Revision oiAfrocrania ( Coleóptera : Chrysomelidae , Galerucinae ) Part I : Species in which the males have head cavities or extended elytral extrusions

Material of Afrotropical Afrocrania Hincks, 1949 (= Pseudocrania Weise, 1892, not Pseudocrania M’Coy, 1851) is revised, and a redescription of the genus is given. This publication is on Afrocrania species in which males have head cavities or extended elytral extrusions. Species without those sexual dimorphic organs will be revised in a subsequent paper. Material of Pseu­ docrania latifrons Weise, 1892, Pseudocrania foveolata (Karsch, 1882) (= Monolepta africana Jacoby, 1894, = Pseudocrania nigricornis Weise, 1895), and Pseudocrania assimilis Weise, 1903 was examined; Pseudocrania basalis Jacoby, 1907 is excluded from Afrocrania; Afrocrania kaethae sp. n., A. luciae sp. n., A. kakamegaensis sp. n., A. longicornis sp. n., and A. ubatubae sp. n. are newly described species.


INTRODUCTION
Galerucinae with slender legs, basi-metatarsus much longer than the remaining four metatarsal articles, and lack any pronotal depressions, are assigned to the "Sectio Monoleptites" sensu Wilcox (1973).The classification and the taxonomic status of the whole group is very unsatisfactory, and a revision of the afrotropical species was started recently (cf. Wagner, 1999).Three hundred and six species have been described from the Afrotropical region (excluding Madagascar), mostly in the genera Monolepta Chevrolat, 1837, (n = 173), Candezea Chapuis, 1879, (n = 39) and Barombiella Laboissiere, 1931, (n = 42).Furthermore, some genera with few spe cies also belong to this typological group.One of these is Pseudocrania Weise, 1892.Weise described a slender, brownish yellow Galerucinae with enlarged basimetatarsus where males are characterized by a cavity on the head and curved fourth antennal articles, Pseudo crania latifrons Weise, 1892, which became type species of the genus by monotypy.Few years later, further spe cies were described in this group: Pseudocrania nigricornis Weise, 1895, a species Weise later synonymized with Monolepta africana Jacoby, 1894 under Monolepta foveolata Karsch, 1882 (Weise, 1903).In that publication a third species, Pseudocrania assimilis Weise, 1903, was decribed and an identification key on Pseudocrania was given.
Only one other species was placed in this genus, Pseu docrania basalis Jacoby, 1907, but recent studies show, it is not closely related to the other species and belongs to another group.Furthermore, Pseudocrania Weise, 1892 is a junior homonym to Pseudocrania M'Coy, 1851, a fossil group of Brachiopoda, and so the name was changedto Afrocrania Hincks, 1949.In his final study of this group, Weise "justified" Pseu docrania as it contains more than one species with males that have the characteristic and peculiar head cavities: "Die Aufstellung einer neuen Galerucinen-Gattung nach einer Art ist ein sehr gewagtes Unternehmen, denn man weiß bei diesen äußerst veränderlichen Tieren nicht, wie der Hase laufen wird, d.h.ob die benutzten Merkmale nichts weiter als auffällige sexuelle Modificationen irgen deiner bekannten Gattung oder wirklich generische Unterschiede sind" (Weise, 1903).
In addition to the species described by Weise, we found a further two species in which the males have head cavi ties.However, there are also species in which the males lack a head cavity, which need to be transferred to Afrocrania or described as new.These species have a peculiar sexual dimorphic character, there are complex folded extrusions along the suture at the elytral base in males.Furthermore, there are some species with simple, shallow "hump-backed" extrusions at the elytral base, which are a common sexual dimorphic character of some Candezea species.This paper deals with Afrocrania species from continental Africa, where the males are characterized by head cavities or complex elytral extrusions.A revision of other Afrocrania species and a key to all the species will be published later.

MATERIAL AND METHODS
The descriptions are based on 322 labelled specimens from the following collections (cf.Tab.1): The Natural History Museum, London (BMNH; S. Shute, M. Brendell, M. Cox); Deutsches Entomologisches Institut, Eberswalde (DEI; L. Behne, L. Zerche); Institute Royal des Sciences Naturelles de Morphometric measurements were made on the external char acters.If available, 6 male and female specimens of each spe- cies were measured.Measurements were made of (Fig. 1): total length from labrum to apex of elytra (TL); length of elytron (EL); width of both elytra (EW); length of pronotum (PL); width of pronotum (PW); total length of antenna (AL).Relative measurements were: length to width of pronotum; width of both elytra to length of elytron; length of second to third antennal article; length of third to fourth antennal article; length of antenna to length of elytron.
For each species a standard set of figures is given.Semi schematic illustrations of the elytra, pronotum, head and right antenna of a male and close-up drawings of the five basal antennal articles of two males and two females per species are presented.The genital characters are illustrated by drawings of the median lobe in lateral, dorsal and ventral view (latter without endophallic structures), the bursa-sclerites of one female in dorsal view and the spermathecae of three different females in lateral view (for terminology of genital structures see Figs 9,12 and 30).For the description of the genotype, Afrocrania latifrons (Weise, 1892), illustrations of the female and male abdomen, pronotum (dorsal and ventral view), meso-and metathorax (ventral), right hind wing (dorsal) and the legs on the right side are given.

Redescription
Body length.3.60-7.00mm; means of body lengths for the species range between 4.07-6.75mm.Females are somewhat larger than males.Larvae and pupae unknown.
Head.Eyes convex and ovate.Frons and vertex occa sionally yellow, usually brownish yellow.The males of some species have a cavity on the frons between the eyes.These cavities vary in depth and detail.Males of species without a head cavity and females of all species bear a roughly heart-shaped, flat extrusion on the frons.Maxil lary and labial palpi brownish yellow to dark brown.Labrum occasionally yellow, usually brownish yellow to black.Antennae in a few species entirely yellow, in most species dark brown or black with the basal articles 1-3 sometimes yellow to brownish yellow.Antennae usually longer than elytra; mean antennal length to elytral length (for different species): 0.97 to 1.41.Antennae of males longer than those of females; mean antennal length in males: 3.25-5.80mm, in females: 3.05-5.20mm.Mean lengths of antennal articles 2 to 3 in males: 0.57-0.80, in females: 0.59-0.78;length of antennal articles 3 to 4 in males: 0.48-0.85, in females: 0.42-0.73.Males of species with a head cavity additionally have the fourth, fourth and fifth or fourth to sixth antennal articles enlarged, curved or horned (Fig. 5C).
Male genitalia.Median lobe symmetrical, straight or slightly ventrally curved in lateral view (Fig. 5E, F).Long and narrow with an enlarged middle section.Apex of median lobe usually dorso-ventrally compressed.Tectum arrow-shaped with pointed apex and narrowed base.Tegmum Y-shaped and attached in basal third of the median lobe.Parameres absent.Orifice varying in shape; ovate, nearly circular or with narrowed sides giving it a pear-shaped appearance.Ventral side of median lobe with shallow groove of varying length, sometimes carrying one spur on each side (Fig. 9C).Spurs are of varying size and location.Endophallus with one pair of slender hooked spiculae and one to two pairs of usually straight spiculae.One pair of straight spiculae is located between or slightly ventral of the hooked spiculae (ventral spiculae) while the second pair is located dorsally and on the outer side of the hooked spiculae (dorsal spiculae; cf.Figs 9A, B; 30A, B).The dorsal spiculae are attached to the centre of the endophallus and are sometimes slightly curved ventrally.
Female genitalia.Spermatheca with slightly widened nodulus and curved middle part (Fig. 5D).Cornu homo geneously curved or proximally straight with a sharper curve in the second half.Bursa-sclerites larger than spermathecae, convex, strongly sclerotised, having 4-6 strong spines.Spines of left and right bursa-sclerites of the same individual often asymmetrical (Fig. 10).
Diagnosis.Afrocrania are mid-sized, dorso-ventrally compressed "Monoleptites" (sensu Wilcox, 1973) with parallel sided elytra.Colouration of the dorsum is homo geneously yellow, brown to reddish brown, occasionally with broader lateral black margins, but without any spots and bands, which are typical characters of most Mono lepta and few Candezea species.The underside, legs and antennal articles 3-11 are usually dark brown or black, in a few species yellow.Head cavities on the irons, horned or curved antennal articles or complex extrusions on the elytral base, are sexual dimorphic characters, which are only found in males of Afrocrania species, and not in Afrotropical Monolepta or Candezea.
The third antennal article of Afrocrania is considerably longer than the second (Fig. 5C, lengths of antennal arti cles 2 to 3: 0.57-0.80).This is also typical of Candezea (Fig. 7C, lengths of antennal articles 2 to 3: 0.62-0.85,Wagner, 2000) but not Monolepta in which the second and third antennal articles are of approximately the same length (Fig. 6C, lengths of antennal article 2 to 3: 0.85-1.10).
Median lobe of Afrocrania is very characteristic and differs from that of Monolepta and Candezea.It is slender, apical part usually elongated, and apex often slightly enlarged (Figs 5E, F).The median lobe in Mono- lepta is usually broader, the apex dorso-ventrally com pressed and not enlarged (Figs 6E, F, cf. Wagner 1999, 2000), while the median lobe in Candezea is cylindrical and slightly conical towards apex (Figs 7E, F).The tectum of median lobe in Afrocrania is pointed at apex, broad in the middle and narrowed at the base.It is usu-   7E, F).
Spermathecae and bursa-sclerites of Afrocrania are similar to those of Candezea but the spermathecal cornu is not as strongly curved as in Candezea.Males of many Afrocrania species can be distinguished very easily from all other afrotropical "Monoleptites" by their secondary sexual organs, the head cavity and the horned or curved basal antennal articles or complex elytral extrusions respectively.Since only males bear such distinctive char acters, and many species are similarly coloured, females are often difficult to distinguish and determination of females to species level is sometimes impossible in the absence of syntopely occurring males.
Distribution.Distributed throughout the Afrotropical Region.All eight species herein revised are only known from Central and East Africa (mainly Cameroon, Gabon, Congo, Kenya, Tan zania).A few species are distributed throughout the region, but the distribution of most species seems to be restricted to western parts of Central Africa (Gabon and Cameroon) and to southern Congo.
Abdomen.Dark brown.Male genitalia.Median lobe slender, homogeneously curved ventrally from base to apex; slightly enlarged in the middle, in the apical third and at apex (Figs 9B, C).Apex dorso-ventrally compressed (Fig. 9A).Ventral groove on each side with one spur near the middle of the median lobe (Fig. 9C); spurs with a very broad base.Ori fice nearly ovate.Endophallus with paired hooked and straight ventral spiculae (Figs 9A, B).
Diagnosis.Males of A. latifrons are characterized by a peculiar head cavity, a slightly curved fourth antennal article and lack of any elytral extrusions.Only A. luciae sp.n. has a similar sized head cavity, which in contrast to A. latifrons is not evenly deep (Fig. 29).Furthermore, A. latifrons has the fourth antennal article curved inwards and a regularly shaped fifth article, while A. luciae has both the fifth and sixth articles slightly curved (Fig. 32A,  B). A. luciae is somewhat larger (total length: males: 5.90-6.35mm, mean: 6.10 mm) than A. latifrons (total length: males: 5.00-5.50mm, mean: 5.21 mm) and has the basitarsus of fore and middle legs enlarged (Fig. 31).Females of A. latifrons tend to be smaller (5.20-6.20 mm, mean: 5.86 mm) than those of other Afrocrania species, except those of A. assimilis (Weise, 1903), which on average are even smaller (5.45-6.10mm, mean: 5.80 mm), and those of A. kaethae sp.n., which are only slightly larger (5.60-6.50mm, mean: 6.00 mm).
Distribution.Recorded from three locations in western Congo, one in eastern Congo and one in Burundi (Fig. 23).
Abdomen.Dark brown.Male genitalia.Median lobe very slender, in dorsal view somewhat conical but significantly enlarged at apex.In lateral view straight with two ventral bends, one in the basal quarter shortly above the orifice and one in the apical quarter below the apex (Fig. 14A).Apex not dorso- ventrally compressed (Fig. 14A).Ventral groove without spurs (Fig. 14C).Orifice nearly circular.Endophallus with paired hooked and straight ventral spiculae (Figs 14A, B).
Diagnosis. A. foveolata is characterized by a peculiar head cavity and horned antennal articles 4 and 5 of the males.There are two other Afrocrania species with a similar median keel in the head cavity, A. assimilis and A. kaethae sp.n. (Figs 18 and 24), but A. foveolata can be distinguished from them as it is the only species having antennal articles 4 and 5 with elongated distal edges ("horned"), whereas the fourth antennal article in A. assi milis and A. kaethae sp.n. is horned (Fig. 20A, B and  26A, B).Furthermore, the fourth antennal article of A. foveolata, in both males and females, is relatively shorter than in other Afrocrania species, i. e. length of antennal articles 3 to 4 is greater in A. foveolata (males: 0.82-0.86,mean: 0.85; females: 0.71-0.75,mean: 0.73).Females of A. foveolata have on average the broadest elytra of all Afrocrania species (elytral width to length: 0.64-0.70,mean: 0.65).
Distribution.Recorded only from Gabon and Congo.Very little material is available and for specimens collected in the Congo no exact location is given (Fig. 23).
No holotype was designated, neither on the labelled speci mens, nor in the original publication.
Diagnosis. A. assimilis is characterized by its head cavity and the horned fourth antennal article of the males.Two other Afrocrania species have a similarly keeled head cavity.A. foveolata can be distinguished by its horned antennal articles 4 and 5. A. kaethae sp.n. has only the fourth article horned (cf.Figs 20A, B, 26A, B and 13A, B), and can also be distinguished from A. assi milis by its shallow head cavity (cf.Figs 18 and 24).Fur thermore, the fourth antennal article in males of A. assi milis (length of antennal articles 3 to 4: 0.44-0.57,mean: 0.50) is relatively much longer than in A. kaethae sp.n. (length of antennal articles 3 to 4: 0.50-0.83,mean: 0.69; cf.Figs 20A, B and 26A, B).It also differs from other Afrocrania species in having an apically and ventrally bent median lobe, a relatively short antennal article 3, in the shape of the spurless ventral groove, and in having ventral hooks at the apex of the median lobe.
Diagnosis.Males of A. luciae sp.n. can be easily dis tinguished by external characters from those of other Afrocrania species.A head cavity without a keel is found also in A. latifrons, but it differs in shape and outline.Curved antennal articles in males also occur in A. lati frons, but only the fourth article is of this shape (Figs 11A,B and 32A,B).Other differences between males of A. luciae sp.n. and A. latifrons are the basitarsus of the fore and middle legs, which are enlarged in A. luciae (Fig. 31A), total length (A.latifrons: 5.00-5.50mm, mean: 5.21 mm; A. luciae sp.n.: 5.90-6.35mm, mean: 6.10 mm), and the spatula-like apex of the median lobe in A. luciae sp.n.In contrast to other Afrocrania species, and Figs 29-34: Morphology of Afrocrania luciae sp.n. 29 -habitus, dorsal; 30 -median lobe, lateral (A), dorsal (B), ventral, without endophallic structures (C); 31-tarsus and distal part oftibia ofprothoracic leg in males of A. luciae (A) and A latifrons (B); 32 -basal antennal articles, male (A, B), female (C, D );3 3 -spermathecae of three different females; 34 -bursa-sclerites, dorsal.Afrocrania kakamegaensis sp.n.
Abdomen.Dark brown.Male genitalia.Median lobe slender and nearly straight, in lateral view curved at orifice.Ventral groove with spurs near the middle of the median lobe (Fig. 37C).
Position of these spurs somewhat variable in different populations.Apex of median lobe slightly enlarged (Figs 37B, C).Tectum broad, maximum width exceeds median lobe at its widest point.Orifice nearly circular (Fig. 37C).Endophallus with paired hooked, straight ventral and more or less straight dorsal spiculae (Figs 37A, B).
Abdomen.Brownish yellow to brown, usually paler than metathorax.
Male genitalia.Median lobe slender and nearly straight, in lateral view slightly curved at orifice; apex of median lobe slightly enlarged (Figs 42B, C).Ventral groove with strong spurs near the middle of the median lobe (Fig. 42C).Orifice with narrowed sides, pear-shaped (Fig. 42C).Endophallus with paired hooked spiculae, straight ventral spiculae, and slightly ventrally curved dorsal spiculae (Figs 42A, B).
Diagnosis.Males of A. longicornis sp.n. are character ized by their long antennae and the peculiar shape of the elytral base. A. longicornis sp.n. is very similar to A. ubatubae sp.n., which also has longitudinal extrusions on the elytral base and lacks a head cavity and horned or curved antennal articles (cf.Figs 41 and 46).However, these two species can be distinguished easily since A. ubatubae sp.n. has significantly shorter and more slender antennae (antennal length to elytral length in males: A. ubatubae sp.n.: 1.22-1.28,mean: 1.25; A. longicornis sp.n.: 1. mean: 1.40;cf. Figs 43A,B and 48A,B).Males of A. longicornis sp.n. have the longest antennae of all Afrocrania species, whereas those of the females are not significantly longer than those of other Afrocrania species.However, both males and females of A. longi cornis sp.n. have a yellow to brownish yellow abdomen, which distinguishes them from all other Afrocrania spe cies herein revised.Furthermore, females of A. longi cornis sp.n. have on average the broadest pronotum of all Afrocrania species (pronotal length to width 0.56-0.62,mean: 0.59).Distribution.A. longicornis sp.n. is recorded from only one location in southern Congo (Fig. 51).
Etymology.This species is named after the very long antennae of the males.Afrocrania ubatubae sp.n.
Abdomen.Dark brown to black.Male genitalia.Median lobe slender and nearly straight; in lateral view curved at orifice.Ventral groove of median lobe with asymmetrical, small spurs in the apical half (Fig 47C).Apex of median lobe slightly enlarged (Figs 47B, C).Orifice ovate (Fig. 47C).Endophallus with paired hooked, straight ventral and straight dorsal spiculae (Figs 47A, B).
Diagnosis.Males of A. ubatubae sp.n. can easily be distinguished from those of other Afrocrania species by the characteristic extrusions on the elytra, but are similar to A. kakamegaensis sp.n. and A. longicornis sp.n. (cf. Figs 36,41 and 46). A. ubatubae sp.n. is very similar to A. longicornis sp.n. in its elytral extrusions, and the shape of the median lobe, but has significantly slenderer and shorter antennae (antennal length to elytral length in males: A. ubatubae: 1. mean: 1.25;mean: 1.40;cf. Figs 43A,B and 48A,B).Females of A. ubatubae sp.n. are the largest of all Afrocrania species herein revised (total length: 6.70-6.80mm, mean: 6.75 mm).

Figs
Figs 24-28: Morphology of Afrocrania kaethae sp.n. 24 -habitus, dorsal; 25 -median lobe, lateral (A), dorsal (B), ventral, without endophallic structures (C); 26 -basal antennal articles, male (A, B), female (C, D); 27 -spermathecae of three different females; 28 -bursa-sclerites, dorsal.Diagnosis.Males of A. kaethae are characterized by a shallow head cavity and horned fourth antennal article.It is most similar to A. assimilis, which also has the fourth antennal article horned in males.However, these two spe cies can be distinguished by the depth of their head cavity, which is much deeper in A. assimilis (cf.Figs 18 and 24), the fourth antennal article in males, which is longer in A. assimilis (length of antennal article 3 to 4: 0.44-0.57,mean: 0.50) than in A. kaethae sp.n. (length of antennal article 3 to 4: 0.50-0.83,mean: 0.69; cf.Figs 20A, B, 26A, B), and by the horned fifth antennal article in A. assimilis.In comparison to other Afrocrania species

TABLE 1 .
Numbers of specimens of each species examined and the source collection.