A. differens spec. nov. a. Last visible abdominal sternites of 6. b. Outline of posterior margin of last visible sternite of,!,. c. Median lobe of aedeagus right side. d. Median lobe of the aedeagus left side. e. Right paramere. f. Left paramere. g. Outline of pronotum. h. Outline of pronotum of A. nesiotes Guign.

7 Orner-Cooper: On species if Afiicophilus 467 Elytra. Black with the sides, more evidently at the shoulders, narrowly brownish testaceus and with a lateral preapical testaceus spot. Micro-reticulate and micropunctate, the mesh of the reticulation very irregularly polygonal and with scattered fine branching lines superimposed as in the other species, and with the punctuation and lines becoming closer and denser behind. Serial rows of punctures slightly irregular and much finer and less conspicuous than in the other species. Scattered punctures are present as usual between the serial rows. Underside. Black with prosternum, epipleura, metasternal processes, first abdominal segment and legs testaceus. The remaining abdominal segments are brownish with lighter margins. The micro-reticulation is as in the other species. Apophysis of the prosternal process rhomboidal with a short point. MALE. First three joints of the anterior and meso-tarsi provided beneath with small suckers. Ultimate and penultimate visible abdominal sternites and aedeagus as in figs 5a, c, d, e and f. The backward projection in the middle of the posterior margin of the penultimate segment is slight. FEMALE. Posterior margin of last visible abdominal sternite as in fig. 5b. LOCALITIES. NIGERIA: Stream and reservoir, Jos plateau, II.IV.1963, o-holotype, -allotype and 2 paratypes; River about Hi- miles from Jos on Kaduna road, 13.IV.1963, 10 and 3<;,. This little species is extremely interesting. The virtual absence of the posterior sharp points of the lateral margins of the pronotum; the poorly developed sucker-like apparatus of the last visible abdominal sternite of the male and reduced projection from the posterior margin of the penultimate sternite, together with the unusual structure of the median lobe of the aedeagus are characters which appear to link the genus Africophilus with the genus Laccophilus whose members constitute the greater part of the subfamily Laccophilinae. ACKNOWLEDGEMENTS My thanks are due to the Director of Entomology of the Natural History Museum of Paris for granting me all facilities necessary for the study of collections in their charge; to the Council of Scientific and Industrial Research, South Africa, for a Senior Bursary and travel grant towards the expenses of the necessary visits to the continental museums; and also to Professor B. R. Allanson, Rhodes University, Grahamstown, for constructive criticism in the preparation of this paper. REFERENCES GUIGNOT, F Dytiscides et Gyrinides nouveaux ou peu connus de l'afrique Occidentale. Bull. Soc. ent. Fr. 10: GUIGKOT, F Nouvelles espece de Dytiscides et de Gyrinides de Madagascar. Naturaliste rnalgache 3: LEGROS, C Un Laccophilinae Nouveau de Madagascar. Naturalisle rnalgache 2: OMER COOPER, J Africophilus jansei n. sp. J. ent. Soc. sth. 4fr. 20: Manuscript received June 18, 1969.